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1.
The Lagoon Olho d'Agua in Pernambuco State, Northeast Brazil has received increasing environmental concern due to significant stress from pollution in the catchment. The existing environmental problems are the result of great pressure from a broad range of human activities, especially in the last 10 years. Serious pollution exists mainly from some industrial and urban activities, which increased intensively after the eighties. There is a strong social and economical pressure for housing and construction near the lagoon, due to the available land nearby beaches and estuarine zone, and recently by growing tourism activities. Uncontrolled land use by low-income communities and the pressure for construction by developers have led to landfilling and to deterioration of water quality in the lagoon catchment. Improvement of the environmental conditions in the catchment needs integrated measures. Guidelines and some specific actions involving several institutions have been established and refer to sanitation and urban infrastructure as the main priorities. A main target is the construction of low-cost sewage system with smaller and decentralised treatment plants.  相似文献   

2.
2015年底,我国全面放开了二孩政策,势必对我国的人口总量和增长态势产生深刻影响,进而影响我国的资源需求和环境压力。在采用队列元素法预测全面放开二孩后我国总人口及各省(市、自治区)人口的基础上,运用城乡人口比增长法预测未来城镇化水平,本文依据这两种预测结果系统探讨人口政策变动对我国资源消费、环境污染的定量预测和具体影响。假定未来的人均资源环境消耗量保持现状不变,按照预测的未来人口总量和增量,得出人口增长对我国资源环境的需求变动。通过计算新增的资源环境需求量,对比需求总量与我国的资源环境供给能力,进一步分析人口增长对资源环境各方面的压力大小。研究发现:全面放开二孩政策后,我国的粮食、生活用能源、生活用水、城乡建设用地的需求量和生活污染物排放量均逐年递增,但变化速率有所差异。为满足未来人口增长所产生的需求,粮食和能源的自给率明显降低,未来将需要更多地依赖进口。全国的供水能力和保障水平急需提高,其中北京、河南、江苏、青海、四川的现状供水能力与未来生活用水需求差距较大。各省建设用地需求差异明显,吉林、湖北、山东、四川、江苏、湖南、新疆、广东、黑龙江、贵州等省市的城市建设用地新增需求量将快速释放,但已有的建设用地储备无法满足预测需求。生活污染物的治理压力加大,环境保护与治理能力应该继续加强。  相似文献   

3.
Primary purposes for catchment management are to establish a cost-effective allocation and use of its water resources and to most effectively apply measures to protect the quantity and quality of the water produced by the catchment. For the latter purpose, diffuse sources of contamination are the greatest difficulty. Diffuse (or non-point source) water pollution poses challenges for public policy and requires innovative management approaches. Solutions ultimately require behavioural change and a broad societal response, and must be flexible and adaptive to stochastic catchment conditions and to long-term trends. Internationally, new models of governance for difficult land and water resource management problems are developing. This paper reviews the characteristics of ‘wicked’ environmental management problems and the specific policy challenges posed by diffuse water pollution. A framework for action is derived and compared to the activities and outcomes of water protection in the New York City watershed. Successes to date in this case indicate that because land management and diffuse sources of pollution have a local basis, protection of water at source necessitates the fostering of local instruments for an adaptive and twin-track strategy of applied research and stakeholder deliberation, supported by multi-level partnerships and an enabling regulatory environment. Although long running, evidence from this case alone is insufficient to establish whether potential trade-offs between water protection and the economic vitality of catchment communities can be fully resolved.  相似文献   

4.
土地利用快速变化对水环境带来较大影响,定量分析土地利用与水环境污染的关系是土地利用结构调整的重要依据。利用3S技术,通过SWAT模型对1983年与2012年昌江流域的水量和水质模拟,分析了土地利用时空变化,结合氨氮、总磷模拟数据,定量分析了土地利用变化下该流域的水环境污染负荷。研究结果表明:该区域林地、草地、水域、城镇及建设用地呈增加趋势,耕地则呈减小趋势。林地占比最大,为70%左右,其次为水田。水田为水环境非点源负荷贡献的第一大来源,且其占流域略多于20%的面积,贡献了该区域总磷总量的53.48%~57.01%和氨氮总量的51.86%~56.57%;农业耕作以25%的地类面积,贡献了60%~65%的非点源污染负荷;旱地的单位面积贡献污染负荷高于林地及城镇及建设用地,表明农业非点源污染是该区域水环境非点源污染的主要来源。  相似文献   

5.
ABSTRACT

As the space carrier of the construction of ecological civilization, land’s green and efficient utilization is an important guarantee for realizing national sustainable development. Based on traditional land evaluation, this paper scientifically defines the green land use, puts land as one of the production factors, and brings energy consumption, environmental pollution, etc. into the input-output system to measure the green land utilization efficiency of the urban construction land of Beijing-Tianjin-Hebei Urban Agglomeration from 2006 to 2016. The study shows that the overall efficiency variation of the urban agglomeration is related with the land and environment policies. Efficiency of 2016 is higher than that of 2006, and energy and environment are the principal factors affecting the green land use. The efficiency of each city is positively correlated with its economic development, negatively correlated with the construction land expansion. Efficiency gaps in different cities are expanding. There is positive correlation with overall weak space between cities, and the partial spatial agglomeration phenomenon appears. Therefore, the green land use efficiency could be improved by improving land utilization efficiency, coordinating economic growth of construction land utilization with environmental protection and taking feasible ways to transregional renovation of the stock ecological land utilization, etc.  相似文献   

6.
Mogan and Eymir Lakes are two shallow lakes, interconnected hydrologically in the close vicinity of Ankara, Turkey. A total of 245 km(2) of the total 971.4 km(2) watershed is under environmental protection status as "G?lba?i Specially Protected Area". Potential impacts from extensive agriculture, recreation, incomplete infrastructure and other human activities, such as residential settlements, are discussed with reference to previous and more recent pollution monitoring. Six monitoring stations enabling follow-up of previous work were selected in this study. These were on the creeks feeding the lake systems. Generally, summer months showed heavier pollution loads, with Eymir Lake concentrating the pollutants due to flow from Mogan Lake. When compared with the 1995 study; COD, total-P, Kjeldahl-N in the six stations were close or slightly decreased in the present study. Suspended solids significantly decreased; possibly due to erosion control measures and decreased domestic wastewater. The improvement in the pollution state of the lakes is attributed to the construction of a sewage system going around Mogan Lake and collecting wastewater discharges and restrictions to urban settlement development around the lakes brought by the 1/25,000 land use plan controlling further impact from residential developments within the protected area boundaries. The study, while addressing water quality and interactions due to human activities in shallow lakes, also discusses problems associated with human impacts in protected areas with the aim of presenting a complicated case study.  相似文献   

7.
The Ethiopian rift is characterized by a chain of lakes of various sizes and hydrological and hydrogeological settings. The rift lakes and feeder rivers are used for irrigation, soda extraction, commercial fish farming, and recreation, and they support a wide variety of endemic birds and wild animals. The levels of some of these lakes have changed dramatically over the last three decades. Lakes that are relatively uninfluenced by human activities (Langano and Abaya) remain stable except for the usual inter-annual variations, strongly influenced by rainfall. Some lakes have shrunk due to excessive abstraction of water; others have expanded due to increases in surface runoff and groundwater flux from percolated irrigation water. Lakes Abiyata and Beseka, both heavily impacted by human activities, show contrasting lake level trends: the level of Abiayata has dropped by about 5 m over three decades because of the extraction of water for soda and an upstream diversion for irrigation. Beseka has expanded from an area of 2.5 to 40 km2 over the last three decades because of increased groundwater inputs from percolated irrigation water. Lake Awassa has risen slightly due to land use changes resulting in increased runoff in its catchment. This paper addresses these lake level changes and their environmental repercussions, based on evidence from hydrometeorological records, hydrogeological field mapping supported by aerial photography and satellite imagery interpretations, water balance estimation, and hydrological modeling. A converging evidence approach is used to reconstruct the temporal and spatial variations of lake levels. The results reveal that the major changes in the rift valley are mainly related to anthropogenic factors. These changes appear to have grave environmental consequences for the fragile rift ecosystem. These consequences demand the very urgent implementation of integrated basin wide water management practice.  相似文献   

8.
太湖流域湖泊水环境问题、成因与对策   总被引:17,自引:0,他引:17  
综合分析了太湖流域存在的的湖泊水环境问题,主要表现为水质全面恶化、洪涝灾害加剧、湖泊生态系统与生物资源破坏和底质污染严重。造成湖泊水环境问题的自然因素与流域地势平缓、亚热带季风气候和地面沉降有关;人为因素如围垦、污水排入湖泊、过量使用农药化肥和湖泊淤积加剧了太湖流域水环境问题的发展。针对当前存在的湖泊水环境问题,提出湖泊水环境整治对策是:树立可持续发展观念,加强流域污染源的控制;重视湖泊水环境的科学研究;加强湖泊水环境水资源的规划与管理;因地制宜地实施湖泊水环境整治工程。  相似文献   

9.
汉江上游是南水北调中线水源地,流域生态环境建设是保障水源地水质安全的关键。针对上游流域水环境污染、土地利用以及水土流失等重大生态环境问题,结合流域数字高程模型及水质调查对其进行了系统分析。结果表明:(1)丹江流域、库区流域及汉中盆地水质较差,CODMn和氨氮成为水源区主要污染物;(2)各子流域区植被覆盖占各自面积的712%~957%,表明流域植被覆盖较好,但沿河岸100 m范围内农业用地占292%~434%,且多为坡耕地;(3)流域水土流失严重,2000年左右流域侵蚀图显示汉江源头、秦岭南及大巴山北均出现了大片年均侵蚀模数>2 200 t/km2的区域,且有日益增强的趋势。提出加大水环境污染整治力度、加强农业用肥管理及河岸带建设、水土保持建设以及加强流域水环境及水土保持监测和科研工作等对策。  相似文献   

10.
城市化进程中人口和建设用地需求增加引发的湿地退化压力日益凸显,熵理论为城市扩张、土地利用结构变化和城市湿地退化压力建模研究提供了新思路。已有研究表明,城市湿地损失、湿地区域建设用地的增加会导致土地利用结构空间熵的数值不断下降,但仅依靠空间熵理论难以定量湿地退化压力。因此依据城市地理学中的重力递减理论,引入距离因素,从湿地区域土地利用空间熵、湿地本身面积、距湿地中心的距离、距商业中心的距离4个要素构建重力空间熵的城市湿地压力模型。研究以1988年武汉南湖湿地遥感影像为基础,制作矢量图,从南湖湿地周边众多湖泊湿地中,随机选取40个样本湿地,分别计算了1988年、1992年、1996年、2000年、2004年5个时期的样本湿地压力值,并利用Kriging空间插值对南湖湿地所受的压力值分布进行可视化处理。结果表明:(1)湿地所在区域土地利用空间熵越小,湿地所承受压力越大;距中心湿地越远越靠近城市商业中心且面积越小的城市湿地更容易发生消亡;(2)根据城市湿地压力模型计算的压力值大的湿地更容易在下一阶段发生显著的损失或消亡;(3)随着城市化的推进,建设用地的扩张,城市湿地承受的压力值逐年增加,当压力值到达0.7左右,湿地存在极大消亡风险。遥感影像解译的结果与按照重力空间熵的城市湿地压力模型计算结果一致,说明该模型能较好地预测城市湿地在城市扩张压力下的演化过程。模型的建成对于城市湿地动态变化和保护规划具有重要意义,了解并把握这一湿地损失过程和趋势,预测城市湿地在城市扩张压力下的演化过程能为城市管理者对城市湿地的具体保护提供方向和指导。 关键词: 城市湿地; 重力空间熵; 压力模型; 城市扩张划具有重要意义,了解并把握这一湿地损失过程和趋势,预测城市湿地在城市扩张压力下的演化过程能为城市管理者对城市湿地的具体保护提供方向和指导。 关键词: 城市湿地; 重力空间熵; 压力模型; 城市扩张  相似文献   

11.
The health status of European aquatic environments, including transitional waters such as coastal lagoons, is regulated by the Water Framework Directive (WFD), which requires the classification of the water bodies' environmental quality and the achievement of a good ecological status by 2015. In the Venice lagoon, a transitional water body located in the northeastern part of Italy, the achievement of a good ecological status is hampered by several anthropogenic and natural pressures, such as sediment and water chemical contamination, and sediment erosion. In order to evaluate the lagoon's environmental quality according to the WFD (i.e. 5 quality classes, from High to Bad), an integrated Weight-of-Evidence methodology was developed and applied to classify the quality of the lagoon water bodies, integrating biological, physico-chemical, chemical, ecotoxicological, and hydromorphological data (i.e. Lines of Evidence, LOE). The quality assessment was carried out in two lagoon habitat typologies (previously defined on the basis of morphological, sediment, and hydrodynamic characteristics) which were selected taking into account the ecological gradient from sea to land, and the differences in anthropogenic pressure and contamination levels. The LOE classification was carried out by using indicators scored by comparing site specific conditions to reference conditions measured in lagoon reference sites, or provided by local, national or European regulations (e.g. Environmental Quality Standards, EQS, for chemicals). Finally, the overall quality status for each water body was calculated by a probabilistic approach, i.e. by reporting the final result as the frequency distribution of quality classes. The developed procedure was applied by using data and information concerning selected LOE and collected from monitoring programs and research studies carried out in the last 15 years in the lagoon of Venice. A set of sampling stations characterized by spatially and temporally coherent information for each LOE was selected, and among these stations, potential reference sites for each water body typology were identified. The quality assessment highlighted that there are specific lagoon areas, especially those located near the industrially developed area, which are highly affected by anthropogenic activities, and that chemical contamination is one of the main pressures affecting ecological status (e.g. macro-benthonic biodiversity) in the Venice lagoon. The integrated quality assessment procedure that was developed provided a new tool supporting decision making, as well as lagoon assessment and management.  相似文献   

12.
1980年以来南京市建设用地扩张阶段性特征   总被引:1,自引:0,他引:1  
以快速城市化地区南京市为例,基于1980~2016年7期遥感影像分类结果,采用规则格网法、等扇分析法和公共边测度法等空间分析方法,分阶段分析36a间城市建设用地扩张强度、方向和模式等特征。结果表明:36a间南京城市建设用地增长迅速,达574.73 km2;在不同时期和不同方向上,南京城市空间扩张强度和扩张模式有很大差异, 36a间南、东北方向扩张强度最大;扩张最快的阶段是2004~2008年,年均扩张55.28 km2;填充式扩张主要发生在主城区内部和已有一定发展基础的地区,蔓延式扩张除围绕主城区向外扩张外,还包括上一阶段飞地式扩张地区的持续发展,飞地式扩张则比较分散,多受开发区、大学城等选址的影响;南京城市建设用地扩张经历了低速扩张-加速扩张—高速扩张—变化趋缓的过程。  相似文献   

13.
By analyzing 26 cases in the EJ Atlas for Sri Lanka, their causes, the impacts, the social actors involved, the forms of mobilization, and the main outcomes of the conflicts, this article examines in what ways activities aiming at economic growth produce socio-environmental conflicts. Such activities increase the social metabolism causing changes that translate into environmental, social, and health impacts which due to inequality of power are unequally distributed. As a result, those who are negatively impacted sometimes mobilize claiming environmental justice. The mining of construction materials to support the boom in the building sector and the expansion of intensive plantations into ‘extraction frontiers’ in new territories, cause deforestation, biodiversity loss, and hurt the local communities. Tourism and industries and new infrastructures are causing displacement, pollution, land degradation, and water shortage, affecting communities of farmers and fishermen that mobilize against the adverse impacts. Those with power to appropriate the natural resources are mostly the state together with international finance institutions and international actors who are able to implement the construction of infrastructures, plantations, and mass tourism. Mobilizations are mostly geared to the protection of livelihoods threatened by loss of access to land, pollution, deforestation, diseases, water scarcity, and new uncertain risks. The protection of the environment demanded by the mobilized groups in Sri Lanka does not aim just to protect nature itself but belongs to a wider movement of an “environmentalism of the poor”.  相似文献   

14.
Lagos, the leading African megacity, is a coastal city located in creeks and riparian environment. In all parts of the city, transactions in marginal lands—riparian or water-logged areas—are increasingly becoming more noticeable. However, while previous studies have focused upon normal land transactions, the dynamics of land uses in marginal regions remain largely unexplained. Information on the dynamics of informal land transactions in the marginal regions of Lagos city is important for urban sustainability. This study therefore interrogates the attributes, uses, values and drivers of marginal land in Lagos using generalized linear model (GLM). Findings show that the predominant land use in marginal areas of Lagos is residential, majority of the lands are less than full plot size, close to river channels and less accessible, and the mean price ranges from NGN 3,156,908 to NGN 4,052,158. The GLM estimations show that distance to river channels/lagoon and buyer’s status have more significant influence on marginal land uses and values in Lagos. These findings have significant policy and practical implications for the city’s land use and sustainability. For urban and environmental sustainability, there is need to stem transactions in coastal marginal environments of Lagos for their obvious implications for climate change, flooding, erosion, sea incursion, building collapse, natural parks and public spaces, river channels and urban greening.  相似文献   

15.
城市建设用地生态效率是城市建设用地在生态建设方面产出与投入的比值,是衡量城市发展品质的重要内容。采用武汉城市圈2006~2015年的面板数据,通过SBM-DEA模型和Malmquist指数对武汉城市圈建设用地生态效率进行测算研究,并通过Tobit模型定量分析了各要素对武汉城市圈建设用地生态效率影响程度。研究结果表明:(1)2006~2015年武汉城市圈建设用地的生态综合效率值总体上呈现螺旋上升的状态,分解效率中纯技术效率是影响综合效率的关键因素;(2)城市圈建设用地生态演变过程可以划分为早期低效阶段、快速提升阶段、不稳定转型阶段;(3)武汉城市圈建设用地生态效率的增长阻力主要是由于技术进步的制约;(4)生态压力、工业发展水平和生态技术水平对城市圈建设用地生态效率产生显著负向影响,而生态投入和产业结构对城市建设用地生态效率产生显著正向影响。  相似文献   

16.
Abstract

Urbanization is the dominant form of land-use change in terms of impacts on water quality, hydrology, physical properties of watersheds and their nonpoint source (NPS) pollution potential at present. Urbanization has changed the source, process and sink of urban NPS pollution, especially raised the pollution load of urban runoff NPS in receiving water. Urban runoff pollution is a hot spot of research on NPS. This paper analyzed type, source and harm of the NPS pollutants of urban runoff and its influence on the receiving water. Through estimating NPS pollution load of urban runoff and summarizing the law and characteristics of urban runoff NPS systemically, study on management and control of urban runoff NPS pollution was focused on the application of BMPs (best management practices). It is a fresh methodology that management and control on NPS pollution from urban surface runoff was analyzed by methods of landscape ecology, environmental economics and environmental management. The paper provided a scientific reference for mitigating urban water environment pressure and an effective method for management and control of NPS pollution from urban surface runoff.  相似文献   

17.
近20年来湘江水质变化分析   总被引:27,自引:2,他引:25  
根据1981~2000年湘江的水质监测数据,选用危害较大的10项污染指标,采用均值指数法对近20年来湘江水质变化进行了分析,并对湘江干流不同河段水质进行了比较。结果表明:湘江总体水质在20世纪90年代呈恶化趋势,致使污染加剧的主要因子是总大肠菌群、总磷、石油类和总汞;主要污染源为工业污染和生活废水污染,近年来生活废水污染日益突出,工业污染中重金属污染明显;在干流不同河段中,株洲、湘潭和长沙河段污染最为严重;估计未来湘江的生活污染和农业污染还会加剧。因此,为确保经济和环境协调发展,湘江污染治理任务依然任重道远。在加大宣传力度,提高公民环境意识,加快城市污水处理设施建设和发展生态农业的同时,应将湘江流域城市生态水源建设提上议事日程。  相似文献   

18.
Segara Anakan is a mangrove-fringed lagoon in Java, Indonesia, which is affected by human activities in the lagoon and its hinterland. Nutrient and sediment input from the Citanduy River which drains an agriculture-dominated hinterland is thought to be an important factor for ecosystem degradation. From dry and rainy season investigations of dissolved inorganic nutrients between May 2004 and August 2006 we infer that the nutrient inventory of Segara Anakan is controlled by a complex mixture of anthropogenic and natural sources and processes. Maximum inputs into the western lagoon were supplied by the Citanduy during the rainy season while tidal exchange with the Indian Ocean dominated in the eastern lagoon with little freshwater input. During the dry season recycling in mangroves appeared to be an additional source of nutrients to the lagoon. Despite an extremely high population density and intensive agriculture in the hinterland nutrient pollution and eutrophication in the lagoon were low to moderate on a global scale. It is probably due to the short residence time of water in the shallow lagoon which indicates that major part of the land-derived nutrient input is rapidly exported to the sea. Although Segara Anakan is a highly perturbed system for decades, it appears that still natural processes exert major control on the nutrient inventory of the lagoon.  相似文献   

19.
重庆市汞污染的观测研究   总被引:1,自引:0,他引:1  
为研究重庆市区汞污染状况,2004年9~11月,同步观测了重庆市近郊铁山坪小流域(TSP)和观音桥(GYQ)两个区域的全沉降、穿透水、地表径流和土壤中的总汞含量,估算了小流域中汞的输入输出通量,分析了城区和郊区的大气汞沉降和分布特征。结果表明,重庆已在一定程度上受到汞污染。在TSP,湿沉降是汞输入的主要方式,也就是说,在TSP,细颗粒是大气汞的主要来源,表层土则是大气汞的一个主要的汇。GYQ区域的汞污染比TSP相对严重。在GYQ,除了湿沉降以外,干沉降是汞来源的重要形式,表明在GYQ,粗颗粒可能对大气汞有很大的贡献。因此,本地源的排放对城区的影响比对郊区的影响大,尤其是城区火电站附近的土壤样品比郊区土壤的汞含量高很多,说明火电站是大气汞的重要来源之一。  相似文献   

20.
基于不同时相的高分辨率遥感影像,采用面向对象的解译方法提取了武汉市2000、2005、2010和2014年的土地覆被信息,从城市扩展强度指数,城市中心坐标迁移和分形维数等方面分析了武汉市2000~2014年城市扩展时空特征。结果表明:2000~2014年间,武汉市城市扩展强度指数为1.41,各主城区城市扩展强度不一,洪山区建设用地的增加对主城区城市扩展的贡献最大;在扩展过程中,武汉市城市分形维数增加,城市空间形态变复杂;其扩展呈现核心-放射扩展模式,并逐渐转向圈层式;自然条件、经济、人口、交通、政策和城市规划是武汉市城市扩展的主要驱动力,但随着交通的发展,自然条件和经济对武汉市城市扩展的驱动作用正逐渐减弱。  相似文献   

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