Modeling River hydro-morphological responses to Land Use Land Cover Change in Tropical Regions: the case of Sebeya catchment, Rwanda.
Abstract
Tropical regions have experienced the fastest Land Use Land Cover Change (LULCC) in the last decades. Furthermore, climate change will likely intensify these changes due to global warming and increased frequency of extreme events. These changes have diverse effects on watershed and river hydro-morphological processes through alterations of the rainfall and runoff patterns, which translate into changes in the water balance components. The magnitude of these effects depends on the watershed characteristics, including size, extent of change, topography, soil, and climate. Understanding the watershed hydro-morphological responses to changes in both climate and LULC -especially in tropical regions where rainy seasons are followed by dry seasons— is vital for effective land and water resources management in the face of future changes.
Sebeya catchment in the western part of Rwanda is prone to flooding, associated with erosive processes, and mass movements. Over the past thirty years, hundreds of people in the catchment have been displaced, while infrastructure and crops have been damaged yearly. In part, this is attributed to the combination of steep topography and the loss of forest cover on fragile soils, coupled with the increased prevalence of extreme rainfall events. Sebeya catchment experienced massive LULCC, including the conversion of forest land to agriculture and graze land, as well as poor mining practices leading to gully development. Gishwati forest is an example of such tremendous changes, whose area decreased from 2,800 ha in 1980s to 600 ha in 2000s. Nonetheless, such phenomena were followed by different conservation and reforestation measures, that increased the forest up to 16,000 ha. The objective of this study, therefore, is to quantify catchment LULCC in the last three decades and predict future scenarios, using remote sensing data and LULC model. Furthermore, a hydrologic model was used to simulate and forecast the associated changes in hydro-morphological and flood frequency.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2022
- Bibcode:
- 2022AGUFM.H53C..04K