Estimation Of Irrigation Water Utilization Coefficient In Hebei Plain Based On Crop Effective Precipitation Of Regional

The irrigation water utilization coefficient is an important index to evaluate the efficiency of irrigation water,and has guiding significance for the analysis of regional water supply and demand balance and optimal allocation of water resources.For the irrigation water utilization coefficient of regional scale,the field scale measurement results are poorly representative.From the perspective of crop actual consumption,the irrigation water utilization coefficient of scale was analyzed and calculated by the net irrigation water consumption which was defined with the difference between the actual evapotranspiration and the effective precipitation of crops.With Yuanshi,Luancheng and Zhaoxian of Shijiazhuang and Feixiang and Guantao of Handan selected as the research areas,winter wheat and summer maize selected as the main research crops,and the county selected as the research unit,the calculation method of regional irrigation water utilization coefficient was studied.Based on the actual situation of the study area,the relationship between the factors affecting the effective precipitation of crops was analyzed,and a suitable estimation model was proposed and verified.Based on the data of net irrigation water consumption,which was calculated by the evapotranspiration and the effective precipitation of crops,and gross irrigation water consumption,the regional irrigation water utilization coefficient was analyzed and calculated.The results showed that,the estimation model of regional crop effective precipitation considering multiple influencing factors had higher estimation accuracy,and the average annual precipitation of regional crops was 393 mm.The average annual evapotranspiration of crop in the study area was 626 mm.The average relative error between remote sensing evapotranspiration and calculated evapotranspiration was 2.6%,and the distribution trend was consistent during the year.The annual average irrigation quota of crops was 234 mm,and the average annual average irrigation water quota of winter wheat and summer maize was 213 mm and 21 mm,respectively.The multi-year average of irrigation water utilization coefficient in the study area was 0.7,which is higher than the provincial irrigation water utilization coefficient.The multi-year average values of irrigation water utilization coefficients of Luancheng,Yuanshi,Zhaoxian,Feixiang and Guantao were 0.70,0.64,0.71,0.83 and 0.74 respectively.