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Water Resour Manage (2008) 22:165190
DOI 10.1007/s11269-006-9149-5
K. Geetha & S. K. Mishra & T. I. Eldho &A. K. Rastogi & R. P. Pandey
Received: 19 March 2006 /Accepted: 22 December 2006 / Published online: 1 February 2007# Springer Science + Business Media B.V. 2007
Abstract A new lumped conceptual model based on the Soil Conservation Service Curve Number (SCS-CN) concept has been proposed in this paper for long-term hydrologic simulation and it has been tested using the data of five catchments from different climatic and geographic settings of India. When compared with the Mishra et al. (2005) model based on variable source area (VSA) concept, the proposed model performed better in all applications. Both the models however exhibited a better match between the simulated and observed runoff in high runoff producing watersheds than did in low runoff producing catchments. Using the results of the proposed model, dominant/dormant processes involved in watersheds runoff generating mechanism have also been identified. The presented model is found useful in the continuous simulation of rainfallrunoff process in watersheds.
Keywords hydrological forecasting . long-term hydrologic simulation . saturation excess overland flow . streamflow . rainfallrunoff . variable source area . curve number . antecedent moisture
Nomenclature
P total rainfallIa initial abstraction
Pe effective rainfall
Ft infiltration at any time t in SCS-CN-based model
K. Geetha : T. I. Eldho (*) : A. K. Rastogi
Department of Civil Engineering, Indian Institute of Technology, Bombay, Powai, Mumbai 400 076, Indiae-mail: [email protected]
S. K. Mishra
Indian Institute of Technology, Roorkee, 247 667 Uttaranchal, India
R. P. Pandey
National Institute of Hydrology, Roorkee, 247 667 Uttaranchal, India
SCS-CN-based Continuous Simulation Model for Hydrologic Forecasting
166 K. Geetha, et al.
ROt rainfall excess (surface runoff) at any time t for 5-days from beginning of storm
DRt subsoil drainage at any time t
PRt percolation at any time t
DSPt deep seepage at any time t in SCS-CN-based model DPRt deep percolation at any time t
SROt surface runoff at any time t, if t>5-daysTHRt throughflow at any time t in SCS-CN-based model
BFt base flow at any time t in SCS-CN-based model
TROt total runoff at any time t in SCS-CN-based modelEVPt potential evaporation at any time t
EVt evaporation at any time t
TRt...