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Measurements and Modeling of the Water Budget in Semiarid High‐Altitude Qinghai Lake Basin, Northeast Qinghai‐Tibet Plateau
Author(s) -
Ma YuJun,
Li XiaoYan,
Liu Lei,
Huang YongMei,
Li Zhou,
Hu Xia,
Wu XiuChen,
Yang XiaoFan,
Wang Pei,
Zhao ShaoJie,
Zhang GuangHui,
Liu BaoYuan
Publication year - 2018
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
eISSN - 2169-8996
pISSN - 2169-897X
DOI - 10.1029/2018jd028459
Subject(s) - evapotranspiration , environmental science , altitude (triangle) , precipitation , ecosystem , streamflow , plateau (mathematics) , climate change , hydrology (agriculture) , physical geography , drainage basin , ecology , geography , geology , biology , geometry , mathematics , cartography , geotechnical engineering , meteorology , mathematical analysis
Water budget plays an important role in ecological functions and biogeochemical cycles on the Qinghai‐Tibet Plateau (QTP). However, the key factors that govern the water budget across spatiotemporal scales in natural conditions are poorly understood, especially in the alpine region. To advance our understanding of how and why the water budget varies at the ecosystem and catchment scales, this study measured and modeled the main water budget components in the Qinghai Lake Basin (QLB) and further investigated the key factors for evapotranspiration and streamflow. The results showed that most monthly precipitation from June to September was greater than the corresponding evapotranspiration from the high‐altitude Kobresia meadow (KMd.) and Potentilla fruticosa shrub (PFSh.) ecosystem, and vice versa for the low‐altitude Achnatherum splendens steppe (ASSt.) ecosystem. The mean annual proportions of evapotranspiration of precipitation for the KMd., PFSh., and ASSt. ecosystems were 0.83, 1.06, and 1.02, respectively, from 2014 to 2015. The study highlights that the high‐altitude KMd. ecosystem is the main contributing area for runoff generation in the QLB. From ASSt. to PFSh. and then to the KMd. ecosystem, the key factors for evapotranspiration switched from water conditions to temperature conditions with the increase in elevation. The future scenario of climate warming and precipitation increase may cause a rise in evapotranspiration and streamflow in the QLB. Moreover, the increasing precipitation may be consumed mainly by evapotranspiration in the high altitude with low slope and by transfer into streamflow in the area with high slope.