关键词: 环境示踪剂, 氯质量平衡, 地下水补给, 巴丹吉林沙漠, 古日乃绿洲

Abstract:

In recent years, Badain Jaran Desert, Northwest of China, has been a focus of international studies. Water chemistry and isotopes of groundwater and surface water samples, and  those of soil moisture profiles in particular, have been studied. Based on these results, we have attempted to formulate an integrated 2D hydrogeological conceptual model for the groundwater system linking Badain Jaran Desert and Gurinai Oasis. The dominant recharge to groundwater underneath the sand dunes is from neighboring Yabulai mountains, the groundwater flows towards northwest to Gurinai. Groundwater emerges into lakes on its flowpath, where it is evaporated.  The final discharge destination of the groundwater is the Gurinai Oasis where it feeds a wetland ecosystem. Vertical recharge from local precipitation through the desert sand is calculated to be minor. Groundwater in the desert was probably recharged from palaorivers sourced from Qilian Mts. and local palaeorainfall in the period between Pleistocene to Early Holocene. In Mid and Late Holocene, the groundwater undergone evaporation and limited recharge. In the last two thousand years aridity has increased, the groundwater table in the desert has declined as a slow process.

Key words: environmental tracer, chloride mass balance(CMB), groundwater recharge, Badain Jaran Desert, Gurinai Oasis