摘要
趋势分析结果显示 ,河源涧区、风沙区、丘陵区各代表流域年径流量均在 1970年前后发生一致性改变 ,即从 1970年以来开始有明显的减少趋势 ,平均减流幅度 (与 195 9～ 196 9年径流相比 )以河源涧区 (大理河 )和丘陵区 (小理河 )最大 ,分别为 36 .33%和 36 .2 1% ,风沙区 (海流兔河 )最小 (2 0 .6 1% )。减流幅度的大小是各类型区下垫面状况、水土保持措施和治理程度、降雨量变化等多种因素综合作用的结果。借助适合于黄土高原降雨 -产流特性的月水量平衡改进模型 ,计算天然状态下降雨应有的产流量与同期实测径流量求得减水效果。结果表明 ,3个地貌类型区 70年代的减水效益没有明显差异 ,而在 80年代减水效果差异显著 ,丘陵区 (小理河 ,2 4.99% ) >风沙区 (海流兔河 ,17.2 8% ) >河源涧区 (大理河 ,13.13% )。上述结论为定量评价黄土高原生态环境建设对黄河水资源及水环境演变的影响提供了数据基础。
Tendency analysis indicate that the yearly runoff of three typical basins (Dali river, Hailiutu river and Xiaoli river), which belong to riverhead gully section, sand and wind section and hill section respectively changed consistently in 1970, namely the annual runoff has showed decreasing tendency since 1970. Compared with the runoff in 1959~1969, the average extents of water reduction in riverhead gully section (Dali river) and hill section (Xiaoli river) are maximal, namely 36.33 % and 36.21 %, respectively, and the one of water reduction in sand and wind section (Hailiutu river) is the least, namely 20.61 %. The variation of the extents of water reduction is mostly caused by integrated results of different underlying surface status, soil and water conservation measures and controlling degree, rainfall variation in different physiognomy type areas. The monthly water balance model for calculating runoff on loess plateau has been used in analyzing the benefits of water reduction by soil and water conservation. The results indicated that the benefits of three typical basins water reduction in 1970s didnt show significant difference, but the benefits of water reduction in 1980s are very significant difference. The benefit of water reduction in hill section (Xiaoli river,24.99 %) is greater than that in sand and wind section (Hailiutu river, 17.28 %) and in riverhead gully section (Dali river, 13.13%). Results above are the basis of evaluating the effect of eco environment of the Loess Plateau on the water resources and the evolvement of water environment of Yellow River.
出处
《水土保持学报》
CSCD
北大核心
2001年第1期90-94,共5页
Journal of Soil and Water Conservation
基金
国家自然科学基金重大项目!( 4 9890 3 3 0 )
中科院"西部之光"项目共同资助
关键词
大尺度流域
地貌类型区
水土保持
减水效益
big scale watershed
physiognomy type areas
soil and water conservation
benefit of water reduction
