| With the population growth and rapid economic development in South Jiangxi,the large number of rare earth mining areas and non-ferrous metals smelting have caused serious water pollution in the south of Jiangxi Province,which has a serious impact on the production and life of residents in the basin.Taojiang river basin is an important part of Gannan area,and it is the main water source in Ganzhou and southern Jiangxi.Rare earth mining area and non-ferrous metal mining area are concentrated in Taojiang River Basin.This paper takes Taojiang basin in Gannan as the research object,and interprets the data of remote sensing images in 2007,2010,2013,2017 and 2019,and divides it into cultivated land,forest land The six types of grassland,water area,construction land and unused land are used to analyze the change of land use type in 5 periods;the economic indicators of phase 5 are used to analyze the trend of economic indicators over time,including population,primary industry,secondary industry,tertiary industry,total planting area of crops,tea garden and navel orange area;sorting out and calculating the change trend of economic indicators with time;sorting out and calculating the changes of land use types in 5 periods;sorting out and calculating the change of economic indicators with the total area of crops,tea garden and navel orange;sorting out and calculating the change trend of Economic The time and space changes of pH,dissolved oxygen,permanganate index,five-day aerobic demand,ammonia nitrogen,fluoride and total phosphorus of 8 hydrological stations in Nanhai pond,Yaotou bridge,Shuikouwei,Xinfeng,Huanglong bridge,Quannanjiangkou and Longtoutan in 5 periods(dry water period),April(flood period),July(high water period),November(flat water period),and the time-space changes of 7 water quality indexes,including pH,dissolved oxygen,permanganate index,five-day aerobic demand,ammonia nitrogen,fluoride and total phosphorus,and their water quality evaluation The change status;the percentage of land use type,economic index and water quality index were analyzed,and the driving factors of water quality change in Taojiang River Basin were obtained.The main research results and contents are as follows:(1)Based on the remote sensing image of 30 m spatial resolution in the fifth phase of Taojiang River Basin,the visual interpretation of the image is divided into six types of land use types,i.e.cultivated land,forest land,grassland,water area,construction land and unused land.The cultivated land and forest land area account for about 94% of the total area of the basin.The linear trend of time shows that the cultivated land area continues to decline and the change of construction land area is the largest The land transfer matrix analysis shows that the transfer of land between different land use types in different periods of time from 2007-2019,2007-2010,2010-2013,2013-2017 and 2017-2019 shows that the transfer out area of cultivated land,grassland and forest land is the largest,and the total transfer area of forest land,grassland and construction land is the most.(2)Taojiang river basin includes Ganxian,Xinfeng,Longnan,Dingnan and Quannan counties.The statistical yearbook of Ganzhou City is sorted out,and the population number of economic indicators,the total output value of the first industry,the total output value of the second industry,the total output value of the tertiary industry,the total planting area of crops,the area of tea garden and navel orange planting are calculated and sorted out.The results show that the agricultural population increases first and then decreases,and non-agricultural The population continues to increase,the population urbanization gradually increases,and the proportion of the population over 60 years old increases rapidly;the change of land use area percentage and the change of economic indicators are analyzed by Pearson correlation analysis.The results show that the population growth is positively related to the percentage of cultivated land and construction land,and negatively related to the percentage of water area.The output value of the first industry is positively related to the percentage of cultivated land The correlation was negative correlation with the percentage of construction land,the output value of the tertiary industry and the percentage of water area,and the unused land was positively correlated with the percentage of tea garden and navel orange planting area.(3)The water quality index data of 8 stations,namely,Xiajiangkou,Nanhai Tang,Yaotou bridge,Shuikou Wei,Xinfeng,Huanglong bridge,Quannanjiangkou river mouth and longtaotan are sorted out.The results show that the water quality indexes of each hydrological station change with time.The results show that Xiajiangkou,Nanhai pond and Longtou beach are the most polluted areas,and the rivers are most polluted by ammonia nitrogen.According to the classification of water quality according to the environmental quality standard of surface water(GB 3838-2002),the water quality of Taojiang river is evaluated.The pollution level of potassium permanganate index,five-day biochemical oxygen demand,fluoride and total phosphorus concentration is basically safe,and the dissolved oxygen pollution level is basically the warning line,ammonia nitrogen is the most polluted and many places are seriously polluted.(4)The correlation analysis was conducted between the land use change and the water quality indexes of five hydrological stations of Xiajiangkou,Yaotou bridge,Shuikou Wei,Xinfeng and Huanglong bridge in the period 2007-2019.The results show that the change of cultivated land and forest land has little influence on water quality change,and grassland,water area and construction land have a great influence on water quality.The correlation analysis between economic index and water quality index in 2007-2019 shows that the changes of three industries and population have a great influence on water quality,and the planting area of crops and tea garden and navel orange have little influence on water quality. |
PDF Full Text Request