| Tabu river lies in the farming-pastoral zigzag zone of semi-arid area in northern China.It is a transition belt of natural environment factors of weather, relief, hydrology, biology etc.The entironment bears frangibility and instability.With the long affect of onrush, wind and hominine etc, the entironment seriously degenerated and deteriorated. It behaves that soil and plowland are degenerated,desert, electropositive, the fertility droped , the bestrow ratio of natural vegetation is laigh,the diversity of biology allayed etc.The desertification seriously jeopardizes human being.With the macroscopical and compositive character of many flat roof,multi- wave band,excessive period of time,more visual angle,much point of view,lots of polarization,RS with GIS has been widely used many domains on resource,environment,zoology research.The desertification change may be reflected by the hue,shape,texture,structure,shadow etc. We may intuitionisticly study the actuality ,observe the dynamic change of desertification,and may offer gist for analysing its cause of formation its prevention and cure,programming.Using landsat TM data in this paper,I study Tabu river drainage area of Siziwang county in Inner Mongolia.With the sustain of ERDAS and Mapinfo software,I studied to compose wave band by quantitative and optimized, remarkably extruded desertification information.I searched after the RS image classification way of desertification research.Using the result of RS image by disposed, linking the investigation on the spot,manifold ground information and GIS Stat. data, I analysed the desertification cause of Tabu drainage area ,and elicited following conclusion.(1) The desertification of Tabuhe drainage area has different eroded character at upriver, middle reaches , lower reaches. It happens water eroding at upriver,wind-water combined to erode at middle reaches ,wind eroding at lower reaches and part of the upriver.It relates to terrain and precipitation.(2).With the participated of morden fluvial course and past fluvial processed material, The desertification of Tabu drainage area has its particularity. The abundant fluvial wash and laky sediment of Tertiary and Quarterary on drainage area slopes,wide lofty plain supply material elements for the desertification.The modern river is the power to carry sand material,the riverway is the conveying channels to carry sand material, it is the base for sand material to diffuse.(3)Tahu river is a typical seasonal river,The desertification of drainage area happened with the natural and factitious factor effected. The river lies in the semi-arid area,the river only has water after rainstorm,its rainfall is very concentrative and abrupt, it induces the gouge to develop on the slopes and the sand material accumulates on the channel exit.The sand material expands with the role of strong wind,and the desertification develops quickly, the strong wind is not only blows the abundant sand material in the channel by abecedarian choosed,but also the power of ploughs fertility falls on upriver and middle reaches and leads the desertification occurs on the high plain.Its own act of human being is very aimless.It spoliatorily exploits resource and makes the desertification happen.The temperature rising in the twenty century helps the desertification developing.(4)To combine RS and GIS ,it exerts powerful role on studying desertification.Because its wide range of research area,if the humans investigated it,it would waste time,strength,money,but if we use RS technology,it would conveniently observe its actuality and change in time,this would save outlay and time. It incarnates the quantity of ground brightness,green grade,temperature,humidity etc. Not only can it qualitative analysis this circs,but also can combine GIS to quantitatively evaluate.(5)At last,I bring forward advice to prevent and cure desertification of Tabu river,it includes to improve the population diathesis,vigorously to develop middle and small city,actively to introduce into external capita...
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