Abstract
IDMM (Irrigation District Management Model), a user friendly, GIS based, menu driven personal computer software program, was developed as a planning and management tool for improved water use and crop growth production in irrigation districts. It consists of IRDDESS (Irrigation District Decision Support System), a crop growth and district simulation model that was integrated into ArcView GIS software. To demonstrate the usefulness of the model, its predictions were compared with those observed in real systems with similar situations. The three simulation modules of IDMM were tested for two locations in the Brownsville Irrigation District (BID) in Texas. The POTPROD (potential production) simulation module, was used to simulate daily crop dry matter production and irrigation regimes during one season for four crops: maize, soybean, sorghum, and cotton. Generally, the larger irrigation volumes and more frequent irrigations resulted in the highest yields. The SIMDIRT (simulation under different irrigation treatments) module estimates potential yield under any combination of irrigation regimes. It was tested for sorghum for one crop season with eleven different irrigation regimes. Results show that actual yields were within 4 % of predicted in three of the irrigation regimes. The SIMWETH (simulation under different weather conditions) module allows the user to estimate yields for as many seasons as desired. Historical or stochastically produced weather data can be used to analyze how potential yields vary under a given irrigation regime over a long period of time. Proper water management in each farmer's field is important in improving the overall performance of an irrigation district; consequently IDMM's capabilities were demonstrated at the farm and the irrigation district levels. One of the most important components of IDMM is its ability to visually display and analyze all information concerning crops, fields, irrigation, gates, etc., providing irrigation districts with information crucial in the process of decision-making.
Nazarov, Azimjon S. (2000). Geographic information system (GIS) and simulation model for management of irrigation districts. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -2000 -THESIS -N39.