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1.
洞庭湖湿地景观格局变化以及三峡工程蓄水对其影响   总被引:3,自引:0,他引:3  
通过对近20 a遥感影像的解译分析,结果表明:洞庭湖湿地景观格局变化较为迅速,在几种湿地景观类型中,芦苇分布面积稳定增长,由475 km2增至751 km2,年均增加13.1 km2,湖草的分布面积比较稳定,而水面与泥滩的分布面积则大幅减少。湿地格局演变总体上呈现芦苇挤占湖草的分布空间、湖草挤占水面泥滩的态势。分析认为泥沙淤积和湖泊水情变化改变了洲滩的淹水历时,引起植被分布的变化,是影响洞庭湖湿地景观格局的主要因素。2000年后,随着泥沙淤积减缓,湖泊水情变化对湿地景观格局影响更为重要,其中三峡水库的运行使洞庭湖中、低位洲滩提前出露,淹水历时缩短,导致湖草的分布界线明显向下延伸  相似文献   

2.
基于Landsat的近20余年东洞庭湖湿地草洲变化研究   总被引:1,自引:0,他引:1  
利用多时相Landsat TM/ETM+影像,采用决策树分类法解译水域、泥沙滩地、草洲3种湿地类型,结合数字高程模型和相关水文信息,通过矩阵转移和贝塞尔曲线插值的方法,对低水位条件下东洞庭湖湿地草洲的时空变化特征进行分析。结果如下:(1)1989~2011年,草洲面积增加30506 km2,泥滩地面积减少27428 km2,水域面积呈波动状态;(2)草洲的主要扩张区域为长洲、新生洲、飘尾洲沿湖盆边缘部分、牛头洲大面积区域、武光洲 柴下洲、中洲 团洲部分;(3)草洲面积按高程分布呈先增后减特征,草洲覆盖的优势区域与非优势区域的高程分界点逐渐降低,水域和泥滩地分布的优势区域高程范围缓慢下移。草洲植被的生长分布和淹水条件关系密切,泥沙淤积和水文条件的改变都能导致淹水条件的变化,进而推进东洞庭湖草洲范围的扩张。此研究对于进一步明确洞庭湖湿地演变趋势及其形成机制具有重要意义  相似文献   

3.
在系统分析淤泥质海岸围填海开发活动对海岸带资源影响的基础上,重点考虑岸滩冲淤变化特性、岸滩资源利用现状、利用潜力以及泥沙淤积对港口航道造成的资源损失,通过成本型、效益型两大类共16个指标,构建了适合淤泥质海岸资源状况评价的压力-状态-响应(PSR)模型,实现了围填海开发活动对海岸带资源影响的综合评估。利用该模型计算了江苏省南通市沿海的围填海活动对海岸带资源影响的评价系数,计算结果为0.596,表明南通当前的围填海开发活动已经对当地的海岸带资源造成了较大影响,在今后的沿海开发过程中,需要注重海岸带资源的节约与保护。  相似文献   

4.
东洞庭湖湿地景观变化研究   总被引:3,自引:0,他引:3  
在遥感和地理信息系统的支持下,对东洞庭湖1989和2001年两个时段的TM(ETM)卫星影像进行了遥感解译。应用景观生态学的理论和方法,对不同景观类型的斑块和面积大小、形状特征进行分析,计算了湿地景观多样性、优势度、均匀度、破碎度及斑块分形维数。定量分析和〖HJ〗研究了1989~2001年东洞庭湖湿地景观的动态变化,结果表明,由于泥沙淤积,东洞庭湖湿地的面积正在日益缩小,湿地景观多样性和均匀度下降,景观优势度和破碎化程度增加,说明东洞庭湖部分湿地景观逐渐从以小斑块、多种景观类型共同控制的景观格局向大斑块、类型较单一的景观格局演变。  相似文献   

5.
上海市滩涂湿地生态系统健康评价及成因分析   总被引:1,自引:0,他引:1  
上海沿江沿海地区是我国重要的滩涂湿地分布区,其滩涂湿地生态系统健康对上海乃至长三角地区的生态安全具有重要意义。基于“压力-状态-响应(PSR)”模型,构建了上海市滩涂湿地生态系统健康评价指标体系,采用熵权综合评价法对研究区域生态系统健康状况进行评价,并设定了相应的健康评价分级标准。结果表明:杭州湾北沿边滩、南汇边滩、浦东边滩、宝山边滩、长兴岛周缘边滩、横沙岛周缘边滩、崇明南滩、崇明北滩均处于亚健康状态;崇明西滩处于较健康状态;而崇明东滩和九段沙湿地处于健康状态。过度围垦、环境污染、互花米草(Spartina alterniflora Loisel)〖JP2〗入侵等胁迫因子是上海市滩涂湿地面临的主要压力。在多重胁迫因子作用下,近30 a〖JP〗来上海滩涂湿地面积锐减,生态系统结构改变,生态功能退化。应重点控制滩涂开发强度,减少污染物排放,并加强对上海市滩涂湿地尤其是大陆边滩的保护,以维护湿地生态系统健康,保障区域生态安全  相似文献   

6.
崇明东滩沿海湿地生态系统健康评价   总被引:1,自引:0,他引:1  
以生态系统健康及压力-状态-响应(PSR)模型作为研究方法,根据沿海湿地生态系统的特点,建立一套沿海湿地生态系统适用的健康评价指标体系。以现有研究数据和统计资料为基础,对长江口崇明东滩湿地进行单因子和综合评价,分别计算其健康度、压力综合指数和响应综合指数。揭示崇明东滩湿地的生态系统健康状况以及形成原因,并提出保护对策和可持续利用的相关建议。研究结果表明:①崇明东滩湿地生态系统的健康度、压力综合指数和响应综合指数分别为0.72、0.64和0.79,总体上仍处于一个较为健康的状态;②崇明东滩湿地生态系统目前的主要压力并不直接来源于土地围垦,而是来源于水环境污染和外来生物入侵。  相似文献   

7.
沉积物的粒级组成特征对于分析湿地沉积环境和搬运趋势有着重要意义。基于自然保护区沉积物样品,利用粒度分析、Shepard三角图、C-M图、端元分析和GSTA搬运趋势模型,研究分析了鄱阳湖南矶湿地沉积物的粒级组成特征、沉积类型、动力环境和泥沙搬运趋势。结果表明,鄱阳湖南矶湿地沉积物主要以细粉砂为主,平均值为55.35%。沉积物粒度参数中平均粒径均值为5.24Φ,空间分布上具有由西南至东北Φ值逐渐减小的趋势。沉积物质地类型主要为粉砂、粘土质粉砂、砂质粉砂和粉砂质砂,其中粉砂约占62.5%。端元分析的结果显示EM1和EM2可能与鄱阳湖本身湖流带来的沉积物搬运有关,EM3则指示了赣江泥沙来源,EM4可能与局地小环境的水动力变化有关。鄱阳湖南矶湿地沉积物粒径趋势格局以东部向西部、北部向南部最为显著,鄱阳湖南矶湿地是在赣江与鄱阳湖之间复杂交互作用下形成。  相似文献   

8.
洞庭湖主要生态环境问题变化分析   总被引:3,自引:0,他引:3  
通过对近几十年来洞庭湖水情、泥沙、污染和湿地生态等不同方面问题的回顾分析,认为在三峡工程建设、洞庭湖退田还湖和极端天气事件影响下,洞庭湖主要生态环境问题发生了一些变化。由于气候干旱化,加之三峡水库蓄水影响,导致洞庭湖入湖水量季节性减少,湖区水位下降,干旱期延长。模拟显示2006和2009年三峡秋季蓄水使洞庭湖出口水位平均下降2.03和2.11 m;由于三口来沙急剧减少,入湖泥沙打破了以淤积为主的模式,2006年洞庭湖第一次出现从拦蓄泥沙变成向长江净输出泥沙。低水位运行不仅对洲滩演进和湖泊水质带来影响,也加速了对湖滩的开发利用,外来物种的发展威胁了湖泊湿地生物多样性和动物栖息地的稳定。同时,湖区复合型水污染威胁加重,洞庭湖水质从2008年的Ⅳ类水下降为Ⅴ类水。洞庭湖在缺水与洪涝矛盾中,正从单一洪灾为主转向矛盾的两个方面共存。这些变化一方面与气候变化有关,也是流域生产由传统农业转向农、林、水、工的综合发展,以及湖泊与流域关系改变的结果。  相似文献   

9.
湿地是世界上最具生物多样性的重要生态系统之一,湿地资源开发利用的时空动态变化对物种生境、分布及多样性有着极其重要的影响。江苏盐城海滨湿地是全球丹顶鹤最重要的越冬地之一,湿地景观的变化势必会影响丹顶鹤生境结构及其质量。本研究以盐城海滨湿地带相对连续的16期遥感解译影像为空间数据源,分析了8个丹顶鹤越冬栖息热点地区的湿地资源利用以及丹顶鹤越冬生境及其质量的时空动态变化,利用逐步回归和典型相关等方法分析湿地资源利用变化对丹顶鹤生境的影响。结果显示:研究区自然湿地大面积地被转变成人工湿地以及非湿地,其主要变化特征是碱蓬、芦苇等自然湿地被围垦成耕地、水产养殖塘等人类活动强度较高的覆被类型;丹顶鹤适宜生境面积持续下降,补充生境及非生境面积都大幅度增加;综合生境因子在每个热点地区总体上呈现下降的趋势,热点地区丹顶鹤生境质量都呈现出分时段、不同程度的下降趋势;丹顶鹤生境质量受到多种覆被类型的综合影响,其中,芦苇湿地和碱蓬湿地对丹顶鹤各种生境因子都有显著影响,主要发挥改善和提高生境质量的作用;盐田、建筑用地和水产养殖塘所产生的干扰是不利于生境质量提高的覆被类型。研究分析表明:芦苇湿地和碱篷湿地作为丹顶鹤越冬最适宜生境,宜进一步加大保护力度;盐田和水产养殖塘等人工湿地作为补充生境,虽然在一定程度上为丹顶鹤提供了食物和水分,但其经营管理活动所产生的干扰则影响了生境质量,因而需减少其在越冬季节的干扰活动。  相似文献   

10.
江苏海岸带土地利用变化及驱动力分析   总被引:7,自引:0,他引:7  
通过对江苏海岸带近13a的土地利用变化和社会经济分析,得出:连云港海岸带以耕地、其他建设用地和农村居民点为主,占81%,海岸带开发程度高;斑块个数增加,景观破碎化增大。盐城以耕地、草地和其他建设用地为主,占77.45%,开发程度中等;耕地、水库坑塘等人工景观面积增大,适宜生物多样性保护的生境面积减少。南通海岸带以耕地和滩涂为主,占88.93%,但两者的面积都在下降;人工景观面积增加。人口增长的压力、政府政策的导向与社会经济的驱动是江苏沿海三市海岸带景观格局变化的主要驱动力。连云港海岸带人口密度增加了13.8%,第二产业产值增加了7.7倍,人类活动的干扰使海岸带破碎明显;盐城海岸带人均GDP增加了4倍,经济利益的驱使,使盐城丧失大面积的草地,海岸湿地遭到破坏;南通海岸带人口密度减小了2.0%,人均GDP增加了5.3倍,第三产业的发展对海岸带干扰较小,海岸带景观破碎度较低。  相似文献   

11.
China has approximately 5.80 × 106 ha coastal wetlands by 2014, accounting for 10.82% of the total area of natural wetlands. Healthy coastal wetland ecosystems play an important role in guaranteeing the territory ecological security and the sustainable development of coastal zone in China. In this paper, the natural geography and the past and present status of China's coastal wetlands were introduced and the five stages (1950s–1970s, 1980s–1991, 1992–2002, 2003–2010 and 2011–present) of China's coastal wetlands conservation from the foundation of the People's Republic in 1949 to present were distinguished and reviewed. Over the past decades, China has made great efforts in coastal wetland conservation, as signified by the implementation of coastal wetland restoration projects, the construction of coastal wetland nature reserves, the practice of routine ecological monitoring and two national wetland surveys, the promulgation of local wetland conservation statutes and specific regulations, the coordination mechanism to enhance management capacity, the wide development of coastal wetland research and public participation, and the extensive communication to strengthen international cooperation. Nonetheless, six major issues recently emerged in China's coastal wetland conservation are evidently existed, including the increasing threats of pollution and human activities, the increasing adverse effects of threaten factors on ecosystem function, the increasing threats of coastal erosion and sea-level rising, the insufficient funding for coastal wetlands conservation, the imperfect legal and management system for coastal wetlands, and the insufficient education, research and international cooperation. Although the threats and pressures on coastal wetlands conservation are still apparent, the future of China's coastal wetlands looks promising since the Chinese government understands that the sustainable development in coastal zone requires new attitudes, sound policies and concerted efforts at all levels. The major strategies for future improvement of China's coastal wetland conservation include: exploring effective measures in response to major threaten factors; improving the conservation and compensation system for coastal wetlands; strengthening coastal wetland legislation and management; increasing funds for coastal wetland conservation and research; and strengthening coastal wetland education and international cooperation.  相似文献   

12.
The influence of anthropogenic activities,especially artificial dykes,on the coastal wetland landscape is now considered as a serious problem to the coastal ecosystem.It is important and necessary to analyze changes of coastal landscape pattern under the influence of artificial dykes for the protection and management of coastal wetland.Our study aimed to reveal the quantitative characteristics of the coastal wetland landscape and its spatial-temporal dynamics under the influence of artificial dykes in the Yellow River delta(YRD).It was analyzed by the methods of the statistical analysis of landscape structure,five selected landscape indices and the changes of spatial centroids of three typical wetland types,including reed marshes,tidal fiats and aquaculture-salt fields.The results showed that:(1)Reduction of wetland area,especially the degradation of natural wetlands,had been the principal problem since the dykes were constructed in the YRD.The dykes created conditions for the development of artificial wetlands.However,the new born artificial wetlands were still less than the vanished natural wetlands.(2)Compared with the open area,the building of artificial dykes significantly speeded up the changes of landscape patterns and the aggravation of the landscape fragmentation in the closed area.(3)The changes of area-weighted centroids of three typical wetland landscapes were greatly affected by dykes,and the movement of the centroid of the aquaculture-salt field was very sensitive to the dykes constructed in the corresponding period.  相似文献   

13.
The idea that integration and synthesis are critical for designing climate change adaptation and mitigation is well entrenched conceptually. Here, we review the concepts of adaptation, synthesis and integration and apply them to the case study of coastal wetlands in South East Queensland, Australia. The distribution and condition of coastal wetlands will change as climate changes. This will create conservation challenges and economic costs, but these can be minimised by drawing from a broad sectoral perspective in undertaking adaptation planning and by ensuring integration into policy. Our review indicates that adaptations to sea level rise that are focussed on wetland and biodiversity conservation are likely to have impacts for urbanisation patterns. Planning regulations that provide spatial buffering around wetlands may give rise to more compact urban forms that may lead to reductions in the cost of defence against sea level rise, reduce energy usage per person and provide more green space. However, more compact urban forms could exacerbate heat island effects and place greater burden on the economically disadvantaged as, for example, single-family homes become more expensive. Planning for climate change needs to balance these equity and cross-sectoral issues in order to reduce the likelihood of unforeseen negative consequences.  相似文献   

14.
The Central Vietnamese coast faces increasing impacts on the local livelihoods of coastal communities as a result of the increasing natural hazards which include tropical storms, heavy rains, and floods. A challenge for the local populations is improving their adaptation capacity to climate change hazards in a sustainable way. This study deals with the impacts of climate change-associated hazards and adaptation capacity in coastal communes of the Ky Anh district, Ha Tinh province along the coast in Central Vietnam. A combination of the Stakeholder Delphi technique and the DPSIR (drivers–pressures–states–impacts–responses) framework was used. Delphi questionnaires allowed assessing the consensus among the respondents of a stakeholder group. Twenty questions and 20 statements were listed reflecting the DPSIR components. Thirty-six panel members, which were randomly selected from four stakeholder groups which included local authorities, farmers, fishermen, and fish traders, were involved in a two-round Delphi process. The results show that, both agricultural and non-agricultural sectors are main drivers (D); migration, calamities, population growth, mineral mining, aquaculture processing, and agriculture are main pressures (P); changes in the frequency of extreme weather events, increasing intensity of storms, floods, and droughts indicate main states (S); changes in agricultural land use and productivity are main impacts (I); construction of and upgrading dykes and irrigation systems should be the principal responses (R) in the vision of the local stakeholders. The Kendall’s W value for the second round is 0.681, indicating a high degree of consensus among the panel members and confidence in the ranks. Overall, the study advocates developing sustainable ecosystems, an upgraded New Rural Planning, and renewable energy strategies as the main local adaptations to climate change hazards in this area.  相似文献   

15.
江苏沿海滩涂地区农户经济行为研究   总被引:10,自引:0,他引:10  
江苏海岸带是中国最重要的海岸带湿地之一。滩涂资源的可持续利用成为当前研究的焦点。农户是滩涂开发的微观经济活动的主体和相对独立的生产单位。农户的经济行为对滩涂开发和利用产生直接和重要的影响。以江苏省盐城市的射阳县、大丰市为例,选择3个典型村庄进行入户访谈式调查.在对220个农户进行了入户随机抽样调查的基础上,利用区域经济动力学原理Logisti模型和Cobb-Douglas生产函数。建立了农户经济行为对环境影响的数量经济模型。研究表明,滩涂区农户经济行为对滩涂环境压力的大小及类型具有直接影响。土地经营规模、土地利用类型、生产投入、投资意向、农户受教育水平等是产生影响的主要因素。找出滩涂资源利用中存在的问题和主要的环境压力在于:农户经济生产方式单一,产业结构不合理;农户教育水平较低,环境意识差;滩涂利用经济效率低.环境压力大;农户抗市场风险能力差。并提出了相应的对策和建议。  相似文献   

16.
Coastal zones provide habitat cores and corridors that maintain the diversity of entire landscapes, and they can form the cornerstone elements of regional conservation strategies. Natural environmental driving factors and excessive anthropogenic activities play important roles in coastal wetland change. Many studies have used remote sensing images to map and assess coastal wetland change on local or regional scales. This paper aims to provide insight into coastal wetland change in the Yancheng National Nature Reserve (YNNR) using remote sensing technology and landscape metrics analysis. The results reveal that grass flat and reed areas have significantly decreased, whereas agriculture fields, aquaculture ponds and built-up areas have continuously increased from 1988 to 2006. The spatial pattern of the coastal landscape has become fragmented and heterogeneous under great pressure from rapid economic development and population growth. The wetland changes have important impacts on natural habitat of the red-crowned cranes. The results of this study provide basic information that is required for developing measures toward a sustainable management and conservation of the YNNR.  相似文献   

17.
Global degradation of coastal ecosystems is influencing the provision of ecosystem services, including fisheries maintenance services. Degradation of the Australian coastal zone and its resources following European occupation has been recognised for some time. This includes the loss of ecologically important coastal wetlands, which have strong trophic and habitat links to fisheries. In NSW, structural flood mitigation works are a principle driver of the decline of coastal wetlands; however, little action has been taken to quantify the extent of decline due to limited information of the pre-European settlement extent of coastal wetlands. We use spatial data sets in GIS to quantify prime fish habitat and calculate the loss of fish habitat for the large coastal floodplains of northern NSW, which are significant contributors to the commercial and recreational fisheries of NSW. The technique is validated by comparison with early maps of wetland distribution. We identified pre-European distribution of available fish habitat of approximately 477,000 ha, of which 87,000 ha was identified as prime fish habitat. Approximately 62,000 ha of prime fish habitat was impacted by drainage of the coastal floodplains in association with flood mitigation works which intensified in the mid-1950s and were largely completed by 1971, equating to a loss of approximately 72 % of prime fish habitat. The declining value of the ecosystem services provided by prime fish habitat following drainage is likely to be substantial. Some actions have taken place to restore the functions of this habitat although significant opportunities remain to reverse this decline through management actions that restore natural drainage and reinstate tidal exchange. These actions become even more important as pressures on coastal wetlands increase with climate change and associated sea-level rise.  相似文献   

18.
鄱阳湖湿地现状问题与未来趋势   总被引:1,自引:0,他引:1  
近年来鄱阳湖秋冬季水文呈干枯态势,湿地生态系统及其关键因子也发生了变化。如何合理保护和利用鄱阳湖湿地引起各方关注。系统综述了鄱阳湖湿地生态系统在水文、江湖关系、水质、水鸟栖息地、渔业资源等方面存在的问题,梳理了引起这些问题的外部和内部因素。针对"一切照常"和"水位调控"两种情景,预测了湿地未来的变化趋势,并指出了当前研究中的不确定性问题。研究认为:鄱阳湖秋冬季的低枯水位,对水质、湿地植被、水鸟栖息地以及鱼类食物资源和"三场"(即:产卵场、洄游通道、索饵场)产生了一定不利影响。建议通过模型模拟和情景预测来分析不同调控方案的影响效果,优化调控方案、将生态系统的负面影响降到最低。  相似文献   

19.
在滨海湿地生态系统服务价值评价中,能值方法克服了传统经济学方法的一些不足,对评价沿海地区发展的可持续性具有重要意义,并成为近十年来环境经济学和生态经济学研究的热点问题。综合国内外滨海湿地生态系统服务价值能值评价的研究进展,就滨海湿地生态系统的供给、调节、文化和支持服务价值的能值估算方法进行了分析。在此基础上,指出了目前该方法应用于滨海湿地生态系统服务价值评价主要存在能值转换率的选用不一致、生态系统服务价值的能值估算方法需要完善、能值分析所应用的滨海湿地类型较少、缺少对人类活动引起的生态系统服务能值变化的评价及检验评价结论正确性的标准等不足,并提出了进一步的研究方向。  相似文献   

20.
To address the growing need for developable land, many coastal cities are draining and filling wetlands, transforming them into urban built-up areas, and thereby substantially altering the structure and function of coastal ecosystems. We demonstrate an integrative approach for investigating the dynamics and impacts of coastal development in China’s Jiangsu Province, where urban expansion has resulted in extensive wetland losses and sea reclamation (the process of creating new land from ocean or coastal waters). Remotely sensed data reveal that landscape change in the study area has been accompanied by an increase in total impervious surface area and an increase in mean surface “heat island effect.” These indicators of change can be detected with remote sensing data and used to support a strategic environmental assessment (SEA) for urban coastal planning. Changes detected in Lianyungang during 2000–2006 suggest that reclaimed areas are environmentally sensitive and should be a focus of concern in future development planning, which has historically targeted coastal salt pond wetlands for conversion to land for the development. Given the current and projected rate of coastal development in China and elsewhere in the developing world, our findings and assessment approach have implications for coastal management decisions in the developing coastal zones of China and other regions of the world that are experiencing rapid urban growth.  相似文献   

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