Temporal And Spatial Analysis Of Water Quality In Minjiang River And Its Sustainable Development

As the most crucial river in northern Fujian Province,the Minjiang River runs through four important cities in Fujian Province.The basin significantly differs in topography,meteorology,environment,hydrology,human activities,and industrial layout.The environment of surface water in the basin is in the process of constant change.Therefore,a comprehensive understanding of the spatial and temporal distribution characteristics and influencing factors of water quality in the Minjiang River Basin is of great significance for improving the water ecological environment management and providing an essential for the sustainable development of the basin.This paper collected water quality data from 22 monitoring points in the Minjiang River Basin.The temporal distribution characteristics of water quality in the Minjiang River Basin were analyzed from two dimensions time and space.The sustainable development of the basin was evaluated.The main research contents include:(1)The third chapter(Analysis of spatial and temporal water quality characteristics in Minjiang River Basin).The spatial and temporal distribution characteristics of water quality in the Minjiang River Basin were analyzed by kernel density estimation and inverse distance spatial interpolation.According to the hydrological characteristics of the basin,the water quality data are divided into two seasons: flood season and drought season,and the spatial and temporal characteristics of water quality in these two periods are analyzed,respectively.In the dry season,the water quality of the Minjiang River Basin did not differ significantly between years,but the water quality differences between regions were noticeable.In the river’s flood season,the basin’s water quality differs in spatial and time dimensions.The water quality in the flood season is worse than in the dry season.The difference between the two seasons is mainly caused by thin changes in some water quality indexes caused by rainfall,temperature,and other factors.The spatial distribution of water quality in the basin generally shows a process of gradual deterioration from upstream to downstream.Some areas of Sanming and Nanping in the middle and upper reaches also appeared in a poor state due to the accumulation of heavy industry,agriculture,and other pollution sources.Located downstream of Fuzhou,due to the dense population of the main urban area and a large amount of domestic sewage discharge,the basin’s water quality is terrible.(2)The fourth chapter(The construction of water quality spatiotemporal model in Minjiang River Basin).The water quality spatiotemporal sequence model of the Minjiang River Basin was constructed by using BP neural network and spatio-temporal sequence model.Aiming at the non-stationary characteristics of water quality spatio-temporal data in the basin,this chapter uses the BP neural network to extract the nonlinear trend of the spatio-temporal sequence.It uses the residual data after extracting the nonlinear trend to construct the spatio-temporal analysis model of the Minjiang River Basin.At the same time,the time-space series model and time series model with static difference method are used as comparison models.It is proved that the time-space series model constructed by BP neural network after extracting nonlinear trend has a better fitting effect on the basin’s water quality data,and the error of the model error is smaller than the other two.This shows that the method fits the spatio-temporal water quality data in Minjiang River Basin.(3)The fifth chapter(Study on Sustainable Development of Minjiang River Basin).Based on the water quality data,population,and economy,the PSR model and matter-element extension evaluation method were used to comprehensively evaluate the water ecological civilization construction level in the Minjiang River Basin.The level of water ecological civilization in the basin has reached a relatively good state in the past five years,which shows that the harmonious development of people and the water ecological environment around the Minjiang River Basin has formed a new pattern,which can better promote the sustainable development of the basin.However,the pollution sources of water quality in different regions around the basin are different,and there is also a significant gap in the investment of environmental governance between regions.Given the problems in each region,sustainable development suggestions for the Minjiang River Basin are put forward.