CARTOGRAPHY OF SURFACE WATER RESOURCES AS A PLANNING AND MANAGEMENT TOOL IN THE SEMIARID REGION: CODE SC.24-X-A-IV (CARTA FLORESTA)

Abstract

In dry regions such as the Brazilian semiarid region, the scarcity of water resources in relation to the demand for water is one of the biggest challenges to be faced by authorities and management bodies. The maintenance of up-to-date hydrographic data, in turn, can be an instrument to support water management actions, especially in dry periods. Thus, the objective of this work is to update the hydrographic data of a sector of the Northeastern semiarid region, corresponding to Code SC.24-X-A-IV (Carta Floresta). Vector files of topographic and geological maps, orbital images from the LandSat 5, LandSat 8 and Google satellites were used, whose features were mapped in QGIS 3.10. Thus, drainage channels, beginning and confluence of drainages and water bodies were recognized and quantified, subdivided into lakes/ponds, weirs, barriers and tanks. From the update, there was an increase in these features between 1985 and 2020, mainly in the dams. It is believed that the updating of hydrographic data is essential, in order to know the spatial distribution of water resources in a precise way, and which can facilitate planning and decision-making during usual droughts and long-term droughts.