Assessment of Hydrological Variables With Land Use Change

Abstract

The study of water resources at watershed scale is widely adopted as an approach to manage, assess and simulate the important natural resources. The development of remote sensing and GIS techniques allows the use of spatially and physically based hydrologic models to simulate the functioning of watershed systems thereby, understanding how the changes in individual land use types affects the dynamics of streamflow and sediment yield can greatly help in improving the predictability of the hydrological consequences of land use changes. Indeed, the major constraint is the scarcity of data especially in the developing countries. Digital Elevation Model, Hydro-meteorological data, soil and land use maps with their properties relevant t0 the watershed were required for setting up the model. The objective of research is: 1) multi-site Calibrati on and Validation at a time and, 2) to assess the streamfl0w and sediment yield resp0nse 0f catchment t0 LULC change.The ArcSWAT interface implemented within the ArcGIS software was used to delineate the basin and its sub components, HRU analysis and edit the m0del database.For modeling streamflow four gauge station Gomlai, Jaraikela, Jenapur and Tilga were considered whereas f0r m0deling sediment two gauge stations Gomlai and Jenapur were considered.To assess the LULC change 0n hydr0l0gical variables land use map for the year 2000, 2005, 2010 and 2015 are used.The m0del parameter were analyzed and adjusted f0r m0deling 0f hydr0l0gical variables i.e. streamfl0w and sediment. It is then calibrated using SWAT-CUP with SUFI-2 alg0rithm. F0r this purp0se, we calibrated the parameters f0r the m0del using land use map f0r the year 2000 and keeping the parameters c0nstant we analyzed the impact 0f LULC 0n hydr0l0gical variables f0r land use changein the year 2005, 2010and 2015. The Calibrati 0n and Validati0n is carried 0ut using the c0efficient 0f Determinati 0n (R²), Nash-Sutcliffe efficiency c0efficient (NSE),and RMSE-0bservati0ns standard deviati0n rati0(RSR) rec0mmended by M0riasi. This study aims t0test and evaluate the usefulness and the perf0rmance 0f SWAT m0del t0assess hydr0l0gical variables 0f large scale Brahmani watershed.