【作者】 陆丽华；

【导师】 车生泉； 傅徽楠；

【作者基本信息】 上海交通大学 ， 风景园林（专业学位）， 2020， 硕士

【摘要】 在中国城市化过程中,乡村地区承载着环境保育、产业振兴和生态宜居的功能,乡村地区不仅有农田、草地与林地等透水地面,还有道路、广场、屋面等不透水地面,目前大多数乡村分散排放径流污染,部分未经处理而直接排放入河流,其他部分会存积散布于排水沟渠,当降雨事件再发生时,产生的径流冲刷沟道累积污染物,快速产生高负荷污染,会严重影响受纳水体的水环境质量。然而,目前研究乡村主要径流污染状况时,大多从面积上采用一些经验或者测量指标,粗略估算其污染总量,而这种估算忽略了乡村径流源汇过程之间复杂的关系,造成估算与径流污染实际过程有所偏差。上海作为国家中心城市和全球性城市,也是长三角城市群的中心城市,引领着长三角区域的协同发展。上海乡村地区具有人口众多、水系丰富、工业及仓储用地较多等特点,为水体污染治理带来一定的困难。青浦区练塘镇位于国家新规划的长三角一体化示范区内,未来是长三角城乡协同发展的示范镇。练塘镇河网密布、水系发达,是我国东部典型的平原河网地区。此外,练塘镇受快速城市化影响明显,其面源污染问题也是我国东部平原河网地区乡村环境治理的共性问题。本文以青浦区练塘镇为例研究上海乡村径流污染源汇过程,通过遥感解译及实地调研,结合水污染理论指标等,定量化辨识练塘镇乡村径流污染特征,明确其主要源汇路径。因地制宜,根据水污染生态修复技术手段,针对乡村低影响开发技术应用进行优化设计,提出适宜当地的设计方案,以期为同类型乡村地区水环境综合治理提供参考依据。研究主要结果如下:1.不同乡村用地组合模式辨识。利用GIS技术统计乡村的用地类型并计算乡村居住用地、工业仓储用地、耕地、园地和林地占比,以用地比例进行聚类分析,得出3种用地组合模式,分别为:耕地占比突出类型(耕地比例在24.70%-76.83%,且硬质率低于40.00%),此类型样地比例80.64%;工矿仓储用地突出型(工矿仓储用地比例在15.68%-54.45%),此类型样地比例9.68%;林地占比突出型(林地比例集中在28.27%-56.88%),此类型样地比例9.68%。2.典型乡村用地组合模式下径流污染特征分析。结合遥感图像的解译以及样地实地踏勘,归纳了10种径流模式特征。并统计分析了三种用地组合下面积比例较大的径流模式,第一类用地为耕地为主型,面积占比最高的径流模式为径流模式8“耕地-排水沟”的径流模式最为突出,占比48.10%。第二类工矿仓储用地为主型,面积占比较大的两类径流模式为市政排水“屋顶/道路-市政管网-水体”,比例为34.20%;径流模式8“耕地-排水沟”的径流模式占比也较高,为36.33%。第三类林地为主型,面积占比较高的两类径流模式为径流模式8“耕地-排水沟”占比30.24%,径流模式9“林地-排水沟”的径流模式占比43.10%。3.不同用地组合主要径流污染负荷特征分析。通过计算样地各径流模式污染产生的负荷,分析典型样地径流污染产生总量和入河量,对比分析三类用地组合模式径流污染特征,确定了三种用地组合下污染负荷较高的径流模式。第一类用地为耕地为主型,径流模式8“耕地-排水沟-水体”的污染负荷占比最高,达到TN 49.30%、TP 59.51%。第二类工矿仓储用地为主型,主要污染贡献径流模式为径流模式6市政排水“屋顶/道路-市政管网-水体”,污染排放占比为TN 59.85%、TP 51.78%。第三类林地为主型,径流模式8(耕地-排水沟-水体)对河流的污染贡献最大,污染贡献为TN 60.82%,TP58.32%。其次为径流模式9林地-排水沟-水体对河流贡献明显,污染贡献为TN 14.47%,TP 27.41%。4.主要径流污染源汇过程生态调控优化设计。通过以上对径流过程集水区面积占比特征、径流过程面源污染特征分析,选取三种用地组合模式下污染负荷较大径流过程,参考国家海绵城市建设中有关径流污染控制指标及乡村地区情况,确定TN、TP的径流污染削减率为不低于70%。并因地制宜,根据实际情况筛选合适生态技术进行改造设计。针对第一类耕地为主的用地组合样地,对其中污染贡献占主导的径流模式8((耕地-排水沟-水体))进行改造设计。根据现状调研发现,主要有耕地靠近河边直接入河和耕地远离河边排水沟入湿塘两种情景。通过在排水沟末端新建人工湿地或者在现有水塘补植水生植物等方式,提高其污染去除率,能够将TN去除率提高到72.00%-84.11%,TP去除率提高到82.09%-88.75%。针对第二类工矿仓储用地为主的用地组合样地,对其中污染贡献占主导的径流模式6(屋顶/道路-市政管网-水体)进行改造设计。根据现状调研发现,主要有市政管网周边有绿地、绿地高于地面径流流不进去和屋顶道路靠近河流,市政管网周边只有河岸带两种情景。通过将现有绿地进行改造优化为下凹式绿地或者透水铺装+生态型河岸带的复合措施等,能够将TN去除率提高到70.01%-83.35%,TP去除率提高到75.03%-82.01%。针对第三类林地为主的用地组合样地,对其中污染贡献占主导的径流模式9进行改造设计。根据现状调研发现,主要有林地进入沟渠排入河流和林地远离河边排水沟入湿塘两种情景。将普通排水沟改造为生态沟渠或补植水生植物将现有水塘改造为湿塘,提高其污染去除能力,能够将TN去除率提高到72.04%-74.03%,TP去除率提高到80.88%-82.07%。日后更为深入的研究,以下两方面可进一步探索:将土壤理化性质加入污染源汇过程的研究中;结合中长期土地利用规划研究区域面源污染。更多还原

【Abstract】 With the improvement of urbanization in China,rural areas function as environmental protection,industrial revitalization and ecological livability.They contain not only permeable land surfaces such as farmland,grassland and forests,but also impermeable ones such as roads,squares and roofs.Currently,runoff pollution is dispersedly discharged in most rural areas.Some is discharged directly into rivers without any treatment,and others are accumulated and dispersed in drainage channels.When rainfall occurs again,generated runoff washes channels and accumulates pollutants,leading to the generation of high pollution loads,which seriously affects the quality of receiving water bodies.However,regarding to current studies on main runoff pollutions in rural areas,the total amount of pollution is roughly estimated with experienced or measured indicators of the size.This estimation ignores the complicated relationship between the source and sink processes of rural runoff pollution,resulting in a deviation between the estimation and the actual process of runoff pollution.As a global and central city of China,Shanghai is also the central city of the Yangtze River Delta urban agglomerations,leading the coordinated development of the Yangtze River Delta region.Rural areas in Shanghai are found with large population and abundant water systems,with a number of large industrial and warehouse land,which have brought difficulties to the water pollution control.Liantang Town,Qingpu District is located within the newly-designed Yangtze River Delta Integration Demonstration Zone and it will be a demonstration town for the coordinated development of urban and rural areas in the Yangtze River Delta in the future.Liantang Town has dense river networks and well-developed river systems,and it belongs to the typical plain river network regions in eastern China.In addition,it is significantly affected by rapid urbanization,and its non-point source pollution is also a common problem of rural environmental governance in the plain river network areas of eastern China.This paper takes Liantang Town,Qingpu District as an example to study the source and sink process of runoff pollution in rural Shanghai.Through remote sensing interpretation and the field investigation,combined with theoretical indicators of water pollution,the characteristics of rural runoff pollution in Liantang Town are quantified to identify their main source and sink paths.Based on local conditions,optimized design targeting to the low-impact development technology in rural areas are applied according to the technology of water pollution ecological restoration.Design schemes suitable for local areas are proposed,to provide references for comprehensive management of the water environment in similar types of rural areas.Main results are as follows:1.Recognition of different rural land combination patterns.Rural land use types were identified with GIS technology and the proportions of rural residential land,industrial warehouse land,cultivated land,garden plots and forest land were calculated.Three types of land combination patterns were derived with cluster analysis on the proportion of land use:the first type of mostly cultivated land proportion(with 24.70%-76.83%of cultivated land and less than 40.00%of impervious surfaces),and this type occupied 80.64%;the second type of mostly industrial and mining warehouse land(with 15.68%-54.45%of industrial and mining warehouse land),and this type occupied9.68%;the third type of mostly forest land(with 28.27%-56.88%of forest land),and this type occupied 9.68%.2.Analysis of runoff pollution characteristics under typical rural land combination patterns.Combined with the interpretation of remote sensing images and field investigations,10 runoff pattern characteristics were summarized.Statistical analysis of runoff modes with largest percentages of sizes under three types of land uses were applied.The first one was mainly cultivated land,and the runoff mode occupying the largest percentage of size is Runoff Mode 8"Cultivated land-drainage"runoff mode,accounting for48.10%.The second one was mainly industrial and mining warehouse land.Two types of runoff modes that occupied largest sizes were municipal drainage"Roof/road-municipal pipe network-water body",with the proportion of34.20%;and Runoff Mode 8"Cultivated land-drainage"runoff model,occupying 36.33%.The third type was forest land,and two types of runoff patterns with highest sizes were Runoff Mode 8"Cultivated land-drainage",accounted for 30.24%,and Runoff Mode 9"Forest land-drainage",accounted for 43.10%.3.Analysis of main runoff pollution load characteristics of different land combinations.By calculating the loads generated by pollution of each runoff pattern in sample areas,the total amount and the amount of river inflow generated by runoff pollution in typical sample areas were analyzed.The runoff pollution characteristics of three types of land combination patterns were compared and analyzed to determine the runoff patterns with high pollution loads under three land combination patterns.The first type was mainly cultivated land,in which the highest proportion of pollution load was Runoff Mode 8"Cultivated land-drainage",with 49.30%of TN and 59.51%of TP.The second type was industrial and mining warehouse land,in which the main pollution contribution runoff mode was Runoff Mode 6(municipal drainage)"Roof/road-municipal pipe network-water body",with 59.85%of TN and 51.78%of TP.The third type was mainly forest land.The largest contribution of pollution came from Runoff Mode 8(Cultivated land-drainage-water body),with 60.82%of TN and 58.32%of TP,and the second one was Runoff Mode 9"Forest land-drainage-water body",with 75.29%of TN and85.73%of TP.4.The optimal design of ecological regulation for the main runoff pollution source and sink processes.Based on the above analysis of the size ratio of catchment areas and the characteristics of non-point source pollution in runoff process,runoff processes with large pollution loads under three land use combination modes were selected.Referring to runoff pollution controlling indicators in national sponge cities constructions and situations in rural areas,the runoff pollution reduction rates of TN and TP were not higher than 70%.According to actual conditions,ecological technologies suitable to local areas were screened out for improvement and design.For the first type of sample areas which were mainly cultivated land,the transformation design was carried out for the runoff model 8(cultivated land-drainage ditch-water body)dominated by pollution contribution.According to the present situation investigation,it is found that there are two kinds of situations that the cultivated land is close to the river and directly enters the river and the cultivated land is far away from the river drainage ditch and enters the wet pond.The removal rate of TN can be increased to 72.00%-84.11%and that of TP to 82.09%-88.75%by constructing constructed wetland at the end of drainage ditch or replanting aquatic plants in existing reservoirs.For the second type of sample areas which were mainly industrial and mining warehouse,the transformation design was carried out for the runoff model 6(roof/road-municipal pipe network-water body)dominated by pollution contribution.According to the current situation survey,there are mainly two scenarios of green areas around the municipal pipe network,green areas are higher than the surface runoff flow and the roof road is close to the river.The TN removal rate can be increased to70.01%-83.35%and TP removal rate to 75.03%-82.01%by transforming and optimizing the existing green space into the lower concave green space or the composite measures of permeable pavement+ecological riparian zone.For the third type of sample areas which were mainly forests,the transformation design was carried out for the runoff mode 9 dominated by pollution contribution.According to the investigation of the present situation,there are mainly two scenarios of forest land entering ditch and discharging into river and forest land far away from river drainage ditch and discharging into wet pond.The removal rate of TN can be increased to 72.04%-74.03%,and that of TP can be increased to 80.88%-82.07%by transforming ordinary drainage ditches into ecological ditches or replenish aquatic plants transform existing reservoirs into wet ponds to improve their pollution removal capacity.For more in-depth research in the future,the following two aspects can be further explored:adding the physical and chemical properties of the soil to the study of the pollution source and sink process;and combining mid-and long-term land use planning to study regional non-point source pollution.更多还原