香溪河流域土地利用格局演变对非点源污染的影响研究

以分布式模型SWAT为研究工具,在气候、土壤等因素不变的情况下,模拟了三峡库区香溪河流域土地利用格局演变对于非点源污染的影响.研究结果表明,自20世纪80年代至2007年,研究区由土地利用所造成的非点源污染TN总体呈减少趋势,4种土地利用情景下模拟得到的年均非点源污染TN分别为1 841.60、824.86、1 790...     

军山湖流域农业非点源污染氮、磷入湖负荷估算

参照国内外相关湖泊研究的方法,在开展流域调查的基础上,按照畜禽养殖污染、农业种植业流失、水产养殖污染和农村生活污染4类途径,结合各乡镇流域面积所占比例、污染源产生量、排放系数和流失系数等估算了军山湖流域农业非点源污染氮、磷的入湖负荷.结果表明,农业种植业流失和畜禽养殖污染是军山潮流域农业非点源污染入湖氮的主要来源,分别占入湖氮总量的37.5％和34.7％,其次为水产养殖污染,占23.2％；畜禽养殖污染是入湖磷的主要来源,占50.8％,其次为农业种植业流失和水产养殖污染,分别占24.4％和20.0％;农村生活污染对入湖氮、磷的贡献率最小.     

浏阳河土地利用变化对非点源污染负荷的影响

以红壤丘陵区典型流域——浏阳河流域为研究区域，利用1986、2000、2005年3个时段的土地利用数据，分析土地利用方式的变化，并结合土壤普查图和降雨数据，在RS和GIS的支持下，利用长期水文影响评价(L-THIA)模型，评估区域长期水文响应，采用相似流域的营养盐输出系数估算非点源污染负荷。结果表明，从1986～2005年期间，林地和草地有向城镇、农村居民点用地和农业用地转化的趋势，其中农业用地由13.75%增加到20%左右，城镇用地和农村居民用地分别由原来的1.34%和0.10%变为2.56%和0.80%，期间非点源污染敏感区面积不断扩大，污染负荷不断增加，TN由1986年的675.56 t增加到2005年的1 001.02 t，TP从15.52 t增加到了23.41 t。     

应用污染模型和地理信息系统评价和管理农业非点源污染

重视农业非点源污染是国际大趋势。美国等发达国家多年研究证实，农业非点源污染是导致水质污染最主要原因之一。研究和控制农业非点源污染已是发达国家政府农业和环保部门主要议程之一。我国大部分地区降水集中，生态破坏导致水土流失严重。近年来化肥农药等农用化学物质的用量不断增加，加上施用技术上的不合理，非点源污染问题日益突出。湖泊、水库、河流已普遍富营养化，并有加剧之势’“。水源中因农药等含量过高造成渔业损失和人类中毒事件也时有发生。随着对农业可持续发展认识的不断深入，研究和控制农业非点源污染的工作已日益受到…     

小流域N、P污染负荷的构成比重研究

对浙江省宁海县颜公河流域N、P污染物负荷的构成比重进行了研究，提出了农业非点源污染造成水体污染的严重性。采用美国农业部的AnnAGNPS模型模拟计算流域中农业面源污染的N、P负荷，并对模型模拟计算的可靠性进行了验证。     

吉林省招苏台河流域农业非点源污染特征研究

招苏台河吉林段为辽河重污染支流,以发展农业为主的产业结构使流域内非点源污染十分严重。采用输出系数法与地理信息系统(GIS)技术相结合,对2003—2012年流域农业非点源污染的组成结构、年际变化和空间分布特征进行研究。研究结果表明:(1)2003—2012年研究区农业非点源TN、TP负荷均呈先增后减趋势,TN负荷平均贡献率由高至低依次为种植业(52.62%)、畜禽养殖业(37.66%)、农村生活(9.72%);TP负荷平均贡献率依次为畜禽养殖业(51.58%)、种植业(30.36%)、农村生活(18.06%);(2)河流两岸1 000m缓冲区内农业非点源污染负荷相对集中,2012年缓冲区内TN、TP负荷分别为流域总负荷的50.30%、54.68%;(3)种植业和农村生活所产生的污染相对稳定,缓冲区内的畜禽养殖业是该流域农业非点源污染防治的重点和突破口。     

农业非点源污染模型研究进展及趋势

对农业非点源污染模型AGNPS作了简要的综述,重点介绍了农业非点源污染模型的结构、原理和输入输出参数,以及该模型在国内外研究现状,同时介绍了运用RS和GIS帮助获得模型参数的方法和途径,最后对模型在中国的发展前景进行了展望。     

上海市黄浦江河网氮污染输入负荷分析和量化计算

河流氮素污染已成为上海市区域内主要环境问题之一。在GLOBAL-NEWS2模型的基础上,对上海市区域河网氮污染输入负荷进行计算和建模。河流氮污染输入负荷模型包括点源输入、非点源输入和上游输入3个部分。结果表明,上海市区域河网氮污染输入负荷总量估算值为68.39Gg/a,其中点源氮输入负荷为15.43Gg/a,非点源氮输入负荷为41.29Gg/a,上游氮输入负荷为11.67Gg/a。非点源输入所占比例最大(60.37%),而其中又以农业氮肥输入为主(19.05Gg/a)。因此,要减少河流氮污染输入负荷,限制农业活动中氮肥的施用量是行之有效的途径。将上海市河网作为一个封闭边界的氮循环流域尺度进行建模和分析,未来需进一步研究氮在流域内的子循环过程。     

海岸带狭义非点源污染的研究现状

非点源污染已经成为中国海洋环境重要的污染源,目前的非点源实验和研究多集中在流域、湖泊和水库范围内,缺乏针对海岸带区域的非点源污染的研究,这类狭义非点源是在雨水作用下直接以地表径流和地下渗透的方式进入沿岸海域的。现今在沿海地区,这类非点源对海洋环境的影响越来越大,由于缺乏完善的政策法规、监测手段、计算方法和防治措施,国内外学者对这部分狭义非点源污染的关注度较小,因而如何科学地认识并有效控制狭义非点源污染成为一个紧迫的研究课题。通过对狭义非点源在法律法规、存在特征和防治措施等方面存在的问题和进展加以探讨,以引起相关研究学者的重视。     

非点源污染模型参数数字化及不确定性研究进展

非点源污染模型是非点源污染量化研究的重要内容.目前,非点源污染模型数量繁多,集总模型不考虑时空变异性,适用流域面积小;分布式模型利用网格划分流域,可以模拟时空变异性,但参数繁多、率定困难、精度达不到要求、难以收集与管理.而全球定位系统、地理信息系统和遥感(合称3S)技术的应用,可以解决参数的选择问题,减少模型中的不确定成分.因此,在未来的非点源污染模型研究中,应重点关注利用3S技术解决参数的选择问题,以及模型参数的敏感性分析和不确定性分析.概述了非点源污染模型的研究进展,重点介绍了3S技术在非点源污染模型中的应用和非点源污染模型中的不确定性分析.     

Spatial distribution and source apportionment of water pollution in different administrative zones of Wen-Rui-Tang (WRT) river watershed, China

Water quality degradation in river systems has caused great concerns all over the world. Identifying the spatial distribution and sources of water pollutants is the very first step for efficient water quality management. A set of water samples collected bimonthly at 12 monitoring sites in 2009 and 2010 were analyzed to determine the spatial distribution of critical parameters and to apportion the sources of pollutants in Wen-Rui-Tang (WRT) river watershed, near the East China Sea. The 12 monitoring sites were divided into three administrative zones of urban, suburban, and rural zones considering differences in land use and population density. Multivariate statistical methods [one-way analysis of variance, principal component analysis (PCA), and absolute principal component score—multiple linear regression (APCS-MLR) methods] were used to investigate the spatial distribution of water quality and to apportion the pollution sources. Results showed that most water quality parameters had no significant difference between the urban and suburban zones, whereas these two zones showed worse water quality than the rural zone. Based on PCA and APCS-MLR analysis, urban domestic sewage and commercial/service pollution, suburban domestic sewage along with fluorine point source pollution, and agricultural nonpoint source pollution with rural domestic sewage pollution were identified to the main pollution sources in urban, suburban, and rural zones, respectively. Understanding the water pollution characteristics of different administrative zones could put insights into effective water management policy-making especially in the area across various administrative zones.     

Seasonal variations of nitrogen and phosphorus retention in an agricultural drainage river in East China

Background, aim, and scope  

Riverine retention decreases loads of nitrogen (N) and phosphorus (P) in running water. It is an important process in nutrient cycling in watersheds. However, temporal riverine nutrient retention capacity varies due to changes in hydrological, ecological, and nutrient inputs into the watershed. Quantitative information of seasonal riverine N and P retention is critical for developing strategies to combat diffuse source pollution and eutrophication in riverine and coastal systems. This study examined seasonal variation of riverine total N (TN) and total P (TP) retention in the ChangLe River, an agricultural drainage river in east China.     

缓冲带在农业非点源污染防治中的应用

论述了缓冲带防治非点源污染的机理和效果，分析了影响缓冲带功能的各个因素。缓冲带能有效地控制土壤与土壤养分的流失，其建设与管理在整个生态环境建设中具有重要地位，目前国内外的研究主要集中于缓冲带对径流中营养物质氮和磷的吸收上，对较大区域环境水质影响的研究不曾多见。为达到防治非点源污染的更好效果，应对缓冲带的设计及各种缓冲带合理配置与布局作更深入的研究，并要与水土保持措施相结合。     

基于SWAT模型的大宁河流域污染物负荷分布特性分析

为了给流域污染物总量控制及分配工作提供理论依据，利用SWAT模型分析了大宁河巫溪水文站控制流域污染物负荷分布特性，结果表明：耕地是泥沙和总磷污染的主要来源，泥沙和总磷负荷分别占整个流域的95%和50%以上；后溪河流域是整个流域内污染负荷最高的支流流域，泥沙贡献率为46.02%，总磷负荷贡献率为60.15%；流域西南部的土壤侵蚀现象较为严重，尤其是子流域17和20；东溪河内子流域7是总磷负荷较高的地区，应重点进行控制。     

PeLM: modeling of pesticide-losses through runoff and sediment transport

A GIS-aided pesticide loss model (PeLM) was developed to simulate pesticide losses through surface runoff and sediment transport in watershed systems. The PeLM could tackle the movement of eroded soil along with surface runoff as well as the pesticide losses in adsorbed and dissolved phases. The contributions of different soil types in the sediment were also examined. The model was applied to the Kintore Creek Watershed of southern Ontario, Canada. The simulation results were verified through observed data, indicating a correlation level of 0.89-0.98. The results also showed that clay particles usually held the largest share of contributions to pesticide losses through soil erosion. This study is significant in the efforts for modeling nonpoint source pollution in watershed systems. It provides useful information and support for the related decisions of watershed management.     

A robust simulation–optimization modeling system for effluent trading—a case study of nonpoint source pollution control

In this study, a robust simulation–optimization modeling system (RSOMS) is developed for supporting agricultural nonpoint source (NPS) effluent trading planning. The RSOMS can enhance effluent trading through incorporation of a distributed simulation model and an optimization model within its framework. The modeling system not only can handle uncertainties expressed as probability density functions and interval values but also deal with the variability of the second-stage costs that are above the expected level as well as capture the notion of risk under high-variability situations. A case study is conducted for mitigating agricultural NPS pollution with an effluent trading program in Xiangxi watershed. Compared with non-trading policy, trading scheme can successfully mitigate agricultural NPS pollution with an increased system benefit. Through trading scheme, [213.7, 288.8]?×?10³ kg of TN and [11.8, 30.2]?×?10³ kg of TP emissions from cropped area can be cut down during the planning horizon. The results can help identify desired effluent trading schemes for water quality management with the tradeoff between the system benefit and reliability being balanced and risk aversion being considered.     

PeLM: Modeling of Pesticide-Losses Through Runoff and Sediment Transport

Abstract

A GIS-aided pesticide loss model (PeLM) was developed to simulate pesticide losses through surface runoff and sediment transport in watershed systems. The PeLM could tackle the movement of eroded soil along with surface runoff as well as the pesticide losses in adsorbed and dissolved phases. The contributions of different soil types in the sediment were also examined. The model was applied to the Kintore Creek Watershed of southern Ontario, Canada. The simulation results were verified through observed data, indicating a correlation level of 0.89–0.98. The results also showed that clay particles usually held the largest share of contributions to pesticide losses through soil erosion. This study is significant in the efforts for modeling nonpoint source pollution in watershed systems. It provides useful information and support for the related decisions of watershed management.     

Establishment of reference conditions for nutrients in an intensive agricultural watershed,Eastern China

Nutrient enrichment from nonpoint source pollution is one of the main causes of poor water quality and biotic impairment in many streams and rivers worldwide. The establishment of reference nutrient conditions in a river system is an essential but difficult task for water quality control. In the present study, the reference concentrations of total nitrogen (TN) and total phosphorus (TP) were estimated in an intensive agricultural watershed, the Cao-E River system of Eastern China. Based on a 3-year water quality monitoring data in the river system, three approaches were adopted to establish the reference concentrations of TN and TP, those are the 75th percentile of frequency distribution of nutrient concentrations in reference streams, the 25th percentile of frequency distribution of nutrient concentration in general streams (including reference and non-reference streams) and regression modeling. Results showed that the nutrient reference concentrations were slightly different from different approaches. By the three approaches, the average reference concentrations for TN and TP in the study system were 1.73?±?0.13 mg l^?1 and 55.23?±?4.77 μg l^?1 with CV of 7.39 % and 8.63 %, respectively. Accordingly, the reference concentrations for TN and TP were recommended to be 1.70 mg l^?1 and 55 μg l^?1, respectively. In the mountainous and intensive agricultural watershed, the major anthropogenic impacts to river water quality were the urban area percentage cover, cropland area with slopes 0–8°, and livestock and poultry waste loads density. These variables could account for 89.7 % and 80.3 % of the total variations for TN and TP concentration, respectively.     

Cooperative identification for critical periods and critical source areas of nonpoint source pollution in a typical watershed in China

Environmental Science and Pollution Research - Critical periods (CPs) and critical source areas (CSAs) refer to the high-risk periods and areas of nonpoint source (NPS) pollution in a watershed,...