HR: 15:10h
AN: H43I-06    [Abstracts]
TI: Evaluating Impacts of Land Use/Land Cover Changes on Water Balance of a Small Watershed using a Distributed Hydrologic Model
AU: * Jha, S K
EM: jha.sanj@gmail.com
AF: Sanjeev Kumar Jha, Department of Civil Engineering; Indian Institute of Technology Kanpur, Kanpur, UP 208016 India
AU: Ostrowski, M W
EM: ostrowski@ihwb.tu-darmstadt.de
AF: Manfred W. Ostrowski, Institute for Hydraulics and Water Resources Engineering, Technical University Darmstadt, Darmstadt, 64287 Germany
AU: Jain, A
EM: ashujain@iitk.ac.in
AF: Ashu Jain, Department of Civil Engineering; Indian Institute of Technology Kanpur, Kanpur, UP 208016 India
AB: The impacts of land use/land cover changes due to varying agricultural practices, urbanization, and forestation/deforestation can impact the water cycle of a region significantly. The changes in the hydrologic characteristics of a region are closely linked to its environment and ecology. Therefore, an accurate evaluation of such impacts is important from the environmental and water resources management point of view. This paper presents the results of an investigative study aimed at evaluating the effects of changes in dynamic land uses on water balance of a small watershed. The detailed meteorological and hydrological data from Tarrawara watershed of area 10.5 hectares in Australia were employed to carry out the sensitivity analyses. The Tarrawara watershed mainly consists of grass, and is used for cattle grazing. The watershed has smoothly undulating terrain with no perennial streams or channels. The climate is temperate with mean annual rainfall of 820 mm and potential evapotranspiration of 830 mm. A physically based, spatially distributed conceptual hydrological model, called Water Balance Model (WBM), developed at the Institute for Hydraulics and Water Resources Engineering, Technical University Darmstadt, Germany, was employed in this study. The WBM model simulates the watershed using a raster element with four layers: infiltration layer, root layer, transport layer, and groundwater layer. Each raster element is capable of simulating the soil-vegetation-atmosphere-transfer system (SVAT) accounting for separation of precipitation into storage processes in a vertical column and runoff generation. The effect of changes in root depth, vegetation cover, leaf area index, and land uses in terms of various combinations of coniferous and deciduous forests on the interception evaporation, soil evaporation, transpiration, evapotranspiration, and through fall have been studied. The data in terms of precipitation (mm), temperature (0C), evapotranspiration (mm/hr), and runoff at 6-minute interval; digital elevation model, soil classification, type of soil with their depth at a particular raster element, and land use characteristics, were used for carrying out the sensitivity analyses. The results obtained in this study indicate that the changes in the dynamic land use/land cover parameters can significantly affect the water balance of a watershed.
DE: 1879 Watershed
SC: Hydrology [H]
MN: Fall Meeting 2005