【作者】 李慧静；

【导师】 包玉海；

【作者基本信息】 内蒙古师范大学 ， 地图学与地理信息系统， 2008， 硕士

【摘要】 植被在地球系统中扮演着重要的角色,植被影响地气系统的能量平衡,在气候、水文和生化循环中起着重要作用,是气候和人文因素对环境影响的敏感指标。由于植被具有明显的年际变化和季节变化的特点,并且是联结土壤、大气和水分的自然“纽带”,在一定的程度上能代表土地覆盖的变化,所以在全球变化研究中充当“指示器”的作用。因此对植被的动态监测可以从一定程度上反映气候变化的趋势,动态监测植被状况和植被覆盖变化也一直是生态环境研究的热点之一。本文利用2002-2006年5-8月内蒙古地区的MODIS数据进行NDVI数据的反演,分析其变化规律及其与气候因子中温度和降水的关系。同时选取了森林、草地、农耕地、沙地四种不同植被覆盖类型区域的10个子区作为研究区,分析了不同植被类型区域NDVI的月际、年际变化规律及其与气候因子的关系,得出的相关结论如下:1)内蒙古地区植被覆盖的基本特征是由西南向东北逐渐增加,与该区降水量分布相同;适中植被区的分布面积最大,裸土区、稀少植被区、很密植被区和茂密植被区分布面积基本相当;在NDVI的数值上,林地>农耕地>草地>沙地;2)月际变化上,5-8月NDVI不断增加,但有地区和植被类型上的差异,总的来说,NDVI变化率5-6月>6-7月>7-8月;林地NDVI的增加主要集中在5-6月,其他月份变化不大;草地NDVI的增加主要集中在6-7月;耕地的NDVI值5-8月期间稳定增长;沙地的NDVI值几乎没有增长;3)年际变化上,2002-2006年间,锡林郭勒盟草地的波动性最大,呈增加-减少-增加-减少的变化趋势;呼伦贝尔林区除了2004年丰水年NDVI有所增加外,其他年份都有所减少;内蒙古西部地区2002-2005年间NDVI不断增加,但2006年下降;且2005-2006年期间,各种类型植被普遍有退化现象;4)NDVI变化与月均温有很好的相关性,东北地区是月均温与NDVI相关的高值区,中部为低值区;NDVI变化与月降水量的相关性不强,但与滞后1月降水和滞后2月降水的相关性良好,与降水相关的高值区分布于内蒙古中部的草地;对于几种气候因子与NDVI的相关性来说,一般是滞后2月降水>滞后1月降水>月均温>月降水量;对于林地和草地来说,各种相关系数高纬高于低纬,对于农耕地来说,各种相关系数基本相当;对于沙地来说,各种相关系数均不高,这与其植被稀少且几乎没有变化有关。更多还原

【Abstract】 vegetation play a important role in the Earth system,it’s have impact on energy balance of earth—atmosphere system, and have significant effect on climate and hydrology and biochemistry cycle. At the same time, Vegetation is a sensitive indicator of climate and human factors influencing environment. The vegetation has obvious inter-annual change and seasonal changes, and has being a natural "bond" linking the soil, air and water, and it can represent changes in land cover to a certain extent, so that vegetation act as a "indicator " in the study of global changes. Because of that vegetation dynamics monitoring can reflect the trend of climate change in certain extent, monitoring vegetation conditions and vegetation coverage in dynamic mode also has been a hotspot on the ecological environment research.In this paper, we use year 2002-2006 MODIS data from May to August do NDVI data of inner Mongolia region inversion. After that we analyze its variety regulation and relationship with temperature and precipitation in climatic factors. At the same time, we selected 10 sub-regional areas of four different types of vegetation coverage area- forests, grassland, farmland, sandy land- as a study area, we analyze different vegetation type areas NDVI changes by year and by month and its relationship of climatic factors, The conclusions are as follows:1)The basic characteristics of the Inner Mongolia vegetation coverage is gradually increasing from southwest to northeast, Equally with precipitation distribution of the same region, the distribution of moderate vegetation region are the largest area; bare soil area, sparse vegetation area, very dense vegetation area and dense vegetation area have equal Distribution proportion; in the number of NDVI,forests> farmland>grassland>sandy land;2)On the occasion of changes by month, in May to August NDVI is overall increase, but there are differences in region and vegetation types. In general, the rate of change is May-June> June-July> July-August; NDVI of forests increased mainly concentrated in May to June, the others is in little change; and NDVI of lawn increased mainly concentrated in the June-July; NDVI of farmland grow steadily in May to August; sandy land almost have no growth.3) To the inter-annual changes, in the years 2002-2006, the grassland of Xilin Gole league have the largest fluctuation,it shows a Trend like increase-decrease-increase-decrease; the forests of Hulun Buir decrease at every year but 2004,because this year is a abundant water year; in Western Inner Mongolia, NDVI increased every year between 2002-2005, but in 2006,it’s decreased; and from year 2004-2006,we found general degradation of vegetation;4)NDVI changes have a good correlation with monthly averaged temperature. the northeastern region is high-value area which related to temperature and NDVI; low-value area is in the central region and the relevance of precipitation is not strong, but it’s have good correlation with lag one month precipitation and lag two months precipitation, the precipitation-related high-value areas are in the central Inner Mongolia grassland area; for the relevance of NDVI and several climatic factors, the regulation is lag two months precipitation>lag one month precipitation>monthly averaged temperature>monthly precipitation in general; for the forest and grass region, the regulation of every correlation coefficients is that the value of high latitudes region is higher than the value of low latitudes region; for the Agricultural Area, the correlation coefficients are equal; for the sandy land, every correlation coefficients are not high, this is because of its scarce vegetation coverage.更多还原