POTENCIAL DE PRODUÇÃO DE ÁGUA DE NASCENTES NO MUNICÍPIO DE CERES (GO)

Abstract

The improvement of watershed management is one of the alternatives to increase water production in municipalities. The present study aimed to analyze hydrological attributes and types of land use and occupation to group micro-watersheds with similar characteristics in the municipality of Ceres-GO. The work stages involved the use of Geographic Information Systems for processing and manipulating remote sensing data, image selection, identifying springs in the images, integrating with hydrographic and relief maps, as well as measuring the physical-hydrological and land use characteristics, and grouping springs with similar features. The hydrological characteristics investigated in each micro-watershed were: perimeter, area, average width, edge distance, Gravelius Index-Kc, axial length, form factor-Kf, drainage density-Dd, direct distance, sinuosity index-S, maximum altitude, average altitude, minimum altitude, altitude at the outcrop, altitude at the meeting with the next course; slope at the spring, flow rate, forest cover, non-forest natural cover, agro-livestock use, non-vegetated area, water bodies cover, MB-3 (Forest; %), MB-4 (Savanna Formation; %), MB-9 (Silviculture; %), MB-11 (Flooded Field/Swampy Area; %), MB-12 (Grassland Formation; %), MB-15 (Pasture; %), MB-19 (Temporary Crop; %), MB-21 (Mosaic of Uses; %), MB-24 (Urbanized Area; %), MB-25 (Other Non-Vegetated Areas; %), and MB-33 (Rivers, Lakes, and Oceans; %). The data were subjected to descriptive analyses, Ward’s cluster analysis, and principal component analysis. The values of perimeter, area, Kc, Kf, and Dd for the micro-watersheds ranged from 2 to 15.9 m, 14.86 to 977.34 ha, 1.28 to 1.72, 0.334 to 1.656, and 0.039 to 1.167, respectively. Most variables showed a medium coefficient of variation. The micro-watersheds occur more frequently at minimum altitudes of 519 to 775 and maximum altitudes of 547 to 1005 m, and the springs, between 534 and 857 m. Ward’s cluster analysis identified six groups of micro-watersheds with similar characteristics, which do not consider the municipality's political boundaries. Based on the principal component analysis, the most important attributes for discriminating the micro-watersheds were flow Kf, sinuosity index S, sinuosity index P, slope, number of courses, Kc, Dd, and direct distance, respectively. The coverage types showed little correlation in the separation of the micro-watersheds and revealed the predominance of agro-livestock use, occupying nearly 80% of the municipality's area. These results can guide new studies and future actions for the management and conservation of water resources in the municipality