| From the point of view of Landscape Ecology, based on the Remote Sensing Image and the other relative data, combined with the function of input, output, management and spatial analysis of GIS, and adopting qualitative and quantitative, present and dynamic methods, this paper preliminarily discusses the landscape pattern, its dynamic change and ecological resilience of Yutian Oasis in Keliya Catchments. It draws a conclusion as follows.(1) Since 1976, the study area has appeared desert as matrix, Keliya River as covered way and farm field and grassland as main patch. This pattern almost has not changed. Though desert decreased and other landscape types altered to some extent, from the point of the whole background, this pattern will exit inevitably and long due to the extreme drought climate and slim water. Only some certain disturbance and spending a long time can change it considerably.(2) From 1976 to 1999, the area of water, h-grass, m-grass and l-grass increased. The big change of grassland has a relationship with increased precipitation, decreased evaporation and rising groundwater level because of the development of irrigation agriculture. While the expansion of water may be due to the building of water conservancy facilities, such as repair of strand or the increase of reservoir and pond. Except the above four types, the others all decreased. Desert reduced obviously. It converted to grassland mostly and farm field partly. Salina reduced enormously for itself. And it converted to all other types. Wetland was destroyed so seriously that half of it has disappeared. Farm field hasn't changed much. (3) Analysis on the diversity index shows that the diversity and evenness gradually increase while dominance decline. The heterogeneity degree enhanced. As far as this study area is concerned, within a period of time the pattern with desert existing predominantly will be changed. Finally the farm field, grassland and desert will evenly develop.(4) Analysis on the fragmentation shows that salina fragmentates most; water incline to concentrate and link; farm field detract to wider range; wetland was disturbed more and more; among the three type grasslands the fragmentation of h-grass is the biggest. L-grass is apt to integrate; desert is the matrix and connectivity is the best.(5) Analysis on the form index shows that the fraction and spread of desert is the biggest wholly; l-grass is next; high and low grass and farm field is in the middle; water, wetland and salina is the smallest. The order just indicates the degree of landscape's being disturbance.(6) Seeing from the process of landscape conversion, farm field, water, wetland, h-grass and l-grass convert violently, m-grass next and desert last between 1970s and 1980s; while between 1980s and 1990s, water and wetland still convert violently, but the other types drive to slow. Connected with the former and the latter, it can be seen that water and wetland are always disturbed highly degree. It is the mirror that water is the vitals of arid oasis and no water no oasis. In arid area, people exist and develop at the cost of consuming the only water resource.(7) Dynamic evolution results show that 1970s-1980s landscape convert violently. In this period, all types that are good to the environment increased. The whole environment got improved. While 1980s-1990s the process of conversion slowed down. Desert decreased with small amplitude; grassland and water increased; wetland went on shrink. The whole environment got further improvement.(8) The forecast the trend of landscape with Markov Chain Model indicates that farm field; water, h-grass and m-grass will go on increasing while l-grass, salina and desert declining. The study area will mainly consist of desert, grassland and farm field.(9) As a whole the ecological protection and trees-planting-to-fix-sand initially at the late 1980s and early 1990s made the great progress. The enlargement of grassland and diminution of desert means the stability's increase in oasis. It prevented the proces...
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