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261.
Kenneth C. Schiff Liesl L. Tiefenthaler 《Journal of the American Water Resources Association》2011,47(1):136-142
Schiff, Kenneth C. and Liesl L. Tiefenthaler, 2011. Seasonal Flushing of Pollutant Concentrations and Loads in Urban Stormwater. Journal of the American Water Resources Association (JAWRA) 47(1):136‐142. DOI: 10.1111/j.1752‐1688.2010.00497.x Abstract: Despite broad observations of first flush within storms, the scientific understanding of seasonal flushing remains incomplete. Seasonal flushing occurs when initial storms of the season have greater concentrations or loads than storms later in the season. The goal of this study was to census stormwater concentrations and loads from an arid, urban watershed to quantify seasonal flushing. Samples were collected every 15 min during the 1997‐1998 wet season from the Santa Ana River and analyzed for total suspended solids. Initial storms of the season generated event mean concentrations 3‐10 times the event mean concentration of storms later in the season. Cumulative flow‐weighted mean concentrations were calculated as the season progressed. Early season storms discharged only 6% of the annual volume, but influenced flow‐weighted mean concentrations well past the midpoint of the wet season. Mass‐based estimates also indicated a disproportionate load in the early portion of the year; over 52% of the annual load was discharged in the first 30% of the annual volume from the highly urbanized lower watershed. Other stormwater pollutants, including six trace metals (Cd, Cr, Cu, Pb, Ni, Zn), were highly correlated with total suspended solids and also exhibited a significant seasonal flush. 相似文献
262.
T.R. McCLANAHAN J.E. CINNER† N.A.J. GRAHAM‡§§ T.M. DAW‡‡ J. MAINA§ S.M. STEAD‡ A. WAMUKOTA K. BROWN††‡‡ V. VENUS§ N.V.C. POLUNIN‡ 《Conservation biology》2009,23(3):662-671
Abstract: Priorities for conservation, management, and associated activities will differ based on the interplay between nearness of ecosystems to full recovery from a disturbance (pristineness), susceptibility to climate change (environmental susceptibility [ES]), and capacity of human communities to cope with and adapt to change (social adaptive capacity [AC]). We studied 24 human communities and adjacent coral reef ecosystems in 5 countries of the southwestern Indian Ocean. We used ecological measures of abundance and diversity of fishes and corals, estimated reef pristineness, and conducted socioeconomic household surveys to determine the AC of communities adjacent to selected coral reefs. We also used Web-based oceanographic and coral mortality data to predict each site's ES to climate warming. Coral reefs of Mauritius and eastern Madagascar had low ES and consequently were not predicted to be affected strongly by warm water, although these sites were differentiated by the AC of the human community. The higher AC in Mauritius may increase the chances for successful self-initiated recovery and protective management of reefs of this island. In contrast, Madagascar may require donor support to build AC as a prerequisite to preservation efforts. The Seychelles and Kenya had high ES, but their levels of AC and disturbance differed. The high AC in the Seychelles could be used to develop alternatives to dependence on coral reef resources and reduce the effects of climate change. Pristineness weighted toward measures of fish recovery was greatest for Kenya's marine protected areas; however, most protected areas in the region were far from pristine. Conservation priorities and actions with realistic chances for success require knowledge of where socioecological systems lie among the 3 axes of environment, ecology, and society. 相似文献
263.
Nadine Marshall Paul Marshall Ameer Abdulla 《Journal of Environmental Planning and Management》2009,52(7):901-918
The social and economic ramifications of marine conservation strategies such as marine protected areas (MPAs) are important to consider prior to their implementation to ensure that they do not exceed the resilience of resource-users and that resource protection might be maximised through compliance and low resistance. This paper presents a framework in which the human dimensions can be more easily and usefully integrated into the design and delivery of conservation initiatives. The framework espouses quantifying (1) the level of dependency on the resource; (2) perceptions towards conservation initiatives; and (3) social resilience. The framework is applied in Salum, Egypt, which is the site of a prospective MPA. 相似文献
264.
基于野外实测光谱的污灌区土壤重金属污染快速监测 总被引:1,自引:0,他引:1
利用光谱反射率反演土壤重金属含量相比传统实验室化学分析方法具有简单高效、成本低、非侵入性等优点。但光谱采集主要局限于实验室内,大大降低了监测的时效性。采集了龙口市污水灌溉区内的32个土壤样本,对9种重金属(Cr、Mn、Fe、Ni、Cu、Zn、As、Cd、Pb)进行了测定,并对土壤光谱进行了野外实测,同时对实测光谱进行光谱变换,提取了去除包络线(CR)、光谱倒数对数(lg(1/R))、一阶微分(RD1)、二阶微分(RD2)4种光谱指标,采用偏最小二乘回归方法(PLSR)建模。结果表明,污水灌溉区内存在严重的土壤重金属污染现象,As、Ni、Cd等重金属富集情况显著,与Fe、Mn呈显著相关的6种元素为Ni、Mn、As、Pb、Zn、Cr,相应的最优建模光谱指标分别为一阶微分(RD1)、二阶微分(RD2)、反射率(R)、反射率(R)、二阶微分(RD2)、去除包络线(CR),验证精度r分别为0.935 3、0.781 4、0.699 6、0.745 8、0.690 1、0.569 6。研究表明,利用野外实测光谱可以提高土壤重金属监测的时效性,预估土壤重金属含量具有一定的可行性,但针对不同的重金属应使用不同的光谱指标建模来达到最优效果。 相似文献
265.
266.
267.
河套灌区春小麦-萝卜复种模式下土壤NO3--N动态 总被引:2,自引:1,他引:1
研究了河套灌区春小麦-萝卜复种模式下,土壤、土壤溶液和地下水NO3--N浓度的动态变化.结果表明:随着试验时间的延长,土壤表层NO3--N含量降低,深层(100~150cm)增加;土壤溶液中、下层NO3--N浓度(70、120cm)显著高于上层(30cm),尤其是在萝卜生长季.当前的灌溉条件下,不同年度、不同生长季土壤NO3--N淋失量的多少与土壤水分的下渗量密切相关,且输入的氮素中有30%以上以NO3--N的形式淋失掉.施肥区地下水NO3--N浓度显著高于未施肥区,且65.5%的水样超过WHO规定的上限(11.3mg/L).总之,经过连续2a的春小麦与萝卜复种可使表层土壤NO3--N含量明显降低,但由于中、下层土壤剖面中残留大量的NO3--N,因此在当前灌溉措施下,短期内NO3--N淋失是不可避免的. 相似文献
268.
There is growing appreciation that protected areas, like all social-ecological systems (SES), are inherently complex and face an unpredictable future under the influence of global environmental change. Adaptive management is the accepted approach for managing complex SES to ensure their resilience, but unless it is supported by a governance system that is itself adaptive it has little chance of success. Scholars have identified certain principles conducive to adaptive governance. Environmental legislation, an important component of the governance system, is often misaligned with these principles. In this paper we assess adaptive governance principles with regard to legislation governing South Africa’s national parks. This assessment indicates that, to enable adaptive governance and adaptive management, legislation should (1) be co-produced by policy-makers, policy implementers and users of protected area ecosystem services; (2) commit and empower management agencies to apply the principles of adaptive governance and adaptive management, particularly in the collaborative development of management plans; (3) commit agencies to review management plans and allow flexibility to adapt plans; (4) ensure that the temporal and spatial scales of the governance system match those of the SES being managed; (5) anticipate change and avoid assumptions of system stability and predictability; and (6) provide for flexible financing mechanisms, so that funds can be prioritised and timed to meet the unpredictable demands of complex systems. 相似文献
269.
湖北省自然保护区建设十分迅速,目前已发展到50余个,占全省国土面积的5.85%。系统分析了湖北省自然保护区的发展态势,并针对保护工作中存在的问题,提出了今后的发展思路与建议。 相似文献
270.
E. J. Sattout P. D. S. Caligari S. N. Talhouk 《Environment, Development and Sustainability》2008,10(1):107-127
The signature and ratification of the convention on biological diversity by the Lebanese government has boosted the declaration
of nature reserves. Cedar forests formed the pilot ecosystems, using international funds, for the implementation of a conservation
programme and development of management plans. Although different in their attributes, all recent nature reserves have the
same basic management objectives and goals but they ignore the idea of taking into account the difference in specific site
features and assets that could boost the success of any management plans. Twelve cedar forests flourish in the Mount Lebanon
chain. These forests are either protected by the forestry law or are declared as nature reserves by the Ministry of Environment.
The results reveal, through Participatory Rural Appraisals and Rapid Rural Appraisals, that religion, geographical location
and land ownership play, to a certain extent, a role in adopting successful management practices of cedar forests. The RRAs
and PRAs spell out the origins of woodcraft, old stories memorized by elderly people and ethnobotanical knowledge. The 4Rs
tools method adopted highlighted the need for more collaboration and synergy of effort between various institutions. The social,
ecological and economic aspects of the regions play a major role in defining the backbone of management plans for cedar forests
in Lebanon. The present paper proposes guidelines for the establishment of a network of cedar nature reserves in Lebanon adopting
collaborative management and assigning a separate role for each reserve; the details rely on the site’s natural features,
as well as socio-economic and cultural characteristics.
Readers should send their comments on this paper to BhaskarNath@aol.com within 3 months of publication of this issue 相似文献