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1.
伊洛河流域典型地区森林景观格局动态   总被引:28,自引:1,他引:27  
以野外调查资料和1983~1999年森林资源分布图为主要信息源,用ARC/INFO作为空间信息处理工具,采用斑块数、平均斑块面积、破碎化指数、斑块伸长指数、分数维、稳定度等指标分析了近20年来伊洛河流域中部典型地区的森林景观格局动态。结果表明,(1) 研究区内森林总面积在增加,斑块数量迅速增大,由556块增至1 494块。其中以刺槐林、经济林和杨树林斑块数量增加最多。景观破碎化程度明显加大。(2) 森林景观要素中灌木林、刺槐林、经济林、杨树林、栎林等斑块的面积有所增加,而非林地、荒草地、疏林、油松林等斑块的面积有所减小;除杨树林外,各森林类型斑块的平均面积都在减小。 (3) 研究区内沟谷植被覆盖面积共减少了220 827.9 hm2;丘陵森林覆被面积由1983年的161 870.4 hm2增加到1999年的312 599.7 hm2,增加了93.1%;斑块数目由79块增加到758块,增加了860%。而丘陵地区斑块平均面积却大大减小;山地森林覆被面积有所减少,由1983年的375 348.6 hm2减小到1999年的338 733.9 hm2,而斑块数却大幅度增加,由1983年的432块增加到1999年的1 127块,增加了695块。(4) 研究区南北山坡森林景观格局变化明显不同,这与南北坡土地类型不同、人类活动方式不同和地形地势的差别有关。  相似文献   

2.
伊洛河流域森林景观变化驱动因素   总被引:2,自引:1,他引:1  
1 Introduction Landscapes are the outcome of the interaction between socio-economic and natural forces (Wrbka et al., 2004). During the evolution of cultural landscapes throughout the world, human activities have become dominant factors shaping most lands…  相似文献   

3.
地理环境因素对伊洛河流域森林景观的影响   总被引:11,自引:2,他引:9  
丁圣彦  梁国付 《地理研究》2007,26(5):906-915
地理环境因素是引起区域森林景观动态变化的主要原因。运用景观生态学的基本原理,借助于地理信息系统技术,分析了自1983年以来伊洛河流域洛宁县森林景观的动态变化。结果显示,森林景观类型总面积呈增加趋势,从1983年的960.34km2增加到1999年的1175.00km2。景观空间动态变化上,森林景观类型转化为非森林景观类型部分主要位于海拔500~1000m的低山区,海拔大于1000m的地区森林景观类型变化较小,而非森林景观类型转化为森林景观类型主要集中在海拔高度小于500m的塬陵区和川涧区。通过建立森林景观类型动态变化与相应高程、坡度、距离居民点中心的远近和与森林边缘距离之间的相互关系,分析了与上述地理环境因素之间的相关性,表明森林景观类型动态变化与上述地理环境因素之间有显著相关关系。  相似文献   

4.
朱磊  刘雅轩 《干旱区地理》2013,36(5):946-954
近几十年来,玛纳斯河流域以耕地面积过度扩张、山区林地与草地退化为代表的一系列不可持续的发展方式已对区域生态安全和土地可持续利用构成了威胁。通过利用遥感影像与GIS方法,以沙湾县和农八师垦区为研究区,定量评价了区域土地利用的空间适宜性,并将其与国家退耕还林还草政策作为主要约束条件,建立元胞自动机模型对研究区景观格局进行了空间优化。结果表明:(1)1976-2012年,研究区耕地面积显著扩张,增加的耕地主要由未利用地、草地和林地转换而来;林地面积净减少幅度达65.90%,转出林地中有58.33%转换为耕地;草地净面积在研究时段内虽略有增加,但仍有6.352×104 hm2的草地转换为耕地,占草地转出总面积的66.03%;(2)耕地、林地和草地适宜性等级处于I级(很适宜)和Ⅱ级(适宜)的面积分别占研究区总面积的79.74%、70.23%和59.82%;(3)优化后,区域内耕地、林地和草地三者的比例由原来的6.04∶0.39∶3.57调整为4.03∶0.99∶4.98。优化结果在一定程度上减缓了耕地的扩张,提高了林地、草地所占比例,有利于该区域绿洲生态系统的稳定性和社会经济可持续发展。  相似文献   

5.
近20年来淇澳岛红树林湿地景观格局分析   总被引:11,自引:2,他引:11  
该文分析近20a来淇澳岛红树林湿地景观格局演变,采用遥感和GIS相结合的方法,利用遥感图像处理软件ERDAS对3个时相(1988年、1995年、2002年)的Landsat TM遥感图像应用专家系统方法分类;结合ARCGIS8.1,辅助FRAGSTATS3.01景观软件计算斑块和类型水平上的景观格局指数。淇澳岛红树林面积呈上升趋势,1988年、1995年和2002年分别为20.16hm^2、28.08hm^2、57.96hm^2;斑块数目从1988年的1个增加到2002年的18个,总斑块密度、平均斑块周长面积比呈上升趋势;平均斑块大小、平均斑块分维数、平均斑块形状指数呈下降趋势。近20a来淇澳岛红树林湿地景观受人为干扰,景观破碎化程度不断扩大,需对湿地多功能景观进行科学调控。  相似文献   

6.
近20年来河南沿黄湿地景观格局演化   总被引:54,自引:7,他引:54  
丁圣彦  梁国付 《地理学报》2004,59(5):653-661
在遥感和GIS技术的支持下,结合河南沿黄湿地的区域特点,确定了河南沿黄湿地景观分类系统,通过采用景观多样性指数、优势度、景观破碎化指数、分布质心和扩展度等景观的空间格局指数,比较系统地分析了近20年河南沿黄湿地景观空间格局变化。结果表明:(1) 河南沿黄湿地的分布面积呈显著下降趋势。1987~2002年湿地面积减少了19.18 %,斑块数量增加了21.27 %,斑块密度净增加0.5倍。斑块总边缘增加了129 0491 m,斑块平均边缘减少了117.84 m。(2) 随着人类干扰强度增加,景观多样性下降,优势度增高。研究区景观多样性指数1987年为1.174,2002年降为0.9803,优势度指数由1987年的0.4355提高到2002年的0.6291。湿地的破碎化程度随着湿地面积的减小和斑块数量的增加,其破碎化程度越来越大,破碎化指数由1987年的0.0141增加到2002年的0.0172。(3) 湿地景观要素中,稻田湿地面积在增加,而水库坑塘、河流、滩地、荒草沼泽地面积都在不断减少,其中荒草沼泽 (芦苇沼泽) 湿地面积减少幅度最大。1987年荒草沼泽湿地占整个湿地地区的0.5%,但到2002年只占0.11%。表明近20年来,人类活动对河南沿黄湿地景观格局变化的影响程度较大。  相似文献   

7.
近20年来中国能源消费碳排放时空格局动态   总被引:2,自引:3,他引:2  
CO2等温室气体引起的全球气候变暖是对人类社会可持续发展的严峻挑战。基于IPCC提供的参考方法,在对中国大陆30个省区(不含西藏)能源消费碳排放量估算的基础上,运用ESTDA框架,通过ESDA、LISA时间路径、时空跃迁和标准差椭圆等方法,从时空耦合的角度分析了1995-2014年中国能源消费碳排放时空格局动态性。结果表明:①近20年来中国省域碳排放具有显著的空间正相关性,碳排放空间差异呈先缩小后扩大的趋势;②LISA时间路径分析显示,中国大部分省区的局部空间结构具有较强的稳定性,1995-2001年和2002-2014年2个时段相对长度都小于平均长度的省区均为18个,大部分南方省区在空间依赖方向上的波动性呈增强趋势,而北方大多数省区则保持相对稳定;③出现协同运动的省区由1995-2001年的13个下降到2002-2014年的10个,表明中国碳排放空间格局具有一定的空间整合性,但呈减弱趋势;④中国省域碳排放的局部空间关联模式和集聚特征具有较强的稳定性,表现为一定的路径依赖或空间锁定特征;⑤碳排放重心在113.739°~114.324°E、34.475°~35.036°N之间变动,整体上有向西北方向移动的趋势。中国碳排放空间分布呈东北—西南格局,且有逐步向正北—正南转变的趋势。中国碳减排的重点是加快发展清洁能源与提高能效并重,优化能源结构和促进各省区产业结构转型,制定差异化的省域碳减排政策,建立碳交易制度。  相似文献   

8.
近20年来湖南公路网络优化与空间格局演变   总被引:3,自引:2,他引:3  
张兵  金凤君  于良 《地理研究》2007,26(4):712-722
基于最短路径模型,以经济权重可达性和经济潜力指数为主要指标,对近20年湖南公路网络演化和空间格局进行分析。结果表明:1984~2004年,湖南公路网络通达性呈现以长株潭为核心的同心圈层结构,呈现"中心-外围"向外递减,到2004年等值线密度趋于平缓,显示以长株潭为强极,外围湘北(岳阳)、湘南(郴州)为次极和湘西(怀化和吉首)为弱极的空间结构;20年来,湖南省内部可达性绝对差距逐步缩小,相对差距逐步加大,经济发展潜力以长株潭为核心沿主要交通轴线呈指状递减。可达性和经济结构相关分析表明,湖南空间结构由1980年代的低级无序状态变为2004年的多核不均衡集聚扩散状态,未来需要大力优化湘西地区可达性和加快经济的发展,促进空间格局向均衡有序的方向发展。  相似文献   

9.
近15年来长江黄河源区的土地覆被变化   总被引:60,自引:3,他引:60  
基于长江黄河源区土地生态分类,利用1986年与2000年两期TM遥感数据的对比和野外实地调查,采用景观生态空间分布格局分析方法,从分布面积变化和类型转移趋向与幅度两方面,分析了江河源区近15年来土地生态系统的空间分布变化与演变格局,结果表明:高寒草地退化显著,较高覆盖度高寒草原与高寒草甸面积减少了15.82% 和5.15%,高寒沼泽草甸分布面积锐减了24.36%;湖泊水域萎缩了7.5%,以长江源区内流湖泊为主;土地荒漠化发展十分强烈,沙漠化土地面积扩展了17.11%,其中黄河源区沙漠化土地年平均扩展率达到1.83%。高寒草原草地的覆盖度下降与荒漠化、高寒草甸草地的覆盖度下降与草原化以及沼泽草甸草地的疏干旱化是区域土地生态系统空间演变的主要趋向,并由此改变了土地覆被的空间分布格局并使该区域生态环境持续恶化。  相似文献   

10.
近300年来中国人口变化及时空分布格局   总被引:2,自引:1,他引:2  
潘倩  金晓斌  周寅康 《地理研究》2013,32(7):1291-1302
基于人口地理学相关理论,以近300a 为时间尺度,以省域为空间单元,利用经修正的清朝、民国及建国后286 个时相的人口数据,建立1724 年、1767 年、1812 年、1855 年、1898年、1936 年、1982 年和2009 年8 个典型时间断面,通过不均衡指数、集中指数、分布重心和空间自相关等分析方法,研究了近300a 来中国人口数量变化及时空分布格局。结果表明:①近300a 来中国人口数量波动上升,按增长曲线特征可分为较快稳定增长期、快速波动负增长期、低速平稳增长期、无序跌宕增长期、急剧波动增长期5 个阶段;② 人口分布逐渐趋于均衡,人口重心迁移幅度不大,总体呈西南-西北-东北-西北的移动趋势;③ 人口分布保持高度自相关,聚集程度波动变化,其中,华东的沪苏地区、山东省、安徽省、浙江省为稳定人口高密度聚集区,华中的河南省为较稳定人口高密度聚集区,西南、西北部分省份为稳定人口低密度聚集区,华北的内蒙古自治区为较稳定人口低密度聚集区,东北的黑龙江省、吉林省为不稳定人口低密度聚集区。  相似文献   

11.
Based on the information from forest resources distribution maps of Luoning County of 1983 and 1999, six indices were used to analyze spatial patterns and dynamics of forest landscapes of the typical region in the middle of the Yihe-Luohe river basin. These indices include patch number, mean patch area, fragment index, patch extension index, etc. The results showed that: (1) There was a rapid increase in the number of patch and total area from 1983 to 1999 in the study area. The fragment degree became very high. (2) The area of all the forest patch types had witnessed great changes. The fractal degree of each forest patch type became big from 1983 to 1999. The mean extension index of Robinia pseudoacacia forest, non-forest, shrub forest, sparse forest, and Quercus species forest increased rapidly, but that of economic forest became zero. The fractal dimension each showed that forest coverage has been promoted. (3) The changes of landscape patterns were different in different geomorphic regions. From 1983 to 1999 the vegetation cover area, the gross number and the density of patch, diversity and evenness of landscape were all reduced greatly in gullies and ravines, but the maximum area and the mean area of patch types were increased. In hilly region, both the forest cover area and the number of patch increased from 1983 to 1999, but the mean area of patch was reduced greatly. In mountain region, even though the area under forest canopy reduced from 1983 to 1999, the patch number was increased greatly, the mean area of all patch types was reduced, the extension index, diversity index and evenness index of landscape were all increased. Furthermore, because of different types of land use, human activity and terrain, the vegetation changes on northern and southern mountain slopes were different. According to these analyses, the main driving forces, such as the policies of management, market economy, influence of human activities etc. are brought out.  相似文献   

12.
The method for simulating the temporal and spatial distribution patterns of leaf area index (LAI) and biomass at landscape scale using remote sensing images and surface data was discussed in this paper,The procedure was:(1) annual maximum normalized difference vegetation index (NDVI) over the landscape was calculated from TM images;(2) the relationship model between NDVI and LAI was built and annual maximum LAI over the landscape was simulated;(3) the relationship models between LAI and biomass were built and annual branch ,stem ,root and maximum leaf biomass over the landscape were simulated;(4) spatial distribution patterns of leaf biomass and LAI in different periods all the year round were obtained.The simulation was based on spatial analysis module GRID in ArcoInfo software ,The method is laso a kind of scaling method from patch scale to landscape scale ,A case study of Changbai Mountain Nature Reserve was dissertated ,Aalysis and primary validation were carried out to the simulated LAI and biomass for the major vegetation types in the Changbai Mountain in 1995.  相似文献   

13.
The expansion of agriculture is posited as one of the main dynamics of forest landscape change globally, and the robust modeling of these processes is important for policy as well as academic concern. This paper concerns a relatively small area of Yiluo River catchment where considerable attention has been paid to slow down the process of the expansion of agriculture into the remaining natural forests. In the present study, we reconstructed the former forest landscape structure and elucidated the landscape change during a period of about 15 years. Three sets (1987, 1996 and 2002) of maps derived from Landsat-5 images were used for analyses. The result showed that there was a decrease in the area of the forest landscape from 995.60 km2 in 1987 to 650.50 km2 in 2002. Then we examined the degree to which forest landscape conversion could be attributed to a set of factors identified as significant at broader scales, namely topography, distribution of the village clusters (centroids), distance from villages (centroids), and distance from forest edge (1987). By using “spatial analysis” in Arc/gis 8.3, the correlation between forest landscape change and driving factors was constructed. This study found that forest landscape conversion in this region was largely explained by elevation, slope and proximity to village.  相似文献   

14.
Microbial production of CO2 in red soil in Stone Forest National Park   总被引:2,自引:0,他引:2  
Lunan stone forest is a kind of typical karst in China,Which is mainly developed under red soil.In the winter of 1999,three study sites were chosen in stone forest national park according to vegetation cover,geomporphologic location and soil types,CO2 concentration was measured with Gastec punp at different dephts of soil (20,40,60cm) and at the same time soil samples were gatered and soil properties such as soil moisure,pH,soil organic content were analyzed and the total nmuber of viable microbes were counted in laboratory,In the study,dependent variable was chosen as the mean soil log(PCO2),and soil properties were chosen as the independent variables.Multiple stepwise regression analysis showed that the totla amount of microbes and soil moisture are the best indicators of the CO2 production,With the equation LOG(PCO2)=-0.039(TNM)-0.056 (Mo) 1.215 accounting for 86% of the variation of the soil CO2 concentration,where TNM is the total number of microbes in teh soil and Mo is the moisture of soil sample.  相似文献   

15.
Tectonic movements and climate changes are two main controllers on the development of landfrorm.In order to reconstruct the history of the evolution of the landform in the Fenhe drainage basin during middle-late Quaternary comprehensively,this paper has provided a variety of geomorphological and geologic evidences to discuss how tetonic movements and climate changes worked together to influence the landform processes,According to the features of the lacustrine and alluvial terraces in this drainage basin,it is deduced that it was the three tectonic uplifts that resulted in the three great lake-regressions with an extent of about 40-60 m and the formation of the three lacustrine terraces.The times when the tectonic uplifts took place are 0.76 MaBP,0.55 MaBP and 0.13 MaBP respectively,synchronous with the formation of paleosol units S8,S5 and S1 respectively.During the intervals between two tectonic uplifts when tectonic movement was very weak ,climate changes played a major role in the evolution of the paleolakes and caused frequent fluctuations of lake levels.The changes of the features of lacustrine sediment in the grabens show the extent of such fluctuations of lake level is about 2-3m.  相似文献   

16.
This study provides a geographical synthesis of the current natural landscape dynamics of the Canarian laurel forest based on the results of a biogeographic study of its structure, composition, and dynamics. Historical socioeconomic changes and recent environmental conservation strategies have led to natural forest dynamics that make it necessary to change our current scientific conception of the Canarian laurel forest landscape. According to the forest transition theory, in the protected areas of Anaga and Teno Rural Parks (Tenerife) and Garajonay National Park (La Gomera), the forest reaction to the gradual abandonment of economic activity reveals how strongly human activity has shaped the features of the laurel forest, which traditionally has been considered to be relatively untouched by humankind. How natural disturbances have affected this forest over the past few years has also contributed to a better understanding of its dynamics. This study explains the key patterns of spontaneous dynamics in the Canarian laurel forest to enrich our understanding of this forest and its landscape, while highlighting the importance of human activity as the catalyst for its current vigorous dynamics.  相似文献   

17.
三江平原沼泽湿地时空动态特征   总被引:3,自引:0,他引:3  
1IntroductionThe wetland ecosystem is the latest one understood by humans and it is the most seriously damaged ecosystem (Williams, 1991). The Sanjiang Plain, located in northeast China, is the largest concentrated area of freshwater wetland in China. Since the 1950s, large-scale reclamation of the marsh in the Sanjiang Plain has been started. According to statistics, the natural marsh has lost about 80% of its total area. The marsh resources in the Sanjiang Plain decreased greatly and the…  相似文献   

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