Nabaoy River Watershed potential impact to flooding using Geographic Information System remote sensing

Abstract

Watersheds are naturally prone to environmental disasters such as flooding. The purpose of the study was to analyze the potential impact of flooding on the Nabaoy River Watershed using Geographic Information System (GIS) remote sensing. Secondary data for flood factors such as slope, elevation, land cover, surface run-off, rainfall, and soil were used and reclassified using the critical scale of factors of flood vulnerability ratings and weighting overlay using the GIS environment to create geospatial data on the potential impact to flooding. Data revealed the following percentages of the susceptibility of the watershed to flooding: very low (8.06%), very highly (19.79%), moderate (22.15%), high (22.84%), and low (27.16%). The main result showed that the upstream area of the Nabaoy river watershed such as Nabaoy, Napaan, Pawa, and Tag-osip was within low to very low flood vulnerability. Meanwhile, the inundation vulnerability intimidation on the downstream side of the Nabaoy river watershed such Cubay Sur, Motag, and low-lying areas of Nabaoy, Napaan, and Tag-osip have moderate to very highly susceptibility to flooding. The results obtained can help the concerned agencies and stakeholders to craft policy and water management plans, adaptive capacity, conservation measures, and resilience programs in response to severe flooding.