基于RS和GIS的塔里木盆地荒漠化动态监测

发布时间：2018-03-24 02:29

本文选题：塔里木盆地　切入点：荒漠化　出处：《新疆师范大学》2017年硕士论文

【摘要】：塔里木盆地作为丝绸之路经济带中段的核心区,蕴藏着丰富的自然资源,但同时也是丝绸之路经济带沿线自然生态环境极为脆弱的地区,该地区土地荒漠化严重,加之人类活动的干扰,特别是水土资源的不合理利用,严重制约着区域的生态安全和经济可持续发展,所以当前掌握塔里木盆地荒漠化过程以及动态变化趋势显得尤为重要。本文基于RS和GIS技术,利用MODIS-NDVI遥感数据,计算植被覆盖度作为评价指标,对塔里木盆地2000—2014年的荒漠化空间格局进行了分析,并探讨了气候变化和人类活动对荒漠化的影响。研究结果表明:(1)塔里木盆地重度荒漠化占比最大(64.63%),中度荒漠化(17.70%)、轻度荒漠化(9.95%)、非荒漠化较少(4.18%)。从空间上看,重度荒漠化面积主要分布在塔里木盆地中部地区,包含塔克拉玛干沙漠,近15年塔里木盆地东北方向荒漠化有所加剧;中度荒漠化主要分布在沙漠与绿洲过渡带区域,沿塔里木河干流中度荒漠化扩张明显;轻度荒漠化区域主要分布于灌丛和草地,主要位于渭干河-库车河绿洲,而非荒漠化区域主要为人类活动的人工绿洲及绿洲边缘;(2)不同程度荒漠化土地面积变化不一,重度荒漠化面积近十余年平均变化速率约为-0.0076 km_2·a-1,略有减少,而中度荒漠化面积增加迅速,以0.0169km_2·a-1速率增加,轻度荒漠化面积小幅上升,非荒漠化面积则显著上升,分别以0.0093和0.0289 km_2·a-1的速率增加;(3)对MODIS数据进行精度评价,总体上评估精度达到了75.25%,说明两种分辨率的数据产品评估荒漠化的结果大体上一致。通过塔里木盆地重心轨迹迁移显示,重度荒漠化15年间向东北方向迁移21.08 km,说明重度荒漠化向东北方向迁移,主要原因是塔克拉玛干沙漠存在北移扩张,而非荒漠化整体向西南迁移了65.23km,迁移方向与水源条件有关,同时还与人工绿洲不断扩张、耕地面积扩大密切联系着。同时对荒漠化加重区域分析得出,环塔克拉玛干沙漠边缘分布着荒漠化加重区域,荒漠化向绿洲扩张,通过栅格计算,2000-2014年荒漠化加重区域占塔里木盆地土地总面积的9.04%;(4)塔里木盆地荒漠化是由气候和土地利用变化共同作用的结果。年降水量与荒漠化关系密切,相关系数为0.45,年均温与荒漠化的相关系数为-0.24;土地利用也发生着显著变化,2000-2014年间,盆地耕地面积持续不断扩张,从23.4×10_3km_2增长到36.58×10_3km_2,近15a间耕地面积增加了13.18×10_3km_2,其中,以沿塔里木河干流区耕地面积增加最快,说明人类活动较为剧烈,同时,强烈挤占了生态用水,加速了绿洲外围荒漠化过程的发展。
[Abstract]:The Tarim Basin, as the core area of the middle section of the Silk Road economic belt, is rich in natural resources, but at the same time, it is also a region where the natural ecological environment along the Silk Road Economic Belt is extremely fragile. The land desertification in this area is serious. In addition, the disturbance of human activities, especially the unreasonable utilization of water and soil resources, seriously restricts the ecological security and sustainable economic development of the region. Therefore, it is very important to master the process of desertification and the trend of dynamic change in Tarim Basin. Based on RS and GIS technology, this paper uses MODIS-NDVI remote sensing data to calculate vegetation coverage as evaluation index. The spatial pattern of desertification in the Tarim Basin from 2000 to 2014 was analysed, The effects of climate change and human activities on desertification are also discussed. The results show that the largest proportion of heavy desertification in Tarim Basin is 64.63m, the proportion of moderate desertification is 17.7070m, the mildly desertification is 9.95m, and the non-desertification is less 4.18. from the spatial point of view, The area of severe desertification is mainly distributed in the central part of Tarim Basin, including the Taklimakan Desert. In the last 15 years, the desertification in the northeast direction of the Tarim Basin has been intensified, while the moderate desertification is mainly distributed in the transitional zone between desert and oasis. The moderate desertification along the main stream of Tarim River is obvious, and the area of slight desertification is mainly distributed in thickets and grasslands, mainly located in the oasis of Weigan River and Kuqa River. In the non-desertification area, the artificial oasis and the oasis edge mainly belong to human activities. The land area of desertification varies with different degrees. The average rate of change in the area of severe desertification is about -0.0076 km_2 / a ~ (-1) in the last decade, which decreases slightly. The moderate desertification area increased rapidly, the 0.0169km_2 a-1 rate increased, the slight desertification area increased slightly, and the non-desertification area increased significantly. The accuracy of MODIS data was evaluated at the rate of 0.0093 and 0.0289 MODIS a-1, respectively. The overall accuracy of the assessment has reached 75.25, indicating that the results of the two resolution data products in assessing desertification are generally consistent. The migration of the center of gravity of the Tarim basin shows that. During the 15 years of severe desertification, the migration to northeast direction was 21.08 km, indicating that the migration of heavy desertification to northeast direction was mainly due to the northward migration and expansion of Taklimakan Desert, but not to the whole migration of 65.23 km of desertification to the southwest. The migration direction was related to the water source condition. At the same time, it is closely related to the continuous expansion of artificial oasis and the expansion of cultivated land area. At the same time, the analysis of the region of desertification aggravation shows that the desertification aggravation area distributes along the edge of Taklimakan Desert, and the desertification expands to the oasis. Desertification in the Tarim Basin from 2000 to 2014 accounts for 9.04% of the total land area of the Tarim Basin. Desertification in the Tarim Basin is the result of climate and land use change. The annual precipitation is closely related to desertification. The correlation coefficient is 0.45, and the correlation coefficient between annual mean temperature and desertification is -0.24.The land use has also undergone significant changes. During the period 2000-2014, the area of cultivated land in the basin continued to expand, from 23.4 脳 10_3km_2 to 36.58 脳 103km2, and the cultivated land area increased 13.18 脳 103km2 over the past 15 years, of which, The increase of cultivated land area along the Tarim River shows that the human activities are more intense, and the ecological water consumption is taken up strongly, which accelerates the development of desertification process in the periphery of the oasis.
【学位授予单位】：新疆师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X171.1;P208;X87

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