亚洲丝绸之路经济带土地退化时空格局及驱动力

发布时间：2018-05-07 03:19

本文选题：亚洲丝绸之路经济带 + 土地退化　；参考：《中国林业科学研究院》2016年博士论文

【摘要】：土地作为一种非可再生资源,是人类基本的生产资料和生存环境,是生态系统中一切生命存在的物质基础。土地退化是在自然因素和人类活动影响下土地生产能力和利用价值显著下降的过程。土地沙化、生物多样性退化和水土流失等土地退化现象日趋普遍和严重,破坏了自然生态系统物质和能量的动态平衡,威胁着全球食物安全和人类健康,并且严重阻碍着经济社会的可持续发展,探究气候变化背景下土地退化的驱动机制是实现自然和人类社会和谐发展的迫切需要和人类亟待解决的问题。干旱地区脆弱的生态系统对气候变化极为敏感,在气候变异和人类不合理的生产活动影响下,土地容易发生退化。新丝绸之路经济带主要位于亚洲内陆干旱区,其严重的水土流失和土地荒漠化等土地退化问题不利于区域经济的合作和可持续发展,因此有必要对该区域内土地退化现状进行监测和评价,该研究对区域生态系统恢复、区域经济合作以及新丝绸之路的顺利推进具有重要的理论意义。本文基于GIMMS3g和MODIS植被指数(NDVI)遥感数据,结合多种气象因子栅格数据,选用线性拟合、多元回归和残差多种方法开展研究区土地退化现状评价,并探究土地变化的驱动机制,定量分析人类活动对不同区域土地退化的影响,为制定丝绸之路土地退化防治措施提供科学依据。主要研究结果如下:(1)研究区内温度和潜在蒸散呈显著上升趋势,降水上升趋势不显著。不同的生态区内地中海林地和灌丛、沙漠和旱生灌丛温度增长较快,热带亚热带低纬度地区的降水变化幅度较大。研究区潜在蒸散增加趋势和干旱指数的减少趋势表明区域干旱程度增加。(2)研究区NDVI高值区位于中国东北、印度半岛和土耳其,植被覆盖较好,低值区集中分布在中国内蒙东部、青藏高原南部、中亚西部和阿拉伯半岛,植被覆盖较差。1982-2013 NDVI年均值呈增加趋势的像元比例为63.76%,主要分布在土耳其、印度半岛大部分地区。NDVI经历了上升-下降-上升的变化趋势,地中海林地和灌丛生态区增加幅度最大,斜率为0.18/100a,气候区内近赤道热带草原变化幅度也较大,趋势率空间均值为0.14/100a。(3)植被年均ndvi与温度、降水空间上主要表现为正相关,正相关像元比例分别为69.64%和74.50%。其中与降水显著相关的像元主要分布在中亚北部和南部,印度西部和蒙古高原东部。与潜在蒸散空间上以负相关为主,负相关显著的区域集中分布在中亚、印度半岛北部、蒙古和中国内蒙北部。与干旱指数的相关系数空间均值为0.19,呈显著正相关的像元比例高达41.47%,集中分布在中亚、印度、蒙古高原和土耳其西部地区。植被ndvi与干旱指数的偏相关系数最高,与温度和标准化降水蒸发指数呈负相关,与降水和潜在蒸散呈正相关。(4)亚洲丝绸之路经济带土地退化指数高值区位于印度半岛、土耳其北部和中国的东北,植被较好,低值区则分布在中国西北、中亚西部和阿拉伯半岛,植被较差,整个区域土地退化呈严重和较严重的像元比例分别为53.29%和32.66%。多年来人类活动对植被变化呈正向作用的区域主要分布在南亚印度、中亚中部和西亚土耳其,负向作用则集中分布在中亚北部等。热带亚热带地区的土地退化现状指数较高,该区域土地退化程度较轻,山地草原、灌丛和荒漠土地退化指数较小,区域土地退化程度较严重。土地退化动态指数表明人类活动对区域植被变化主要起促进作用,其中对山地草原和灌丛的植被生长促进作用最强。(5)回归方程模拟气候-植被关系表明80年代人类活动对区域植被呈负作用,90年呈正向作用。热带森林、草原和灌丛残差呈显著增加趋势,人类活动促进了区域植被生长。季节性淹没草原和稀树草原ndvi残差呈显著下降趋势,人类活动对该区域植被呈抑制作用。寒带气候区和苔原气候区ndvi残差表现为降低趋势,其他气候区ndvi残差呈增加趋势,近赤道热带草原区和热带稀树草原气候区增加趋势显著,表明人类活动对该区域植被生长影响强烈。(6)中国北方ndvi和初级生产力(npp)空间均值分布呈东南高,西北低的空间格局,ndvi和npp呈显著的增加趋势,趋势率分别为0.07/100a和148gc/m2/100a2。人类活动促进了中国东北和陕西南部ndvi的增加,抑制了内蒙中北部和新疆北部的增加。气候变化抑制了东北和新疆北部ndvi的增加,促进了内蒙东部、陕甘南部和青藏高原东部的植被变好。潜在npp(pnpp)和npp残差(rnpp)在空间上均以增加趋势为主表明气候变化和人类活动对植被npp的促进作用,趋势率范围为0—10gc/m2/y2的像元所占比例分别为68.59%和57.03%,主要分布在研究区的东部和中部。人类活动对植被NPP呈抑制作用的区域主要集中在新疆北部和内蒙东北部。
[Abstract]:Land, as a non renewable resource, is the basic production data and living environment of human beings. It is the material basis of all life in the ecosystem. Land degradation is a process of significant decline in land production capacity and use value under the influence of natural factors and human activities. Land desertification, biodiversity degradation and soil erosion. The phenomenon of land degradation is becoming more and more common and serious, which destroys the dynamic balance of material and energy in natural ecosystems, threatens the global food safety and human health, and seriously hinders the sustainable development of the economy and society. To explore the driving mechanism of land degradation under the background of climate change is an urgent need to realize the harmonious development of natural and human society. The fragile ecosystems in arid areas are extremely sensitive to climate change, and land is prone to degradation under the influence of climate variability and irrational human production activities. The new Silk Road Economic Zone is mainly located in the arid region of Asia, and its serious soil erosion and desertification, such as land desertification, etc. It is not conducive to regional economic cooperation and sustainable development, so it is necessary to monitor and evaluate the status of land degradation in the region, which has important theoretical significance for the restoration of regional ecosystems, regional economic cooperation and the smooth advancement of the new silk road. This paper is based on remote sensing data of the GIMMS3g and MODIS vegetation index (NDVI). In accordance with the grid data of various meteorological factors, the land degradation status of the study area was evaluated by linear fitting, multiple regression and residual methods, and the driving mechanism of land change was explored and the influence of human activities on land degradation in different regions was quantitatively analyzed. The main research was to provide scientific basis for the development of land degradation prevention measures in the silk road. The results are as follows: (1) the temperature and potential evapotranspiration in the study area are rising significantly, and the trend of precipitation rising is not significant. The temperature of the coastal woodland and shrubs, deserts and dryland shrubs in the mainland of different ecological areas is increasing rapidly, and the precipitation changes in the tropical and subtropical low latitudes are larger. The potential evapotranspiration trend and the drought index in the study area are higher. The decrease trend indicates that the degree of regional drought is increasing. (2) the high value area of NDVI in the study area is located in Northeast China, India Peninsula and Turkey, the vegetation covers better, the low value area is concentrated in the east of Inner Mongolia, the southern part of the Qinghai Tibet Plateau, Western Central Asia and the Arabia Peninsula, and the ratio of the average annual value of vegetation coverage to poor.1982-2013 NDVI is increasing. 63.76%, the main distribution in Turkey, most of the India Peninsula,.NDVI experienced a rising - decline - rising trend, the Mediterranean woodland and shrub ecological area increased the maximum, the slope is 0.18/100a, the climate zone near the equatorial tropical steppe is also larger, the average trend rate of spatial mean of 0.14/100a. (3) average annual vegetation NDVI and temperature, There is a positive correlation in the precipitation space, and the proportion of positive correlation pixels is 69.64% and 74.50%., respectively. The pixels which are significantly related to precipitation are mainly distributed in the northern and southern parts of Central Asia, in Western India and in the eastern part of the Mongolia plateau. The negative correlation is mainly in the potential evapotranspiration space, and the region of negative correlation is concentrated in Central Asia and the north of India peninsula. The spatial mean of correlation coefficient of drought index and drought index in Mongolia and Northern Inner Mongolia is 0.19, and the proportion of significant positive correlation pixel is up to 41.47%. It is concentrated in Central Asia, India, Mongolia plateau and Western Turkey. The partial correlation coefficient of vegetation NDVI and drought index is the highest, and is negatively correlated with temperature and standardized precipitation evaporation index. There is a positive correlation between precipitation and potential evapotranspiration. (4) the high value area of the land degradation index of the Asian Silk Road Economic Zone is located in India Peninsula, north of Turkey and northeast of China, with good vegetation and low value areas in Northwest China, Western Central Asia and Arabia Peninsula, with poor vegetation, and a serious and serious proportion of land degradation in the whole region. In the years of 53.29% and 32.66%., the areas where human activities have positive effects on vegetation change are mainly distributed in South Asia India, Central Asia and Western Asia, and the negative effect is concentrated in northern Central Asia. The index of land degradation in tropical subtropics is higher, and the land degradation in this region is relatively light, and the grassland, shrub and shrubs in this region. The land degradation index of desert land is smaller and the degree of land degradation is serious in the region. The dynamic index of land degradation indicates that human activity plays a major role in promoting regional vegetation change, among which the vegetation growth of mountain grassland and shrubs is the strongest. (5) the regression equation simulation climate vegetation relationship shows that in 80s human activities were on the regional vegetation. The negative effect was positive in 90 years. The residual difference in tropical forests, grassland and shrubs increased significantly. Human activities promoted the growth of regional vegetation. The NDVI residual of seasonal inundated grassland and savanna showed a significant downward trend, and human activities inhibited the vegetation in the region. The NDVI residuals in the cold zone and the tundra climate region were reduced. Trend, the NDVI residuals in other climatic regions are increasing, the increasing trend of the near equatorial and tropical savanna climate areas is significant, which indicates that human activity has a strong influence on the vegetation growth in the region. (6) the spatial mean distribution of NDVI and primary productivity (NPP) in northern China is higher in the southeast, and the spatial pattern of the northwest is low, and the NDVI and NPP are significantly increased. In addition, the trend rates of 0.07/100a and 148gc/m2/100a2., respectively, promoted the increase of NDVI in northeastern China and southern Shaanxi, inhibited the increase of North Central Inner Mongolia and Northern Xinjiang. Climate change inhibited the increase of NDVI in northeastern and Northern Xinjiang, and promoted the vegetation in eastern Inner Mongolia, Gannan and the east of the Qinghai Tibet Plateau. NPP (pNPP) and NPP residuals (rnpp) are mainly in space to increase the trend of climate change and human activity to promote the vegetation NPP. The proportion of the trend rate range from 0 to 10gc/m2/y2 is 68.59% and 57.03% respectively, mainly in the eastern and middle parts of the study area. It is concentrated in northern Xinjiang and northeast of Inner Mongolia.

【学位授予单位】：中国林业科学研究院
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S158.1

【参考文献】