基于SHAW模型的河套灌区秋浇渠系优化配水模型研究

河套秋浇是为满足来年春播作物水盐需求而进行的保墒淋盐灌溉。针对传统基于作物需水预测成果进行渠系配水存在的预报依赖性强和中长期预报精度低问题,本文提出了一种不需要作物需水预测成果的渠系优化配水模型框架,该框架依据春播初期作物水盐要求,将SHAW模型嵌入优化配水模型,确定秋浇配水计划。河套灌区永济灌域2016年秋浇配水计划编制实例研究表明:与传统基于需水预测的配水方法相比,新方法得到的配水计划可以在不增加渠首引水量及渠道输水损失总量基础上显著提升淋盐效果,使春播初期0～40 cm土层水盐状态更加适宜于作物播种,春播初期土壤0～40 cm土层平均盐分超标由60%以上降低至5%以下,同时配水公平性也得到提升。

Study on optimal water distribution model of canal system for autumn irrigation in Hetao Irrigation Area based on SHAW model

Autumn irrigation for soil moisture conservation and salt leaching in Hetao irrigation area is to meet the demands of water and salt for the next spring sowing crops. In view of the problems of strong dependence and low accuracy of medium and long-term prediction in traditional water distribution of canal system based on crop water demand prediction, a framework of optimal water delivery scheduling model without crop water requirement prediction is proposed in this paper. According to the demands of soil water and salt in early spring sowing stage,the SHAW model is embedded into optimal water distribution to determine the autumn water distribution plan. A case study on the water distribution plan of autumn irrigation in Yongji of Hetao irrigation area in 2016 shows that: comparing the traditional water distribution method based on water demand prediction,the water distribution plan obtained by new method can significantly improve the salt leaching effect without increasing amount of water diversion at the head of the canal and total water loss,so that the soil layer condition of 0~40cm gets more suitable for crops at the beginning of spring sowing. The superscalar of average salinity is reduced from more than 60% to less than 5%, and the fairness of water distribution is also improved.