Analysis Of Water Quality And Driving Force In Ningde Aquaculture Area

Coastal zone is the ecosystem being most active and frequent in human activities.The development and utilization of coastal resources by humans inevitably brings many ecological and environmental problems,and also threats the sustainable development of social and economic development in coastal areas.As one of the typical human activities in coastal ecosystem,the rapid development of aquaculture in recent years has aggravated the water pollution in coastal waters and has also created a huge challenge to the sustainable development of fisheries.Therefore,it is important to study the current status of water quality in aquaculture areas and the impact of aquaculture activities on water quality.Ningde is the famous "hometown of large yellow croaker"in China and the aquaculture industry is the local pillar industry of Ningde.Due to the high dependence of the coastal economy on aquaculture,the extensive and high-density farming methods over the years combined with the high-risk characteristics of the aquaculture industry itself have put enormous pressure on the water environment and policy making and planning in the coastal areas of Ningde.In summary,in order to explore the impact of aquaculture activities on water quality in coastal ecosystems,and provide some guidance for sustainable development of aquaculture and fishery policies and planning,this paper carried out water quality status assessment,the analysis of influencing factors on water quality spatial distribution and driving force analysis of water quality seasonal change,taking Ningde coastal aquaculture areas as research areas,based on the water quality survey data and satellite remote sensing data.The contents of water quality status mainly include water quality assessment in different seasons and spatial-temporal variation of water quality.The assessment of water quality status is carried out using single factor indexes and comprehensive indexes.In addition,the spatial distribution characteristics of water quality and the characteristics of water quality changes were analyzed qualitatively.Based on the spatial distribution characteristics of water quality,this paper analyzed the factors affecting the spatial distribution of water quality by Pearson correlation coefficient method.Based on the study of water quality change,this paper uses the method of driving analysis for land use change to find out the significant driving factors of water quality seasonal changes and explore its driving mechanism.Among them,the influencing factors and driving factors are mainly from the aspects of natural environment and human society.The main conclusions of this article are showed as follows:(1)Suspended matter,nitrogen and phosphorus are the main water pollution factors.The results of Comprehensive Pollution Index and Nutritive Quality Index indicate that the study area is in heavy pollution level and eutrophication level both in summer and winter.The water quality distribution is spatially heterogeneous,and it shows opposite trends of the water quality changes in the two types of comprehensive indexes.Besides,the content of nitrogen and mercury is relatively high in sediments.(2)The factors affecting water quality in summer include the closest distance of the coastline,the distance to the nearest residential area and the distance to the nearest floating raft.The factor affecting water quality in winter is aquaculture status.(3)The biggest driving factors for the water quality change of two types of comprehensive index are the aquaculture density in summer and the distance to the residential area,followed by the change in aquaculture density.This paper quantitatively explores the impact of aquaculture activities on water quality,and provides a reference for studying the relationship between aquaculture and water environment and the spatial and temporal dynamics of water quality as well as driving force analysis.It points out that the future research directions is to include more factor indicators for better quantitative analysis and it also provides feasible recommendations on local fishery policies.