Supergene ecological effects induced by groundwater and its thresholds in the arid areas

This paper is based on the actual survey data, analyzed the relationship between groundwater and ecological environment in arid and semi-arid area, pointed out that groundwater in the arid and semi arid areas boasts not only the resource properties and economic value, but also the important ecological value. The ecological value of groundwater is reflected in four aspects: the maintenance of base flow in rivers, lakes and wetland coverage; the supply of physiological water demanded by vegetations; the mediator of soil moisture and salt content and the watchdog of the stability of geological environment (such as land subsidence, etc.). On this basis, the present paper forms the concept of ecological value of groundwater, and constructed the threshold system between supervened ecology and such multi-dimensional indexes as groundwater table, water quality, water and salt content in vadose zone, groundwater exploitation in arid and semi arid areas, thus providing a scientific basis and technological support for the regulation of the state of groundwater and the maintenance of a virtuous circle of ecological environment and sustainable development and utilization of water resources.