基于景观格局指数的基本农田保护区集中连片性研究——以济南市历城区为例   总被引：1，自引：0，他引：1       下载免费PDF全文

张保华  王雷  白振华  潘庆龙  汤庆新  肖燕 《山东国土资源》2014,30(2):80-82

耕地与基本农田保护是我国土地管理、土地利用规划的重要内容。新一轮土地利用总体规划修编及数据库建设中要求基本农田调整布局更加集中连片。该文应用景观格局指数,研究了济南市历城区基本农田保护区规划调整中集中连片性的变化。结果表明,除保护区图斑面积标准差外,图斑平均面积、图斑面积变异系数、图斑边界密度、最大斑块指数、平均欧式邻近距离5项指标均表明,规划调整后基本农田保护区布局上更加集中连片。为基本农田保护区布局的集中连片性判断提供了简便易行的方法。  相似文献   

利用生产动态及地震资料分析井间河流相砂体连通性     

王海更  汪利兵  刘洪杰  刘建华  刘卫林  申春生 《海洋地质译丛》2014,(3):66-71

渤海PL油田是位于渤海湾盆地的大型河流相油田,在其注水开发过程中,亟需准确认识注水井与生产井之间的砂体连通性,以便优化和调整注采井网,提高采收率.针对油田砂体横向变化快,纵向上薄砂体发育的特点,利用丰富的压力、水淹等生产动态资料及相位转换后赋予地质意义的地震资料综合分析砂体的连通性,进一步完善和修正了早期以地质及测井资料确定的砂体连通性分析成果,并引入注采连通率概念,用来定量表示井组范围内注水井与生产井之间的砂体的连通性.该套方法在PL油田注水优化及井网调整研究中得到了充分的体现,对其它河流相注水开发油田井组范围内井间砂体连通性研究具有一定的借鉴作用.  相似文献   

Effects of corridor networks on plant species composition and diversity in an intensive agriculture landscape     

Qian Tang  Guofu Liang  Xunling Lu  Shengyan Ding 《中国地理科学(英文版)》2014,24(1):93-103

The development of modern agriculture has resulted in much homogenization of the landscape consisting of large patches of farmland,so small remnant non-crop habitats especially linear corridors play an important role in the conservation of species and the maintenance of ecosystem functions.However,little attention has been paid to the effects of corridors structural characteristics on the plant species restricted to such habitats.In this study,we selected three types of corridors including ditch,hedgerow and road,and ana-lyzed their structural characteristics.The plant species presented in these corridors were investigated,and the species diversity,abun-dance and frequency were estimated.Moreover,spatial arrangements of corridors were classified into different types to discuss whether there were significant effects of corridor network on plant distribution.The results show that three types of corridors have different ef-fects on plant species composition and diversity.The one-one combined corridor networks and total network associated by three corri-dors have more complex structural features than each single type of corridor.However,there is no strong correlation between the corri-dor networks with their plant species.We suggest that carrying out a pointed vegetation survey at corridor intersections to further test the relationships between structural features of corridor and plants is necessary.  相似文献   

Species distribution and diversity,habitat selection and connectivity: introduction to the Third Special Issue on Spatial Ecology     

Shawn William Laffan  Andrew K. Skidmore  Janet Franklin 《International journal of geographical information science》2014,28(8):1527-1530

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Go with the flow: geospatial analytics to quantify hydrologic landscape connectivity for passively dispersed microorganisms     

Alexander Hohl  Ross K. Meentemeyer 《International journal of geographical information science》2014,28(8):1626-1641

Understanding the diverse ways that landscape connectivity influences the distribution of microbial species is central to managing the spread and persistence of numerous biological invasions. Here, we use geospatial analytics to examine the degree to which the hydrologic connectivity of landscapes influences the transport of passively dispersed microbes, using the invasive plant pathogen Phytophthora ramorum as a case study. Pathogen occurrence was analyzed at 280 stream baiting stations across a range of watersheds – exposed to variable inoculum pressure – in California over a 7-year period (2004–2010). Using logistic regression, we modeled the probability of pathogen occurrence at a baiting station based on nine environmental variables. We developed a novel geospatial approach to quantify the hydrologic connectivity of host vegetation and inoculum pressure derived from least cost distance analyses in each watershed. We also examined the influence of local environmental conditions within the immediate neighborhood of a baiting station. Over the course of the sampling period, the pathogen was detected at 67 baiting stations associated with coastal watersheds with mild climate conditions, steep slopes, and higher levels of inoculum pressure. At the watershed scale, hydrologic landscape connectivity was a key predictor of pathogen occurrence in streams after accounting for variation in climate and exposure to inoculum. This study illustrates a geospatial approach to modeling the degree to which hydrologic systems play a role in shaping landscape structures conducive for the transport of passively dispersed microbes in heterogeneous watersheds.  相似文献   

基于人工降雨模拟试验的坡面水文连通性   总被引：8，自引：0，他引：8       下载免费PDF全文

王盛萍  姚安坤  赵小婵 《水科学进展》2014,25(4):526-533

为揭示降水入渗时坡面水文连通性特征以及坡度和雨强等对水文连通性的影响,研究基于人工降雨模拟试验,分别采用结构性指标径流长度（Flowlength,l_F）和功能性指标相对地表连接函数（Relative Surface Connection Function, F_RC）分析不同坡度坡面（5°、15°、25°;面积为150 cm×50 cm）在不同雨强（25 mm/h、50 mm/h、70 mm/h和86 mm/h）条件下的水文连通性。研究结果表明:坡面水文连通结构主要由l_F为0~100 mm的径流路径组成,其栅格频率高达90%以上,而l_F为100~500 mm的栅格频率为3%~8%。水文连通性的迅速发展主要集中在降水事件的开始阶段,而一定阶段以后入渗速率与地表储水速率基本持平,水文连通性呈现出较为稳定的发展趋势。坡度增大整体上有利于水文连通性的发展。5°坡面对应水文连通面积比率整体小于其他坡度。由于雨强增大到一定范围时将增加地表糙率,从而阻碍水文连通性的发展,研究中仅25 mm/h对应水文连通性明显区别于其他雨强,而其他雨强间则在多数情况下水文连通性差别较小。  相似文献   

沉积岩平行层面与垂直层面方向热导率与孔隙连通性之间的关系     

龚建洛  张金功  惠涛  黄传卿  张林晔  孙志刚  陈晓军 《吉林大学学报(地球科学版)》2014,(6):1789-1797

根据对渤海湾盆地沾化凹陷泥质岩、粉砂岩、砂岩和白云岩平行层面与垂直层面方向热导率差异及孔隙连通性差异特征的研究,探讨了沉积岩平行层面与垂直层面方向热导率与孔隙连通性之间的关系。热导率实验结果表明:沾化凹陷泥质岩、粉砂岩和砂岩的平行层面方向热导率大于垂直层面方向热导率;白云岩的平行层面方向热导率小于垂直层面方向热导率。沉积岩平行层面与垂直层面方向热导率差异和孔隙连通性差异之间具有正相关性。孔隙特征分析结果表明:孔隙连通性较好方向,热导率也较高;孔隙连通性较差的的方向,热导率也较低。  相似文献   

半封闭海域生态修复策略研究——以渤海为例          下载免费PDF全文

张少春  宋静静  刘凯凯  于道德  李友训  马健  李彬  王先磊 《海洋开发与管理》2022,39(9):3-10

渤海作为我国唯一的半封闭型海域,是京津冀城市群蓬勃发展的战略支撑和关键依托,其生态环境的稳定与沿岸人类福祉息息相关,其生态环境修复是近年来该领域的研究热点。文章重点围绕全球气候变化和人类活动对渤海生态环境的影响进行了剖析,通过综合对比分析国内外其他类似水域或地区的生态修复既有成果,立足渤海水域特点和现状,提出动态思维与整体保护原则、生境连通性修复原则、不同时空尺度修复原则等生态修复原则,并指出渤海生态修复需理性规划渔业经济活动,统筹考虑渤海生态与冲淡水之间的关系,建议运用前瞻性的思维模式和理念,合理预测、规划、定位、配置、实施和维护渤海生态系统的稳定,重点探索应对全球气候变化的最佳适应性管理策略。  相似文献   

The role of perched aquifers in hydrological connectivity and biogeochemical processes in vernal pool landscapes,Central Valley,California     

Mark Cable Rains  Graham E. Fogg  Thomas Harter  Randy A. Dahlgren  Robert J. Williamson 《水文研究》2006,20(5):1157-1175

Relatively little is known about the role of perched aquifers in hydrological, biogeochemical, and biological processes of vernal pool landscapes. The objectives of this study are to introduce a perched aquifer concept for vernal pool formation and maintenance and to examine the resulting hydrological and biogeochemical phenomena in a representative catchment with three vernal pools connected to one another and to a seasonal stream by swales. A combined hydrometric and geochemical approach was used. Annual rainfall infiltrated but perched on a claypan/duripan, and this perched groundwater flowed downgradient toward the seasonal stream. The upper layer of soil above the claypan/duripan is ～0·6 m in thickness in the uplands and ～0·1 m in thickness in the vernal pools. Some groundwater flowed through the vernal pools when heads in the perched aquifer exceeded ～0·1 m above the claypan/duripan. Perched groundwater discharge accounted for 30–60% of the inflow to the vernal pools during and immediately following storm events. However, most perched groundwater flowed under or around the vernal pools or was recharged by annual rainfall downgradient of the vernal pools. Most of the perched groundwater was discharged to the outlet swale immediately upgradient of the seasonal stream, and most water discharging from the outlet swale to the seasonal stream was perched groundwater that had not flowed through the vernal pools. Therefore, nitrate‐nitrogen concentrations were lower (e.g. 0·17 to 0·39 mg l^?1) and dissolved organic carbon concentrations were higher (e.g. 5·97 to 3·24 mg l^?1) in vernal pool water than in outlet swale water discharging to the seasonal stream. Though the uplands, vernal pools, and seasonal stream are part of a single surface‐water and perched groundwater system, the vernal pools apparently play a limited role in controlling landscape‐scale water quality. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

Functional analysis of landscape connectivity at the landscape,component, and patch levels: A case study of Minqing County,Fuzhou City,China     

《Applied geography (Sevenoaks, England)》2017

Maintaining forest landscape connectivity is one of the most effective ways to alleviate natural forest fragmentation and biodiversity loss problems. Recently, graph theory based metrics have been used as powerful tools in the assessment of landscape connectivity. However, the functional features of landscape units at different structure levels, based on which outcomes can be enriched and advice can be given for practical applications, have been overlooked. In this study, a series of graph-based connectivity indices was calculated to 1) evaluate the optimal threshold distance, 2) identify the key landscape units at the component and patch levels, and 3) classify the functional types of components and patches and analyze functional patterns at different structural levels. The relationship between patch size and patch functional performance in maintaining landscape connectivity was discussed. With a natural forest area in Minqing County of China as the study area, recommendations regarding forest conservation and connectivity enhancement were provided based on the research conclusions. This study provides a way to comprehensively analyze habitat fragmentation and functional patterns for local forest conservation.  相似文献