Study On The Landscape Patterns Change And Its Impacts On The Eco-environment Of The Middle Stream Of Tarim River

Analyzes of the landscape patterns change is the research hotspot of the landscape ecology at present. The paper chooses the middle stream of Tarim River, which eco-environment is fragile with relatively strong human activities, as the target area, and utilize remote sensing technology to obtain the basic data of landscape patterns of study area in 1973,1992 and 2000. Then on the basis of 3S technology and landscape ecology techniques, analyzes the characteristics of landscape patterns change in middle stream of Tarim River in recent 30 years, provides a scientific basis for exploitation and eco-environment protection of the study area. The result shows:1. Use PCI and ENVI, integrate with the real conditions of study area, by digital image processing, classify the RS images of study area in 1973,1992 and 2000, The classification accuracy is 95.35%,96.47%与98.22%. Then, on the bases of classification results and anterior research results, analyzes the evolvement dynamics of landscape patterns on 1973~1992 and on 1992~2000.2. On 1973~1992, the area proportion of shrubbery and meadow in study area had been increased. The area proportion of woodland, water area and other area had been decreased. Furthermore, the change rate of shrubbery was the quickest, was annual 0.268%. According to the landscape patterns changed over in 1992, 0.75km~2 of farm land was changed over from woodland. On 1992~2000, the area proportion of shrubbery, meadow and other area in study area had been increased. The area proportion of woodland and water area had been decreased. Furthermore, the change rate of shrubbery was also the quickest, was annual 1.063%. According to the landscape patterns changed over in 2000, 4.03km~2 of farm land was changed over from woodland.According to the landscape patterns transformation matrix, the landscape patterns change speed on 1992~2000 was quicker then on 1973~1992, especially, the change speed of woodland was reached to -1.604. It indicates that, forest resources have been come under great breakage, and desertification has been gradually increased.3. On 1973~1992, comprehensive trends, LUCC R_t was 0.51%. At space, the space dynamic change degree of meadow was the heaviest, and it was 11.79%, the woodland trends degree was the least, and it was 3.08%; On 1992~2000, comprehensive trends, LUCC R_t was 1.85%. It shows that, LUCC R_t of study area on 1992~2000 is almost quicker three times than on 1973~1992. At space, the space dynamic change degree of farm land was the heaviest, and it was 70.38%, the woodland trends degree was the least, and it was 5.95%.4. On 1973~1992, the changing amount of land utilized degree of study area was -0.20%, Re<0. It proves that the land use is at redressed period or recessionary period. On 1992~2000, the changing amount of land utilized degree of study area was -0.84%, R_e<0. It proves that the land use is at the period that should be developing to the redressed period that benefit to ecological comeback.5. The hydrological status of Tarim River is the main natural reason that leading to the landscape patterns change. Open up land, Runoff decrease, water quality deterioration, digging economical vegetation and oil exploitation are the reasons that leading to the landscape patterns change in study area.6. The landscape patterns change of the middle stream of Tarim River in recent 30 years, has worked negative effects to the eco-environmental situation and economical development of the study area. Mostly represents as: degradation of surface vegetation, desertification, and degradation of swamps and deterioration of soil conditions. Therefore, some effective measures should be put up for the sake of eco-environment protection, and assure sustainable economic development.