资源环境科技发展态势分析平台

The Inland River Area of China (IRAC), being the most water-stressed region in the world, faced with increasingly severe ecological degradation risk and water shortage issue under global climate warming. Previous studies indicated that the climate of IRAC have changed from warm-dry to warm-wet, because both precipitation (P) and air temperature have increased. However, the analysis in this study, considering the effects of climate change on hydrologic cycle rather than simply on climate conditions, indicates that there has been no substantial change from a warm-dry to a warm-wet climate in the IRAC during 1948-2010. The Standardized Moisture Anomaly Index (SZI), which is a comprehensive multiscalar drought indicator, was used to identify the patterns of dry and wet weather. The Global Land Data Assimilation System 2 (GLDAS2) Noah model, based on advanced land surface modeling and data assimilation techniques, were used to provide input surface water-energy variables for calculating SZI. The results show that both the forcing data and the output of the GLDAS2 Noah model are in good agreement with different types of observations. The variabilities in SZI are more consistent with evidence of multiple droughts (including residual water/energy ratio, evapotranspiration deficit, and historical drought records) than the Standardized Precipitation Index (SPI) and the Standardized Precipitation Evapotranspiration Index (SPEI). Based on SZI, it is known that increases in the water supply (P) are balanced by the increased water demand caused by significant climate warming; that is, terrestrial water storage has generally remained balanced over the past four decades.