Simulation of tile flow for a flat tile drained watershed in East Central Illinois (Part I)

摘要

The 48,900 ha Little Vermillion River (LVR) watershed located in East Central Illinois is predominantly tile drained by random tile drainage systems. The entire watershed drains into the Georgetown Reservoir which is a source of water supply to itspopulation of 10,000. Subsurface tile flow and crop management data have been collected during last seven years from different tile-drained fields located in various parts of this watershed. DRAINMOD and Root Zone Water Quality Model (RZWQM) were used tosimulate the tile flow at six of these fields under different tillage and cropping management practices, for years 1993-1998. Most sensitive parameters of each of these models were calibrated for different fields using measured data for two successive crop years consisting of corn and soybeans respectively. The calibrated parameters were then used to simulate tile flow for remaining years for each field. Results indicate that both model simulate tile flow within an acceptable range. However, DRAINMOD simulated results are closer to the actual observed values. Detailed results are presented in this paper.