摘要
根据三峡库区小江流域水文、地理和非点源污染等特点,通过分析引起流域吸附态污染负荷年际变化的主要因素,提出了流域土壤侵蚀模数、输沙模数的动态计算方法。鉴于与吸附态污染负荷有关的流域降雨、土壤、地形、植被、水土保持、泥沙输移比等因素具有空间不确定性的特点,构建了基于盲数理论的非点源吸附态磷污染负荷动态分布模型。应用所构建的模型,借助GIS技术,模拟和定量计算了小江流域1997—2007年各年的土壤侵蚀模数和吸附态磷负荷量。模拟结果表明,降雨侵蚀力因子和地表径流量是流域内吸附态磷负荷年际变化的重要因素;而吸附态非点源磷负荷的空间变化与土地利用类型关系密切,不同土地利用类型输出磷负荷的大小依次为:旱田及混合地、草地、水田、林地和城镇用地。通过验证表明,所建模型合理,运用盲数理论来研究流域非点源吸附态负荷可行。
The dynamic calculation methods of soil erosion modulus and sediment discharge modulus were brought forward by analyzing the key factors of yearly adsorbed load variation for Xiaojiang River Watershed in the Three Gorges Reservoir Area. The dynamic distribution model of annual adsorbed non-point source phosphorus load, based on the watershed characteristics of hydrology, geography and non-point source pollution, was built up. In view of space uncertainty characteristics for parameters in the model which are related to rainfall, soil, to- pography, vegetation, soil and water conservation, sediment delivery ratio and so on, the theory of blind number was introduced to deal with them. Applying GIS technology, the soil erosion modulus and adsorbed phosphorus load of Xiaojiang River Watershed from 1997 to 2007 were simulated and quantitatively calculated. The simulation results showed that the factor of rainfall erosion and runoff are the important factors which effect annual variation of adsorbed phosphorus pollution load, and that the space distribution of adsorbed non-point source phosphorus was closely related to the types of land-use, and the size of contribution rate was glebe and mix-ground, grassland, paddy field, woodland and urban land in turn. The validation revealed that the established model in which parameters were taken as the factors of blind number can be successfully applied for the assessment of the adsorbed non-point source pollution load for the watershed.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2009年第9期1880-1887,共8页
Journal of Agro-Environment Science
基金
中国科学院西部行动计划"三峡库区水土输出与面源污染控制试验示范"(KZCX2-XB2-07)
重庆市科技攻关计划项目"三峡库区面源管理技术与农村生活污染控制示范"(CSTS2008AB7083)
关键词
三峡库区
非点源污染模型
不确定性信息
吸附态磷
盲数
Three Gorges Reservoir Area
non-point source pollution model
uncertainty information
adsorbed phosphorus
blind number