延安燕沟流域次降雨泥沙来源分析  

Sediment sources analysis of the Yangou watershed under a certain rainstorm event in the Hilly-gully Region of Loess Plateau

作　　者：徐学选[1,2] 琚彤军[1,2] 郑世清[1,2] 

机构地区：[1]西北农林科技大学水土保持研究所 [2]中国科学院水利部水土保持研究所,陕西杨凌712100

出　　处：《中国水土保持科学》2008年第3期38-42,共5页Science of Soil and Water Conservation

基　　金：国家“973”课题“水土流失环境效应评价理论与指标体系”(2007CB407205-5);国家科技支撑计划课题“坡面降雨径流调控与高效利用技术”(2006BA09B01)

摘　　要：延安燕沟流域属于水土流失治理的重点区，退耕还林（草）措施引起的生态环境改善和经济发展带动的山区道路建设压力对本地区侵蚀环境和侵蚀动力机制产生了巨大影响，坡面水土流失与道路水土流失对比关系发生了新变化。在坡面侵蚀得到初步治理的新环境下，道路侵蚀则上升为主要地位。依据燕沟流域2005年7月2日的5年一遇暴雨引起的不同土地利用类型下的侵蚀产沙监测结果，结合流域卡121站测得的流域产沙总量，分析各土地利用类型产沙量对流域总产沙量的贡献，并依据流域土地利用的演变，反演林草植被恢复与道路建设对流域泥沙来源的作用。研究结果表明：在次降雨条件下，道路的产沙强度为支道山路500t／km^2、干道山路3163t／km^2、运油道路1万3500t／km^2，而农、林、草地的产沙强度为6．184t／km^2；道路产沙强度远大于农、林、草地的产沙强度：占流域面积1％的道路产沙量占总产沙量的42．3％，占流域面积70．5％的草地、灌木林地产沙量仅占流域的26．7％。退耕还林（草）措施使流域坡面产沙量大为降低，流域产沙量减少41．2％，但由于道路产沙量增加，抵消了减沙效益的58．0％，因此，黄土丘陵区植被恢复后，应将水土流失治理重点放在防止道路侵蚀方面。The Yangou watershed is located in Yanan in the most erosive region. At present the vegetation restoration in large scale and high intensity of oil exploiting had brought huge influence on driving forces for the erosion environment change. The balance of slope land erosion and road erosion had been changed a lot. After most slope land had been restored by vegetation, road erosion became more and more important, especially under the massive road constructing for oil industry. In this paper, sediment yield under the event of rainfall on July 2, 2005 which was a rainstorm with yearly possibility of 20 % had been surveyed and analyzed, that including sediment from land under different uses （crop-land plot, vegetation plots, hard road surface） and also 3 types roads （narrow mountain-road, mountain-road, and mountain-transport way）. The sediment yield intensity of the 3 type roads was respectively as 500 t/km^2, 3 163 t/km^2, and 13 500 t/km^2 under the rainfall event. On the other hand, the sediment from cropland and grass, shrub land was within 6 - 184 t/km^2. The results also showed that sediment from road area which only had 1% of total area accounted for 42.3 % of the total sediment yield, far beyond that from other land types in the watershed. Sediment from grass-land and shrub-land, which had 70.5 % of watershed area, shared 26.7 % of the total sediment. The research also showed that the 41.2% of total sediment could be detained by re-vegetation. On the contrary, that road constructing brought heavy sediment which off-benefit by 58.4%. Based on this research, some key suggestions had been put forward that could be used to adjust the strategy form slope management to road erosion protection.

关 键 词：产沙强度 土地利用 次降雨 燕沟流域 

分 类 号：S157.2[农业科学—土壤学] S157.1[农业科学—农业基础科学]