自补给灌溉系统设计

在西北干旱地区,苦咸水可开采量为31.55亿m3[1]。宁夏是全国水资源最为紧缺的地区之一,根据宁夏水资源公报,宁夏多年平均地表水资源量9.493亿m3,地下水资源量30.73亿m3,人均当地水资源占有量仅为137m3,不到全国平均水平的1/10,不到世界平均水平的1/40。与地表水相比,宁夏可利用的地下水资源较为丰富,其苦咸水资源量占地下水的35.21%。苦咸水中Na+、Cl-含量高,水带咸味,而Cl-、Ca2+、Mg2+、SO42-含量高,水有涩味。[2]短根植物由于其根系短小且蒸腾速率高,水肥补给不足且缺失严重。短根植物有着自身生长发育对水肥的需求模式,依据其需水需肥规律进行灌溉施肥,才能较大限度地利用有效水源,真正实现抗旱节水。拟利用正渗透技术淡化本地区的苦咸水,并将其应用于短根植物节水自补给灌溉系统中的营养来源,以促进我国节水技术的发展和节水措施的应用,节约水资源,提高水资源的利用效率。

In the arid areas of northwest China,the recoverable brackish water is 3.155 billion m[1].Ningxia is one of the regions with the most shortage of water resources in China.According to the Ningxia Water Resources Bulletin,the average surface water resources in Ningxia for many years[2]are 949.3 million m,and the groundwater resources are 3.073 billion m.The per capita occupancy of local water resources is only 137 million m,less than 1/10 of the national average and less than 1/40 of the world average.Compared with surface water,Ningxia is rich in available groundwater resources,but its brackish water resources occupy 35.21%of the total water area.The content of Na+and Cl-in brackine water is high,and the water has a salty taste,while the content of Cl-,Ca2+,Mg2+and SO42-is high,and the water has a astringent taste.Because of short root system and high transpiration rate,water and fertilizer supply are insufficient and lack seriously.Short-rooted plants have the demand pattern of water and fertilizer for their own growth and development.Only by applying irrigation and fertilization according to the law of water and fertilizer,can effective water resources be utilized to a large extent and drought-resistant and water-saving be realized truly.The main starting point of this system is to desalinate brackish water in this region with positive osmosis technology and apply it to the nutrient source measures in the water-saving self-replenishing irrigation system of short-rooted plants,so as to promote the development of water-saving technology and the application of water-saving measures in China,save water resources and improve the utilization efficiency of water resources.