KMS XINJIANG INSTITUTE OF ECOLOGY AND GEOGRAPHY，CAS
| 2000-2013年塔里木河干流植被覆盖度时空变化特征及影响因子分析 | |
| 郭辉 | |
| Subtype | 硕士 |
| Thesis Advisor | 李向义 ; 包安明 |
| 2016 | |
| Degree Grantor | 中国科学院大学 |
| Place of Conferral | 北京 |
| Degree Discipline | 生态学 |
| Keyword | 修正的三波段最大梯度差模型 尺度上推 植被覆盖度 时空变化特征 影响因子 塔里木河干流 |
| Abstract | 植被覆盖度（Fractional Vegetation cover，简称FVC）是指植被（包括叶、茎、枝）在地面的垂直投影占统计区的面积比，是表征地表植被覆盖状况的重要参数。植被覆盖度及其变化特征是区域生态环境变化的重要指标。本文利用地面观测数据结合Landsat TM和MODIS数据，基于尺度上推的研究思路，采用修正的三波段最大梯度差模型反演植被覆盖度，分析了塔里木河干流2000-2013年植被覆盖度时空分布及其动态变化特征并探讨了影响因素。研究结果表明： （1）地面观测数据、Landsat TM与MODIS数据相结合进行尺度上推的研究方法，其尺度转换相对误差控制在4%以内，进而可以实现分析大范围长时间序列植被变化。 （2）塔里木河干流年内植被覆盖度最大值出现在7、8月份，2000-2013年平均植被覆盖度变化整体上呈现增长的趋势，上、中、下游年均植被覆盖度主要表现为上游>中游>下游；2000-2013年植被覆盖度空间分布差异明显，其中植被覆盖度增加区域主要分布在塔河上游平原及中下游沿河道或稍远河道及台特玛湖附近区域，而中游受到输水堤防的影响，植被覆盖度表现为微弱退化，速率为-0. 0869/年。 （3）伴随着塔里木河流域综合治理工程的实施，塔里木河干流植被覆盖度未来趋势变化将会朝着变好的方向发展。塔里木河干流-上游段受人为干扰较大，耕地未来趋势变化主要表现为最高改善趋势比，达61.03%，但主要通过毁坏灌木林为代价以满足农业生产需求，中游段受到输水堤防的影响，该段未来趋势主要表现为退化趋势，下游在生态输水工程的影响下，未来趋势变化主要由退化向改善发展。 （4）为了满足人类生产生活需要，塔里木河干流-上游段耕地面积增加幅度最大，而灌木林面积减少幅度最大，说明在塔里木河干流-上游段虽然植被覆盖度在增加，但是以牺牲自然植被来发展农耕用地而造成的。空间上，近河道处植被覆盖度为增加的趋势，远离河道处植被覆盖度为减少趋势并且北岸呈现减少趋势的面积明显大于南岸，面积比分别为80.15%，78.6%；时间上，中游植被覆盖度减少速率为-0.0869/年，中游北岸植被覆盖度下降速率明显高于南岸，分别为-0.2278/年，-0.0294/年。 （5）伴随着大西海子水库下泄水量的增减变化，下游植被覆盖度同样经历了显著增加（2000-2005年）-急剧减少（2006-2009年）-快速恢复（2010至今）的过程；同 时随着远离大西海子水库，生态调水工程效益减弱。 |
| Other Abstract | Fractional vegetation cover (FVC) refers to the percentage of the vertically projected area covered by vegetation which includes stem, leaf and branch as a fraction of the entire study area. FVC is an important parameter to characterize land surface vegetation and also an important indicator to understand the regional ecological environment changes. This paper, by using ground observation data with Landsat TM data and MODIS data, based on upscaling method，employing the modified three-band maximal gradient difference model which reverses fractional vegetation cover , analyzes the spatial-temporal change characters ,dynamic changes of fractional vegetation cover as well as the influencing factors on the mainstream of the Tarim River from 2000 to 2013. The result indicates that: （1）The methodology of upscaling through combining the ground observation data with Landsat TM data and MODIS data can realize the analysis of a wide range and long time series change in vegetation change.Sscale conversion error controlled within 4%. （2）The maximun value of fractional vegetation cover appears in July and August within a year on the mainstream of the Tarim River, the annual average fractional vegetation cover changes overall show a positive trends and the order is upper stream >middle stream>down stream; the fractional vegetation cover on the mainstream of Tarim River has a significant spatial variation where the plain of the upper stream and the near river channel or slightly away from river channel and near Taitema Lake on down stream are the increased area in fractional vegetation cover, however, the fractional vegetation cover shows a slightly decreasing trend on the middle stream affected by the water transport dike and the rate is -0. 0869/year. （3）Along with the comprehensive improvement project on the Tarim River, the fractional vegetation cover towards to the good direction in the further. The upper stream shows the highest improve trend in the future and the area ratio is the 61.03%, while this trend is to meet the demand of agricultural production by destructing shrub as price; there is a decreasing trend only in the future on the middle stream affected by the water transport dike and the trend from degradation to improvement in the future on the lower stream benefitted from the Ecological Water Diversion Program. （4）The degradation of the fractional vegetation cover due to the degeneration of the Land cover change fundamentally result from the construction of the water transport dike and the combined effect of the water transport dike and the ecological brakes bring the slightly decreasing trend on the middle stream of the Tarim River from 2000-2013. Spatially, there is an increasing trend of fractional vegetation cover near the river channel and the decreasing trend far away from the river channel, the area ratio of the decreasing trend on the north bank obviously greater than south bank and the area ratio are 80.15%, 78.6%, respectively; temporally, the decreasing trend rate is -0.0869/year, the decreasing trend rate of fractional vegetation cover on the north bank higher than south bank and the decreasing trend rate are -0.2278/year，-0.0294/year, respectively. （5）Along with the fluctuations of the release of the water yeild on the DaXiHaiZi reservoir, the fractional vegetation cover has undergone a significant increase (2000-2005)-dramatic decrease (2006-2009)-rapid recovery (from 2010 to present); the farther away from the DaXiHaiZi reservoir the more the benefits of the Ecological Water Diversion Program reduce. |
| Subject Area | 生态学 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.xjlas.org/handle/365004/14686 |
| Collection | 研究系统_荒漠环境研究室 |
| Affiliation | 中科院新疆生态与地理研究所 |
| Recommended Citation GB/T 7714 | 郭辉. 2000-2013年塔里木河干流植被覆盖度时空变化特征及影响因子分析[D]. 北京. 中国科学院大学,2016. |
| Files in This Item: | There are no files associated with this item. | |||||
Items in the repository are protected by copyright, with all rights reserved, unless otherwise indicated.
Edit Comment