| In this work, based on the theory and method of landscape ecology, with Suzhou district of Jiuquan city, Gansu province as the studied area, we studied the regional ecological security pattern using the GIS technology of this area. Digital elevation model(DEM) were combined with landscape pattern index and land ecological suitability, to investigate the landscape pattern characteristics and characteristics of the ecological suitability and build the regional ecological security pattern of Suzhou district. Finally, by using the minimum cumulative resistance model to determine the resistance of the urban sprawl boundary, we provided the scenario for urban land expansion mode with regional ecological security pattern or without ecological security constraints, and both of the two kinds of landscape patterns were analyzed. The main research results are listed below:(1)According to the land using classification, there are 10 types of landscape components in the studied area. The unused land, which is the landscape matrix,accounts for 63.5% of the whole studied area. The rest components of landscape types exist in the form of plaques in the region. Water areas and roads act as corridor. The area of cultivated land, forest land and unused land decreased with the increasing of elevation, water distributed in low altitude regions. Distribution of other landscape characteristics also affected by the elevation significantly, the global ecological resources distribution in the studied area is uneven. The area with elevation1131m-1439 m has all kinds of landscape composition distribution.(2)In general, for Suzhou district, the FN, the VI, the H, and the CONT of different elevation is obviously different. Within the whole studied area, landscape evenness index(E) and landscape dominance index(D) diversity is fewer.(3) In Suzhou district The percentage of farmland, forest land and grassland to the total land area is 21.3%, 2.3%, and 8.2%, respectively. The difference of distribution characteristics between regions with different elevation is significant. All of the farmland distributed in low elevation regions, the first class forestland distributed evenly in the every elevation area, the second class forestlands are mainly distributedin the regions of lower elevation. The grasslands are mainly distributed in elevation1131m-1439 m and elevation 1942m-2544 m.(4)Based on the characteristics landscape pattern and the land ecological suitability of Suzhou district, regional coordinated, functional complemented regional ecological security pattern was built. The pattern was composed of mountain ecological conserving area, oasis ecological agriculture area, desert sand control area. Mountain ecological conserving area mainly includes five towns located at the northern foot of Qilian mountain, the area is located in the apex and waist of alluvial area, land is big and ditch is deep, especially in the remote village, its sparsely populated. The oasis ecological agriculture area is located in the middle and low zone of alluvial fan,mainly includes the town Qingshui, the town Shangba, and the town Zongzhai, this towns holds fertile and deep soil, convenient for irrigation, thus forms the land usage pattern in which food production prioritized, forestry and animal husbandry is also considerated. Desert sand control area distributed in all over the region of Suzhou.(5)In this study, the urban area which has important effects on the future development and ecological environment in Suzhou was chosen as “source” plaques. Height, the distance from the main road, the recent distance were used as resistance factor.Through the establishment of ecological land minimum cumulative resistance modal for simulating the trend of its expansion, and analyzed the result of the preliminary scence. |
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