Multitemporal Analysis of the Water Mirror of the Jaburu I Reservoir Through Remote Sensing Tools in the Years 2013 to 2020

Abstract

In regions with the influence of the semi-arid climate, water scarcity is clear, which is a consequence, among other factors, of negative precipitation scenarios that lead to prolonged droughts. Such characteristics reverberate negatively on the socioeconomic development of the society involved. In this context, water storage in dams can be considered an important strategic alternative that requires special attention in search of mitigating the water deficit in these regions. Thus, the present work aimed to carry out a multitemporal analysis of the water mirror of Açude Jaburu, located in the municipalities of Ubajara and Tianguá, Ceará, from 2013 to 2020. For this, the Normalized Index by Difference of Water (NWDI), using images from the Landsat 8 satellite, Collection 1 Tier 1, LANDSAT/LC08/C01/T1_RT, calibrated for Top of Atmosphere (TOA) reflectance, through bands 3 and 5, with a spatial resolution original 30 m. The main results show that the years with the greatest decline were 2014 and 2015 with 192.21 and 175.05 hectares of less water. The years 2018 and 2019 showed expansion, with 130.86 and 295.65 hectares, respectively. To evaluate the data discussed in this work in terms of correlation with rainfall in the area, the Spearman correlation test was used, which presented a p-value equal to 0.9349, assuming that there is no relationship between rainfall and the area of the mirror. of water. Further studies in the area are suggested to understand which factors can compromise the water availability in the reservoir, as well as to confirm, through larger series, if there is really no correlation between the water surface area and the amount of rainfall in the area. Finally, it was found that the remote sensing tools proved to be effective in the analysis of the water surface of the studied area, as well as having a positive potential to contribute to the proper management of surface water resources in a region with a semi-arid climate.

Keywords
remote sensing; NDWI; water resources