230-Modelling Hydrological Impacts of Continuous Contour Trench Conservation Systems.

Abstract

Continuous Contour Trench (CCT) system, developed for plantation in non-arable lands in low rainfall areas, has been found to be very effective in soil and water conservation, leading to considerably high groundwater recharge. In the present study, physically based distributed hydrological modelling system MIKE SHE was applied to a CCT treated watershed for assessing the impact of the conservation treatment. The MIKE SHE simulated the groundwater levels, soil moisture, surface runoff and peak runoff rates satisfactorily. Further, the model was observed to be capable of simulating the hydrological balance correctly even for the past years, in spite of non-availability of extensive data. The model was found to be sensitive to grid size; vertical and horizontal hydraulic conductivities, Strickler's roughness coefficient for overland flow and vegetation parameter, C2. The CCT system resulted in 89-100% reduction in surface runoff, 32% increase in groundwater recharge and 30% increase in the plant evapotranspiration with respect to the untreated watershed.