Groundwater Recharge Rate and Recharge history during the Last 1200 Years in the Badain Jaran Desert

摘要

The long term recharge at the site was estimated to be 0.96-1.36mm yr-1 by using the chloride mass balance method from three boreholes with depth of 7.4-22.5m, which show that no effective modern recharge is taking place, but that the lakes are supported by regional groundwater flow, the age of the water being late Pleistocene as inferred from the isotopic compositions. The unsaturated profiles well preserved the climatic change events of 10-20 years duration and the climate can be subdivided into 3 wet periods and several dry periods. It was a dry episode before 1300 AD. At ca. 1500-1550 AD, which is an important datum, the climate occurred the violent change from drought to wet.