北方防沙屏障带防风固沙生态系统服务功能变化评估

发布时间：2019-03-19 09:21

【摘要】：我国西北地区由于地处大陆深处年均降雨量较低,同时蒸发量大,加之人口过快增长给环境带来了的巨大压力,使得人类过度开垦放牧等,这些因素综合作用造成我国北方地区沙漠化面积日益扩张。长期以来,我国投入大量人力物力进行防风固沙工作,尽管取得了一定的成效,但整体上我国沙漠化形势依然严峻。本研究所选取的研究区北方防沙屏障带主要分布于内蒙古自治区、甘肃省、青海省和新疆维吾尔自治区等省份,是我国“两屏三带”生态安全战略格局的重要组成部分,在维护我国生态安全中具有重要地位。论文采用修正风蚀模型(RWEQ)定量研究北方防沙屏障带1982-2011年间的防风固沙功能的时空变化特征,分析影响变化的因素,并通过探究屏障区两侧近30年来我国沙尘暴活动强度变化趋势来预测北方防沙屏障带的屏障效应,主要结论如下:(1)北方防沙屏障带的防风固沙能力大小依次是内蒙古防沙屏障带、河西走廊防沙屏障带以及塔里木防沙屏障带;1982-2011年河西走廊防沙屏障带的整体防风固沙功能变化趋势呈现增强趋势,塔里木防沙屏障带中部和内蒙古防沙屏障带的东北部地区防风固沙能力呈现减小趋势。(2)北方防沙屏障带生态系统变化研究中,塔里木防沙屏障带南部植被覆盖度变化显著,中部NPP变化显著;河西走廊防沙屏障带西北地区植被覆盖度变化显著,中部地区叶面积指数变化显著;内蒙古防沙屏障带植被覆盖度、NPP以及叶面积指数显著变化区域离散分布在屏障区内。北方防沙屏障带土地利用类型中2000-2010年农田净转出面积最高,大部分地区转出成为草地、灌丛。(3)分析土地利用变化在近十年里对防风固沙服务功能的影响发现:北方防沙屏障带各土地利用类型固沙物质量序列依次为草地沙漠农田灌丛裸地林地城镇,草地是控制北方防沙屏障带风力侵蚀,起到防风固沙作用的主要土地利用类型。(4)整体上看,北方防沙屏障处于低植被覆盖和较低植被覆盖,在北方防沙屏障带植被覆盖度变化程度分成的7个等级中,与屏障带防风固沙能力呈现正相关的只有中度及以上增加的区域,其余范围的植被覆盖度变化程度与防风固沙能力呈现负相关。(5)本文基于“中国强沙尘暴序列及其支撑数据集”利用反距离权重空间插值法对我国1980-2007年沙尘暴强度的时空变化进行空间插值分析,结果表明我国北方沙尘暴活动较为剧烈的地区集中在南疆盆地南部边缘、阿拉善高原地区和内蒙古东北部的锡林郭勒盟地区;从地理位置上看,北方防沙屏障带是建立在靠近沙尘源区的绿色生态安全屏障,利用位于这些区域下风向的各个气象站的沙尘暴强度变化时间序列曲线来预测我国北方防沙屏障带屏障作用效应最好的是内蒙古防沙屏障带,塔里木防沙屏障带最差。从沙尘暴强度变化趋势看,重点应加强内蒙古防沙屏障带生态屏障建设。
[Abstract]:Due to the low average annual rainfall in the depth of the mainland, the large amount of evaporation, and the enormous pressure on the environment caused by the rapid population growth, the northwest region of China has over-cultivated and grazing, and so on. These factors have caused the desertification area to expand day by day in the northern part of China. For a long time, a great deal of manpower and material resources have been put into the work of preventing wind and fixing sand in our country, but the situation of desertification in our country is still severe in the whole, although some achievements have been made. The sand barrier zone in the northern part of the study area is mainly distributed in Inner Mongolia Autonomous region, Gansu Province, Qinghai Province and Xinjiang Uygur Autonomous region, which is an important part of the ecological security strategic pattern of "two screens and three zones" in China. It plays an important role in maintaining the ecological security of our country. In this paper, a modified wind erosion model (RWEQ) is used to quantitatively study the spatial and temporal characteristics of the function of wind and sand fixation in the north of China from 1982 to 2011, and the factors affecting the change are analyzed. The barrier effect of the barrier zone in the north of China is predicted by exploring the trend of dust storm activity intensity on both sides of the barrier area in the past 30 years in China. The main conclusions are as follows: (1) the anti-sand barrier zone of Inner Mongolia, Hexi Corridor and Tarim; From 1982 to 2011, the overall wind-proof and sand-fixing function of the barrier zone of Hexi Corridor showed an enhanced trend. In the middle part of Tarim anti-sand barrier zone and the northeast area of Inner Mongolia sand barrier zone, the wind-proof and sand-fixing capacity showed a decreasing trend. (2) the ecosystem changes of the sand-proof barrier zone in the north of China were studied. The vegetation coverage changes significantly in the southern part of the sand barrier zone of Tarim, and the NPP changes significantly in the middle part of Tarim Basin. The vegetation coverage, NPP and leaf area index in the barrier zone of the Hexi Corridor changed significantly in the northwest region and in the middle part of the corridor, and distributed in the barrier area in Inner Mongolia, where the vegetation coverage, the vegetation coverage and the leaf area index changed significantly in the sand barrier zone in Inner Mongolia. In the north of China, the land use type of the sand barrier zone was the highest in 2000-2010, and most of the areas were transferred to grassland. (3) analyzing the influence of land use change on the function of wind-proof sand-fixing service in the last ten years, it is found that the sequence of sand-fixing material quality of land-use types in the northern sand-barrier zone is grassland, desert, farmland, scrub, bare land, woodland, town, and so on. Grassland is the main land use type to control wind erosion and sand fixation in the north of China. (4) on the whole, the sand barrier in the north is under low vegetation cover and lower vegetation cover. Among the seven grades of vegetation coverage variation of the barrier zone in the north, only the areas with moderate or higher increases were positively correlated with the wind-proof sand-fixation capacity of the barrier zone, and there were only a few areas with a positive correlation with the windbreak and sand fixation capacity of the barrier zone. There is a negative correlation between the change degree of vegetation cover and the ability of wind and sand fixation. (5) based on "China strong sandstorm series and its supporting data set", this paper uses the inverse distance weight spatial interpolation method to study China from 1980 to 2007. The spatial and temporal variation of dust storm intensity was analyzed by spatial interpolation. The results show that the areas with severe sandstorm activity in northern China are concentrated on the southern edge of the southern Xinjiang Basin, the Alashan Plateau area and Xilingol League area in the northeast of Inner Mongolia. From the geographical point of view, the northern anti-sand barrier zone is a green ecological security barrier built near the dust source area. Based on the time series curves of dust storm intensity variation at various meteorological stations located in these areas, the best barrier effect of sand barrier zone in northern China is in Inner Mongolia and the worst in Tarim. From the change trend of dust storm intensity, emphasis should be placed on strengthening the construction of ecological barrier of sand barrier zone in Inner Mongolia.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X171.1;X826

【参考文献】