【作者】 汪晓妍；

【导师】 杨武；

【作者基本信息】 浙江大学， 环境科学， 2019， 硕士

【摘要】 海岸带是人类活动最活跃和频繁的生态系统,人类对海岸带资源的开发和利用不可避免带来了许多生态环境问题,同时也阻碍了沿海地区社会经济的可持续发展。水产养殖作为典型的海岸带人类活动之一,其近年来的迅猛发展不但加剧了近岸海域的水污染,也对渔业的可持续发展形成了巨大挑战。因此,研究水产养殖区域的水质现状和水产养殖活动对水质的影响非常重要。宁德是著名的“中国大黄鱼之乡”,水产养殖业是当地的支柱产业,由于其沿海地区经济对水产养殖的高度依赖,多年来粗放型和高密度养殖方式加上水产养殖产业本身的高风险特点,使得宁德沿海地区的水环境和政策规划等面临巨大压力。综上,为探究海岸带生态系统中水产养殖活动对水质的影响,且为水产养殖可持续发展和渔业政策及规划等提供一定指导,本文以宁德沿海水产养殖地区为研究区域,基于水质调查数据和卫星遥感数据等,分别进行水质现状评价、水质空间分布影响因素分析和水质季节变化驱动力分析,此外还对沉积物质量进行了简单的评价和分析,使水生态环境质量评价更加完善。水质现状部分主要包括水质现状评估和水质时空变化的内容。水质现状评估通过单因子指数和综合指数两方面进行,此外还定性分析了水质的空间分布特征和水质季节变化特点。在水质空间分布特征的基础上,通过Pearson相关系数法研究影响水质空间分布的因素。在水质季节变化的研究基础上,本文利用土地利用变化驱动分析的方法找出水质季节变化的显著驱动因子并探索其驱动机制。其中,影响因素和驱动因子主要来自自然环境和人类社会两方面。文章主要结论如下:(1)悬浮物和氮磷是最大的水质污染因子,综合污染指数和营养状态质量指数结果说明该研究区域夏季和冬季都处于重污染等级和富营养化水平。水质分布具有空间异质性,且水质变化在两类综合指数上呈现出相反的变化趋势。此外在沉积物中氮元素污染较大,汞重金属元素富集较高。(2)夏季影响水质的因素包括海岸线的最近距离、到最近居民地的距离和到最近浮筏的距离等,冬季影响水质的因素有水产养殖状态等。(3)两类水质综合指标季节变化的最大驱动因子分别是夏季的水产养殖密度和到居民地的距离,其次是水产养殖密度变化量。本文定量地探究了水产养殖活动对水质的影响,为水产养殖和水环境之间的关系和水质时空动态研究及驱动力分析提供了参考,并指出未来的研究方向在于纳入更多的因子指标更好地进行定量分析,且就当地渔业政策方面提供了可行化建议。更多还原

【Abstract】 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.更多还原