土地利用方式对珠江河口生态环境的影响分析

Impact of Land Use Patterns on Eco-environment in Pearl River Estuary

本文探讨了珠江三角洲近年来主要土地利用方式的变化,其中城市化和植被覆盖的减少,以及农业施肥量的增加,是造成陆源污染物增加的主要原因。分析了影响珠江河口生态环境的主要陆源污染物(泥沙、氮磷营养元素、重金属和有机物)的产生和迁移过程,以及对河口生态环境的影响关系。从分析中可以看到,土地利用的变化能够影响陆源污染物质的产生和迁移,合理的土地利用方式是降低陆源污染物质,改善珠江河口生态环境的重要措施。陆源物质的产生与水循环密切相关,利用流域分布式水循环模型量化研究不同土地利用下的陆源物质产生、迁移以及对河口生态环境的影响是未来主要发展方向。

In recent years, land use patterns in Pearl River Delta have changed a lot in such fields as aggravation of urbanization level, decreasing of vegetation coverage rate, and reduction of agricultural land, leading to in changes composition and amount of main land-source pollutants （sands, nutrient elements of nitrogen and phosphorus, heavy metals and organic pollutants）. Landsource pollutions result in continuous deterioration of water environment in Pearl River Estuary and degradation of ecological functions, which leads to decrease of biodiversity, bioenrichment of heavy metals and organic pollutants, frequent breakout of red tides, deterioration of wetland functions and so on. The composition and amount of land-source pollutions is affected by land use patterns, so it is important for ecological restoration of Pearl River Estuary environment to make clear the relationship between land use patterns and pollution of estuary environment and to decrease the amount of land sources pollutions by changing land use patterns. The relationship between land use and estrtary has characteristics of basins, frequently affected by outside, and water cycle is one of very important driving factors. So distributed hydrological models which have developed rapidly in recent years are methods to solve this scientific problem.