三峡水库上游河流入库面源污染负荷研究

Load of Non-Point Source Pollutants from Upstream Rivers into Three Gorges Reservoir

借鉴水文分割法的原理,在基流分割的基础上,建立了面源污染负荷估算公式.基于相关性分析、回归分析,提出了污染类型判定和数据补插原则.以2004和2005年的水文水质数据为基础,将该方法应用于三峡库区上游河流入库面源污染负荷研究,并采用相关系数法作为对比,对该方法在应用中可能导致的结构性偏差予以探讨.结果表明,2004年嘉陵江、长江干流、乌江三江入库CODMn,总氮和总磷的污染负荷（以包含溶解态和颗粒态成分的总物质通量表示）分别为168.96×10^4,70.30×10^4和10.95×10^4t;2005年分别为228.24×10^4,66.64×10^4和14.24×10^4t;在总量组成中,面源是三江入库污染物的主要来源,占总入库负荷的60%-80%;在空间分布上,长江干流对入库面源污染负荷的贡献占绝对优势,嘉陵江、乌江的面源污染总贡献率仅占13.4%-39.4%;在营养物负荷组成方面,氮对水体的影响以溶解态氮作用为主,磷对水体的影响以颗粒态磷作用为主.水文分割法的改进值得进一步关注,但在尚未出现十分科学、合理的改进算法时,该方法仍不失为面源负荷研究的有效方法.

Hydrological segmentation provides an effective approach for quantifying non-point source （NPS） pollutant load. Using this concept, a calculation formula for NPS load was established based on the segmentation of base flow. Combined with correlation and regression analyses, principles for identifying pollutant flux type and interpolating data were proposed, and the method was further improved. The NPS load from upstream rivers into the Three Gorges reservoir was studied using water quality and hydrological data from 2004 and 2005. Furthermore, a correlative coefficient method was used to compare and explore the structural error caused by the hydrological segmentation method. The results, expressed as total pollutant flux of dissolved pollutants and particles, showed that the NPS loads of CODMa, TN and TP from Jialing River, Yangtze River and Wu River in 2004 were 168.96 × 10^4 ,70.30 × 10^4 and 10.95 × 10^4 t, respectively, and in 2005 were 228.24 × lift, 66.64 × 10^4 and 14.24 × 10^4 t, respectively. Compared with point sources, NPS pollutants accounted for 60%-80% of total influx load. Regarding the spatial distribution, the Yangtze River had a dominant proportion while the Jialing and Wu Rivers only had 13.4% to 39.4%. As for the nutrient composition, the effect of nitrogen on the water was mainly through dissolved nitrogen. However, the effect of phosphorus was largely through particles. The results suggested that, although the hydrological segmentation method should be improved, at present the current hydrological segmentation method is still effective.