| Land is not only an important source of people to gain energy and material, has also an inhibitory effect for people’s lives and production. with desertification happened frequently and intensly, a lot of land resources consumed, So land use dynamic change and driving force research appears more urgent in oasis- desert ecosystem area, Systematic study of regional land use change and landscape pattern change for sustainable use of land resources and ecological balance is of great significance.This paper aimed at ecological environment protection and management of Southern oasis in Xinjiang, and selected three different farms of Division 1 as the research area, which were farm 5, farm 10, farm 12, and respectively analyzed their land use change and driving force factors, landscape pattern change and ecological safety, based on TM i mage and the theory of land use/cover change(LUCC) and landscape ecology, combined with the long-term statistics of different farms, within the aid of Arcgis10.0, Fragststs3.4 and SPSS and other software,,in 2000, 2005, 2010 and 2014, and got the following conclusion:(1) During the period of 2000-2014, different farm land use status has obvious differences in different time. cultivated land generally increased over time, but farm 12 cultivated land area increased from 2000 to 2005,and deceased from 2005 to 2014, farm 10 cultivated land area overall time increased from 2000 to 2014,garden, construction land obviously increased, traffic land and other land, desert grassland area decreased, water showed the fluctuate state; farm 5 and farm 10 land dynamic were performance for 2000-2005 < 2005-2010 < 2010-2014, farm 10 land dynamically showed 2000-2005 > 2005- 2010 > 2010-2014, in single land dynamics, garden and desert grassland have the biggest land dynamic in 2000-2014; farm 5 has changed the most of land use type to desert grassland, followed by the cultivated land. Farm 10 and 12 turned out of the land type more for other land, desert grassland and arable land, the most changing land type was the garden. Farm 5 has a small proportion of agricultural land, farm 10 has the largest, and farm 12 in the middle.(2) The main factors of dynamic change of land use include natural driving and social economic driving. The natural environment changes of farm 5, 10 and 12 were small. Therefore, natural factors were not the main influence factor, caused the land use variations in three farms, and social economy was the most direct factor caused land use change. Specifically, the overall three farms in the main aspects were influenced by economic factors, demographic factors and technical factors, which the economic factors of farm 5 and 10 was more prominent, population and technological factors of farm 5 and 12 have a more obviously driving effect. From the specific indicators, farm 5, 10 and 12, although there exi sted the imbalance of economic development, and the different technical level, but economic development, agricultural production, fruit production were main factors caused land use change in the three farms. The fruit production of farm 10 and 12 in driving forces has more prominent, and farm 5 mainly in fruit production, though the fruit tree area driving still played an important role, but the economic development and employment population factors driving were more prominent.(3) Three farms administrative divisions has not changed in the 15 years between 2000-2014 years, so the area unchanged overall landscape area, in three farms the largest patch area accounted for landscape total volume(LPI) became smaller, the total length of the edge(TE) and edge density(ED) became larger, indicating that the adjustment of economic structure and the impact of human activities, landscape fragmentation was more internal differentiation, fragmentation worsened, and Shannon diversity index and Simpson index also showed inconsistent trends; from view of different landscape types, different landscapes dynamics change were different, in general, the other land, desert grassland, water three landscapes frequently converted internal between Therefore landscape indices 2000--2014 showed fluctuation trend, the overall trend of the three farms, increased landscape fragmentation, reduce the overall index, which was not conducive to the improvement of the ecological security landscape.(4) Vegetation coverage of three farms has an increasing trend. the sparse vegetation area of farm 5, 10 and 12 gradually reduced in 15 years from 2000 to2014, high vegetation coverage increased, showed that with the social and economic development, large areas of sparse grassland converted to high coverage of arable land and garden.(5) Different farms’ desertification from 2000 to 2014, in 15 years decreased in extremely severe desertification, severe desertification and moderate desertification area, slightly desertification area increased, indicated that with the three farms economic development, they also strengthened the protection of the ecological environment, farms interior vegetation coverage and desertification extent developed toward positive direction.(6) In terms of ecological safety, farm 5, 10 and 12 ecological safety were all low, generally between 0.3 to 0.6, in the early warning and fragile state, farm5 ecological safety state declined since 2000-2010, the ecological security index dropped from early warning(0.431) to vulnerable(0.238), but since the 2010-2010 had a tendency to turn good ecological safety, and the farm 10 has a contrast to the farm 5 dynamic change, raised from 2000-2000, but showed decrease trend from 2010 to 2014, farm 12 characterized a rise since the 2000-2000, but from 2005 to 2014, the ecological security degree was reduced, but not obviously decreased. Overall, excessive increased cultivated land or garden area were all cause ecological safety decrease, only a modest proportion relation of both, at the same time strengthen the work in improving the vegetation coverage, reducing the desertification and so on, it would fundamentally improve the regional ecological security. |
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