Comparison of precipitation and evapotranspiration of five different land-cover types in the high mountainous region  

作　　者：Yong Yang RenSheng Chen YaoXuan Song ChunTan Han JunFeng Liu ZhangWen Liu 

机构地区：[1]Qilian Alpine Ecology and Hydrology Research Station,Key Laboratory of Ecohydrology Inland River Basin,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou,Gansu 730000,China

出　　处：《Research in Cold and Arid Regions》2017年第6期622-630,共9页寒旱区科学（英文版）

基　　金：financial support from the National Natural Sciences Foundation of China(41401041)and the National Basic Research Program of China(2013CBA01806)

摘　　要：Many rivers originate in high mountainous regions. However, the effects of climate warming on the runoff and water balance in these regions remain unclear due to the lack of observational data from harsh environments, and the variable influences of climate change on alpine land-cover types with different water balances. Using observations and simulations from Coup Model, water-balance values collected at five alpine land-cover types(steppe, shrub meadow, moist meadow, swamp meadow, and moraine) in a small alpine watershed, the Qilian Mountains in Northwest China, from October 2008 to September 2014, were compared. Measured evapotranspiration, multilayer soil temperatures and water contents, and frozen-depth data were used to validate Coup Model outputs. The results show that elevation is the primary influence on precipitation, evapotranspiration, and runoff coefficients in alpine regions. Land-cover types at higher elevations receive more precipitation and have a larger runoff coefficient. Notably, climate warming not only increases evapotranspiration but also particularly increases the evapotranspiration/precipitation ratio due to an upward shift in the optimum elevation of plant species. These factors lead to decrease runoff coefficients in alpine basins.Many rivers originate in high mountainous regions. However, the effects of climate warming on the runoff and water balance in these regions remain unclear due to the lack of observational data from harsh environments, and the variable influences of climate change on alpine land-cover types with different water balances. Using observations and simulations from Coup Model, water-balance values collected at five alpine land-cover types(steppe, shrub meadow, moist meadow, swamp meadow, and moraine) in a small alpine watershed, the Qilian Mountains in Northwest China, from October 2008 to September 2014, were compared. Measured evapotranspiration, multilayer soil temperatures and water contents, and frozen-depth data were used to validate Coup Model outputs. The results show that elevation is the primary influence on precipitation, evapotranspiration, and runoff coefficients in alpine regions. Land-cover types at higher elevations receive more precipitation and have a larger runoff coefficient. Notably, climate warming not only increases evapotranspiration but also particularly increases the evapotranspiration/precipitation ratio due to an upward shift in the optimum elevation of plant species. These factors lead to decrease runoff coefficients in alpine basins.

关 键 词：global WARMING LAND-COVER TYPES water balance ELEVATION RUNOFF coefficient 

分 类 号：P426[天文地球—大气科学及气象学]