An assessment of land cover change as a source of information for conservation planning in the Vhembe Biosphere Reserve     

《Applied geography (Sevenoaks, England)》2017

Determining changes in land use/land cover (LULCC) can be used to assess and monitor habitat loss as one of the five global priority causes of biodiversity loss. In South Africa, two national land-cover (NLC) datasets have been developed from satellite imagery obtained in circa 1990 and 2013/2014. The Vhembe Biosphere Reserve (VBR), designated in 2009, is located in the north of the Limpopo Province in South Africa and has a surface area of 30,457 km². The aim of biosphere reserves is to provide a landscape-scale framework for conservation and sustainable development of an area. The area within a biosphere reserve is prioritised by designating it into one of three zones 1) Core, 2) Buffer, and 3) Transitional Zones. Two national parks and six provincial reserves (PAs) are the current and form part of the proposed updated core areas (pCAs) of the VBR. Intensity analyses was used to assess LULCC in the VBR. The pCAs cover 39.7% of the surface area of the VBR. The PAs cover 39.7% and only 15.8% of the surface area of the pCAs and VBR respectively. Based on the NLC 2013/2014 a majority of the VBR, pCAs and PAs consisted of indigenous vegetation dominated by Woodland/Open bush, Grassland, and Thicket/Dense bush. The extent of transformed land in the VBR declined from 1990 to 2013 by 1697.7 km². The total amount of change and mean annual change in the VBR was 53.1% and 2.31% respectively. The overexploitation of fuel wood by rural communities in rural areas of the VBR, was partly responsible for the targeted loss of Woodland/Open bush to Thicket/Dense bush and Grasslands. The unquantified presence of novel vegetation and alien invasive plants means that the NLC 1990 and 2013/2014 overestimates the quantity and distribution of the remaining indigenous vegetation in the VBR. In order to address this the distribution of alien and indigenous invasive plant species in the VBR needs to be determined and used to update future NLCs. Assuming a worse-case-scenario of all the coal deposits in the VBR, including the Kruger National Park, being mined it would amount to 24.7% of the surface area of the VBR. Only 6.8% of the area of all the coal deposits in the VBR was transformed with 93.2% currently remaining untransformed. It is recommended that transformation of indigenous vegetation to one of the seven transformed land cover categories and more specifically from coal mining should be restricted to the VBR's Transition Zones.  相似文献   

生态保护红线成效评估框架与指标方法   总被引：1，自引：0，他引：1  

侯鹏  王桥  杨旻  李静  翟俊  蔡明勇 《地理研究》2018,37(10):1927-1937

生态保护红线是在自然保护区、重点生态功能区、风景名胜区、森林公园等诸多区域生态管理制度不断实践基础上,面对中国国土开发和生态保护的复杂关系,继承和创新提出的一种新型区域生态管控制度,已经成为推动国家生态文明建设的重大战略。如何科学评估生态保护红线保护成效,服务于生态保护红线综合管理和保障区域生态安全,成为普遍关注的热点问题之一。针对已有的区域生态保护成效评估案例的不足,基于划定生态保护红线是为保障国家和区域生态安全的基本认知,围绕着生态保护红线“生态功能不降低、面积不减少、性质不改变”的管控目标,以生态保护红线对区域生态系统保护作用为主要出发点,提出生态保护成效评估框架和指标方法。生态保护成效评估以生态系统类型构成和生态系统服务功能为内容主线,通过多维度时空尺度拓展,耦合分析生态保护红线内外、实施前后的生态状况变化,综合评估生态保护红线对保障区域生态安全的贡献和改善区域生态状况的作用。进而,可以关联分析可能引起生态保护红线生态状况变化的管控政策、制度和其他间接驱动因素,评估政策实施成效评估。实证上选择海南省生态保护红线和广东省严格控制区为案例进行了讨论。  相似文献   

北京石花洞地质遗迹环境和地质灾害问题     

王海芝  任凯珍 《城市地质》2008,3(4):22-25

通过北京石花洞地质遗迹保护区实地调查和有关资料分析,提出了保护区的环境问题和治理建议。  相似文献   

中国东中西部城市土地储备决策绩效比较研究     

王振坡  翟婧彤  郑丹 《地域研究与开发》2016,(4):120-125

运用数据包络分析(DEA)模型,对2013年中国内地34个大中城市土地储备决策绩效进行总体评价和比较分析。研究结果表明:东部地区城市土地储备决策效率最高,西部次之,中部最低;土地储备决策效率受到纯技术效率和规模效率的共同作用,且规模效率作用较大;影响东中西部城市土地储备决策效率投入产出的主要因素各不相同。基于此,从深化土地及相关制度改革和提升政府管理效率两个层面提出土地储备决策绩效优化策略,从而提高土地资源利用效率、优化城市空间结构。  相似文献   

An Analysis of the Coastal Fish Assemblage of the Ustica Island Marine Reserve (Mediterranean Sea)   总被引：2，自引：0，他引：2  

Gabriele La Mesa  &Marino Vacchi 《Marine Ecology》1999,20(2):147-165

A study of the coastal fish assemblages in the marine park of Ustica Island (Southern Tyrrhenian Sea, Mediterranean) was conducted from June 1994 to September 1995 and from June 1996 to September 1997. The principal aims of the research were to: (1) define the faunistic features of local fish communities; (2) assess the effectiveness of the protection regime of the marine park on the fish assemblages ('reserve effect'); (3) provide information on the distribution of some Epinephelus and Diplodus species in the shallowest depth zone of the island. During seasonal surveys, underwater visual censuses were carried out at several sites located in three zones of the island, each with a different level of protection. Observations were made along 250 m² transects at 3–5, 10–15 and 25–30 m depth ranges. Additional surveys were made by SCUBA diving and snorkelling. A statistically significant effect of depth on the fish community parameters was observed, whereas differences linked to protection level, zones, sites and seasons were not significant. The abundance and frequency of occurrence of some species, particularly dusky grouper Epinephelus marginatus , were positively correlated with the degree of protection of the different zones of the marine park. Certain sites of the island are important as nursery areas for three species of the genus Diplodus ( i.e., D. puntazzo, D. sargus and D. vulgaris ).  相似文献   

成矿系统的结构与聚矿功能   总被引：8，自引：1，他引：7  

李人澍  朱华平 《地学前缘》1999,6(1):103-113

成矿系统结构对成矿动力学条件的约束与促进,引起系统固有聚矿功能的巨大变异。成矿系统动力学包括：系统运转的动力组合、系统物质运动总方向和轨迹、矿质活动空间规模形态及单位空间中成矿微过程的频度。系统结构定性分析表明：系统结构的完善程度和成矿动力学条件的优劣与系统聚矿功能的强度正相关。系统结构完善程度可由结构紧致度（Ｉ）表征,系统聚矿功能可用标准富集量（Ｑｓ）反映,它是矿床储量（Ｑ０）经成矿难度系数（Ｃ）变换的归一化指标。经结构定性半定量分析,对成矿系统聚矿功能作出初步排序,具强烈非线性成矿特征的花岗岩浆成矿系统和环流热液成矿系统的聚矿功能最高  相似文献   

A CASE STUDY OF SEDIMENT IMPACT ON THE ECOSYSTEM     

QIN Huapeng  LIANG Lin  NI Jinren  LI Yitian 《国际泥沙研究》1999,(2)

IINTRODUCTIONInthepast,thesedimenttransportisconsideredinmostengineeringproblemsbecauseofitssignificanteffectonreservoir,navigation,floo'dingcontrolandstabilityofcoastallines(Xuetal.,1992;Heetal.,1997).Inrecentyears,impactsofsedimentontheecologicalhabitatshavebeennotedbymanyenvironmentalists(Klaus,1997).Itseemsthattheconceptofsedimenthazardsorsedimentimpactsmustbeextendedandtheenvironmentalorecologicalimpactmustbeincludedinanycomprehensiveassessment.Forexample,thelarge-scaleconstructiono…  相似文献   

大陈洋产卵场保护区综合健康状况评价          下载免费PDF全文

刘明智  蒋日进  杨凡  印瑞  朱帅麟  张洪亮  李振华  张亚洲  王忠明  李鹏飞 《海洋与湖沼》2023,54(1):303-311

产卵场保护区建立是养护渔业资源和渔业可持续发展的重要方式,为验证大陈洋产卵场保护区建立的效果,以大陈洋产卵场保护区为研究区域,基于层次分析法(analytic hierarchy process),以2018年春(4月)、秋(11月)两季渔业资源和环境调查数据为依据,从产卵场保护区的环境和生态(一级指标)角度考虑,建立以污染物、水质、群落结构、资源密度等7个二级指标和26个三级指标的评价体系,通过综合健康评价指数(comprehensive health indicator,Ic,h),表征大陈洋产卵场保护区健康状况,并利用2021年春(4月)、秋(11月)两季渔业资源调查数据与保护区建立初期渔业资源情况进行对比。结果显示:2018年大陈洋产卵场保护区春季和秋季Ic,h分别为0.514和0.511,均处于亚健康状态。虽然保护区内环境状况优良,但保护区内生物多样性低,资源密度和资源补充群体数量不足,这表明大陈洋产卵场保护区渔业资源情况不容乐观。经过一段时间的恢复,保护区内渔业资源情况略有所好转,说明保护区的设立有一定的效果。综合健康评价体系在一定程度上客观地反映了大陈洋产卵场保护区健康状...  相似文献   

浅析四川省金矿床资源储量概况及成矿类型     

宋元宝  杨怀超  白富政  张伟  牟昀屹  侯从强  杨志军  王丹 《四川地质学报》2020,40(1):56-59,63

四川省岩金矿主要分布于阿坝州北部-东部及甘孜州和凉山州-盆地西部地区,其次是广元市-绵阳市西北部的"金三角"地区的分布特征。通过研究和归纳,本文将矿床类型归纳为11个三级亚类,并根据该11个类型对矿床规模进行统计,得出了数量上四川省以岩浆热液型金矿为主,其次为砂矿性金矿为主,再次为海相火山岩型金矿的结论。在此基础上,对四川省的金矿勘查工作程度、开发利用情况进行了评述,希望能够起到抛砖引玉作用,为省内金矿的勘查开发利用及找矿提供一定思路。  相似文献   

多层构造油藏纵向细分计算单元对储量参数及结果的影响     

颜冠山  刘宗宾  宋洪亮  韩雪芳  王欣然 《地质与资源》2020,29(4):342-350

为满足油田中后期精细开发及后续调整挖潜的需要,亟需进行更精细的储量研究,其中最重要的一环就是纵向细分计算单元.对于多层构造油藏,纵向细分主要根据油层组内隔夹层分布特征、小层物性特征,细分到以小层或者分布特征和物性相近且纵向上连续分布的小层组合为计算单元.根据纵向细分计算单元前后储量参数选值的理论推导,结合储层的沉积展布特征,认为含油面积范围内无储层尖灭时,仅平面油层厚度差异较大的油藏平均有效厚度变小.含油面积范围内储层尖灭时,正常三角洲沉积储层的油藏各参数一般都变小;而辫状河三角洲沉积储层的油藏一般平均有效厚度变小,平均有效孔隙度和平均含油饱和度变大.这一结论可以有效指导储量评估过程中纵向细分计算单元方案划分,为同类油田的精细储量研究提供技术支撑.  相似文献