Estimation Of Irrigation Efficience At Different Scales In The Middle Stream Of Hei River Irrigation District

Irrigation efficience has been Chinese and foreign scholars believe is an important index for the efficient use of irrigation water level due to the presence of spatial variability and reuse water and other issues, irrigation efficience water index spatial scale effect exists, in a small scale not the same as on the efficiency on a large scale is efficient. For problems and shortcomings water efficiency evaluation of traditional irrigated areas, the paper is located in the middle reaches of the Heihe River irrigated oasis PCG background, pilot studies of water balance elements of different scales. Construction of different scales can be used to obtain the water balance elements of dual crop coefficient SIMDualKc Irrigation water balance model to calculate the influence of the water balance elements of effective utilization coefficient of irrigation water analyzed at different scales variation of effective utilization coefficient of irrigation water indicators for the scientific evaluation of irrigation water efficiency to provide a reference. The main contents and conclusions of this study are as follows:(1) In support of GIS and RS technology,The irrigation distribution main canal irrigation area as the control unit, the soil and land use and planting structure were reclassified, established the soil attribute database for each soil type basin.According to the measured field data, construct irrigation area water balance model, through the dual crop coefficient SIMDualKc model was calibrated and verified to determine the model parameters apply to the ground.(2) 16 typical plots field scale was determined by division of the Yingke irrigation area of different soil types and planting structure,13 branch scales were determined by dividing irrigation area of the main irrigation canal system. The planting structure of the branch scale is obtained by superimposing the map of land use and planting structure.(3) Calculate the 16 field experimental plots in 2012 and 2013 for two years, the water balance elements 13 branch canals and the whole scale irrigation area and irrigation water efficient utilization coefficient. And effective utilization coefficient of irrigation water each scale to make the impact of factors.Area-weighted average of effective utilization coefficient of irrigation water, the weighted average effective utilization factor of 16 field experiments cells.(4) 2012 and 2013 data for two years, effective utilization coefficient of irrigation water 16 test cells is between 0.46-0.9 field scale, effective utilization coefficient of irrigation water 13 branch canal between 0.19-0.85 scale, scale Irrigation effective utilization coefficient of irrigation water is about 0.50, the biggest impact of leakage field scale and efficient use of irrigation water branch canals scale factor.