This paper includes three parts. Firstly, it evaluates tourism resources of South Jiangsu based on the "Chinese tourist resources general survey norm". Then it analyzes the quantity and the spatial characteristics of the eminent tourism resources of south Jiangsu based on GIS. The result of comprehensive evaluation and spatial analysis showed that the humanity tourism resources play fundamental roles in the structure of the eminent tourism resources, and the natural tourism resources are important parts; and in the spatial distribution, the tourism resources show the characteristics of "strap" and "circle", and disequilibrium distribution in region.
Secondly, it makes use of the graph theory to analyze the spatial structure of the eminent tourist resources and analyzes the topological properties of the tourism resources network using several indexes such as β, γ indexes, accessibility index, average directory length and the shortest path matrix, etc.
In the end, the paper pays attention to the spatial structure of tourism resources -city relations. Non-equilibrium index and geographical relation ratio are used to observe the spatial structure between the eminent tourism resources and the five cities in south Jiangsu.
Urban sprawl has sparked a new debate over land-use policy in Beijing metropolitan area in China during past three decades. Increasing populations and economics intensify the urban growth and cropland encroachment. The metropolitan area has gone through a rapid urban growth and transformation from rural to developed land over a short period of time and provided an excellent study area for this study. Using historical land use maps and a spatially explicit dynamic cellular automata urban sprawl model we present applications of a spatially explicit model of land use change. The use of the results for environmental assessments is illustrated by calculating spatial indices to assess the impact of land use change on forest fragmentation. It is concluded that spatially explicit modeling of land use change yields important information for environmental management and land use planning. We quantify the urban sprawl and model the spatial landscape pattern change in Beijing metropolitan area, China. These results constitute a foundation for spatial and ecosystem models to predict long-term environmental impacts of land use change in China.
Increasing populations and economics intensify the urban growth and cropland encroachment in Beijing metropolitan area. In this paper we investigated the effects of recent urban sprawl (1991-2001) in Beijing metropolitan region, People's Republic of China on ecosystem net primary production (NPP). The analysis employed a mechanistic model of NPP in combination with satellite-derived and ecological data. Our analysis shows that urban growth in the 10-year study period significantly altered the urban ecosystem component of the regional carbon cycle. The annual amount of atmospheric carbon assimilated into phytomass through NPP was reduced by approximately 50.71×104 Mg C (-15.08%). More than half of this reduction is attributed to the loss of cultivated land. Vegetation removal and road disturbance by the expansion of urban areas reduced the amount of carbon uptake.
KEYWORDS: Ecosystems, Vegetation, Carbon, Process modeling, Data modeling, Ecology, Geographic information systems, Satellites, Climatology, Near infrared
This study was conducted to develop an appropriate assessment technique to define impact of mountain-desert-oasis ecosystem on net primary productivity (NPP) in northern foothills of Tianshan Mountains. Geographic Information System (GIS) was used to estimate land use/land cover of the mountain, desert and oasis zones. An ecological process model was used to estimate NPP by using data entirely derived from satellite. The results show that landscape heterogeneity was important factor to affect NPP values in mountain-desert-oasis ecosystem. Simulated results indicated a total annual NPP of 1.5081×1014 g C for selected transect in 2002. There was 32.67% of total NPP which came from oasis areas, 28.16% from alpine meadows areas, 9.15% from forests area. Mean NPP values over the selected transect was 150.29 g C m-2 year-1 in 2002. However, NPP values varied greatly with different geography and season.
Since we started the National Key Project of Fundamental Research (China), “The research on eco-environmental evolution, control and adjustment for arid land in Western China,” four years ago we have made a number of important progresses. These progresses include many research fields: the palaeoclimate rebuilding and environmental change; the development process and driving forces of oases; the water-salt balance and main hydrology processes of oases; the oasis ecosystem’s structure, ecological process and stability; the coupling mechanism of three major ecosystems of mountain, oasis, and desert; the ecological landscape patterns’ evolution and its responses climate change; the ecological environmental effects of large industrial (construction) projects; the cause and spatial-temporal distribution of desertification; the establishment of experimental demonstration bases of ecological recovery and rebuilding; and adjustment and control of ecosystem and management models.
In the last several decades, the responses of vegetation to global changes at regional and global scales have been studied with many mathematical models primarily driven by point meteorological observations. In this study, the net primary productivity (NPP) of Xinjiang, China is simulated using the GLObal Production Efficiency Model (GLO-PEM) which is a semi-mechanistic model of plant photosynthesis and respiration and driven entirely by satellite observations. With the available satellite observation data acquired from NOAA’s Advanced Very High Resolution Radiometer (AVHRR), the seasonal and inter-annual changes of NPP in the Xinjiang area are analyzed for the time period of 20 years from 1981 to 2000. Large spatial variability of NPP is found in this area. The temporal trends of NPP in different regions of the area differed significantly. However, for the whole area the mean annual NPP decreased in the 1980s and increased in the 1990s. Seasonal variations of NPP are large and inter-annual changes are moderate. The correlations between the simulated NPP and the precipitation and temperature suggested that precipitation and temperature played major roles in the variations of NPP.
We used Landsat TM imagery and GIS to quantify the rates and patterns of landscape change of two different oasis ecosystems transects --- Fukang oasis and Yutian oasis in Xinjiang Uygur autonomous region, P. R. China. Human dimension is a major disturbance agent throughout the area and desert-oasis ecotone is also important. Maximum likelihood classification of satellite imagery identified landscape class types and changes among the landscape mosaics in two transects. Rate and pattern of the spatial and temporal of landscape change in two oases agricultural landscapes were detected at class and landscape level. The resulting landscape changes have a multitude of consequences; for agricultural production, landscape aesthetics, recreational and amenity values of the landscape, and for biodiversity.
Results show that further intensification of the intensively managed landscape has led to an increasingly homogeneous, large-scale landscape featuring fewer boundaries. In contrast, reduced management in the oasis-farm system has resulted in an increasingly heterogeneous, small-scale landscape. The main pattern and key factors of dynamic changes of oasis-desert heterogeneity with frequent human’s activities especially land use were discussed. Because land use changes are triggered by socioeconomic forces in two oases, a through comprehension of historical change will enhance our capability to predict future landscape dynamics and devise effective landscape management strategies.
Fractional vegetation cover data (FVC) based on the annual maximum NOAA/AVHRR NDVI (Advanced Very High Resolution Radiometer normalized difference vegetation index) data and the ground meteorological data have been used to analyze the relationship between the temporal and spatial evolution of ecological landscape pattern and climate change in Xinjiang autonomous region, China from 1982 to 1993. It is found that during this period, the averaged oasis cropland or low-damp forest-shrub meadow occupies 7.50% of the whole region, desert dune/barren desert 25.70%; temperate semi-arbor desert 21.70%; temperate shrub and semi-shrub desert 8.36%; alpine subalpine desert steppe 7.71%; temperature gramineous and ruderal steppe 7.63%; mountain forest steppe 2.13%; high-cold barren 8.93%; high-cold low semi-shrub desert 9.08%; water/ice 1.26%. Compared with the 30-year (1961-1990) climatology, the 12-year averaged annual surface air temperature and precipitation does not incur over the mountain region; instead it occurs over the region with a concentrated distribution of oases, suggesting the positive role of oases in adjusting regional climate. The area of temporal steppe also increases with the increase of precipitation and temperature. Together, these results demonstrate that, during the 12-year period, the condition of vegetation cover has been improved and large-scale desertification does not occur in Xinjiang.
NDVI(Normalized Difference Vegetation Index) values range from -1.0 to +1.0, areas with NDVI < 0 rarely contain any vegetation, while NDVI >0.6, vegetation cover reaches 100%. The FVC (Fractional Vegetation Cover) values range from 0 to +1.0. Above this threshold the fractional vegetation cover increases approximately as the square of the NDVI, and reaches 100% at an upper NDVI threshold, which is considerably less than 1.0. In arid and semi-arid regions, FVC is superior to NDVI. In this article we got the classification rules by using the resolution 1km FVC combining with DEM (Digital Elevation Model) to classify the vegetation types in arid parts of western China. This classification system was used to classify all FVC images of the resolution 8km*8km from 1982a to 2000a, in this way, we got the classification maps of vegetation for every year. From these classification maps we calculated three majority maps from 1982-1989a, 1990-1995a and 1996-2000a. Supported by software ARC/INFO allowed us to decided wheter cells were degraded or improved after comparing every cell value at same location in three serial maps and then getting the evolution map of vegetation. The main results are as follows: 1) the vegetation in all of arid west China has increased; 2) the vegetation was increased and the rate is higher than in all study area; cells showing improvement in mountainous areas are almost equal to cells showing degradation3) there were two types of improvement patches; the oasis patch increases around old oases and the plain sparse desert patch has also increased; 4) degradation patches appear more frequently in the lower reaches of the Tarim River, in all reaches of Cherchen River, the Jungger basin and to the south of Alxa Right County of Inner Mongolia; 5) in mountainous areas, most of the improvement cells took place in the south of the Tianshan mountains and Pamir high plain, degradation cells are located on the slope of the north Kunlun mountains as a long narrow region and big patch assembled in the Aljin Mountains and the north slope of the Qilian Mountains.
Based on aerial images the GIS technique supported by ARC/INFO software was used to analyze the oasis-desert landscape heterogeneity and its dynamics of Fukang transect with spatial scale change, using landscape structural indices to reveal and compare the structural characteristics of oasis-desert landscape heterogeneity, which was useful to study the dynamics process of landscape heterogeneity through time from different aspect in arid area, which was useful to study the dynamics process of landscape heterogeneity. The results show that oasis-desert landscape in studied area was controlled by the combination of environment heterogeneity, human dimension and activities, and natural vegetation succession. The mutation, contrast and heterogeneity of ecological interface between oasis and desert ecosystem increased. Rare natural or non-regional mosaic of patch show obvious sensitivity to spatial scale, the change ratios of theirs area and perimeter are greater than large patch. With the disturbance of moderate scale more small patchiness combines into more large patchiness. But more patchiness of mosaic will vanish with violent disturbances or isolations of scales. At the same time it has proved that the analysis of landscape heterogeneity is quite effective research means in ecology to measure and quantify the relationship, interaction and response between the structure and function, patterns and processes of oasis-desert ecosystem.
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