Resources Science ›› 2017, Vol. 39 ›› Issue (2): 263-275.doi: 10.18402/resci.2017.02.09

• Orginal Article • Previous Articles     Next Articles

Variation in soil water content along different altitude gradients in the Qinghai Lake Watershed

Lei LIU1(), Xiaoyan LI1,2(), Zhiyun JIANG1, Junqi WEI1, Mujia NAN3   

  1. 1. College of Resources Science and Technology,Beijing Normal University,Beijing 100875,China
    2. State Key Laboratory of Earth Surface Processes and Resource Ecology,Beijing Normal University,Beijing 100875,China
    3. Sanjiaocheng Sheep Breeding Farm,Gangcha 812300,China
  • Received:2016-04-27 Revised:2016-09-18 Online:2017-02-25 Published:2017-02-20

Abstract:

Understanding soil water content variation at different altitudes is fundamental to identifying spatial variation in water resources across a watershed,especially under a changing climate. Here,we evaluated spatial and temporal variation in soil water content along different altitude gradients in the Qinghai Lake watershed. With the integrative consideration of temperature,precipitation,evapotranspiration and the normalized difference vegetation index(NDVI)during the growth season,water deficits of areas at different altitudes were explored. We found that the average soil water content(ASWC)during the middle of the growing season was the maximum(28.79%),higher than the beginning and end of the growing season in 2015,22.81% and 22.91,respectively. ASWC increased with altitude during the growing season,and there was a positive correlation between them,particularly in the middle of the growing season(P < 0.01). The analysis of water budget indicated that regions with altitudes of 3200~3300m were water deficit regions in the watershed,with a decrease of 1.24% in soil water after a growing season. Water budgets in regions with altitudes of 3300~3400m and 3400~3600m were almost balanced,which increases of 0.54% and -0.57%,respectively; an increase of 3.69% was identified in regions with altitudes of 3600~3800m. Regions with altitudes higher than 3800m were considered as water supply regions in the Qinghai Lake watershed. However,the water supply regions have been highly vulnerable to climate change and will decrease sharply if climate warming continues. This will influence water resources deeply in the watershed and have critical effects on the basin and its society and ecosystems.

Key words: Soil moisture, elevation gradient, temporal and spatial variation, climate change, Qinghai Lake basin