干支渠渠系水利用系数的确定与预测

Determination and Prediction of Water Efficiency of Trunk and Branch Channels

通过对灌区1989～2008年20年的干支渠配水资料分析,确定历年渠首、斗口水量,并用GM(1,1)灰色预测模型对2种流量进行拟合,从而确定出干支渠系水利用系数。另外,还对灌区历年干支渠渠系水利用系数进行模拟,结果发现2种拟合模型平均相对误差分别为1.849%和1.036%,均能满足模型误差要求,并分别用这2种拟合模型对灌区未来5年的干支渠渠系水利用系数进行预测,确定灌区未来5年的干支渠渠系水利用系数在0.706～0.680变动。

Water distribution data of trunk and branch channels at irrigation districts during 20 years from 1989 to 2008 were analyzed to determine the first side of the ditches and sublateral canal water yield over the years,and the above two flows were fitted by using GM（1,1） Grey Prediction Model,finally,water efficiency of trunk and branch channels were determined.Besides,water efficiency of trunk and branch channels at irrigation districts were modeled over the years.The results showed that the average relative error of the two fitting models were 1.849 % and 1.036%,respectively,and could satisfy the error＇s demand of the models.Then the two models would be used to predict the water efficiency of trunk and branch channels at irrigation districts in the next 5 years,and water efficiency of trunk and branch channels at irrigation districts would be determined between 0.706 and 0.680 in the next 5 years.