title: Global pattern for the effect of climate and land cover on water yield.
abstract: Research results on the effects of land cover change on water resources vary greatly and the topic remains controversial. Here we use published data worldwide to examine the validity of Fuh's equation, which relates annual water yield (R) to a wetness index (precipitation/potential evapotranspiration; P/PET) and watershed characteristics (m). We identify two critical values at P/PET=1 and m=2. m plays a more important role than P/PET when m<2, and a lesser role when m>2. When P/PET<1, the relative water yield (R/P) is more responsive to changes in m than it is when P/PET>1, suggesting that any land cover changes in non-humid regions (P/PET<1) or in watersheds of low water retention capacity (m<2) can lead to greater hydrological responses. m significantly correlates with forest coverage, watershed slope and watershed area. This global pattern has far-reaching significance in studying and managing hydrological responses to land cover and climate changes.
authors.affiliation: South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.
authors.forename: Guoyi
authors.initials: G
authors.lastname: Zhou
authors.affiliation: Earth &Environmental Sciences and Physical Geography, University of British Columbia (Okanagan campus), Kelowna, British Columbia, Canada V1V1V7.
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Wei
authors.affiliation: South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.
authors.forename: Xiuzhi
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Forest Ecology, Guangdong Academy of Forestry, Guangzhou 510520, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Zhou
authors.affiliation: South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Liu
authors.affiliation: South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.
authors.forename: Yin
authors.initials: Y
authors.lastname: Xiao
authors.affiliation: Eastern Forest Environment Threat Assessment Center, USDA Forest Service, Raleigh, North Carolina 27606, USA.
authors.forename: Ge
authors.initials: G
authors.lastname: Sun
authors.affiliation: Earth &Environmental Sciences and Physical Geography, University of British Columbia (Okanagan campus), Kelowna, British Columbia, Canada V1V1V7.
authors.forename: David F
authors.initials: DF
authors.lastname: Scott
authors.affiliation: Beijing Institute of Technology, Zhuhai Campus, Zhuhai 519088, China.
authors.forename: Shuyidan
authors.initials: S
authors.lastname: Zhou
authors.affiliation: Guangzhou Institute of Geography, Guangzhou 510070, China.
authors.forename: Liusheng
authors.initials: L
authors.lastname: Han
authors.affiliation: Guangzhou Institute of Geography, Guangzhou 510070, China.
authors.forename: Yongxian
authors.initials: Y
authors.lastname: Su