Evaluating the Impact of Drought on Surface and Groundwater Dependent Irrigated Agriculture in Western Oklahoma

摘要

As the demand for freshwater resources and agricultural products increases rapidly, it has become extremely important to identify the susceptibility of agricultural ecosystems in arid/semi-arid regions to drought events. Irrigation has always provideddrought resiliency, but irrigation systems, water supplies, and cropping patterns are significantly variable among irrigated areas. In this study, drought sensitivity was investigated using remote sensing techniques for two areas in the Oklahoma Panhandle (OK-Pan) and in southwest Oklahoma (OK-S W), with the former ha ving access to Ogallala aquifer and the latter receiving irrigation water from a surface reservoir. The results showed that the remotely sensed irrigated area at OK-Pan was not impacted by rainfall or occurrence of severe and exceptional drought periods. The irrigated area at OK-SW, on the other hand, was strongly correlated with the amount of rainfall. In addition, the fraction of the total OK-SW area occupied by irrigated croplands dropped from 44% in 2010 (no drought) to near zero in 2011, when an exceptional drought was accompanied by the inability of the local reservoir to deliver the entire irrigation demand. The dramatic loss of irrigated lands, and consequently crop yield, highlights the crucial role of irrigation in sustaining viable agricultural production in the arid/semi-arid regions and provide insight into the future of groundwater-dependent imgated areas if non-renewable aquifers are fully depleted.