【作者】 周娟；

【导师】 郑天柱； 童桂凤；

【作者基本信息】 扬州大学 ， 工程硕士（专业学位）， 2022， 硕士

【摘要】 近些年来,随着快速城市化进程,扬州主城区地表下垫面发生剧烈改变,林草地、湿地、水体等具有生态调节功能的空间逐渐被建设用地占据,不透水面增加干扰水文循环过程,影响城市河网水系的连通度,对水环境质量造成不利影响。在此背景下,研究扬州市主城区土地利用格局及水环境演变趋势,并以此为基础分析河流水质对土地利用格局的响应关系显得尤为重要。本文以扬州市主城区2010-2020年土地利用数据、水质数据为研究对象,结合统计分析,量化河流水质对土地利用格局的响应,研究结果表明:1、对城镇化进程响应最显著土地利用类型是城镇用地、农村居民点和水田。城镇用地呈现集聚发展的特点,以侵占水田为代价;农村居民点属于离散型扩张;耕地(水田、旱地)转出面积远超转入面积,占补不平衡。在高强度人为开发活动下,景观破碎度增加,但景观趋于规则化;水田、水体作为优势地类的主导作用减弱;各种地类的聚集化程度高提升景观整体连通性。2、大型水体的覆盖频率年际变化不显著,而微小水体变化明显,这种变化规律同样适用于年内季节性水体变化。2010-2020年间水质情况逐渐向好转变,对水质污染贡献较多的指标是TN、TP。部分水质指标季节性差异不明显,表明除受季节性降水影响较大的面源污染外,无季节性排放规律的点源污染和工农业活动也是水质的重要制约因子。各项指标间存在显著相关性,TP和NH3-N在各断面分布差异性最大。3、土地利用格局水质的相关性呈现汛期优于非汛期的特点,说明降水径流是面源污染的重要途径。耕地(水田、旱地)、水体、建设用地是对水质影响最显著的地类,水田和建设用地与水质为显著负相关,而水体、旱地则为正相关。景观水平的景观格局指数与水质的相关性在1000 m缓冲区尺度最显著。其中PD、ED、SHDI与水质呈显著正相关,CONTAG与水质呈显著负相关,表明景观破碎度、异质性、多样性增加能有效改善河流水质。更多还原

【Abstract】 In recent years,with rapid urbanization process,the yangzhou city underlaying surface radically changes according to the surface,grass land,wetland,water,and so on has the control function of the ecological space is gradually occupied by a right to use construction land,opaque surface increase interfere with the hydrologic cycle process,affect the connectivity of urban river water system,poses a serious threat to water environment quality.In this context,it is particularly important to study the evolution trend of land use pattern and water environment in yangzhou city,and to analyze the response relationship between river water quality and land use pattern on this basis.Based on the land use data and water quality monitoring data of yangzhou urban area in 2010 and 2020,this paper quantifies the response of river water quality to land use pattern through statistical analysis.The results show that:1.The most significant responses to urbanization are urban land,rural settlements and paddy fields.Urban land is characterized by agglomeration and development at the cost of occupying paddy fields.Rural residential area belongs to discrete expansion;Arable land(paddy field,dry land)transfer area far exceeds the transfer area,accounting imbalance.Under the high intensity of human exploitation,the degree of landscape fragmentation increases,but the landscape tends to be regular.The leading role of paddy field and water body as the dominant land type weakened;The aggregation degree of various land types improves the overall connectivity of landscape.2.The interannual variation of coverage frequency of large water bodies is not significant,while that of small water bodies is obvious.This variation rule also applies to the seasonal variation of water bodies within a year.From 2010 to 2020,the situation of water quality gradually changed for the better,and the indexes contributing more to water pollution are total nitrogen and total phosphorus.The seasonal differences of some water quality indexes were not obvious,indicating that point source pollution and industrial and agricultural activities without seasonal discharge law were also important restricting factors of water quality except the non-point source pollution which was greatly affected by seasonal precipitation.There was significant correlation among all the indexes,and the distribution difference of total phosphorus and ammonia nitrogen was the greatest in each section.3.The correlation of land use pattern water quality in flood season is better than that in non-flood season,indicating the important way of precipitation runoff source pollution.Cultivated land(paddy field and dry land),water body and construction land have the most significant impact on water quality.Paddy field and construction land have a significant negative correlation with water quality,while water body and dry land have a positive correlation.The correlation between landscape pattern index at landscape level and water quality was most significant at 1000 m buffer scale.Patch density,edge density and aroma diversity index were significantly positively correlated with water quality,while sprawl index was significantly negatively correlated with water quality,indicating that the increase of landscape fragmentation,heterogeneity and diversity could effectively improve water quality.更多还原