Effects of changes in alpine grassland vegetation cover on hillslope hydrological processes in a permafrost watershed

CORC > 成都山地灾害与环境研究所 > 中国科学院水利部成都山地灾害与环境研究所 > 山地表生过程与生态调控重点实验室

	Effects of changes in alpine grassland vegetation cover on hillslope hydrological processes in a permafrost watershed
	Wang Genxu; Liu Guangsheng; Li Chunjie
刊名	JOURNAL OF HYDROLOGY
	2012-06-11
卷号	444 页码:22-33
关键词	Alpine grassland Vegetation degradation Hillslope water cycle Influence Permafrost watershed
ISSN号	0022-1694
通讯作者	Wang, GX
中文摘要	Two main types of grasslands on the Qinghai-Tibet Plateau, alpine swamp and alpine meadow, were selected for this study. Monitoring plots were constructed on each type of grassland with varying degrees of vegetation degradation. The impacts of alpine grassland cover changes on the hillslope water cycle were analyzed in terms of runoff generation, precipitation interception, dew water formation, and soil water dynamics of the active layer, etc. The results showed that different types of grasslands led to different runoff generation regimes; namely, runoff varied linearly with precipitation in alpine swamp, whereas in alpine meadow, runoff exhibited an exponential precipitation-dependence. The decrease in vegetation cover in alpine swamp leads to a decrease in soil moisture content in the top 20 cm of the soil, a delay in the thawing start time in the spring, and a decrease in both surface runoff and subsurface interflow. In alpine meadow, however, the decrease in vegetation cover led to a significant increase in the depth of topsoil moisture content during the thawing period, earlier occurrence of thawing, and an increase in the runoff generation ratio. The alpine meadow vegetation canopy had a higher maximum interception ratio and saturation precipitation than alpine swamp vegetation. With the decrease in vegetation cover, the rainfall interception ratios decreased by almost an identical range in both the alpine meadow and alpine swamp grasslands. Dew water commonly occurs on alpine grassland, accounting for about 12.5-16.5% of precipitation in the same period, and thus, is an important component of the water cycle. With the degradation of vegetation, surface dew water decreased; however, the ratio of dew water formed in the air to the total amount of dew water rose significantly. At the hillslope scale, the changes of alpine vegetation cover had a great influence on the water cycle, which were partly attributed to that the changes of alpine vegetation cover directly altered the surface energy balance, surface water cycle processes, and the thermal and hydraulic properties of active soil.
英文摘要	Two main types of grasslands on the Qinghai-Tibet Plateau, alpine swamp and alpine meadow, were selected for this study. Monitoring plots were constructed on each type of grassland with varying degrees of vegetation degradation. The impacts of alpine grassland cover changes on the hillslope water cycle were analyzed in terms of runoff generation, precipitation interception, dew water formation, and soil water dynamics of the active layer, etc. The results showed that different types of grasslands led to different runoff generation regimes; namely, runoff varied linearly with precipitation in alpine swamp, whereas in alpine meadow, runoff exhibited an exponential precipitation-dependence. The decrease in vegetation cover in alpine swamp leads to a decrease in soil moisture content in the top 20 cm of the soil, a delay in the thawing start time in the spring, and a decrease in both surface runoff and subsurface interflow. In alpine meadow, however, the decrease in vegetation cover led to a significant increase in the depth of topsoil moisture content during the thawing period, earlier occurrence of thawing, and an increase in the runoff generation ratio. The alpine meadow vegetation canopy had a higher maximum interception ratio and saturation precipitation than alpine swamp vegetation. With the decrease in vegetation cover, the rainfall interception ratios decreased by almost an identical range in both the alpine meadow and alpine swamp grasslands. Dew water commonly occurs on alpine grassland, accounting for about 12.5-16.5% of precipitation in the same period, and thus, is an important component of the water cycle. With the degradation of vegetation, surface dew water decreased; however, the ratio of dew water formed in the air to the total amount of dew water rose significantly. At the hillslope scale, the changes of alpine vegetation cover had a great influence on the water cycle, which were partly attributed to that the changes of alpine vegetation cover directly altered the surface energy balance, surface water cycle processes, and the thermal and hydraulic properties of active soil. (C) 2012 Elsevier B.V. All rights reserved.
WOS标题词	Science & Technology ; Technology ; Physical Sciences
类目[WOS]	Engineering, Civil ; Geosciences, Multidisciplinary ; Water Resources
研究领域[WOS]	Engineering ; Geology ; Water Resources
关键词[WOS]	LAND-USE CHANGES ; RUNOFF CHARACTERISTICS ; TIBETAN PLATEAU ; QINGHAI-TIBET ; RIVER-BASIN ; SOIL ; CATCHMENT ; GENERATION ; CLIMATE ; REGIONS
收录类别	SCI
语种	英语
WOS记录号	WOS:000305108000003
公开日期	2013-09-10
内容类型	期刊论文
源URL	[http://ir.imde.ac.cn/handle/131551/6280]
专题	成都山地灾害与环境研究所_山地表生过程与生态调控重点实验室
作者单位	Chinese Acad Sci, Inst Mt Hazards & Environm, Chengdu 610041, Peoples R China
推荐引用方式 GB/T 7714	Wang Genxu,Liu Guangsheng,Li Chunjie. Effects of changes in alpine grassland vegetation cover on hillslope hydrological processes in a permafrost watershed[J]. JOURNAL OF HYDROLOGY,2012,444:22-33.
APA	Wang Genxu,Liu Guangsheng,&Li Chunjie.(2012).Effects of changes in alpine grassland vegetation cover on hillslope hydrological processes in a permafrost watershed.JOURNAL OF HYDROLOGY,444,22-33.
MLA	Wang Genxu,et al."Effects of changes in alpine grassland vegetation cover on hillslope hydrological processes in a permafrost watershed".JOURNAL OF HYDROLOGY 444(2012):22-33.