摘要
汉江上游是南水北调中线水源地，流域生态环境建设是保障水源地水质安全的关键。针对上游流域水环境污染、土地利用以及水土流失等重大生态环境问题，结合流域数字高程模型及水质调查对其进行了系统分析。结果表明：（1）丹江流域、库区流域及汉中盆地水质较差，COD60和氨氮成为水源区主要污染物；（2）各子流域区植被覆盖占各自面积的71．2％～95．7％，表明流域植被覆盖较好，但沿河岸100m范围内农业用地占29．2％～43．4％，且多为坡耕地；（3）流域水土流失严重，2000年左右流域侵蚀图显示汉江源头、秦岭南及大巴山北均出现了大片年均侵蚀模数〉2200t／km^2的区域，且有日益增强的趋势。提出加大水环境污染整治力度、加强农业用肥管理及河岸带建设、水土保持建设以及加强流域水环境及水土保持监测和科研工作等对策。
The upper Han River basin （approximately 95 200 km2）is the water source area of the Middle Route of the South to North Water Transfer Project（MR-SNWTP）, thus, water conservation and eco-envi- ronmental construction for MD-SNWTP is of great importance. Reasonable river basin planning and management can play an important role in maintaining a sound ecological environment. In recent decades, due to anthropogenic activities and climate change, the ecosystems of the basin are degrading. Water samples were measured in October 2006, land use and land cover（LULC）pattern was characterized and water and soil erosion was determined by integrating a digital elevation model and LULC data in the paper. The results show that（1）water quality in Dan River, Danjiangkou Reservoir catchment and Hanzhong Plain is declining, and chemical oxidation demand and nitrogen are the major pollutants; （2）vegetated land cover ac counts for more than 70% ,while agricultural land use occupies 29.2%-43.4% in riparian zone at subwatershed scale; （3）there is increasing soil erosion,and subwatersheds with erosion modulus of more than 2 200 t/km^2 · a occur in headwaters,the south of Qinlin Mountain and the North of Daba Mountain respectively. The critical problems including water pollution, unreasonable land use practice and soil erosion urgently need approaches of ecological alleviation in the basin to promote environmental reconstruction. Thus,the following countermeasures are put forward, to work out waste water treatment plan and build sewage treatment plants; to manage agricultural fertilizer and construct riparian zone l to construct water and soil conservation;to establish long time water quality and soil conservation monitoring plans.
出处
《长江流域资源与环境》
CAS
CSSCI
CSCD
北大核心
2009年第3期275-280,共6页
Resources and Environment in the Yangtze Basin
基金
国家“十一五”科技支撑项目(2006BAC10B02)
中国科学院“百人计划”项目(O629221C01)
关键词
南水北调中线
汉江上游流域
生态问题
the Middle Route of the South to North Water Transfer Project
upper Han River basin
ecologic crisis
