摘要
植被覆盖是影响土壤侵蚀的关键因素之一。选择代表官厅水库上游地区的北京市延庆县上辛庄坡地径流场7个不同植被盖度坡面径流小区为研究对象,采用垂直照相法以15天为一个周期观测和控制小区植被盖度,采用传统取样和测定方法测定小区产流后的径流量、泥沙量及污染物流失量。利用2003年和2004年7个植被小区24场降雨径流泥沙资料,分析了不同植被盖度下径流量、土壤侵蚀模数及污染物流失量,来定量说明植被覆盖对面源污染的影响。研究结果表明:土壤流失量与植被覆盖度之间呈负指数相关关系,当植被覆盖度达到30%时,土壤流失量已小于北方土石山区的土壤容许流失量200t/km2;随植被覆盖度的增大径流量和污染物流失量逐渐减小,与覆盖度为0的裸地小区相比,当植被覆盖度达到50%时,径流与污染物减少效益均达到65%以上。
Soil erosion is regarded as from all people in the world. Serious a global environment p soil erosion causes land roblem, which gets more and more attention degradation, destroys land resource, but also breaks down the ecological environment of the downstream by silting up riverbank and polluting water and accelerating drought, flood and salinization. It is necessary to effectively control water loss and soil erosion so as to get sustainable development. The process of the soil erosion is affected by rain, soil, slope and plants cover factors, etc. All factors are combined in the erosion process but the effect of each factor is not the same. One of them such as plants cover can be dominant and reduce sediments, even eliminate the soil erosion. The plant cover is the very important factor in the water and soil conservation.
The seven plots in Shangxinzhuang monitoring site of Yanqing county are selected to conduct investigation through the overhead camera to monitor and control the plant cover degree every 15days and using the traditional sample collecting and analyzing method to measure the amount of the soil loss, runoff and contamination. The 24 observational data of 7 plots are collected from 2003 to 2004 to quantitatively analyze the plant cover＇ s effect on the soil erosion. The main conclusion drawn from the study is presented as follows： Firstly, the relationship of the soil loss and the plant cover is with obviously negative exponential correlation, when the cover degree is higher than 30% and the soil loss is far less than soil tolerance loss of 200t/km^2 . Along with the increase of plant cover degree, the amount of the runoff and the contamination reduces gradually. Compared with the bare plots, the reduction efficiency of the plant plots＇ runoff and contamination can be higher than 65 % when the plants cover degree is 50 %.
出处
《资源科学》
CSSCI
CSCD
北大核心
2006年第5期196-200,共5页
Resources Science
基金
北京市科委重点项目(D0704004000091)
北京市优秀人才培养项目(编号:20051D0200203)
关键词
官厅水库上游
植被覆盖度
面源污染
土壤侵蚀
Upper reaches of the Guangting Reservoir
Plant cover
Non-point source pollution
Soil erosion
