Optimal Management of Potential Water and Sediment Yield from Urban Hilly Watershed

Abstract

The sustainable ecological management of soil and water yields from hilly watersheds of an urban area is a real challenge from the perspective of economic and structural feasibility. It is of key importance for future city planning to implement ecological management practices (EMPs) optimally in urban hilly watersheds incorporating future urban growth. To achieve this, here, the Revised OPTimal EMP Model with Linear Programming for Single Ownership (R-OPTEMP-LS) is applied to manage the water and sediment yield calculated concerning a future LULC scenario of a hilly urban watershed of Guwahati city, India. The future LULC of the study area has been derived by using the ASEA (Assessment of Settlements in Eco-sensitive Area) model. The model parameters were input from the “Master Plan for Guwahati Metropolitan Area – 2025”. It is found that in 2025, although the sediment yield from the watershed can be managed by executing the optimal combinations of EMPs, the peak runoff will be manageable only if the rainwater harvesting system will be strictly installed along with the EMPs. The model result says that for a 36.73% increase in the urban settlement in the hilly watershed from 2015 to 2025, there is a 33.4% increase in the total cost of EMPs. The high economic investment to control the adverse consequences of urban development in the hilly areas of Guwahati city emphasizes the need for strict conservation of those ecologically sensitive areas.