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Heihe River Basin is our land planning and regional sustainable development research and practice in one of the most active areas, with the continuous development of the Heihe River oasis, water projects have been more obvious contradictions, which oasis of Heihe River region poses a severe development tests, especially the middle reaches of Heihe artificial oasis unreasonable development, so that the Heihe River Basin oasis growing role of ecological barrier dysfunction, and even has become a major source of dust storms. Study the changes in the region oasis, you can change the drive mechanism analysis oasis lay the foundation for the governance of the local ecological environment, desertification, etc. to provide the fundamental basis and reference. In this paper, RS, GIS and GPS technology support, using visual interpretation and documentation reconstruction method oasis of Heihe River River area was rebuilt. The first study through field visits, survey visits, and refer to local libraries, archives, and government and other places to collect the relevant information on the different types of data were established to determine their own interpretation of signs or object feature; then manually digitized for liberation, 1957,1963,1968,1973,1975 and 1977 oasis reconstruction. Finally arithmetic functions using GIS and spatial analysis method to determine the spatial distribution of typical year oasis location, extent and area, compare the changes from one year to the oasis, and a brief analysis of the causes of changes in the oasis. Conclusions are as follows: From the number of features, the oasis in the middle reaches of Heihe area expanded to major trends. The trend on the middle reaches of Heihe oasis presented \Only from 1957-1963 oasis area decreasing trend, area experienced an increasing trend in other periods. Changes in the number, the smaller the early liberation oasis, only 150510.82hm2; to 1957 showed a larger increase in area increased to 319497.76 hm2, the average annual growth 18776.33hm2; latter area decreased to 1963, an area of ??292835.80 hm2 with an average annual decrease 4443.66 hm2; oasis area after another showed an increasing trend, but the relatively slow growth to 1977 oasis area of ??353498.10hm2. 2. From the spatial distribution of point of view, an oasis of Heihe River and its tributaries, mainly in Heihe two side, the old trunk circumference and along both sides of the river and canal outward expansion. Even during the shrinking oasis, an oasis area is also reduced over previously developed land, reclaimed abandoned for some reason, after some time again exploitation. From the district distribution, oasis change is not exactly the same, and the county district with more severe changes in the area, either expansion or contraction, no laws broken oasis patch comparison. They are mainly distributed in the high-profile county south central Linze County, Ganzhou central and northwestern, central and northern folk music, Shandan Central, Su Ming flower areas. 3 From the process point of view, the development of the Heihe River region oasis gradual transition from an unstable state to a relatively stable state. From 1949 to 1963, a large area of ??the first expansion of the oasis, and later a large area of ??atrophy, an oasis in an unstable state. After 1963, growth is relatively slow oasis, oasis change is also more stable. However, due to oasis and desertification always exist, but the oasis of an area larger than the area of ??desertification, thus expanding the overall trend showed oasis, oasis of the total area is relatively stable causes. 4 Middle Reaches of Heihe oasis change is mainly caused by social factors, but at some stage natural factors also play a crucial impact. Liberation and 1957, with the rapid population growth and the rapid development of productive forces, the oasis area of ??rapid expansion. From the 1958-1963 period, due to agricultural policy mistakes and frequent natural disasters, the population declined significantly, a large number of cultivated land were abandoned, making artificial oasis area substantially reduced. In 1963, the population is still in the high birth rate, low death rate and high growth phase, in the \In 1966, due to climate, more precipitation, less severe weather, to the oasis extension provides more favorable conditions. On the other hand, the population under control, but the total population is still increasing agricultural policy was to promote and encourage farmland capital construction, land reclamation, and conduct field canal system supporting projects to improve water conditions, so that the middle reaches of the land development steadily.
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