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ABSTRACT This paper reviews recent work in the fields of ecology and economic ecology that contribute to a better understanding of the grazing and erosion debate. The approach is through dynamical systems models represented by differential equations and expressed by the phase space diagrams for systems. The trophic web concept constrained by competitive and societal objective functions is found to be suitable to free-range grazing in environments that are spatially variable in their productivity. New models are needed for the case of grazing managed by shepherds.

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ABSTRACT Evaluating runoff and field soil losses by either empirical or physically based erosion models, requires an understanding and assessment of rainfall characteristics affecting the erosion (sub)processes. ln spite of shortcomings and many criticisms on the worldwide use and applicability of RUSLE (Revised Soil Loss Equation), this empirical model still gains worldwide popularity for estimating erosion on a farm field or micro-catchment scale. One of the limits of the model is the assessment of its climate factor in terms of rain energy and maximum storm intensity, both factors combined in the erosivity factor R, although they not easily available nor easily determinable. Therefore attempts are made to look for more easily determinable rain characteristics such as the monthly precipitation for evaluating the rain aggressiveness (or rain erosivity) on a monthly or yearly basis. As agro-climatological zones have typical rain distributions and rain concentrations, the Modified Fournier Index (MFI) and the Precipitation Concentration Index (PCI), both calculated from monthly precipitation values over a number of successive years, will be used to characterize zones in Venezuela. Monthly rainfall data were collected for at least 10 successive years from nine stations in Venezuela: three stations in the Llanos Centrales, four stations in the Llanos Occidentales and two stations in the semiarid zone of Lara State. According to the available data sets, two different procedures were used to calculate (MFI): In the first procedure the monthly rainfall amounts are averaged over a number of years. The (MFI) is then calculated from this averaged rainfall data set and reported as (MFI)l. In the second procedure the (MFI) is calculated from the monthly rainfall amounts of each individual year and the (MFI) averaged over a number of years. Those long term average values are reported as (MFI)2. Temporal aspects of the rainfall distribution within a year was defined by the Precipitation Concentration Index (PCJ) also based on monthly rainfall amounts and calculated following the two procedures as for determining the (MFI). From those stations of which R = Eho was available an attempt was made to relate R to (MFI).

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ABSTRACT Steeplands, when cleared from forests, are susceptible to erosion by rainfall and are prone to land degradation and desertification processes. The dominant factors affecting those erosion processes and hence the resulting runoff and soil tosses are the aggressiveness of the rainfall during the successive plant growth stages, the soil cover-management, but also the topography (slope length and slope steepness). Depending on the type of (agro) climatological zone, the runoff water should either be limited and controlled (excess of water) or should be enhanced and collected from the slope on the downslope cropping area if water is short (negative soil water balance). Examples are given of practical applications in Ecuador where alternative soil conservation scenarios are proposed in maize cultivation in small fields on steep slopes. Adding peas and barley in the rotation of maize and beans resulted only in a slight decrease of the soil losses. Subdividing the fields into smaller pareeis proved to give the best reduction in soil loss. Because the average slope steepness is high, erosion control measures such as contour ploughing and strip cropping have only small effects. Erosion and its effect on productivity of a sorghum -livestock farming system are assessed on four different areas in Venezuela with different levels of erosion. A Productivity Index (PI) and an Erosion Risk Index (ERI) were used to classify the lands for soil conservation priorities and for alternative land uses. Intensive agriculture can be applied on slightly eroded soil, whereas severely eroded soil can be used with special crops or agro-forestry. Semi­ intensive agriculture is possible on moderately eroded soil. Reforestation of drylands in Chili requires understanding of the infiltration/runoff process in order to determine dimensions of water harvesting systems. Infiltration processes in semi-arid regions of Chile were evaluated, using rainfall experiments and constant-head infiltration measurements. Correlations between infiltration parameters and locally variable characteristics as soil structure, field slope and stoniness were investigated for six different sites, aiming at improving the design and positioning of runoff collecting systems.

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Abstract Soil conservation in the highlands of South-East Asia is essential for sustainable agro-environmental development. The effectiveness of soil conservation treatments developed in runoff plots was investigated in farmer-managed plots on a natural catchment. This was achieved by the development and scientific evaluation of modified and novel cropping practices in a representative highland catchment in Yunnan Province, China. Wang Jia Catchment covers 40. l hectares near Kedu, in Xundian County, north-east Yunnan (25°28'N, 102°53'E). The initial project consisted of an evaluation of the effects of modified cropping practices on maize productivity and soil properties. This programme was extended to investigate ways of increasing the productivity of maize, wheat and soybean on fragile slopes in a sustainable and environmentally-friendly way. The approach incorporates modified and novel agronomic and soil conservation measures, with the evaluation of their agricultural!, environmental and socio-economic impacts using multidisciplinary approaches. This European Union funded project involved an international research team from Belgium, China, Ireland, Thailand and the U.K. Five coordinated work packages were implemented. Involving: (1) Background agricultural! and environmental assessment of Wang Jia Catchment. (2) Implementation and evaluation of modified and novel cropping systems for wheat, maize and soybean in the catchment. (3) Cost-benefit analyses of the socio-economic impacts of the changed cropping practices. (4) Comparative scientific evaluation of the cropping techniques in the highlands of northern Thailand. (5) Dissemination of project outcomes and establishment of training programmes for best practice in highland rural development. The lessons of the Project for promoting sustainable agro-environmental development in tropical and subtropical highlands include: (1) Recognizing the importance of both 'north-south' and 'south-south' co-operation in development projects, (2) Integrating local people as full partners in the research programme, (3) Matching the different 'time horizons' of the different stakeholders and (4) Developing multidisciplinary teams, including biophysical scientists and socio-economists.

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ABSTRACT The Tietê-Paraná Hydroway corresponds to 2.400 kilometers of navigable area between the Tietê and Paraná rivers, integrating six Brazilian states: São Paulo, Paraná, Goiás, Mato Grosso, Mato Grosso do Sul and Minas Gerais. It stands from the municipality of Conchas in São Paulo State and ends in the lake of the Itaipu Hydroelectric Power Plant in Paraná State, comprising 1.642 km of major routes and 758 km of secondary routes. The area of study includes six hydrological basins in the influence area of the Tietê-Paraná Hydroway particularly in its Tietê Branch, involving the territorial area of 225 municipalities which consist of 28% of the total number of municipalities and 23% of the total population of São Paulo State. Inside these basins there are some densely populated urban areas and the major industrial region of the inner portion of São Paulo State. The main technical parameters used in the soil erosion analysis consists of: the natural soil erosion susceptibility of the terrains and the land use types, considering the effects of the land use in each particular terrain. By using aerial photographs of 1972 and field investigation data of 1990, linear erosion incidences were mapped. A value of erosion density was achieved considering the number of linear erosions and the area of each hydrological basin. The critical basins for the occurrence of linear erosion were obtained by considering the value of erosion density and the natural erosion susceptibility of the terrains. The maior critical areas present high and very high erosion susceptibility, and great number of linear erosion processes. It was also possible to identify the municipalities with great potential to generate impacts to the Hydroway by considering: the urban erosion condition, number of linear erosions in rural areas and the classes of high and very high susceptibility existing in the municipal area. The silting up of sediments in the border of reservoirs in the main channel of navigation and in transposition points (bridges, landfills, terminals and others) are the major impacts due to erosion processes in the region.

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ABSTRACT Soil erodibility is one of the key factors on some sediment and soil erosion models such as USLE, MUSLE, RUSLE, AUSLE (USLE modified in LS factor) and MMF and represents like K factor and is function of particle distribution, organic mater, soil structure and permeability. Traditional methods do not take spatial variability and estimate precision of variables in to consideration and amount of them are constant across the whole of soil series. This study was performed to assess spatial variability of soil erodibility and its relevant variables at MEHR watershed from Khorasan province, in northern Iran. Interested network was designed by 110 samples like nested- systematic with distance about 50, 100, 250 and 500 meter across the study area by preparing point map at GIS. Sampling points were identified in field by an Global Positioning system. Soil sampling was done at depth of O-Sem of ground surface and permeability was studied at depth of 5-30 cm. Some soil properties such as particle distribution and organic mater were measured at laboratory. Particle size distribution was determined by Hydrometer method and Organic matter was measured by wet oxidation approach. Then spatial analysis was done. Yariography analysis on soil attributes according to soil erodibility, showed that Gaussian, exponential and spherical models were the most models to predict spatial variability of soil parameters. The range of spatial dependencies was changed from 320 to 3200 m. Soil attribute maps prepared by kriging technique using models parameters. Then soil attributes were composed by Wischmeier (1978) formula in lllwis media to calculate K factor. Amount of soil erodibility changed from 0.13 to 0.91 that it's maximum and minimum was identified in east and southwest of studied area. Soil spatial variability pattern, is similar to silt pattern due to high effect of silt on soil erodibility, Also that is partially confirmed with geology map, indicated which soil erodibility attribute controlled by parent material. High amount of soil erodibility in southwest area of given study area showed need to more attention for conservation the soil and control erosion.

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ABSTRACT Severely eroded lands of southern Guam are referred to as BadLands. These are actively eroding areas of very deep, well-drained saprolite derived from tuff and tuff breccia. These badlands are exposed to overland tlow, wind and rain causing sever erosion as the result of rapid runoff from the pitted, sloping sites void of vegetation. Through soil removal or sediment transport, erosion also alters the inherent physical and chemical properties of these soils. This alteration resulted in degradation, in tum affecting the environment as well as water quality in the down stream. The on-site damage from erosion is indeed a problem to environmental ecosystem of the island. Sediment lost due to erosion clogs rivers, lakes, and waterways. It reduces the water storage capacity of reservoirs and canals and increases flooding. The challenge facing soil and environmental scientists is to develop conservation and restoration strategies at the farm as well as at the watershed level that address crop production and natural resources protection needs, within a framework of increasing environmental and financial constraints. In our soil conservation program at the College of Natural and Applied Sciences of the University of Guam we have adopted integrated approaches to evaluate a variety of strategies, including the effect of conservation tillage and residue management, crop rotation with leguminous plants (sunnhemp) as green manure as well as the use of composted organic wastes as soil amendment for organic matter build up, all for soil rehabilitation and restoration of the badlands in southern Guam. In a companion study we are evaluating the effectiveness of Vetiver technology as a sediment trap to mitigate sediment transport in a typical watershed basin in southern Guam. This paper discusses the methodology as well as up to date data that shows the effect of Vetiver technology on sediment trapping at the watershed level.

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ABSTRACT Urban erosion in Brazil can be related to the Jack of a planning that considers the particularities of the environment and the socioeconorruc conditions of the urban development. ln that sense, the occurrence of erosive processes generally is associated to areas of irregular population settlement, where there is no planrung. Along the Island of Maranhão it may be encountered rills and gullies on those areas, putting at risk houses and people's Iives. The main factors of superficial and subsurface water flow, that generate rill and gully processes, are the soil properties, rain regime, characteristics of the slopes, soil use and deforestation. ln that sense, the environmental situation observed in São Luís is prone to gullying. Rocks of high porosity and Iow hardness are found. It is one of the most dissected parts of the Island of Maranhão. The annual rain regime is marked by a rainy period and another one with rain deficiency. The soils present, in tactile-appearance identification, high contents of sand and silt and clear colours, which are the evidence of Iow organjc matter content. The original vegetation cover has been cleared intensely. Considering the current conditions, the soils are, in general, very susceptible to the erosive processes, mainly when submüted to human intervention, without plannjng. Monüoring of the erosive processes carried out since January 2001 demonstrates a recurrence of soiI erosion, where the vegetation was removed, on slopes between 5° and 15°, occupied by irregular population settlements, without basic urban infrastructure, especially sanjtation, rajn pipes and paved roads. The erosion presents itself more intense in those areas of recent demographic expansion, where areas with potential environmental risk can be found, provoking land degradation and silting up of the water bodies, patrimony tosses and death risk. Therefore, the understanding of the factors that generate erosive processes, as well as the application of control measures and prevention are fundamental actions to the public safety.

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ABSTRACT The present paper describes the observed data concerning water erosion for different experimental plots of São João do Cariri experimental basin located in a typical semiarid region of Brazil. The semiarid area of Paraíba state presents long drought periods, different types of vegetal cover and great spatial variability of intense rainfall events. Ali those factors are conditionate to the erosion process, since they directly influence the sediment yield, agricultural! soil loss and, consequently, the degradation of rural areas. This study presents the application of KINEROS2 model (kinematic runoff and erosion model), to the erosion plots of 100 m2 in São João do Cariri experimental basin located in the semiarid area of Paraíba state. The main objective of this work is to model the erosion process and to try to quantify the intluence of the vegetal cover and slope degree for several! events observed into two erosion experimental plots. The application of the model enclosed the selection of the precipitation data and calibration of the physical basin parameters. The observed data showed that these bare plots presented, larger sediment yield than when they are with vegetal cover. The simulation results showed that the initial degree of soil saturation (S;) and the rain splash coefficient (c1) were the most sensitive parameters during the calibration process, presenting small values of S; for the bare plots and small values of (c1) for the plots with vegetal cover. Finally, the results showed that the KINEROS2 model can be also considered a promising too! for the simulation of the runoff and erosion processes in the semiarid area of northeastern Brazil.

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ABSTRACT Airning to define the conditioning features responsible for the different erosion processes actuating at the drain heads between Jacuí and lbicuí rivers - at Peripheral Depression in Rio Grande do Sul, we analysed the geologic/geomorphologic aspects defining a set of marks due to the relief evolution, in which the details are presented as interfluvial depressions - pseudokarstic forms, rill erosion and large burrows, ali of them interlaced to the hydrodynamic system. Based on a cartographic chart, satellite images, structural analysis of the sedimentary components and the examination of the hardness presented by severa! samples of water collected at, approximately, 15 and 48 meters deep, we verified the existence of complex surface structures (approximately 30 meters deep) associated to the apparently simple topographic forms (hills with ample areas of captivation and long ramps), geological events as fault lines and the stratigraphic arrangement of the sedimentary materiais. These are the predisposing elements of the erosion forms here analysed, showing that the origin of these forms is beyond the anthropogenic action scale, becoming necessary the realization of systematic interconnected stratigraphic and surface geometry studies.

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ABSTRACT The Serra das Confusões National Park is the largest park in northeastern Brazil, with a total area of 502902ha, including 9 municipalities, ali in Piauí State, with the headquarters located in Caracol City. The Park is situated on the top of a plateau, latitude 8º30'S; 9º30'S, longitude 43ºW; 44ºW, drained by channels which flow northwards to Parnaíba river, the main river of Piauí State. Serra das Confusões National Park area is in on morphoestructural and morphoclimatical units inside the Piauí-Maranhão sedimentary basin plateau of the interplateau depression with a semiarid domain, covered by caatinga vegetation (RADAMBRASIL, 1973). The transition zone between Caatinga and Cerrado on the plateau, depressions and complex areas has a vegetation named Carrasco. This paper aims to show a preliminary version regarding geology, geomorphology, pedology and hydrological dynamics on the environmental characterization of the Park and therefore to identify risk areas, to create a use planning and management for the area to improve a better use for these potentials. The Parks geomorphological analysis can be justified by the high importance to understand the natural and social reality of the National Park, showing restrictions on use, always airning the sustainability of the ecosystem delicate equilibrium, the physical environment, together with the visitor's safety.

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ABSTRACT The environmental planning in hydrographic micro basins may minimize the incidence of environmental impacts as consequence of the human indiscriminate action. The hydrographic basin is worldly recognized as the best unit for handling natural resources. Thus, a methodology for diagnosis of the real situation of natural resources, in a basin, turns to be a necessary tool for the preservation and management of these resources. The identification of the different kinds of predominant vegetables informs, chiefly, about the levei of soil protection, since the vegetation is responsible for the protection against the impacts of the raindrops (splash), by the reduction of the speed of surface outflow (runojj), through the increasing of the land ruggedness and greater soil structure constitution that may offer greater resistance to the action of the erosive processes. Besides, the collected data about the covering vegetation generally comes along with the information about the current use of the soil, since they both are strictly related. Several authors have pointed out the importance of geo morphological mappings of environmental planning projects. The use of the cartography and geo morphological information aim to represent the physiography of the landscape, considering the elements identification or environment of transport and accumulation, characterization of the morph genetics processes, and the human action implications. From the environmental point of view, the landforms are factors that influence the local hydrological conditions and specific top climatic. ln this sense, the micro basins of Ribeirões dos Apertados and Três Bocas located between the municipalities of Londrina and Arapongas, North of Paraná, though constituted by fertile soils, Nitossolos and Argissolos, present a mainframe of environmental degradation common to other micro basins of the region, or, the lack of banks vegetation, the action of erosive processes, blocking the water fountains, and turrung unviable the maintenance and increasing of the productivity of these areas. This study aims the composition of an environmental diagnosis of a limited area between two micro basins, as well as to evaluate the system of handling the soil and the effectiveness of conservationists' practices that have been used in order to present an environmental planning. lt can be observed that in some agricultural areas, at Ieast in the beginning, between two micro basins, some conservationists practices were used as handling and use of rural soil, the build of terraces, recovering of dirty roads, and suitable handling of the agricultura( defensive packing, among others. But what is really outstanding in the properties, like everything else in Paraná state, is the introduction of The Direct Planting System. The results of these actions mainly when working together with the responsible organs of agricultura( management, are effective in the improvement of environmental conditions for the agricultura( development activity, rather with the increasing in production and maintenance of the environmental balance in the micro basins. lt was noticed also that in many rural properties of the studied area, are beginning to adopt the direct planting system. However, it is necessary to guide the human occupation in order to keep safe the areas intended to be of environmental preservation, aiming the conservation of the natural resources, the strong environmental fragility and high susceptibility to erosion of this area of study.

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ABSTRACT The extraction of gold in the Amazon, since 1970, has grown fast from a politic that was resulted in the creation of gold extraction reserves in this region. ln the Madeira River the gold exploration is noticeable because of the deposition of mercury in the environment. This metal is toxic and it resists to degradation process, transforming itself chemically, till it gets to its organic form, known as very toxic. Its extensive usage in the gold recover has caused impacts to the environment and consequently to the population, according to studies already done. This study has as its goal to value the pollution by Hg in soils and the variation according to soil fractions. The soils were collected by profiles in 10 areas in the Madeira River. The determination of organic matter was done, according (BRASIL, 1999). To Hg determination it was selected the fraction <200 mesh (<74 m), analyzed by atomjc absorption spectrophotometer coupled vapor cold generation (Bastos et. al, 1998). Soils of the kind Latosols and hydromorphic were identified. The Latosols presented from 288 to 641 g.Kg-1 of clay and from 266 to 111 g.Kg-1 of thin send, from the horizon A, (superficial) to B2 (sub-superficial). The increase of values of clay makes the function of organic matter in the superficial horizon better (from 20,2 to 19.0 %). The Hg concentration in these horizons varies from 25,5 to 641,4 g.Kg-1 in the superficial horizon. The hydromorphic, especially, the Fluvic Neosols, present thin area, 396 to 57 g.Kg-1 and clay from 254 to 654 g.Kg-1 from A1 to A2. The horizon A2 presents 467 g.Kg-1 of silt, 13,6 % of OM and 147,31 gHg.Kg-1. Among the soils groups of the studied area, it is noticed more Hg concentration with the increase of values of silt and clay, that consequently presents more tenor of OM, and that subsidizes the organic mercury forming.

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ABSTRACT This work evaluates natural soil fertility on plain and flooded terrace areas, at Madeira River-RO fluvial plain, based on physics and chemicals analyses, (pH, OM, AI+2 + H+, exchange bases K+; Ca+2; Mg+2 e AI+\ physic-chemical (CEC, m% and V%), from the city of Porto Velho-RO to the city of Humaitá-AM. This kind of soil analysis is accomplished based on the percentage of base saturation (V%), which consists on physic-chemical phenomenon of ion absorption on clay and organic matter (OM) minerals. The soil samples were collected from temporary flooded plain strips and fluvial terraces with 20 km of intervals and 10 profiles described along the way, totalizing forty one (41) horizons. Using the EMBRAPA (1997) methods, the horizons A and B of each profile were considered. The results indicate four profiles with natural fertility deficiency: the Yellow Latosols at profile l and 2, Plintosols at profile 6 and Fluvic Neosols at profile 10, which may be related to the soil acidity, associated with high values of Al+3, as well on plain soils (Plintosols and Fluvic Neosols), as fluvial terrace (Latosols). Soils under the influence of flooding regime present high V%. The potential CEC values of analyzed horizons, were found low in consequence of the mineral composition of the clay, its values were correlated to the OM activities. However, the highest clay samples activities have been found on the superficial horizon of Plintosols at profile 6 (Cavalcante Community), where the potential CEC has arisen despite of reduction of OM content. The CEC varies from soil to soil, and what determine its values are the organic colloid/clay structures and the quantity of OM.

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ABSTRACT Deforestation and shift of land use to agriculture, is of great concern in Golestan Province and has brought hazardous problems of flooding, landslide and soil loss. Soil organic carbon, total nitrogen content, available phosphorous and potassium, calcium carbonate content, thickness of A horizons and some important soil properties were studied on forested soils and compared with the adjacent deforested and cultivated soils. The studied soils were formed on a hillslope with parent material consisted mainly of loess deposits. Forested and deforested soils were classified as Calcic Hapludolls and Typic Hapludolls, respectively. The studied soils were all calcareous with the pH value of 7-7.9. The soil texture was silty clay loam with the silt content of 54-60%. The results revealed that the soil organic carbon, total nitrogen content and available potassium, were significantly lower in the deforestated soils. The thickness of mollic horizons was also reduced after deforestation in all studied pedons. While calcium carbonate contents of the subsurface horizon of the forested soils are significantly higher compared to the surface horizon due to the leaching processes, it is considerably high in the surface horizons of the deforested soils and does not change significantly with depth. This points to the effect of deforestation and cultivation practices which has led to soil erosion and the subsequent exposure of the highly calcareous subsurface horizon. Available soil phosphorous did not show any significant change by deforestation.

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ABSTRACT Agricultural practices that promote increased diversity and abundance of soil macrofauna may improve soil quality and productivity, due to the influence of soil macrofauna on organic matter breakdown, nutrient cycling and soil structure. Southern Lempira department in Honduras is an environment where farmers could benefit greatly from such an increase in soil quality. The landscape is hilly, with steep slopes and shallow soils that are susceptible to erosion. The need for shorter fallow periods, a decrease in the use of slash-and-burn agriculture, and promotion by extension agents has resulted in the large-scale adoption of an indigenous agroforestry system known as the 'Quesungual System', based on slash-and mulch of vegetation, rotation of maize, sorghum and beans and inclusion of naturally regenerated trees and shrubs within cropped fields. This paper presents research on the effects of four common land use types (secondary forest, recently cleared agroforestry fields, mature agroforestry fields and silvopastoral fields) in the Quesungual area on soil macrofauna abundance and community composition. Sampling methods recommended by the Tropical Soil Biology and Fertility Institute were used to collect soil macrofauna in three representative fields of each type of land use, giving 12 study sites in total. Soil macrofauna communities were highly variable, both within representative fields, between representative fields of the sarne type, and amongst land uses. Soil macrofauna density ranged from an average of 1637 ± 359 individuais m-2 for young Quesungual fields to 831 ± 199 individuais m-2 in secondary forest sites. Silvopastoral fields and older Quesungual fields recorded intermediate values of 1508 ± 390 individuais m-2 and 1182 ± 233 individuais m-2 respectively. Myriapoda and Isoptera were consistently affected by conversion of forest to agricultural land uses, decreasing and increasing in abundance respectively. At depths below 1O cm, soil macrofauna communities appeared relatively similar in ali three agricultural uses, but differed from secondary forest. Ali land uses surveyed contained substantial soil macrofauna communities, which may be the result of incorporation of diverse organic matter inputs in the form of mulch pruned from trees, diverse vegetation and a continuous litter cover.

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ABSTRACT The hills of the district of Guabiraba, Recife - PE, show evidences of recent geomorphic disequilibrium as a consequence of an unbalanced erosive budget, mostly attributed to changes in land use. This paper seeks to provide a diagnostic for the recent erosive behavior within this environmental unit of the Municipality of Recife, which overlies the Barreiras Formation sediments, based on the application of a morphostratigraphical approach combined to the sedimentological analysis of recent correlative deposits. lnitially, through the usage of remote sensing imagery, a comparison was drawn between two different instants of landscape evolution: 1984 and 2002. The geomorphologic dynamics for that time lapse was assessed by the construction of geomorphic and morphodynamic maps according to Tricart (1977). That procedure has permitted the qualitative evaluation of the erosive behavior for the established timeframe, through the confrontation of spatial arrangements resulting from distinct geomorphic processes. The mapping of process-sensitive geomorphic features was coupled with the description of sedimentological properties of correlative deposits and their source areas. This has enabled the characterization of the superficial structure of the landscape. By comparing digital imaging, geomorphic maps and sediment properties, for the time period considered, it was possible to draw the conclusion that the area has evolved towards the stabilization of its morphodynamic units, displaying a sizeable reduction of gullied areas, as a response to the spreading of the "phytoresistatic equilibrium front", mainly on the hills covered by a second growth anthropicized savanna. Another significant geomorphological change observed, was the elevation of the local base levei, on the foot of the widespread radial gullies by the coalescence of a system of alluvial fans, which are locally dammed and disconnected of the main collecting drainage, by the lanes of an interstate highway. This damming has substantially diminished the erosive energy of the gully system.

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ABSTRACT This study aims at analyzing the deforestation evolution correlated to the proposal of a territorial planning implanted by Rondônia Social-Economical and Ecological Zoning - SEEZ - decree number 4.297 signed in July 2002), regulated in 2002. ln order to determine the indicators of degradation (deforestation), we opted for the analysis of maps of deforestation elaborated in the years: 1973, 1991 and 1999. We used digital classification of sensor image TM/Landsat (scenes 230/68, 231/67, 231/68, 232/66 e a 232/67, bands - 3, 4 e 5), and digitalized in a Geographic Information System - GIS/SPRING version 4.0 e COREL DRAW-10. The SEEZ/RO establishes three zones: zone - 01, destined mainly to agriculture and cattle raising activities, zone - 02, composed by special areas and zone 03 represented by areas of restricted use (Conservation Unity). The deforestation in Rondônia increased in the period from 1978 to 1999, when the deforested area passed from 420.000 hectares to 5.418.059 hectares, respectively, which corresponds to 23, 71% of the state of Rondônia.

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ABSTRACT This paper <leais with the issues of environmental impacts derived from the continuous process of metropolitan growth, and aims at identifying and analysing the erosive processes occurring in an area that has been legally designated as an environmental reservation, therefore said to be of strict permanent preservation. This research is focused on the understanding of causal relationships that unleash events of environmental disequilibrium, following the illegal systematic remova) of the regolith for providing building materiais to local civil construction entrepreneurs. It was possible to demonstrate the links between the spatial distribution of superficial materiais (soils, sediments and regolith) and the levei of stability of distinct geomorphic units, through the use of a morphostratigraphic approach. The area portrays a dissected hilly topography, lying within the lirnits of "Recife Metropolitan Area", and therefore suffering the consequence of rapid changes in land use, epitomized by the extensive remova) of natural vegetation and exploitation of its deeply lateritized regolith, in spite of being protected by State Laws. Deforestation allied to the remova) of the deeply weathered regolith has caused a rearrangement of the area's morphodynamic units (Tricart, 1977), as shown by both field and lab-work. However, it was found that the diversity of the pedological cover in the area, as a dynamic response of the lithology to the east coast tradewinds tropical climate, commands the distribution of superficial processes, favoring the ocurrence of mass movements, intense linear erosion, damming of superficial waterflow, reworking of sub-recent Aeolian sediments and building of coalescing alluvial fans. Finally the research threw light on the understanding of the linkages between rates of gemorphological dynamics and soil cover in a costal humid tropical environment.

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ABSTRACT Dryland farming on Fuerteventura and Lanzarote (Canary Islands, Spain), which has an annual rainfall of less than 150 mm/year, has been based traditionally on water harvesting techniques (known locally as "gavias"). Periods of high productivity alternate with those of very low yield. The systems are sustainable in that they reduce erosive processes, contribute to soil and soil-water conservation and are largely responsible for maintaining the soil's farming potential. ln this paper we present the cherrucal fertility status and nutrient balance of soils in five "gavia" systems. The results are compared with those obtained in adjacent soils where this water harvesting technique is not used. The main crops are wheat, barley, maize, lentils and chick-peas. Since neither organic nor inorganic fertilisers are used, nutrients are derived mainly from sediments carried by runoff water. Nutrients are lost mainly through crop harvesting and harvest residues. The soils where water harvesting is used have lower salt and sodium in the exchange complex, are higher in carbon, nitrogen, copper and zinc and have similar phosphorous and potassium content. lt is concluded that the systems improve the soil's natural fertility and also that natural renovation of nutrients occurs thanks to the surface deposits of sediments, which rrux with the arable layer. The system helps ensure adequate fertility leveis, habitual in arid regions, thus allowing dryland farrrung to be carried out.

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ABSTRACT The use of salic pyroclasts as soil mulch is a common management practice in arid conditions in southern and south-eastern parts of the island of Tenerife (Canary lslands, Spain). lt forms the basis for a traditional farming technique, which is known locally as 'jable'. ln its various forms the practice, used at heights of 300-1500 metres, covers an area of 3,850 hectares. The present work examines its influence on soil temperature and particularly on the estimation of Classes of Soil Temperature (Soil Survey Staff, 1999). Soil temperature was measured monthly at 50 cm depth in six covered plots and in adjacent uncovered plots, ali located at different altitudes: 325-375, 600, 825 and 1275 m. ln each season, measurements were also taken at 0, 10, 20, 30, 40 and 50 cm. The thickness of the mulch covering varied between 23 cm and 43 cm. The natural altitudinal soils sequence was as follows: aridisols, vertisols and vertic inceptisols, and inceptisols. The covered soil is currently used to grow grapes and/or potatoes while the natural soil has natural vegetation. The results evidence the buffering effect of the system, which is more marked at the lower heights of the sequence. Whereas the natural soils have a hyperthermic temperature regime (annual soil temperature, mean 22ºC, and a difference between mean summer temperature, mst, and mean winter temperature, mwt, > 6ºC) the soils under the pumice are isohyperthermic (mean 22ºC and mst-mwt < 6ºC). At approximately 600 m, the natural soils are thermic (I 5:Smean<22ºC and mst-mwt >6ºC) and the covered soils are isothermic (mst-mwt < 6ºC). This situation is maintained up to 800/900 m, where the buffering effect of the pumice is less pronounced. The temperature profiles are also influenced by the system. ln the natural soils, temperature decreases with depth, while in the covered soils this occurs only in summer. The management system helps prevent high temperatures and enables the soil to be used for farming.

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SUMMARY The National Water Agency - ANA is responsible for the implementation of the National Water Resources Policy, that policy mentioned in the Law n. º 9.433/97, has to be integrated to the others, municipalities, estate and federal Policies, on the soil and water conservation aspects, to obey the item VI, of article 24, from the Federal Constitution, amongst others laws listed below: Law n.º 9.984/00 Law n.º 6.225/75 Therefore, a specific law does not exist but a delegation of powers to the Ministry of Agriculture for the promotion, supervision and orientation of the national land use and soil conservation policy. This competence was executed through programs of that Ministry and despite the generated advances, for example, with the National Program of Watersheds, that had success in some states of the south and southeastern region, in years 70 and 80, but it had problems. The implementation of these programs was subjects to the interests of the governing and ministers who had occupied the folder of the Ministry of Agriculture, occurring discontinuities and not having of fact the creation and implantation of one policy of state on national land use and soil and water conservation. It is in the context of the interaction of the soil and water conservation with the water availability and its multiple uses, imposes the implantation of one national land use and soil and water conservation policy, better formatted, in order to prevent discontinuities. However, even so all the related legal body to the subject mentions “incentives” for the soil and water conservation, its viability is tied necessarily with the regulation of these devices, that never was considered and remains in open. Had the great interaction between soil and water and considering the effect that the land use and the conservation of the soil on the quality and quantity of water from the watershed, consider it is proposed the articulation and development of one national land use and soil and water conservation policy.

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ABSTRACT Sand dune stabilization programmes in Iran has been highly successful. A considerable portion of the active dunes in the study area has already been stabilized ,and a good cover of annual and perennial species has been established. Here again this very successful program of sand dune fixation has raised another problem, once the protection is ensured, how to economically use this land. Three main possibilities may be considered: 1-production of firewood, wood and paper 2-production of pasture and animal products. 3-production of agricultural crops. Production of firewood does not appear to be an economically viable option in Iran. Light grazing has been proposed as a way of utilizing the stabilized areas of the dunes for food production. However, the delicate balance of dune system could be disrupted very easily. Thus in order to utilize the stabilized sand dune systems more efficiently, some high value crop or cash crops production is another alternative, where irrigation water is available. Dunes are equally suitable for growing cash crops but their fertility and high permeability appears to be a limiting factor. Thus to carry out this experiment AMB layers were spread in two different depth, namely 45 and 60 Centimeters using AMB machine. Severa! cash crops such as watermelons, melons, cucumbers and tomatoes were planted and irrigation treatments were set up. This experiment indicated spectacular results in the production of Charleston Gray watermelon with the yield of 50 tons/ha and Honey Drop melon with 20 ton/ha, using drip irrigation system. Sprinkler system was not suitable due to high evaporation rate of water in this region. Furthermore sand particles ejecting from soil surface during sprinkling-drop impact damaged crop leaves and consequently decreased yield. Since infiltration rate in sand dunes is very rapid, conventional irrigation methods such as flood or furrow irrigation are highly inefficient. Thus implementation of the results of this research by farmers can play an important role in increasing water use efficiency as well as their livelihood.

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ABSTRACT Between the late 60's and early 90's intensive exploitation of residual soil for civil construction took place in the municipality of Ubatuba, North Coast of São Paulo State. Tropical climatic conditions associated with a hilly landscape bordered by the Atlantic Ocean gave rise to thick (10-30m) weathering profiles derived from Precambrian granitic-gneissic rocks. Exploitation of large volumes of this material required only very simple technology, which on the other hand has caused highly adverse environmental impacts, such as deforestation, soil erosion, land instability hazards, scenic deterioration, pollution and disturbance of local water flow regime. This paper deals with the devising of strategies thus identifying stakeholders and describing their roles both on the dereliction and reclamation processes related with residual soil exploitation. The evaluation approach focused on the analysis of the regulatory framework and its practical implications and issues in terms of licensing for mining operations, commercialization of construction materiais, and the relations of such mining activities with regional and urban planning. A survey of stakeholder viewpoints was successfully achieved through a two-day workshop. The attendance included decision-makers, officials and representatives of governmental and regulatory bodies (Federal, State and Municipal), environmental research institutions, private miners (entrepreneurs) and consultants, public attorney, and NGOs. The outcomes have indicated that State and local authorities properly managed to stop illegal exploitation of residual soil in the early 90's. However no land reclamation was undertaken until present. One of the main problems would be related with the procedures for mining and environmental licensing that were considered to be too complex and long (usually involving up to seven decisional instances and 2,5 years in average). Other key issues and needs identified included: a) organization of a database in a Geographic Information System; b) formulation of a Regional Mining Directive Plan consonant with the other Management Plans; c) regulation of land ownership; d) regulatory framework able to reconcile development and preservation so that to prevent illegal mining; e) development of integrated models for reclamation taking comprehensive consideration to aggregate production, reduction of risks and land recovering.

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ABSTRACT Land clearing has been the traditional tool for creating greater agricultural production since time began. Ali who consume the products of the land, in whatever form, are part of the sacrifice, willing or not, of biodiversity to generate sustenance and wealth (Declaration of Madrid, 2001). The farmer is omnipresent in areas which produce food and fibre and in many where timber is a product ; he should be encouraged to become a "steward of the land", receiving environmental services payments for this responsibility. These are not subsidies, first because the off-farm benefits to society of ZT adoption (achieved, overwhelmingly, at the farmer's expense) generate huge social transfers and, second, the WTO regulations do not classify these payments as such. The mitigation potential of land use intensification with integrated ZT crop x Iivestock systems (ICLZn, can vary between 0.8 and 2.5 ha of reduced demand for land clearing for each hectare in the system. By using a ZT crop ley for two to four years, the cost of pasture renovation is defrayed and pasture carrying capacity is trebled, from an average of about 0.7 animal units (AU)/ha to over 2 AU/ha. Both historical data surveyed and five spreadsheet models of real farms developed in this study, substantiate this. The study also shows higher net present value (NPV) and internai rate of return (IRR) values accompanying this new technology. Brazil has now established a national programme for ICLZT. Financial and other incentives, such as farmer and technician training, good technical backstopping from on-farm-research and preferential access to credit, are required to overcome the initial risk of change and incremental investments required to adopt the new technology. Recommendations are made for a fiscal package which emphasizes the "carrot" approach, but which sharpens the "stick", when necessary. Also proposed are international credit projects for large-scale adoption of ICLZT systems.

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ABSTRACT This study was aimed at assessing the possibility to use digital photographs to evaluate success of the reclamation of a gravel-mined degraded area. The indicator used to measure success was the degree of vegetation ground cover. Photographs were taken with a Canon camera (model Power Shot A 100). On 11th of October 2003, in a sunny day (without clouds), a total of 24 photographs were taken of the centre of the 24 experimental plots. Ali the 24 photographs were processed with ENVI 3.5 software following the sarne procedures applied to process satellite scenes. ln each scene analysed, two classes - vegetation cover and bared soil - were identified with the maximum likelihood algorithm. Results showed that digital photographs can be used in the quantification of vegetation ground cover and that the technique employed in this study can be applied to evaluate methodologies of reclamation of mined areas in which the establishment of vegetation is expected. The technique tested in this study can be employed by government agencies in charge of land reclamation plans because it is efficient in determining vegetation ground cover, is easy to perform and is not expensive.

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ABSTRACT Satellites can offer important spatial data for the assessment of soil erosion. This study was conducted to explore how satellite imagery could be used for evaluating erosion in a I O*1O km area in the Brazilian Cerrados. Products obtained from a variety of satellite sensors were analyzed for the purpose of (1) detecting erosion features; and (2) qualitatively mapping erosion risk. Erosion detection was done through visual image interpretation. Optical Terra ASTER images allowed for a better detection and delineation of major gullies as ENVISAT ASAR imagery. Gully dynamics could be assessed by jointly interpreting aerial photos of 1979 and a high-resolution QuickBird image of 2003. QuickBird also allowed for the detection of smaller erosion features, like rills. Erosion risk mapping was performed for the complete study area with a simple qualitative method integrating information on slope and vegetation cover. Slope was calculated from the SRTM DEM, and NDYI, being indicative of vegetation cover, was obtained from a wet-season ASTER image. Both factors were automatically classified based on their relative susceptibility to erosion. The erosion risk map was constructed by combining both classifications with the minimum-operator. The accuracy of the map was good (75 %) when compared to field estimates of erosion risk. The method presented therefore allowed for a quick and proper indication of spatial differences of erosion risk in the study area, particularly concerning rill and sheet erosion.

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ABSTRACT The hydrographic basin of stream Puitã, located in the southwest of the state of Rio Grande do Sul - Brazil, is characterized by quaternary superficial formation. These formations are dominated by erosive features and sand strands located in the geological compartment of hills as well by bushes located on the hillside and ciliary's bushes located along the course of the water together with the campestre vegetation. The use of the land stands out with plots of land used to agriculture, intensified in the last decades. The agricultural activities left the soil fragile, causing erosive features. This study aims to identify the existent relationship between the type of vegetation and the soil degradation in the region of the hydrographic basin. The methodology is based on digital classification of Landsat-TM satellite images, data acquired between 1984 e 2004, on the correlation analysis between degraded areas, classes of land use and vegetation's types. The results showed thematic maps that allowed identifying the different fragilities and susceptible areas to the sandification process. The multitemporal approach allowed to evaluate the modifications of the mapping classes and to identify the expansion or retracting of sand strands and erosive processes. lt was detected that the agricultural use is the responsible agent for the amplification of the soil fragility.

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ABSTRACT The empirical and scientifically documents prove that misuse of natural resource causes degradation in it. So natural resources conservation is important in approaching sustainable development aims. ln current study, Landsat Thematic Mapper images and grazing gradient method have been used to map the extent and degree of rangeland degradation. ln during ground-based data measuring, factors such as vegetation cover, litter, plant diversity, bare soil, and stone & graveis were estimated as biophysical indicators of degradation. The next stage, after geometric correction and doing some necessary pre-processing practices on the study area's images; the best and sui Table vegetation index has been selected to map rangeland degradation among the Normalized Difference Vegetation Index (NDVD, Soil Adjusted Vegetation Index (SA VI), and Perpendicular Vegetation Index (PVD. Then using sui Table vegetation index and distance parameter was produced the rangelands degradation map. The results of ground-based data analysis reveal that there is a significant relation between increasing distance from critical points and plant diversity and also percentage of litter. Also there is significant relation between vegetation cover percent and distance from village, i.e. the vegetation cover percent increases by increasing distance from villages, while it wasn't the same around the stock watering points. The result of analysis about bare soil and distance from criticai point was the sarne to vegetation cover changes manner. Also there wasn't significant relation between stones & graveis index and distance from critical points. The results of image processing show that, NDVI appears to be sensitive to vegetation changes along the grazing gradient and it can be sui Table vegetation index to map rangeland degradation. The degradation map shows that there is high degradation around the critical points. These areas need urgent attention for soil conservation. Generally, it shows that the most parts of rangelands in studying area have been degraded. So conservation priorities on degraded rangelands have been recognized based on current degradation.

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ABSTRACT The water erosion m semiarid region of northeastern Brazil is mainly influenced by the intense rainfalls, which can occur during long periods of drought, when a large amount of sediment yield can be observed during such events. Thus, this paper aims to study the rainfall frequencies in such region through the wavelet transform. An application of wavelet analysis is done with long time series of the total monthly rainfall amount of several places from Paraíba state in northeastern Brazil. The main frequency components in the time series are studied by the global wavelet spectrum and the modulation in separated periodicity bands were done in order to extract additional information, e.g., the 8 and 16 months band was exarnined by an average of ali scales, giving a measure of the average annual variance versus time, where the periods with low or high variance could be identified. ln Taperoá II and Bodocongó raingages, important reductions were observed in the average variance for the following periods: 1998 to 2000 and 1993 to 1997, which can be considered as dry periods. Although, the precipitation in Taperoá II and Bodocongó raingages showed a similar global wavelet spectrum, their wavelet spectrum revealed particular features. This study can be considered an important tool for time series analysis, which can help the studies concerning soil erosion and land degradation, mainly when they are applied together with runoff-erosion simulations.

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ABSTRACT The tourism is today, thankfully, an important alternative to the economical dynamization of stagnated areas that have potentiality for its development. Among the different modalities of tourism, some can, with success, be developed in the rural area - among them the ecotourism and the rural tourism. Considering that the tourist activities need to promote the environmental conservation so that the sarne ones reach its sustainability, once when degrading the environment in which they happen, they degrade themselves. The objective of the work is it of evaluating the potentialities for the development of the tourism in the rural areas as instrument capable to avoid or to minimize the degradation of the lands in semi-arid environment in the Northeast Region of Brazil, having the environmental education as guide base of the handling of those activities for the several involved actors. The research focuses the Poles of Development of Eco-tourism in the area, confronting the socioeconomic realities to the tourist possibilities offered by the natural resources and cultural patrimonies. It grew starting from cabinet studies and of field, propitiating the recognition of the discrepancy among the potentiality for the development of the tourism in the rural area and its occurrence, demonstrating the divergence among the speech contained in the National Politics of Tourism and its practice, once this continues to motivate, in different ways, the tourism in the coastal areas, where they are driven the largest amount of financial investment, so much in infrastructure terms as in training of human resources. But, at the sarne time, it was also possible to identify areas where tourist activities are being capable to promote the decrease of the human pressure on the natural resources, especially in what it concerns to the vegetable covering and the soil, that promote the degradation of the lands and, in certain cases, the origin and intensification of the phenomenon of the desertification.

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ABSTRACT The Industrial Revolution was followed by an increase in the rates of urbanization, paiticularly after the second-half of the 20th century. In this context, Sao Luis, the capital city of Maranhao State, adopted a housing development policy that was aimed at reducing the housing deficit in the municipality. Tiie construction of the Cidade Operaria housing complex was a response to these explicit social needs, which have intensified since the 1970s. The occupation of the complex, however, resulted in considerable darnage to the ecological integrity of the adjacent habitats. The complex is located in the catchrnent basin of the Paciencia and Santo Antonio rivers, at the center of the Maranhao Island. This study analyzes the spatial and temporal dynamics of the area's urbanization process, which occulTed in three phases: the period between 1976 and 1981 saw the removal of the original vegetation cover in some areas, as a result of the first settlement in Parque Zelandia. During that period, subsistence agricultme was cornmon practice along the margins of st:rearns and rivers. The second phase corTesponds to the constrnction of the Cidade Operaria housing complex, which occtmed between 1981 and 1988. During that time, 860 ha of land were cleared and urbanized, resulting in considerable environmental damage. Changes of relief, due to grading and eaithmoving activities, lead to itrnversible modifications it1 the course of rivers and streams; many tributaries of the rivers Paciencia and Santo Antonio had theit·s springs smothered by eaithfills; construction of houses and the use of asphalt on roads reduced soil penneability, increasing the depth of the water table; the release of untreated sewage containinated the drainage basins. During the thit·d phase, which staited in 1988, the environmental degradation was intensified by the occupation of areas adjacent to the housing complex. This model of urbanization has caused ÜTeversible damage to the hydrology and water quality in the study area, and this aiticle aims to provide an incentive for the creation of land-use planning and management strategies that include protective and restorative measures to reduce degradation of catchment basins as a result of urbanization.

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ABSTRACT Sewage sludge and composted garbage are available in large quantities to be employed as sources of organic matter for revegetation projects of mined spoils in the Brazilian Federal District (DF). These sources were used for growing baru (Dipterix alata Vog.) on mined spoils in the Brazilian Cerrado and the growth and mortality of 99 seedlings treated with these organic matter soruces were measured. In 4 months, rates of survival ranged from 56.7%, for trees treated with compost, to 96.7% for plants treated with sewage sludge. The compost seems to have toxic effects on seedlings, since the treatments with 35, 45 and 50 Uhollow had no survivals. After the first period of growth, the study was able to show that the best rate for plant development with sewage sludge was 20 and 30 Uhollow (57% and 47). For plants treated with compost, the best result was obtained with the smallest dosage (5Uhollow), where the growth is similar to the best results obtained with the sludge (47%). In larger doses the growth varied between 6% and 24%, span in which the results obtained in the control treatments, chemical treatment (16%) and no treatment (12%) are also found. Therefore, the increase in growth of the seedlings is a function of the dosage and type of organic material employed.

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ABSTRACT The small farm Santa Eulália occupies a privileged area in the landscape composition of the city of São Luis, being situated in one of the vectors of urban expansion, the edges of the avenue Euclides Figueiredo, on the northwest of the island of Maranhão, next to the center. In the decade of 1980, the small farm was inserted in area of permanent environment protection and in the beginning of the decade of 1990, Santa Eulália received great landscape alteration for interest in creating the housing development Santa Eulália for an estimated population of 35 thousand inhabitants. The intervention was made aiming to organize the growth of the city, however the execution of the work generated a great controversy, as much political as environmental, but also social, with the argument that the area destined to the implantation of the housing development would be of permanent preservation and placed on the side of a garbage deposit that served as a deposit of solid residues for ali the cities of the island. After the deforestation of 107.32 hectares and the implantation of the primary infrastructure in the place that involved services of embankment, drainage and pavement, the work was seized by the Brazilian Institute of the Environment and Renewable Natural Resources (IBAMA), but the main environmental impacts had already occurred or was occurring. Due to the land filling, embankment, previous cut of palm trees and mangrove, some foci of erosion with the creation of several gullies had originated and had a consequent sanding of creeks due to the material carried by the raio, besides that, the exposed soil is poor and with lateritic concretions . These factors made it difficult to attempt the forest resetting of the area in study. Therefore, the recovery of ali the area becomes necessary in order to leave it with a profile similar to the original, mainly in the areas considered untouchable for the Brazilian environmental legislation.

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ABSTRACT The sandy lands are a process of scouring with sand forming a sandy area, which corresponds to a reworking of the sands due its constant mobility, involving the transformation of not solids deposits is sandy areas. This work tried to establish the characterization of this phenomenon of scouring with sand in a local levei, occurring in arenaceous areas in the Northeast of the state of Paraná, specifically in the urban site of Paranavaí. It was also made an evaluation of the environmental degradation as well as different causes for what provoked these sandy areas. Being an area with a high levei of soil decomposition with the highways routes crossing it, it was necessary, besides bibliographic data that allowed a theoretical basis, a research applied in order to supply subsides for future planning related to the space organization. The evolution of the use and soil occupation in this area has been processed within an urban planning which considered by no account neither soil characteristic, the vegetation nor the predominant climate in that region. The mechanisms of region atmosphere circulation were analyzed, the alterations or attributes of the climate as well, aiming to identify the genesis of the erosion sandy and possible time and space distribution. Initially, the main characteristics of the region were collected, components e processes working on the land model. It was observed how it worked and the use and occupation of the soil in past times and currently. During 2004, using the Environmental Fragility Letter, the areas of erosion were identified, ravines and strong erosion that compounds the first stages of the focused problem. The sandy land is a process that involves erosion, transport, e accumulation, meaning most of times the loosing of Biosphere productivity. For monitoring these risk areas some measuring canes were made to measure the soil loss, which were used in severa! spots of erosion in the urban area in Paranavaí. The measurement happened in every two months for a year in six different pre-established spots through satellite image that turned it valid in the study field. Ali together, the pluviometrical leveis were analyzed to be related to the soil losses. It was observed initially that the causes of these facts were reflection of inappropriate handling of the urban soil, and in second time it was noticed that it had a broaden reach, involving from ecological unbalance, to politics, social and economical interests. Among them; the stabilization of this sand scouring some suggestions were made: the plantation of some trees in specific seasons of the year which hold the best conditions for their developing, for instance, during the Winter the temperature is lower and the insolation lower as well, consequently it provokes a higher levei of soil humidity.

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ABSTRACT The assessment of soil degradation in natural ecosystems must necessarily be performed from a non-conventional perspective, focused on agricultural productivity. Thus, the assessment of soil degradation in natural ecosystems requires the definition of standards with which to compare other soils and thus evaluate their quality. ln order to define these standards and manage appropriately lhe processes involved in the degradation and variation of soil quality, it is necessary to understand and establish in detail the genetic processes that have taken place in that area and have led to the formation of a mature soil, which would be considered to be standard, as a non-degraded soil. ln accordance with these ideas, we present in this work the evolutive and regressive succession of the soils and examples of the utilization of this methodology to evaluate soil degradation in arid zones and those in high desertification risk in the Canary Islands.

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ABSTRACT The Agenda 21 and the United Nations Convention for Desertification Combat defines desertification as the degradation of lands in arid regions, semi-arid and sub-wet dried, resulting from various factors, among them the weather variations and the human activities. This understanding, besides marlcing the geographical space to be taken into consideration, undoes with the clearly climatic view of the question and proves that desertification has its origin in complex interactions of physical factors, biologics, political, socials, cultural and economics. However, it's necessary to recognize that there are generally more serious causes, as the poverty, that leaves no alternative for the husbandmen only get from land the maximum possible to supply the family's immediate necessity even affecting its subsistence for a long time. ln terms of world, semi-arid regions represent 1/3 of the planet's surface, where lives 1/5 of the population, more than 1 million people. Twenty-two per cent is the participation of these areas in the production of foods. The Semi-arid of Brazil is registered as one of the physiographic zones of the Northeast Region, representing about 57% of this territory. The organization of the economical process, historically based on extensive cattle breeding and agriculture, and on the existence of some products of larger importance in the market, like the case of cotton was, always based on an agrarian structure dominated by land concentrations. In the more diffused desertification process in the North-eastern semi-arid this pattern has been constructed on alarming proportions, aggravated and reaffirmed by the occurrence of periodic droughts and the peculiarities dueto the systems of production that appear from this process directly contrary to the correct manners of use of the natural resources, in option to, where and how to develop the agricultural activities.

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ABSTRACT The human survival is closely connected to the use we do of our natural resources existing in our planet, in a way that this connection depends on the consumption habits and apprehension of these goods. During the last century (XX), we noticed a boom of technology and a great changing in the habits of the world population. With the information globalization and knowledge, the environmental situation in the planet was more evident, and we concluded that the mankind should rethink the model of exploration of the natural resources. (Stockholm, Rio-92, Agenda 21 among others), and even the social paradigms. The proposal of this work is make a factual approach in this ocean of knowledge and discussions about the environmental problems currently presented in our society. It was chosen as a study unity the Hydrographic basin, specifically the physical processes presented at Ribeirão das Marrecas micro basin river. Collecting the data, basically a physical environmental inventory, characterizing the environment as most detailed as possible of the micro basin by consulting the cartographic documents available and bibliographic information. To the developing of the micro basin hydrographical of Ribeirão das Marrecas, it was necessary the confection of several themes letters. Each item of the inventory was translated into basic themes maps: geological, geo morphological, downward slopes maps, hydrographic, climatologically, the use of the soil and pedological. The intervention unit "hydrographical basin" presents advantages and disadvantages. The main advantage is that this territorial unit relates the effects/causes of the environmental more clearly and easier measuring. So, we intend to establish the recovery proposals presenting some mitigating alternatives or solving conflicts in the area of the micro basin. Due the region peculiarities, concerning to the dynamic economical and social factors, it becomes imperative that the civil responsibility takes it over in response to the environmental passive, whether they come from naturals means or from the action of man.