三峡库区小流域土地利用结构对土壤养分流失及水质影响  

Effects of Land Use on Soil Nutrient Loss and Water quality in the Three Gorges Reservoir Area of China

作　　者：马良 黄志霖[1] 华琳 MA Liang;HUANG Zhi-lin;HUA Lin(Key Laboratory of Forest Ecology and Environment,State Forestry Administration,Research Institute of Forest Ecology Environment and Protection,Chinese Academy of Forestry,Beijing 100091,P.R.China)

机构地区：[1]中国林业科学研究院森林生态环境与自然保护研究所,国家林业局森林生态环境重点实验室,北京100091

出　　处：《水生态学杂志》2022年第1期1-7,共7页Journal of Hydroecology

基　　金：国家重点研发计划(No.2017YFC05053)。

摘　　要：三峡水库生态屏障区土地利用类型及其结构快速变化,直接影响入库的土壤侵蚀、径流及土壤养分流失输出;研究土地利用结构对地表径流养分输出及地表水质影响,可为控制地表水质和水体富营养化提供基础数据。选取三峡库区低山丘陵区的秭归县兰陵溪小流域集水区,代表以林地(S1)、林地+园地(S2)、园地(S5)为主的典型土地利用结构,自动采集水样,常规监测及典型降雨径流过程连续监测,探究地表径流土壤养分氮磷浓度的动态变化过程。结果显示,雨季集水区间径流的氮素浓度存在较大差异,S5的氮磷输出浓度都显著高于S1和S2(P<0.05);集水区间径流的氮磷浓度变幅差异显著(P<0.05),氮磷输出浓度表现为S1<S2<S5;园地为主集水区(S5)径流养分浓度对降雨响应较S2和S5迅速。研究表明,适当增加林地比例,控制园地、耕地比例以及在河岸边设立缓冲林带,实行茶林间作等方式,可降低径流氮磷浓度;通过优化土地利用结构,可降低土壤氮磷输出负荷。The rapid changes of land use type and structure in the ecological barrier area of Three Gorges Reservoir directly affects soil erosion, runoff and loss of soil nutrients to the reservoir. In this study, we explored the impact of land use structure on surface runoff, loss of nutrients and surface water quality in the Three Gorges Reservoir area, aiming to provide basic data for managing surface water quality and eutrophication. The Lanlingxi watershed in Zigui County, located in the low mountain and hilly area of lower Three Gorges Reservoir, was selected for a study case. A total of nine sampling sites were set in the study area(S1-S7 at the outlet of each tributary, S8 in the main stem of the Lanlingxi River and S9 at the outlet of the watershed). Three typical land uses, forest(S1), forest-garden(S2), and garden(S5)dominated in the study area. From March to October of 2017, water samples from the catchment area were collected by routine monitoring and by continuous monitoring at the three representative sites(S1,S2, S5) during rainfall events. Monitoring data was then used to explore the dynamics of soil nitrogen and phosphorus transport in surface runoff. In the rainy season there was a significant difference in nitrogen concentrations in the runoff from different catchment areas, and nitrogen and phosphorus concentrations in runoff from garden land(S5) was significantly higher than in runoff from forest land(S1) and forest-garden land(S2)(P<0.05). There were also significant differences in the concentration ranges of nitrogen and phosphorus in runoff among the catchment areas(P<0.05). Nutrient concentrations in the runoff from the S5 catchment area responded rapidly to rainfall. Based on the results of this study, we recommend increasing the proportion of forest land by more tightly controlling the proportion of land that is cultivated, constructing forest buffers along river banks, and intercropping tea within forested land. These measures will help optimize land use, thereby reducing concentrations of nitr

关 键 词：土地利用 土壤养分 三峡库区 氮磷负荷 兰陵溪小流域 

分 类 号：X821[环境科学与工程—环境工程]