Evaluation On Availability Of Field Irrigation Water For Crop Interplanting In Shallow Groundwater Irrigation Area

Availability of field irrigation water were studied in a field of a largest-sized irrigation district-Hetao Irrigation District in the western arid area of China respectively according to its unique characteristics of hydrology and water resources and autumn irrigation. Field experiment were done so as to analyze and confirm the transfer relationship between irrigation water, precipitation, soil water, ground water, crop water. A new method to evaluate field irrigation water in a whole year including crop grow and non-crop grow period were studied. Interplanting of spring wheat and summer corn which is representative plant pattern were selected in this study. Water-saving potential of field irrigation water in the plant pattern were appraised scientific and general. At the same time, field irrigation water efficiency were calculated to evaluate the availability of field irrigation water. This study will provide scientific thereunder for the irrigation area alteration that circumfuse water-saving. Main conclusions as follows:(1) According to the theory of water balance, the transfer relationship between irrigation water, precipitation, soil water, ground water, crop water were studied in SPAC, and the dynamic process of five related water transfer were described. The results indicate that five related water commute complex and frequent in Hetao irrigation area which have unique characteristics of its shallow groundwater. Groundwater could be used by supplying to soil water, so it is wrong to deem leak water as invalidation water simplely. (2) The availability of field water in Hetao Irrigation District that have shallow groundwater were estimated based on the five related water transfer relationship in SPAC and dynamic viewpoint. The availability of leak water and water storage in root zone were considered. The results indicate that the availability of spring wheat and summer corn interplanting is 80.6% in present irrigation program. So there is some water-saving potential.(3) The availability of autumn irrigation water were appraised in Hetao irrigation area. Autumn irrigation is a particular irrigation system designed to wash soil salt into deeper...