Climate change, land management, and water resources in the Drylands East Asia

Background/Question/Methods

The vast Drylands East Asia (DEA) consists of several large geographic regions including the Qinghai-Tibet Plateau, Loess Plateau, and Mongolia Plateau. The region is of great importance to the functioning of the earth system under a changing climate. In the past three decades, due to the unprecedented land use/land cover change, urbanization, industrialization and climate change, water stress in many areas in the DEA have reached a dangerous level that threatened the sustainability of the region. In addition to reviewing literature on the causes of water crisis observed in the region, as case studies, we examined water balances at a basin and a regional scale using multiple modeling techniques, including remote sensing-based EC-MOD model, watershed water balance model (WBMPlus), and an evapotranspiration model calibrated for the Loess Plateau region. 

Results/Conclusions

Our synthesis study suggests that landuse change and human water withdrawal account for most of the observed water resource declines in the study region. However, climate change will have profound impacts on areas where local water supply and ecosystem services rely on melting glaciers.  The current large scale soil conservation practices and vegetation-based ecological restoration activities such as reforestation should be comprehensively evaluated to assess their broad impacts on water resources such as groundwater recharge and water yield downstreams. Large uncertainty remains to predict future water availability in DEA due to uncertainty in predicting climate change patterns.  Facing the large uncertainty of climate change and socioeconomic changes in the drylands, decision making processes and institutions must adopt a robust and adaptive framework to achieve long term sustainability.