北洛河流域不同地貌和植被类型区径流演变特征及控制因素  

Trend of Streamflow and Its Controlling Factor Under the Regional Vegetation Restoration in Beiluo River Basin

作　　者：张亭亭[1,2] 张建军[2,3,4] 郭敏杰[2,3,4] 陈利利[1,2] 张晓萍[2,3] 

机构地区：[1]西北农林科技大学资源环境学院,陕西杨凌712100 [2]西北农林科技大学黄土高原土壤侵蚀与旱地农业国家重点室,陕西杨凌712100 [3]中科院水利部水土保持研究所,陕西杨凌712100 [4]中国科学院研究生院,北京100049

出　　处：《水土保持学报》2014年第4期78-84,共7页Journal of Soil and Water Conservation

基　　金：中国科学院重点部署项目(KZZD-EW-04-03-03);中国科学院知识创新项目(KZCX2-XB3-13);国家自然科学基金(41101265;41230852)

摘　　要：采用水文统计法,以北洛河流域丘陵沟壑区、高塬沟壑区、阶地平原区以及林区等不同地貌类型和覆被区水文测站资料为基础,分析其近50年来流域径流变化趋势、程度以及极端降雨事件下的稳定性,对比辨析区域尺度流域径流演变特征和控制因素。结果显示,总体上北洛河流域年径流量呈显著减少趋势,年均变率为-0.19mm/a。林区流域径流比较稳定,而非林区流域,无论哪种地貌类型,均呈显著减少趋势,变幅为-0.11^-0.66mm/a。丘陵沟壑区年径流量发生跃变时间在1999年左右,高塬沟壑区和阶地平原区变化时间则在1994年。在水文序列的3个阶段,即1979年前、1979年后水土流失治理效应期以及1999年后的退耕还林时期,丰水流量(5%)不受地貌类型差异和森林覆被与否的影响,各流域均呈持续减小趋势。而枯水流量(95%),受水土流失综合治理影响,各流域首先表现出一致地增加趋势,然后受退耕植被恢复类型和程度影响,在不同地貌类型间有差异。以草灌恢复为主的丘陵沟壑区流域,枯水流量持续增加,以林灌恢复为主的高塬沟壑区和阶地平原区反而呈减少趋势。平水流量(50%)在各流域间反应均变化较小。多重分形临界指数分析认为,总体上阶地平原区和林区流域径流稳定性最好,其次为高塬沟壑区,丘陵沟壑区稳定性最差。区域水土流失综合治理和植被恢复,对各流域1%~5%和5%~50%频域下的降雨-产流调控作用均比较有效,而对≤1%极端降雨事件的作用有限。结果表明,森林覆盖与否及植被恢复类型等生态因素,而不是地貌类型,控制着区域尺度径流演变过程和程度。The daily streamflow data in 7 sub-catchments which located in the hilly-gully region, the hilly- gully region of tableland, the terrace plain and the forest covered region, respectively, in the Beiluo river basin were used to analyze the trend of streamflow, the stability under extreme rainfall events to check the stre- amflow characteristics on regional scale and the controlling factors. Nonparametric test methods of Mann- Kendall and Pettitt were used to check the trend of annual stremflow and their change points. The critical moment of qD in multifractals was used to analyze the streamflow stability. The results showed that the an- nual streamflow in the Beiluo river generally had a significantly negative trend and the average annual rate was --0.19 mm/a. The streamflow in the forest region was relatively high stable than other sub-catchments no matter what kind of geomorphic type, where the annual streamflow had significantly negative trends ran ging from --0.11 mm/a to --0.66 mm/a. The Pettitt＇s test indicated that the change points occurred around 1999 in the hilly and gully region, while around 1994 in the hilly-gully region of tableland and the terrace plain region. The high flow （5%） in each sub-catchment showed a continuous decreasing trend without effects of landforms and forest cover. Affected by the soil and water conservation measures, the low flow （95G） showed a consistently increasing trend in all the sub-catchments, then a different trend under the veg- etation restoration. The low flow turned out to be an increasing trend in the hilly-gully region where grass and shrub was mainly restored, while a decreasing trend in the hilly-gully region of tableland and the terrain plain where arbor and shrub mainly restored. The median flow （50%） in each sub-catchment was relatively small. The qD showed that, the streamflow in the forest region and the terrace plain region had the high stability, followed by the hilly-gully region of tableland, then the hilly-gully region. The qD also showed t

关 键 词：径流变化 地貌类型 林区流域 水土流失治理 退耕还林(草) 北洛河 

分 类 号：P333[天文地球—水文科学]