基于农业节水的干旱区绿洲可持续发展研究——以渭干河流域为例

Sustainable Development of Oasis in Arid Area Based on Agricultural Water-saving:A case study in the Weiganhe River Basin,Xinjiang,China

建立节水型社会是中国的一项基本政策,也是解决渭干河流域水资源可持续利用问题的战略选择。渭干河流域是典型的灌溉农业区,农业灌溉大部分仍采用粗放型的土渠输水、大水漫灌方式,水资源流失严重,灌溉定额偏高,渠系入渗量高达14.01亿m3,农业节水潜力很大。在现有水量不可能增加的情况下,调整农业内部种植结构,发展节水农业是解决区域水资源短缺的有力措施。通过对2015年和2020年工业、城市化和生态用水进行预测,确定农田灌溉可用水量。选取渭干河流域9种种植面积最大的农作物,参考作物蒸散量及作物系数,得出各类农作物的实际需水量,并与现有灌溉量比较,发现现有灌溉量远大于作物的实际需水量,通过节水灌溉和水渠改造,可节约用水10.59亿m3。而且研究区的粮食种植面积亦远大于需求,即使未来10年不再扩大粮食种植面积,也比需求面积多出近2万hm2,如根据实际需求去调整,可节约1.05亿m3的水量,能极大缓解水资源紧缺的局面,将灌溉量控制在可用水量范围内,为加快城市化和工业化进程,保护区域生态提供充足的水资源保证。

The water-saving society construction is a basic policy in China and a strategic choice to obtain the sustainable use of water resources in the arid lands. The Weigan River basin is a typical irrigation farming region in the arid lands, the majority of agriculture irrigation is extensive, such as earth canal and flooding irrigation. The water loss is serious, irrigation quota is high, canal infiltration is more than 1.4 billion m3, and the water-saving potential of agriculture irrigation is large in the Weigan River basin. On the condition of no increase of water quantity in the near future, adjusting the agriculture internal planting structure and developing water-saving agriculture is a favorable measure to solve water shortage problems. In this paper, the determination of the amount of water-using in agriculture irrigation based on a prediction of industry, urbanization and ecological water requirement was made. We selected nine kinds of crops with large acre- age, took the amount of evaporate-transpiration and planting index of these crops as reference factors to con- clude the actual amount of water-consuming of the crops. Compared with the current irrigation amount, we found that the current irrigation amount was greatly larger than the actual demand of the crops. We might save water more than 10^8 m3 by water-saving irrigation and water channel improvement. The actual grain planting area of the study region is out of the scale in need. Even if we will not expand the grain planting ar- ea any more in the next decade, there still exists nearly 20 000 hm2 beyond the minimum needed area. If we adjust the planting area according to actual demand, we may save neraly 100 million m3 water. It can greatly ease the water shortage and control the irrigation amount in a range of available water. Meanwhile, it can also provide plenty of water resource for ecological protection, urbanization and industrialization.