【作者】 常月明；

【导师】 王心源；

【作者基本信息】 安徽师范大学 ， 自然地理学， 2004， 硕士

【摘要】 我国北方的农牧交错带，是一个气候、地貌、水文、生物等自然环境要素的过度带，生态环境具有脆弱性和不稳定性。这里在流水、风及人为因素的长期影响和作用下，生态环境退化和恶化现象极为严重，主要表现在：草地与耕地退化、沙化、盐渍化, 土地生产力下降、自然植被覆盖率低下、生物多样性减少等，这些尤以土地荒漠化危害最大。遥感技术以其多平台、多波段、多时相、多视场、多角度、多极化等综合的特点，并与GIS结合被广泛用于资源、环境、生态众多领域的研究。土地荒漠化可通过RS图像的色调、形态、纹理结构等的变化反映出来。用RS图像可以直观地研究荒漠化现状、监测荒漠化的动态变化，并为分析荒漠化成因以及荒漠化治理的规划提供依据。本文以内蒙古四子王旗的塔布河流域为研究对象，利用陆地卫星TM数据，在RS处理软件ERDAS和地理信息系统软件Mapinfo等的支持下，研究了波段优化组合、增强突出荒漠化信息，并探索了荒漠化研究的遥感图像分类方法。利用RS图像处理结果，结合实地考察、统计资料及数据统计分析，分析了塔布河流域的荒漠化成因，得出以下结论：（1）塔布河流域的荒漠化具有上、中、下游不同的侵蚀特点：上游段的水蚀特点，中游段的风水复合侵蚀特点，下游及上游部分地区的风蚀特点。这主要受地形以及降水有关。（2）河道在荒漠化发育上起着“起搏器”作用。它既有现代河流过程参与，也有过去河流作用的沉积物质参与。在该流域坡面上和广阔的高平原上，丰富的第三系和第四系河湖冲积-沉积物为荒漠化提供了物质基础。现代河流是搬运沙物质的动力，河道则成为沙物质的搬运通道，宽阔段是沙物质扩散的场地。（2）气象-气候条件深刻影响本区荒漠化。该流域位于阴山山脉北端，是寒潮、<WP=5>大风的通道，整个流域内，每年春季的大风不仅使耕地粗骨化，而且还把干枯的河床中为人类扰动的沙物质向两边的耕地蔓延，导致大量的肥沃土地沙化。由强降雨形成的洪流把上游坡面上的沙物质搬运到中下游的宽谷中沉积，特别在植物的固沙作用下，明显地造成沙物质的大量积聚。在该区无降水的其它时间，河道干涸无水，沉积的沙物质呈分散、疏松状态，极易为风扬起。（3）人类活动加剧荒漠化。人口的增长和落后的农、牧业生产方式，导致对土地粗放的经营和过度开发。特别在二十世纪八十年代以来冬春季的气温升高的背景下，更是加速了土地荒漠化进程。（4）遥感和GIS技术结合，在研究荒漠化方面发挥了巨大的优势。由于研究区范围广大，人工调查费时、费力，费用耗费也大，利用遥感技术可以及时的对大面积荒漠化现状及其变化进行监测，既经济又省时，它可以通过图像的颜色、纹理、形状、阴影等反映出地面及植被的亮度、绿度、热度、湿度等量，它不仅可定性的研究这些情况，还可以结合GIS定量地作出评估。（5）提出了该流域土地荒漠化治理的合理建议。对南部丘陵地带的严重水蚀区，采用工程措施治理，并做好拦蓄降水；北部草原地带做好网围、栏围的草库仑保护工作；调整农林牧产业结构，发展科技养畜，选择合适的造林树种和适当的地段造林；提高河滩地的粮食产量，退掉坡耕地，种草种树；加强法律措施，严禁滥采、滥伐、滥牧等破坏生态环境的行为；提高人口素质，转移人口对环境的压力。更多还原

【Abstract】 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 <WP=7>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更多还原