首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到18条相似文献,搜索用时 156 毫秒
1.
河南沿黄湿地景观格局及其动态   总被引:3,自引:2,他引:1  
By using GIS and remote sensing techniques, the paper discusses how human activities have changed along the Yellow River in Henan province, China and how these altered activities have influenced the wetland landscape pattern change from 1987 to 2002. Results show that the total area of the wetland reduces dramatically compared to 1987, the total area of wetland reduces by 19.18%, the number of the patches in 2002 increases by 21.17%, the density increases by 50%, and the total perimeter increases by 1,290,491 m. Disturbed by human activities, landscape diversity index decreases from 1.1740 in 1987 to 0.9803 in 2002. During the last 20 years, the total area of the rice wetland increases, while the others decrease. Among those, the area of the bulrush wetland decreases most. In 1987, it takes 0.5% of the total area, but in 2002, it only takes 0.11%. The interpenetration of human influences on the wetland natural system has been long and close. The impacts of human activities on the spatial pattern of the wetland landscape along the Yellow River in Henan from 1987 to 2002 are great.  相似文献   

2.
ECOLOGICALLY STRATEGIC POINTS IN LANDSCAPE AND SURFACE MODEL   总被引:2,自引:0,他引:2  
YuKongjian 《地理学报》1998,53(B12):19-20
Various processes occur across a landscape, including ecological processes such as the movement of species, the flow of nutrients, the spread of fire and other disturbances, and the diffusion of pollutants, economic processes such as land conversion for agricultural production, marketing of new product, transportation and immigration; political and diplomatic processes such as the construction of political influence sphere at local, national and global scale. At the fact of limited space and resources on the surface of the earth, a generic issue regarding these processes across the landscapes is: how to control (promote or retard) the processes efficiently, namely using less energy and space for a bigger influence sphere. The overall assumption for this issue is that, there are some positions and portion in a landscape that may have critical influence on a certain process across the landscape. These critical positions in a landscape are called strategic points. Occupancy of these strategic points may give a process the momentum of controlling and covering the landscape more effectively, due to their quality of; Initiative, occupancy of these points may give the process the advantage of leading the game; Co-ordlnation, occupancy of these points may give the process the advantage of forming an overall influence sphere; Efficiency, occupancy of these points may give the process the advantage of having a bigger coverage of the landscape while costing less energy. By identifying and using these critical positions and portions in the landscape, therefore, may unproportionately increase the efficiency of controlling this process. It is further assumed that, in order to take control of the landscape, the process has to overcome a certain resistance. A resistance surface can therefore visualize the dynamics of the process itself. The resistance surface resembles a topographic surface, indicating where the process (flow) diverges or converges. It is, therefore, possible to identify strategically important positions or portions in a landscape that may have important influence on the dynamics of the process. Assuming species movement across a landscape is a competitive gaming process of control and coverage against some resistance, this paper discusses a methodology of identifying strategic points according to the properties of resistance surfaces which resembles a gaming board as well as a topographic surface. Three types of resistance surfaces are discussed: The archipelago type: where lower resistance islands are surrounded by higher resistance matrix, representing such landscapes as agricultural fields dotted with native forest patches. The network type: where the lower resistance portions form a linear network surrounded by higher resistance matrix. The plateau type: where, areas with higher resistance are surrounded by lower resistance matrix. Accordingly, five types of strategic points are identified in terms of their locations. They are strategic points at saddle points , at intersections, at the center, at an edge and at a corner. Strategic points for biodivershy conservation are minimax points in a given resistance surface associated with the dispersibility of a certain species. A case study is used to illustrate the methodology. The rules leading to the strategic points are largely hypothetical, though supported by a limited number of observations. This approach may provide a framework and a new model of thinking for field observations of landscape ecology as well as landscape change.  相似文献   

3.
4.
Landscape spatial pattern mainly refers to the distribution of patches, which are different in size and shape in space owing to the interaction of various ecological activities. In landscape ecology study, landscape pattern has been one of the key study areas. Water body landscape plays an important role in the development history of a city, but at present city water body landscape in many cities has been destroyed, hence protecting water body in the city is becoming more and more important. In order to protect city water body landscape reasonably, the precondition is to probe the dynamics of water body landscape. Based on historical data and remote sensing data, six indexes including patch number, patch area, landscape dominance index, fractal dimension, patch density and connectivity index etc. were used to analyze landscape pattern dynamics of water body in Kaifeng city since the end of the Qing Dynasty (in the 20th century). The results showed: (1) Since the end of the Qing Dynasty, landscape area of water body in Kaifeng city increased first and then decreased from 1898 to 2002AD; the landscape dominant degree had the same changing tendency with the area. (2) Patch number of water body landscape in Kaifeng city had an increase from 1898 to 2002, but maximum area of patch, minimum area of patch and average area of patch decreased, which resulted in an increase in landscape fragment degree. (3) Connectivity index decreased and fractal dimension increased from 1898 to 2002. The reasons for these changes were the repeated overflows and flooding of the Yellow River and the influence of human activities.  相似文献   

5.
The research of ecology and landscape reestablishment of river floodplain is considered favorable to its conservation and development.The similarity and difference among river floodplain,wetland,riverside and shore have been reviewed,as well as the progress in the research of floodplain ecology reestablishment in quantitative evaluation,vegetation restoration,the influence on animal habitat and the application of eco-engineering;and of the landscape reestablishment in resource development and utilization,landscape feature and changes,landscape function,structure and control.The potentially important fields are expected to be the change of landscape pattern in different scales,the reasonable protection and utilization in the floodplain tourism,the simulating and monitoring of landscape dynamics,the planning and designing methods of floodplain landscape and the management of floodplain ecosystems.  相似文献   

6.
榆林地区景观变化探测模型   总被引:3,自引:1,他引:2  
Landscape is a dynamic phenomenon that almost continuously changes. The overall change of a landscape is the result of complex and interacting natural and spontaneous processes and planned actions by man. However, numerous activities by a large number of individuals are not concerted and contribute to the autonomous evolution of the landscape in a similar way as natural processes do. There is a well-established need to detect land use and ecological change so that appropriate policies for the ;egional sustainable development can be developed. Landscape change detection is considered to be effectively repeated surveillance and needs especially strict protocols to identify landscape change. This paper developed a series of technical frameworks on landscape detection based on Landsat Thematic Mapper (TM) Data. Through human-machine interactive interpretation, the interpretation precision was 92.00% in 1986 and 89.73% in 2000. Based on the interpretation results of TM images and taking Yulin prefecture as a case study area, the area of main landscape types was summarized respectively in 1986 and 2000. The landscape pattern changes in Yulin could be divided into ten types.  相似文献   

7.
景观类型分析在土地覆被变化中的作用   总被引:1,自引:1,他引:0  
  相似文献   

8.
Based on four phases of TM images acquired in 1990, 1995, 2000 and 2005, this paper took Kitakyushu in Japan as a case study to analyze spatial change of land use landscape and corresponding effects on environmental issues guided by landscape ecology theory in virtue of combining technology of Remote Sensing with GIS. Firstly, land use types were divided into 6 classes (farmland, mountain, forestland, water body, urban land and unused land) according to national classification standard of land use, comprehensible ability of TM image and purpose of this study. Secondly, following the theory of landscape ecology analysis, 11 typical landscape indices were abstracted to evaluate the environmental effects and spatial feature changes of land use. Research results indicated that land use has grown more and more diversified and unbalanced, human activities have disturbed the landscape more seriously. Finally, transfer matrix of Markov was applied to forecast change process of land use in the future different periods, and then potential land use changes were also simulated from 2010 to 2050. Results showed that conversion tendency for all types of land use in Kitakyushu into urban construction land were enhanced. The study was anticipated to help local authorities better understand and address a complex land use system, and develop improved land use management strategies that could better balance urban expansion and ecological conservation.  相似文献   

9.
1 Introduction Agriculturallandscape is the m osaics ofnaturaland hum an-managed patches thatvary in size, shape and arrangement(Forman and Gordron,1986).The spatialpattern in the landscape may influence a variety of ecological processes,such as water run…  相似文献   

10.
In this study, we attempt to put forward a conception of landscape ecological niche, enlightened by international scholars on extending the ecological niche theory from spatial niche to functional niche. That is helpful for comprehensively appraising landscape spatial patterns and ecological functions, also, presents a new method for analyzing landscape features from multidimensional aspects. The practice process is demonstrated by taking Yan'an region in northwestern China as a case. Firstly, the indices system including spatial attribute and functional attribute is established for assessing landscape ecological niche. Additionally, two-dimensional figures are drawn for comparing the spatio-temporal features of landscape ecological niche in 1987 and 2000 among the 13 administrative counties. The results show that from 1987 to 2000, towards Yan'an region, spatial attribute value of landscape ecological niche changes from 1.000 to 1.178 with an obvious increment, and functional attribute value changes from 0.989 to 1.069 with a little increment, both of which enhance the regional landscape ecological niche. Towards each county, spatial attribute value of landscape ecological niche increases to different extent while functional attribute value changes dissimilarly with an increment or a decrement.  相似文献   

11.
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   

12.
近30年来藏北高原湖泊变化对气候波动的响应   总被引:7,自引:1,他引:6  
According to the analysis of the climate materials including the topographic map in 1975, the TM and CBERS satellite remote sensing materials from the 1980s to 2005 as well as the air temperature, precipitation, evaporation rate, maximum depth of snow and the biggest depth of frozen soil in the past 45 years, the water level area of four lakes at the southeast of Nagqu, Tibet including Bam Co, Pung Co, Dung Co and Nuripung Co show a distinct trend of expansion in the past 30 years. In 2005, the water level area of the above four lakes increased by 48.2 km2, 38.2 km2, 19.8 km2 and 26.0 km2 respectively compared to 1975, with the respective increase rate of 25.6%, 28.2%, 16.2% and 37.6%. That is closely related to the warming and humidified climate change in the recent years such as rise of the air temperature, increase of the precipitation, decrease of the evaporation rate and permafrost degradation. Foundation: National Natural Science Foundation of China, No.40761005 Author: Bian Duo (1966–), Professor, specialized in application of remote sensing and GIS on environment.  相似文献   

13.
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   

14.
Land use change plays an important part in the studies of global environmental change and regional sustainable development. The change of soil quality can particularly reflect the impacts of human socio-economic activities on environment. Taking the coastal plain of south Hangzhou Bay as a study case, we analyzed the effects of land use changes on organic matter (OM), total nitrogen (TN), total phosphorus (TP), available phosphorus (AP), available potassium (AK), total salinity (TS), pH value in soil genetic layers, and assessed soil quality change related to different land use types from 1982 to 2003. The results show that: (1) The general change tendency of soil quality in the coastal plain of south Hangzhou Bay declined obviously in A layer and slightly rise in B (or P) layer and C (or W) layer. The contents of TP decreased generally in all soil genetic layers, but the variety difference of other soil quality indices was relatively great. (2) The change of soil quality in the areas where land use changed is far more remarkable than that with land use unchanged. The value of quality variety is A layer 〉B (or P) layer 〉C (or W) layer. (3) The changes of soil tillage, cultivation, fertilization, irrigation and drainage activities related to land use may make some soil-forming processes disappeared and bring in other new processes which will affect the soil quality and soil genetic layers directly.  相似文献   

15.
中国东北漫岗黑土区切沟侵蚀发育特征   总被引:4,自引:0,他引:4  
In this study, short-term gully retreat was monitored from the active gullies selected in representative black soil area, using differential global positioning system (GPS). With the support of geographic information system (GIS), multi-temporal digital elevation models (DEM) were constructed from the data collected by GPS and used for further analysis. Based on the analysis of multi-temporal DEM, we discussed the erosion-deposition characteristics within gully and a developing model for black soil gully area of Northeast China was proposed. The results are: (1) The analysis of the monitored gully data in 2004 indicated that the retreat of gully head reached more than 10 m, gully area extended 170–400 m2, net gully eroded volume 220–320 m3, and gully erosion modulus 2200–4800 t·km−2·a−1. (2) Compared with the mature gully the initial gully grows rapidly, and its erosion parameters are relatively large. The erosion parameters have not only to do with flow energy, but also with the growth phase. (3) There are significant seasonal differences in gully erosion parameters. The extension of gully area and width dominates in winter and spring without marked net erosion while changes mainly occur in gully head and net erosion in rainy season. (4) It is remarkable for freeze-thaw erosion in the black soil area of NE China. The gully wall of SG2 extended 0.45 m under freeze-thaw effect in 2004, and the distance of gully head retreated maximally 6.4 m. (5) Due to freeze-thaw action and snowmelt, gully is primarily in the interior adjustment process in winter and early spring. There are much more depositions compared with that during rainy season, which can almost happen throughout the gully, while erosion mostly occurs near head, esp. for gullies having a relatively long history of development. On the other hand, the process of energy exchange with exterior dominates in rainy season. It is considered that this cyclic process is an important mechanism for gully growth in high latitude or/and high attitude regions. Foundation: Key Project for National Natural Science Foundation of China, No.40235056; The Ph.D. Programs Foundation of Ministry of Education of China, No.20030027015; China Postdoctoral Science Foundation, No.20070410482; Doctoral Foundation of University of Jinan, No.B0620; National Natural Science Foundation of China, No.40672158; Key Subject Foundation Supported by Shandong Province Author: Hu Gang (1976–), Ph.D and Associate Professor, specialized in soil erosion, environmental evolution and regional planning.  相似文献   

16.
近5年青海省植被覆盖变化的遥感监测   总被引:3,自引:2,他引:1  
This paper used five years (2001-2006) time series of MODIS NDVI images with a 1-km spatial resolution to produce a land cover map of Qinghai Province in China. A classification approach for different land cover types with special emphasis on vegetation, especially on sparse vegetation, was developed which synthesized Decision Tree Classification, Supervised Classification and Unsupervised Classification. The spatial distribution and dynamic change of vegetation cover in Qinghai from 2001 to 2006 were analyzed based on the land cover classification map and five grade elevation belts derived from Qinghai DEM. The result shows that vegetation cover in Qinghai in recent five years has been some improved and the area of vegetation was increased from 370,047 km^2 in 2001 to 374,576 km^2 in 2006. Meanwhile, vegetation cover ratio was increased by 0.63%. Vegetation cover ratio in high mountain belt is the largest (67.92%) among the five grade elevation belts in Qinghai Province. The second largest vegetation cover ratio is in middle mountain belt (61.80%). Next, in the order of the decreasing vegetation cover ratio, the remaining grades are extreme high mountain belt (38.98%), low mountain belt (25.55%) and flat region belt (15.46%). The area of middle density grassland in high mountain belt is the biggest (94,003 km^2), and vegetation cover ratio of dense grassland in middle mountain belt is the highest (32.62%), and the increased area of dense grassland in high mountain belt is the greatest (1280 km^2). In recent five years the conversion from sparse grass to middle density grass in high mountain belt has been the largest vegetation cover variation and the converted area is 15931 km^2.  相似文献   

17.
Snowpacks samples were colleted from two glaciers: Baishui No.1 glacier and Hailuogou No.1 glacier in June, 2006. The method of sea-salt ions tracer, correlation analysis and trend analysis were used in this research in order to confirm the source of main ions, it is indicated that Na^+ is mainly from marine moisture and other ions mainly originate from land dust. The non-marine source percent of Cl^-, NO3^- , SO4^2-, K^+, Ca^2+ and Mg^2+ is 52%, 99%, 100%, 98%, 99.9% and 83%, respectively, in Hailuogou No.1 glacier, while the corresponding value in Baishui No.1 glacier is 68%, 99%, 100%, 98%, 99% and 59%. The non-marine source of ions is from dust of Central Asia arid regions carried by westerly circulation and the plateau borne-areas with Qinghai-Tibet Plateau winter monsoon in two glacial areas. However, the import of local dust in glacial area has made a great contribution to ions concentration in Baishui No.1 glacier, which accounts for the reason why the ions concentration in Baishui No.1 glacier is much higher than that of Hailuogou No.1 glacier. It is obvious that the source of each ion is different between Hailuogou No.1 glacier and Baishui No.1 glacier. There are three reasons which can explain it: firstly, the difference in the internal environment of glacial area, such as lithology, mountain-valley wind system, topographical relief and so on; secondly, the influence exerted by ions elution in snowpacks section, and ions elution in Hailuogou No.1 glacier is very strong; and thirdly, the difference caused due to varying ions transporting styles, deposition modes, chemical characteristics and post-ions-deposition process.  相似文献   

18.
Based on the cost-benefit data (1980-2002) of farm products and China Agriculture Yearbooks, this paper studies the regional disparity in the changes of the agricultural land use in China during the period 1980-2002 from three aspects such as the degree of intensity, the sown area and the abandoned farmland. The results show that: (1) The degree of intensity of land use in the westena region during 1980-2000 has a strong uptrend, but in the eastern and central regions the degree of intensity descends obviously and has shown a continuous downtrend since 1997. (2) The total sown area shrinks notably in the eastern region, while it enlarges constantly in the western region. (3) The sown area in the eastern, central and western regions has gone through a similar cyclic process: down (1980-1985)-up (1985-1991)-down (1991-1994)-up (1994-1999)-down (1999-2002). However, there are obvious differences in amplitude variation and tendency among them. The sown area has shrunk in the eastern region and expanded in the central and western regions especially before 1999. (4) The most cases of abandoned farmland are reported in the central region, the second in the eastern region and the least in the western region. The abandonment phenomena chiefly occurred during 1992-1995 in the eastern region, and during 1998-2002 in the central region.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号