The Characters of the Capillary Water Rise and its Ecological Significance in Desert Lake-Basin Region, Northwest China

Abstract

Field observations, theoretical analyses and laboratory experiments indicated that the capillary fringe plays an important role in maintaining the ecological environment of desert salt lake. Taking Ulan Buh Desert as an example, this paper simulated capillary water rise process by using an experimental device and proposed ecological significance based on observation of 107 phreatic water wells.The results show that the theoretical maximum height of capillary water rise may reach 2.39m; velocity of capillary water rise is fast at first, and then is slow, it finally tends towards steady; the amount of capillary water rise may reach 34.4cm per unit area. Moisture content in vadose zone is inversely proportional to the summation of depth of groundwater and height of capillary water rise, if the depth of groundwater is within 1-8m. Characters of Capillary water rise determine the water supplying condition, further control the distribution pattern of the desert vegetation species.