Research On The Oasis Landscape Change In The Minqin Typical Oasis Based On 3S Technology

Minqin oasis is in the lower reaches of Shiyanghe river basin in the arid island region, on the northwestern of China. It is one of the typical oasises in our country. Using RS, GIS and GPS, the process and the regularity of landscape pattern change are studied from 1992 to 2006 in Minqin oasis based on the theory of landscape ecology. Then, studied the salinization and the groundwater with the combined collection data. Finally, predicted the tendency of landscape change over the next few years. The main results are as follows:1. Landscape pattern change of the oasis. During 1992 to 2006, the indexes of LPI, SHEI and SHDI were all ascending, while the index of IJI and CONTAG were descending. The index of FRAC_MN was increasing. The area of arable land, woodland and salinate fields is increasing, while the area of sandlot and wild grass ground was declining. There was a great degree of land-use change. It had a mutual conversion during various types of landscape. The land reclamation and abandonment are both existing.2. Salinization landscape change of the oasis. From 1992 to 2006, the entire area of salinate fields was descending. But the change is different in different types of salinate fields. Different types of salinate fields converted each other. The internal change of the salinate fields is fiercely.3. Oasis groundwater change. From 1998 to 2006, the groundwater table depression is quickly. The burial depth of groundwater in the heartland is deeper than that in the boardland. The process of the decline of groundwater table is differential with different periods. The groundwater salinity is ascending year by year. The ascending tendency of the groundwater salinity in the northern oasis is remarkable, while the south ascending tendency is gently relatively.4. The prediction and analysis of the oasis landscape change. From the research results, we can know that the desertification and the salinization of Minqin oasis will become severe in the next few years. To 2010, the total desert area will be proximately 1134.99km2, and the salinization area will be 149.01km2. The area of arabel land, woodland and wild grass ground will be decreasing. The reduce area is 34.40km2, 10.55km2 and 33.37km2 separately. Meanwhile, from 2002 to 2010, there is a mutual conversion each other.5. In order to achieve the sustainable development of Minqin oasis, this research analysized the drive force from the two aspects, natural factors and human factors. Finally, it provided the ways to restore the ecological oasis and recommendations, which include controlling the increase of population, reasonalbe use of water resources, implementation of the relocation of population, returning farmland to forest and grass, adjust industrial structure and set up monitoring and supervision system.