中国水土保持科学2018，Vol.16Issue(1)：56-64,9.DOI:10.16843/j.sswc.2018.01.007
泾河干流上游森林覆盖率水文影响的年份和月份差异
Yearly and monthly difference in the hydrological impact of increasing forest coverage in the upstream of Jinghe River
摘要
Abstract
[Background] Many activities of vegetation restoration have been implemented in the Loess Plateau of northwest China since the 1950s in order to improve the ecological environment.These have led to a significant increase in the forest coverage,which is being and going to be enhanced in the future due to its unique role in active responses to the global climate change.However,a series of recent studies confirmed that the increase of forest coverage caused a significant runoff reduction and concequently endangered the safe and sustainable usage of water resources.Therefore,based on the forest-water relationship a quantitative evaluation of regional hydrology on the impact of afforestation is urgent and benificial to the vegetation restoration and watershed management.[Methods] Collecting the measured meteorological data during the period of 1997-2003 in the upper reaches of Jinghe River in the Loess Plateau of northwest China,we used the calibrated eco-hydrological model of SWIM to evaluate the hydrological impacts of forest coverage change on the the evapotranspiration and runoff.The evaluation was based on simulation results from many scenarios of forest/vegetation restoration.[Results] 1) Under the scenarios of converting grassland to forestland,the yearly evapotranspiration increased and runoff decreased linearly with the rising forest coverage.Within the studied period of forest coverage increase (0-18.13％),the changing rate corresponding to an increase of forest area of 10％ of watershed area was 8.93 mm increase for the yearly evapotranspiration,but a 6.04 mm decrease of the yearly runoff.2) The impact on yearly evapotranspiration by forest coverage change showed a yearly difference because of the difference in annual precipitation.A 10％ increase of forest coverage led to an increase of yearly evapotranspiration of 10.1 mm in dry years,8.6 mm in normal years,and 8.5 mm in wet years;but a decrease of yearly runoff of 9.0 mm in dry years,5.6 mm in normal ears,and 5.1 mm in wet years,respectively.3) There was also a monthly difference in the responces of yearly evapotranspiration and water yield to the increase of forest coverage.The evapotranspiration was increased in the Spring (March-May) and the early Summer (June),decreased in the period from the mid Summer (July and August) to the mid Autumn (September and Octomber),and not significally changed in the late Autumn (November) and Winter (December,January and Februry);whereas the runoff decreased in the Spring and Summer,but increased in the mid Autumn (September,Octomber),and not obviously changed in Winter.[Conclusions] In summary,the increase of forest coverage in the studied watershed led to an increase of yearly evapotranspiration and a decrease of yearly runoff.These hydrological impacts were more significant in dry years than in normal years and wet years.The hydological impacts of forest coverage change on the evapotranspiration and runoff diffred among the months,much significantly in the Spring and Summer than in the Autumn and Winter.关键词
森林面积/降水/蒸散/径流/黄土高原Key words
forest area/precipitation/evapotranspiration/runoff/Loess Plateau分类
资源环境引用本文复制引用
贺亮亮,张淑兰,李振华,于澎涛,徐丽宏,熊伟,李楠,王彦辉..泾河干流上游森林覆盖率水文影响的年份和月份差异[J].中国水土保持科学,2018,16(1):56-64,9.基金项目
国家自然科学基金重点项目“气候变化背景下黄土高原土地利用影响径流的空间尺度效应”(41230852) （41230852）
国家自然科学基金重大项目“黄土高原森林生态系统水源涵养机理及尺度效应”(41390461) （41390461）
国家自然科学基金面上项目“基于景观格局演变的泾河上游土壤水空间格局形成机制与尺度效应”(41471029) （41471029）
国家林业局宁夏六盘山森林生态站项目 （）
宁夏生态修复与多功能林业综合研究中心和宁夏农林科学院科技先导资金项目“宁夏半干旱黄土丘陵区多功能人工林研究与示范”(NKYJ-15-27) （NKYJ-15-27）
