Research On The Landscape Dynamics And Desertification Origination Of Mu Us Sandland

As a global environmental problem, desertification is one of the "research hotshots" all over the world. It has been demonstrated that the landscape ecology, a newly interdisciplinary, plays a very important role in the planning and management of resources development and the environmental conservation. Viewing from the point of landscape ecology and using some advanced techniques, I.E. remote sensing (RS) and geographical information system (GIS), the author studied the landscape classification and cartography, expanding dynamics, and the origination of desertification in Mu Us Sandland. The main results are as follows:(1) Based on the recent achievements from the abroad researchers, a set of methodologies in landscape classification and cartography of wind eroded, desertified land in arid and semi-arid areas were suggested and applied to the landscape cartography for different areas of the sandland at two scales, i.e. 1:500,000 and 1:50,000.(2) Some landscape ecology principles and methods were applied to reveal the landscape dynamics after the 1950s in the Mu Us Sandland. The result shows that landscape in the Mu Us Sandland has been suffering from dramatic changes from the 1950s to the 1990s. The area of the desertified lands has been expanding and, at the same time, the degree of desertification has been severely increasing and the landscape heterogeneity gets greater.(3) The spreading velocity of the desertified lands in the Mu Us Sandland from the 1950s was calculated, and the conclusions include the obvious spatial and temporal variations in the development of desertification in this period. In temporal, the developing speed of desertification from the late 1970s on is apparently lower than that in the 1960s and the early and mid-1970s, and desertified lands in some regions represent a negative growth;In spatial, the developing speed of desertification in the northwest pure grazing lands is much higher than those in the east and the south in which are partially farming and grazing areas. These conclusions will be beneficial to effectively evaluating the developing situation and tendency of desertification in the ecotone of fanning and grazing areas in north China.(4) The origination of desertification in the Mu Us Sandland was analyzed. At the decades of time scale, the expansion of the desertfied lands is majority provoked by human activities, while the climate fluctuation is only the background conditions for the development of desertification. This provides scientific basis for rational land use planning in arid and semi-arid areas.(5) The relationship between the landscape pattern and landscape process in the process ofdesertification are discussed and the variation regulation of the main element types in the landscape were obtained. The result proves that, to some extent, the landscape heterogeneity is positively correlated to the disturbance intensity in the landscape, but is irrelevant to the severity of desertification.