Water Use Efficiency Spatiotemporal Change and Its Driving Analysis on the Mongolian Plateau

Area of Science:

• Ecology
• Environmental Science
• Remote Sensing

Background:

• Water use efficiency (WUE) is crucial for understanding carbon and water cycles in terrestrial ecosystems.
• Evaluating long-term temporal and spatial changes in WUE is essential for ecosystem management.

Purpose of the Study:

• To analyze the spatiotemporal variation characteristics of WUE on the Mongolian Plateau from 1982 to 2018.
• To identify the influencing factors on WUE, including climate and vegetation changes.

Main Methods:

• Utilized remote sensing data to assess net primary productivity (NPP) and evapotranspiration (ET).
• Applied various statistical methods to analyze WUE patterns and correlations with precipitation, soil moisture, temperature, and drought severity index (DSI).
• Investigated the impact of vegetation phenology and human activities on WUE.

Main Results:

• A significant decline in annual WUE was observed in 27.02% of the Mongolian Plateau over 37 years.
• Two abnormal surges in seasonal WUE (April-October) occurred from 1997-1998 and 2007-2009.
• WUE exhibited strong resilience to water disturbances but weak resistance to temperature and DSI anomalies. Vegetation changes had a higher explanatory power for WUE than meteorological factors.
• Human activities significantly increased WUE in eastern, central, and southern regions.

Conclusions:

• WUE dynamics on the Mongolian Plateau are complex, influenced by both climatic and anthropogenic factors.
• Understanding these dynamics is vital for predicting ecosystem responses to environmental change.
• The findings offer a reference for carbon-water cycle research in the region.