Combined effects of precipitation and air temperature on soil moisture in different land covers in a humid basin

• Published in: Journal of hydrology (Amsterdam) Vol. 531; pp. 1129 - 1140
• Main Authors: Feng, Huihui, Liu, Yuanbo
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-12-2015
• Subjects: Air temperature; AMSR-E; Basins; Climate; Clusters; Forests; Freshwater; Land cover; Precipitation; Soil moisture; Water resources management; China, People's Rep; Precipitation; Land cover; AMSR-E; Soil moisture; Air temperature
• ISSN: 0022-1694; 1879-2707
• DOI: 10.1016/j.jhydrol.2015.11.016

•Investigates responses of climate on soil moisture in different land covers.•Response of soil moisture to air temperature is more sensitive than precipitation.•Land cover is a dominant factor for soil moisture in normal climate conditions.•Climate is a dominant factor for soil moisture in extreme conditions.•Forest cover might mitigate drought.
Soil moisture is a key variable in hydrological processes. Although the combined effects of multiple climatic factors in different land cover conditions are highly valuable for water resource management, a complete understanding of these effects remains unclear. This study used a cluster analysis approach to investigate the combined effects of precipitation and air temperature, rather than a single factor, in different land covers for an area over the Poyang Lake Basin in China from 2003 to 2009. Specifically, monthly soil moisture was classified into eight clusters according to the change in precipitation and air temperature; the clusters describe a range of climates from the extreme of wet–hot to that of dry–cold. For an individual climate factor, our results showed that the contribution of air temperature to soil moisture is greater than that of precipitation, and the effect of air temperature is more sensitive in different land covers. When considering the combined effects of precipitation and air temperature, soil moisture varies with land cover; however, the variation in a normal climate cluster is greater than in an extreme climate cluster. This indicated that land cover is the dominant factor in soil moisture variation in normal climatic conditions, whereas climate is the dominant factor in extreme conditions. As climate shifts from the wet–hot to the dry–cold cluster, soil moisture decreases for all land covers, with the minimum rate occurring in forest conditions. Meanwhile, soil moisture deficit and saturation are more likely to occur in grassland and forest areas, indicating that forest cover might mitigate drought. The results of this study provide an effective approach to investigate the combined effects of climate factors on soil moisture for various land covers in humid areas. This study also supports the management of water resources in changing climates.