Investigation And Evaluation Of Water Ecology In Villages And Towns In Jiangxi Province

Water is an important part of the environment,but due to the impact of human production and life,the quality of surface water and groundwater continues to deteriorate.Township water body is an important carrier of ecology and environment in rural areas as well as the lifeline of agricultural production.Under the background of increasingly serious water pollution and urgent need to control,the investigation and evaluation of water environment and ecology of township water body is particularly important.Therefore,this study carried out ecological investigation and evaluation of water bodies in villages and towns in Jiangxi Province in summer(July 2022),autumn(October 2022)and winter(February2023),mainly focusing on three types of water bodies in towns and villages: ponds,reservoirs and river gully.The water quality was evaluated by single factor index,comprehensive nutrition index and single factor analysis of variance.In addition,plankton and benthos were analyzed from the biological composition and density,and the plankton were evaluated according to Shannon-Wiener biodiversity index,Pielou evenness index,Margalef abundance index,plankton dominant species analysis,and environmental factor correlation analysis.The findings are as follows:a.Nutrient index: COD is the most important environmental pollution factor.Most of the nutrient salt concentrations in reservoirs,rivers and ponds meet the three standards of surface water and fishery standards respectively,and most of the index concentrations are higher in summer but lower in winter.The high concentration in summer may be caused by the deterioration of water quality caused by summer high temperature,crop fertilization and other factors.The low concentration in winter may be related to the improvement of water quality due to the dilution of precipitation runoff and lower water temperature.b.Comprehensive nutritional analysis: The eutrophication degree of reservoir and river channel in summer was higher than that in autumn and winter,and showed a decreasing trend.The eutrophication degree of river gully is higher than that of reservoir,which is related to pollution sources such as residential areas or farmland near river gully.c.Plankton: A total of 81 species of phytoplankton were found in 6 phyla,and the total density of phytoplankton was lower in summer and winter than in autumn.The proportion of cyanobacteria in autumn is the most,which is the typical characteristic of autumn nutritive lakes.There was a significant positive correlation between phytoplankton cell density and total phosphorus,indicating that total phosphorus was beneficial to the growth of phytoplankton cells.50 species of zooplankton were found in 3 phyla.The total density of zooplankton in autumn is lower than that in summer and winter,which is related to the loss of the dominant position of zooplankton due to the growth of phytoplankton in autumn.COD,ammonia nitrogen and total nitrogen were significantly negatively correlated with Pielous,indicating that they could promote the growth of dominant species and not promote uniform growth.d.The density of benthic animals is the highest in Fengcheng Pelteobagri pelteobagri culture area in summer,among which the density of quadracobagri pelteobagri is the highest.Quadracobagri pelteobagri is an ideal natural food for some freshwater fish with high nutritional value.In autumn and winter,the densities of benthic animals in Nanfeng turtle culture area were the highest,and the densities of nematodes and siphonodiscus were the highest respectively.There are significantly more species of benthic animals in winter than in summer and autumn,which indicates that the structure of benthic animals in winter is more abundant,and the water quality in winter is better than that in summer and autumn,which corresponds to the results of the analysis of water nutrients and the degree of eutrophication.