平原感潮河网地区河道水体表观污染评价及来源解析

以佛山市大沥镇河道为研究对象，采用表观污染指数法及表观污染类型的分类方法，从污染程度和污染类型2个角度对平原感潮河网地区河道水体表观污染状况及污染源进行评价，并利用正定矩阵因子分解模型定量解析污染源。结果表明：佛山市大沥镇河道水体表观质量整体不佳，表观污染类型以混合主导型为主，夏季和晚春的表观污染程度重于早春。不同片区水体表观状况从优至劣依次为镇水围片区>白沙片区>盐联围片区>黄岐盐联围片区>谢边涌及香基河片区>泌冲片区>后海片区。退潮时段河道水体表观质量较差，且涨退潮对镇南部河道水体表观质量影响较大。不同表观污染类型河道的污染源类型及贡献率不同，有机主导型（黑臭）的主要污染源为点源污染（52.61%）；有机主导型（水华）的主要污染源为农业面源（35.98%）；营养主导型的主要污染源为种植业污染（51.43%）；无机主导型的主要污染源为地表径流（41.50%）。研究显示，大沥镇河道水体表观污染时空变化较为显著，不同表观污染类型的污染源具有差异性，需分类治理，从而改善水体表观状况。

Apparent pollution evaluation and source analysis of river water bodies in the tidal river network area of the plains

Taking the river course in Dali Town, Foshan City as the research object, the sensation pollution index (SPI) and the classification method of apparent pollution types were utilized to evaluate the apparent pollution status and pollution sources of the river course water in the plain tidal river network area from two perspectives of pollution degree and pollution type, and Positive Matrix Factorization model was used to quantitatively analyze the pollution sources. The results showed that the landscape river in Dali Town, Foshan City had poor overall apparent quality. The apparent pollution type was mainly mixed-dominant and the level of pollution was found to be heavier in summer and late spring compared to early spring. The apparent conditions of different areas were in the order of Zhen Shuiwei Area>Baisha Area>Yan Lianwei Area>Huangi Yanlianwei Area>Xiebian Chong and Xiangjihe Area>Michong Area>Houhai Area. Overall, the apparent quality of the river channel was poor during low tide periods, and the varying tides greatly impacted the perceived apparent quality of the river in the southern region of the town. The types and contribution rates of pollution sources in river channels varied depending on the level and type of pollution. For organic-dominated (black and odorous) water, the primary source of pollution was point sources, accounting for 52.61% of the pollution. Meanwhile, for organic-dominated waters with blooms, agricultural non-point sources contributed the most pollution at 35.98%. In cases of nutrition-led pollution, the primary source was found to be plantation pollution, contributing to 51.43% of the total pollution. Finally, for inorganic-dominated pollution, surface runoff was the main source, accounting for 41.50% of the pollution. In conclusion, it was noteworthy that there existed significant temporal and spatial changes in the apparent pollution levels of the rivers in Dali Town. Furthermore, the pollution sources causing various types of apparent pollution differed, indicating a need to classify and treat them accordingly to enhance overall conditions.