CROSOWAT - A DECISION TOOL FOR IRRIGATION SCHEDULE

A numerical model has been developed to predict the soil moisture cont ent over the root zone depth as a function of time and to estimate the irrigation water requirements in humid basins under various managemen t options. An implicit finite difference model for transient one dimen sional flow, backed up by routines for computing various components of the field hydrological cycle such as evapotranspiration, effective ra infall, surface runoff, capillary rise, etc. is proposed. The paper de scribes the assumptions made, theoretical considerations of various su bmodules; system flowchart, hardware requirements and details of input -output. Comparison of the model predicted soil moisture profiles with the field observations is also given along with the results of numeri cal experiments carried out with the model in the form of sensitivity analysis for various model parameters. Statistical error analysis is a lso given to prove reliability of the model for estimation of irrigati on water requirements.