Surface Water Pollution in the Yangtze River Delta：Patterns and Countermeasures＊1

摘要

On the basis of field investigations, observations and experimental data combined with environmentalmonitoring information, the status and the spatial and temporal patterns of surface water pollution over thepast ten years in the Yangtze River Delta have been assessed. The water quality of large rivers is still verygood but most of the medium-sized and small rivers have been very seriously polluted. The appearance ofblack and odorous conditions in rivers in the urban areas has increased due to serious pollution by organicmatter with consequent high oxygen demand. Annual increases in N and P concentrations in lakes haveaccelerated eutrophication. The water quality of rivers in small towns is rapidly deteriorating. The mainsources of surface water pollution include industrial and domestic sewage, animal manures, chemical fertilizersin farmland, and polluted sediments in rivers and lakes.Countermeasures against these sources of pollution are presented. Regional laws and regulations