Land Use Change Of Jinta Oasis And It's Environmental Impact In Arid Northwestern China

Arid area mainly consists of the mountain, desert and oasis. The oasis, which is one of these three systems, is an unique geographical landscape in arid area. The oasis have developed unceasingly, and kept transformational between stability and instability since the time of its generation. Its development was mainly due to the significant change among the constituent elements, such as the water - soil - vegetation climate - human activities, as well as changes in land use patterns. These cause the ecological environment and stability changes in the oasis area.For decades of development and construction in last century, the oasis area in arid northwestern China is of significant expansion and is the main place for humanity production and life, which has become the base for humanity further to open up the desert and the mountains. But in some areas, there have been serious problems in oasis eco-systerm, that is, desertification, salinization and so on. These have the significant influence to the production of people's livelihood, and seriously endangered the stability of the oasis and its internal environment of human existence.With the depth and development of the global change research, the study on land use and cover change has become one of the hot issues. The global climate change has impact to the land use, changes the land cover, disturbs the land use patterns in farming systems. In some areas, land use changes also have given rise to serious land desertification. This shows that land use and land cover change is extremely important in the global environmental change. In arid areas, land use and cover change is an important influence factor to its eco-environmental changes. Land use and cover change will have a significant impact to the development and the existence of oasis, as well as its stability. So, in order to do more in-depth study on the oasis, it is necessary for us to carry out the researches for land use and cover change.This paper takes Jinta Oasis as the study area, which located in the typical temperate arid zone of Northwest China. The objective of this study is to develop technology for analysising and asessing the dynamic changes of the oasis land use for the past 15 years (1988-2003) through the satellite remote sensing images and GIS. It is also for mining and extracting the relationship between land use change and the oasis environment. Land use in Jinta Oasis are divided into six types, namely, cropland, forestland, grassland, water area, urban or built-up land and unused land. The results showed that cropland, urban or built-up land and unused land has increased significantly: the area of cropland increased by 30.03 km2, urban or built-up land by 13.35 km2, unused land by 15.52 km2; but the area of grassland and forestland declined rapidly, which decreased by 58.06 km2 and 1.76 km2, respectively. Due to the land use changed dramatically in the Jinta Oasis, it caused some serious problems of environmental degradation, such as land desertification, declining of groundwater levels. Based on above these, the tendency, causes of land use change and environmental problems caused by land use change were analysed. These also give an analysis of land use change from the end of the 80's in the 20th century to the early 21st century. It not only give a view of the oasis ecosystem stability and sustainable development in arid areas, but also has important theoretical value and practical significance for further study of the oasis.The content of this study is divided into six parts: The first part is the preface, which describes the background of the main topic, the significance of research and so on; The second part mainly introduces the research methods and writing routes; The third part is an overview of Jinta Oasis, including its natural conditions and socio-economic situation; The land use change of Jinta Oasis is analyzed in the fourth part, which is the focus of the thesis; The fifth part analyses the change of land use in Jinta Oasis resulting to environmental impacts; The sixth part is the last part of the study, containing the conclusions, recommendations and shortcomings, which concludes the research findings and some suggestions for the sustainable development of oasis in Arid areas of China are put forward in this paper.