Studies On The Distribution Of Organic Carbon, Nitrogen, Phosphorous And Their Correlation In Chaohu Wetland Sediments

Lake Eutrophication is highlighted in international eco-environmental research. Lakes, rich in natural resources and important in eco-environment, play an indispensable role in social and economic development. And China possesses a variety of lakes. According to a related survey, it's mainly Lake Entrophication that restricts the sustainable development of lakes in China. Chao Lake, one of the five freshwater lakes, has seen an increasing water degradation in recent years due to natural and human factors, which retards the sustainable economic and social growth of the areas along the lake.This thesis focuses on Chao Lake of severe entrophication and of shallow water, analyzing the distribution of organic carbon, nitrogen and phosphorus in Chao Lake wetland sediment and of the size of the sediment particles. This thesis also unfolds the entrophication proceeding of Chao Lake wetland and the inner source pollution system, which provides scientific statistics for formulating and implementing measures to prevent and solve the problem of entrophication and pollution.The achievements of this thesis:1. The distribution of organic carbon, nitrogen and phosphorus in Chao Lake wetland sediment is obviously vertical: In general, the amount of carbon, nitrogen and phosphorus decreases with the deepening of the vertical profile in spite of occasional curves.2. The amount of organic carbon, nitrogen and phosphorus in Chao Lake wetland sediment is relatively great in the surface of the soil. In addition, the geographical location of the sediment also determines the amount of these minerals—the western part larger than the eastern part on average. The strange distribution in the eastern part of the lake could be attributed to the disturbance of human economic activities, the chemical features of the soil and the composition of certain minerals, etc. But water entrophication of the western part is more severe than that of the eastern part.3. The total amount of organic carbon and nitrogen is well-balanced while phosphorus is still the main cause of entrophication in Chao Lake. Under the influence of lake dynamic sediment, environmental factor and sedimentation rate, the organic substances in Chao Lake wetland sediment have mixed sources.4. Study on distributional characteristics of TN, TP and Organic mattter in sediments of different grain size showed that the contents of TN, TP, and organic matter had obvious grains-size effect, and the contents were distributed as silt and clay fraction(Ⅳ)> very fine sand fraction(Ⅲ)and fine sand fraction (Ⅱ)> medium sand fraction(Ⅰ)and larger fractions.5. In recent years, with social and economic development of the areas along Chao Lake, Lake Entrophication tends to deteriorate, due to its inner source pollution and outer source pollution.