新疆木垒县梧桐窝子普查区荒漠化动态变化研究

发布时间：2018-10-30 06:25

【摘要】：本文利用遥感数据先对新疆木垒县梧桐窝子煤田普查区的植被、盐渍化和浅层地下水三个方面进行了研究,最后结合三个方面对研究区进行了荒漠化综合评价。在利用2000-2012年的MODIS数据、气象及高程数据对研究区的植被变化趋势及影响因素进行分析过程中,发现虽然研究区内植被整体生长较差,但在这13年间全区植被有转好趋势,并且区内植被长势与降水、相对湿度和地形均存在大体的正相关关系,其中植被对降水的响应滞后1个月,而区内植被最适宜生长的高度是1640-1830m。对研究区的盐渍化分析是利用1989、2000和2010年的TM数据,采用决策树和阈值划分结合,对研究区的盐渍化情况进行提取和统计。结果发现全区盐渍化程度低,盐碱地面积不超过2%,其中2010年盐碱地面积最大,而2000年盐碱地面积最小,对比气象数据后推测短时降雨、气温和年降水量是造成研究区年际盐渍化变化的原因。由于研究区内缺乏地下水数据,因此本文利用DEM数据和TM数据提取的坡度、起伏度、汇流累积量、盐渍化和植被情况,采用层次分析法对浅层地下水赋存概率进行了预测,结果表明研究区浅层地下水资源匮乏,极有可能存在浅层地下水的区域仅为全区的2.56%,且主要分布在北部盐池、中部冲沟和地表水体周围。为了对研究区的荒漠化情况进行分析,本文用植被覆盖率对研究区进行了荒漠化分区并计算其土地转移速率,结果表明研究区在2000-2012年间荒漠化程度有所好转。为了进一步对研究区的荒漠化程度进行综合评价,本文统计了研究区盐渍化的变化速率和浅层地下水赋存概率的分区情况,并对两图分别统计了与植被指数的关系。结果表明研究区内浅层地下水赋存概率低,浅层地下水资源匮乏,但其与植被生长存在良好的正相关关系;而盐渍化面积扩张快且程度加重,对研究区的植被生长存在明显的抑制作用。因此,综合上述三个方面的情况,本文认为尽管研究区的荒漠化程度出现好转趋势,但是其盐渍化程度的快速扩张和浅层地下水资源的匮乏势必会对该区的发展造成限制,整体的荒漠化形势并不乐观。
[Abstract]:In this paper, three aspects of vegetation, salinization and shallow groundwater in the general survey area of Wutongwo coalfield in Muli County, Xinjiang were studied by using remote sensing data. Finally, the comprehensive evaluation of desertification in the study area was carried out in combination with three aspects. Using MODIS data, meteorological and elevation data from 2000 to 2012 to analyze the trend of vegetation change and its influencing factors in the study area, it is found that although the overall growth of vegetation in the study area is poor, the vegetation in the whole area has a trend of improvement in the past 13 years. There is a positive correlation between vegetation growth and precipitation, relative humidity and topography, in which the response of vegetation to precipitation lags by 1 month, and the height of vegetation growth is 1640-1830 m. The salinization analysis of the study area is based on the TM data of 19892000 and 2010, and the decision tree and threshold division are used to extract and statistics the salinization in the study area. The results showed that the salinization degree in the whole area was low, the saline-alkali land area was not more than 2, the saline-alkali land area was the largest in 2010, and the saline-alkali land area in 2000 was the smallest. Air temperature and annual precipitation are the causes of inter-annual salinization in the study area. Due to the lack of groundwater data in the study area, the slope, fluctuation, accumulation of runoff, salinization and vegetation, extracted from DEM data and TM data, are used to predict the occurrence probability of shallow groundwater in this paper. The results show that the shallow groundwater resources are scarce in the study area. The area where there is shallow groundwater is only 2.56 in the whole area, and it is mainly distributed around the salt pond in the north, the gully in the middle part and the surface water body. In order to analyze the desertification in the study area, this paper uses vegetation coverage to divide the study area and calculate its land transfer rate. The results show that the desertification degree of the study area improved from 2000 to 2012. In order to further evaluate the degree of desertification in the study area, the change rate of salinization and the partition of probability of occurrence of shallow groundwater in the study area are analyzed in this paper, and the relationship between the two maps and the vegetation index is analyzed respectively. The results show that the occurrence probability of shallow groundwater in the study area is low, and the shallow groundwater resources are scarce, but there is a good positive correlation between the occurrence of shallow groundwater and the growth of vegetation. The salinization area expanded rapidly and the degree of salinization increased, and the vegetation growth in the study area was inhibited obviously. Therefore, in view of the above three aspects, this paper holds that although the degree of desertification in the study area is improving, the rapid expansion of its salinization and the scarcity of shallow groundwater resources are bound to limit the development of the area. The overall situation of desertification is not optimistic.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X171.1

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