Effect of land use land cover change on runoff characteristics using curve number: a GIS and remote sensing approach

Runoff is an important hydrological process and can cause negative effects such as soil erosion, excessive flooding over the river basin area. Changes in land use land cover are dynamic processes and can strongly influence runoff potential in the long run. The objective of the study is to analyse runoff from the curve number for different land use land cover classes and to derive land use land cover effect on runoff over Ambica river basin using QGIS for a period of 20 years, i.e., 1990-2010. SRTM digital elevation maps, Landsat 5 images, and soil maps extracted from the global hydrological soil group were processed in QGIS. A semi-automatic classification plugin was used for land use land cover classification and land cover classes such as urban area, forest, barren land, vegetation, and water bodies were identified. Significant changes in land use land cover patterns were observed during the study period. The results on the effect of land-use change on runoff can be seen as a warning for landuse managers and policymakers, who should aim at stopping and reversing the current land-use trends of the Ambica river basin.