Linking GIS and a Surface Irrigation Model to Evaluate Regional Effects of Furrow Irrigation Strategies PDF Download

Author: Russell N. Faux
Publisher:
ISBN:
Category : Furrow irrigation
Languages : en
Pages : 230

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Book Description
The shallow aquifer in Northeast Malheur County, Oregon is polluted with Nitrates at concentrations exceeding federal drinking water standards. Efforts to solve the groundwater problems in this area have focused on developing farm management practices that will increase groundwater quality while maintaining agricultural production. Furrow irrigation is the dominant practice for irrigating row crops in this region. One potential way to improve water quality is to increase furrow irrigation performance on a regional scale. In this study a surface irrigation model, SRFR, was linked to a geographic information system (GIS) for the purpose of evaluating alternate furrow irrigation strategies in Malheur County, Oregon. SRFR is a physically based model that simulates water flow and distribution in irrigated furrows. The model accepts the management parameters that influence the outcome of an irrigation and in return provides measures of water application efficiency, amount of deep percolation, amount of surface run-off, and other performance indicators. The GIS, constructed using ARC/INFO software, contains the spatial data required to run SRFR on individual fields in the region. The data for the GIS were acquired using many different sources and techniques in order to meet the input resolution required by the irrigation model. The primary goal of this research was to develop a tool for evaluating irrigation practices on a regional scale, accounting for the diversity of physical circumstances and management practices that occur within a complex of several hundred farms. The particular application of this tool was for control of nitrate pollution of groundwater in the vicinity of Ontario, Oregon. The integrated system was used to estimate a base condition irrigation that is representative of current irrigation practices. The system was then used to assess irrigation performance using three alternative practices: 1) separate management of wheel and nonwheel compacted furrows; 2) use of an automated control system to vary application set times; and 3) cutback irrigation. Although this represents only a limited assessment of the alternatives that might be considered for the study area, preliminary results suggest that under certain field conditions irrigation efficiency can potentially improve more then 20% over the base condition using alternate strategies. The system demonstrated tremendous potential for identifying trends and variability in system performance in the region.