An overview of non-conventional water resource utilization technologies for biological sand control in Xinjiang, northwest China

In a desert ecosystem, water plays a very important role in most ecological properties and processes. Located in the hinterland of the Eurasian continent, Xinjiang is covered by the sandy Gobi Desert, which is dotted with patchy oases. Land desertification is becoming a serious problem as the rapid growth in population and increased exploitation of water and soil resources increases. However, water that could be used to combat desertification is relatively scarce. Most of the conventional water resources are used in industry, agriculture and for social and economic development. Therefore, we need to develop non-conventional water (NWRU) for biological sand control. After 30 years of research, four types of NWRU technologies have been developed. (1) Non-irrigation afforestation technology using moisture, stored in the humid sandy subsurface, is applicable in the regions where precipitation is more than 100 mm per annum, of which most is snow fall; (2) water harvesting afforestation technology that collects snowmelt water and rainfall has been developed in the regions where precipitation is more than 100 mm and where the land is overlain by a low-permeability soil; (3) flood water irrigation afforestation technology, using summer floods, is feasible in regions with abundant flood water and where their occurrence coincides with the vegetation growing season; and (4) drip irrigation afforestation technology, using underground brackish water, has been developed in regions where abundant underground brackish water can be supplied through irrigation systems. This paper reviews the four types of NWRU technologies for biological sand control in Xinjiang and provides some technical references for combating desertification in similar areas around the world.