Abstract：This study distinguishes the direct and indirect effects of rainfall changes on the water balance in a watershed. The water balance is used to build a model based on Eagleson's ecohydrological optimality theory to describe the vegetation cover response to rainfall changes. An attribution analysis distinguishes the direct effect of rainfall on the water balance shifts and the indirect effect of vegetation cover which is influenced by the rainfall. This method is applied to the Xilamulun-Laoha River basin in the Horqin Sands area. The results show a positive correlation between the vegetation cover and the rainfall with the relationship affected by the rainfall intensity and frequency. Increased rainfall mainly increases the evapotranspiration and soil water storage during the non-growing season. Increased rainfall has a positive effect on every water balance term. However, the indirect effects of the vegetation cover result in negative changes to all the water balance terms, except for the evapotranspiration. The relationship between the evapotranspiration efficiency and the rainfall is affected by the response of the vegetation cover to rainfall changes.
莫康乐, 丛振涛. 考虑植被对降雨变化响应的流域水量平衡[J]. 清华大学学报（自然科学版）, 2017, 57(8): 851-856.
MO Kangle, CONG Zhentao. Water balance in a watershed considering the response of vegetation cover to rainfall changes. Journal of Tsinghua University(Science and Technology), 2017, 57(8): 851-856.
Porporato A, Laio F, Ridolfi L, et al. Plants in water-controlled ecosystems:Active role in hydrologic processes and response to water stress Ⅲ. Vegetation water stress[J]. Advances in Water Resources, 2001, 7(24):725-744.
[2]
Roderick M L, Rotstayn L D, Farquhar G D, et al. On the attribution of changing pan evaporation[J]. Geophysical Research Letters, 2007, 34(17), L17403.
[3]
YANG Dawen, SHAO Weiwei, Yeh P J F, et al. Impact of vegetation coverage on regional water balance in the nonhumid regions of China[J]. Water Resources Research, 2009, 45(7), W00A14.
[4]
Gerten D, Schaphoff S, Haberlandt U, et al. Terrestrial vegetation and water balance:Hydrological evaluation of a dynamic global vegetation model[J]. Journal of Hydrology, 2004, 286(1-4):249-270.
[5]
PIAO Shilong, FANG Jingyun, JI Wei, et al. Variation in a satellite-based vegetation index in relation to climate in China[J]. Journal of Vegetation Science, 2004, 15(2):219-226.
[6]
Baudena M, Boni G, Ferraris L, et al. Vegetation response to rainfall intermittency in drylands:Results from a simple ecohydrological box model[J]. Advances in Water Resources, 2007, 5(30):1320-1328.
[7]
CHUAI Xiaowei, HUANG Xianjin, WANG Wanjing, et al. NDVI, temperature and precipitation changes and their relationships with different vegetation types during 1998-2007 in Inner Mongolia, China[J]. International Journal of Climatology, 2013, 7(33):1696-1706.
[8]
Djebou D C S, Singh V P, Frauenfeld O W. Vegetation response to precipitation across the aridity gradient of the southwestern United States[J]. Journal of Arid Environments, 2015(115):35-43.
[9]
MO Kangle, CONG Zhentao, LEI Huimin. Optimal vegetation cover in the Horqin Sands, China[J]. Ecohydrology, 2016(9):700-711.
[10]
Bosch J M, Hewlett J D. A review of catchment experiments to determine the effect of vegetation changes on water yield and evapotranspiration[J]. Journal of Hydrology, 1982, 55(1-4):3-23.
[11]
ZHANG Shulei, YANG Hanbo, YANG Dawen, et al. Quantifying the effect of vegetation change on the regional water balance within the Budyko framework[J]. Geophysical Research Letters, 2016, 43(3):1140-1148.
[12]
XU Xiangyu, YANG Dawen, YANG Hanbo, et al. Attribution analysis based on the Budyko hypothesis for detecting the dominant cause of runoff decline in Haihe Basin[J]. Journal of Hydrology, 2014(510):530-540.
[13]
Eagleson P S. 生态水文学[M]. 杨大文, 丛振涛, 译. 北京:中国水利水电出版社, 2008.Eagleson P S. Ecohydrology[M]. YANG Dawen, CONG Zhentao, trans. Beijing:China Water Power Press, 2008. (in Chinese)
[14]
ZHANG Xiaoying, CONG Zhentao. Trends of precipitation intensity and frequency in hydrological regions of China from 1956 to 2005[J]. Global and Planetary Change, 2014(117):40-51.
[15]
阿拉木萨, 慈龙骏, 杨晓晖, 等. 科尔沁沙地不同密度小叶锦鸡儿灌丛水量平衡研究[J]. 应用生态学报, 2006(1):31-35.A Lamusa, CI Longjun, YANG Xiaohui, et al. Water balance of different density artificial Caragana microphylla shrubs in Horqin sand land[J]. Chinese Journal of Applied Ecology, 2006(1):31-35. (in Chinese)
[16]
刘新平, 赵哈林, 何玉惠, 等. 生长季流动沙地水量平衡研究[J]. 中国沙漠, 2009(4):663-667.LIU Xinping, ZHAO Halin, HE Yuhui, et al. Water balance of mobile sandy land during the growing season[J]. Journal of Desert Research, 2009(4):663-667. (in Chinese)
2017, Vol. 57 
