宁夏银北地区灌溉水资源的合理利用

Rational utilization of the water resources for irrigation in the northern area of Ningxia

宁夏银北地区位于银川平原引黄灌区下游.由于黄河水量逐年减少,引黄灌溉已不能足量满足农业灌溉的需求.干渠平行排列,渠系过长,渠道分级不明显,不适应现代灌区管理和调度的要求.输水渗漏损失严重,导致引黄灌区下游灌期灌溉水量的严重短缺.银北地区为盆地地下水排泄区,地下水量丰富,但水质较差,矿化度(TDS)较高,不能单独用于农田灌溉.因此,合理利用地表水和地下水,确定他们合适的混合比例,以满足银北地区农田灌溉水的需求,意义重大.运用Phreeqc模型软件的Mix模块进行模拟,提出利用地表水(黄河水)、地下水,确定合理的混合比例,以满足银北地区灌水需求及适合农田灌溉的需要,又不引起土壤盐渍化,为当地农业生产服务.

The northern area of Ningxia is located to the lower reaches of irrigation area of the Yellow River. Because the water amount of the Yellow River decreases year after year, it can not meet the irrigation for agriculture. The trunk channels are parallelly built with long distances and graded unobviousely, which can not fit the management and dispatch in pesent irrigation areas. The serious leakage of the channels leads to the shortage of water for irrigation in the northern area of Ningxia plain. The northern area of Ningxia is the basin area for groundwater drainage with a great quantity of groundwater of bad quality with high TDS, which can not bc used to irrigate farmland alone. Therefore, the surface water and the groundwater must be utilized rationally and suitable ratio for mixture must be confirmed so as to meet the farmland irrigation in the northern area of Ningxia. Mix module of Phreeqc model was used to simulate the ratio of mixture between the water of the Yellow River and groundwater to meet the farmland irrigation and not to cause the salinization of soil for the local agricuhural production.