EVALUATION OF LAND USE LAND COVER AND SEDIMENT DYNAMICS OF KULFO RIVER CATCHMENT BY INTEGRATING InVEST AND SATELLITE INFORMATION

Abstract

Land use/land cover (LULC) change has emerged on the global stage as a result of the realization that changes on the land surface affect climate, ecosystems, and its services. Kulfo river catchment experiences a lot of human disturbances due to population growth, intensive agricultural expansion, and increasing urban demand for charcoal, fuel wood and timber; resulting in forest and land degradation. The importance of this analysis was to classify land use and land cover changes (LULC) using two algorithms, which was important for evaluating changes, and to estimate soil loss and sediment export using an Integrated Valuation of Ecosystem Services and Tradeoffs Sediment Delivery Ratio (InVEST SDR) model. The catchment's LULC change was classified using satellite images from the years 2000, 2010, and 2020 to better understand the significant changes that occurred within the area. The classification result shows that over the given time periods, agricultural and barren lands have increased while forest and grassland have decreased. This output was considered as an input map for InVEST SDR model in addition to rainfall erosivity and soil erodablity factors and Digital Elevation Model (DEM) maps to determine catchment soil loss and sediment export. Agricultural area produced the highest rates of sediment export, followed by barren land, shrub land and grass lands, when compared to other land uses land covers. The forest produced the least amount of sediment. The average result spatial soil loss of Kulfo catchment was 41.5tons ha−1 yr−1 with the total sediment export of 6.0- millions of tons at the outlet in 2020 year. The obtained sediment export value was also validated to the observed value (6.5 million of tons) at the outlet of the catchment. These means, the estimated sediment export value using InVEST SDR model is almost similar with observed value. It indicates that InVEST SDR can be used for identifying erosion hotspots and prioritizations of sub-catchments for soil and water conservation (SWC) planning. To reduce sedimentation problem and ensure sustainability of the catchment need to special attention for implementing recommended SWC intervention and also need experimental based scientific research