新疆渭干河流域土壤盐渍化时空变化及成因分析

以1985 年渭干河流域土壤普查数据、1998 年Landsat TM影像和2008 年CBERS影像为数据源, 通过人机交互解译方式获取3 个时期土壤盐渍化分布状况, 然后采用GIS空间分析方法对23 年来土壤盐渍化时空变化特征进行分析。结果表明:①1985-2008 年, 总趋势是随着流域灌区和耕地面积的扩大, 盐渍化耕地也随之增加, 土壤盐渍化耕地面积由13.32×10⁴hm²增至13.78×10⁴hm²。②流域土壤盐渍化现象普遍, 主要分布在绿洲的下部边缘地带, 河流中下游、地势平缓低洼等区域, 盐渍化耕地在绿洲内部呈条形状分布, 在绿洲外围呈片状分布。③河道、渠系和水库渗漏、耕作制度不合理、土地不平整和气候变化等多种因素导致渭干河流域土壤盐渍化扩大, 但在局部地区由于生态恢复和改良利用措施, 使得土壤盐渍化面积也有缩减。     

近25 a来塔里木盆地灌区土壤盐渍化时空变化特点与改良治理对策

依据科学和可操作性原则,建立研究区土壤盐渍化等级分类体系和解译标志.通过对三期塔里木灌区土壤盐渍化信息数据的对比研究,结果表明了该区土壤盐渍化是自然和人为因素共同作用的产物,人类活动促进了盐渍化的发展;塔里木灌区土壤盐渍化主要分布于盆地的北部和西部,危害重点地区是喀什、叶尔羌河流域等地.并由老灌区向新灌区、中重度向轻度...     

新疆焉耆县土地盐渍化遥感监测

土地盐渍化不仅会造成地表土壤资源的破坏和农业生产的巨大损失,而且对干旱区绿洲的生态安全也构成了极大威胁,已成为一个全球性的环境(土地)退化问题。研究土地盐渍化动态演化过程及其空间分布特征,有助于了解土地盐渍化变化规律与发展趋势,对于干旱区的粮食生产安全及经济发展无疑具有重要意义。利用遥感和GIS技术,以新疆焉耆县为例,基于土地利用现状图和1976、1994和2009年的MSS、TM、ETM遥感影像,系统分析了区域土地盐渍化的动态演化过程和空间分布特征。研究结果表明,1976-2009年间,尽管焉耆县的土地利用类型未发生显著变化,但土地盐碱化的面积却呈现显著增长趋势,并已达到研究区面积的8.85%;研究时段内,盐碱化持续加重区域的面积比例相对较高,盐碱沼泽和重度盐碱土地在研究区所占面积比例分别增加了2.97%和1.31%,这表明焉耆县土地盐碱化程度发展较快,今后需改善灌溉及排水方式,合理利用地下水。     

长江流域人口-土地-经济城镇化的时空耦合协调性与驱动因子分析

运用熵值法对长江流域2008年、2013年及2018年3个时期105个地级市的人口、土地、经济城镇化水平进行多维评测;依托ArcGIS平台分析城镇化的时空演变特征及耦合协调性的时空集聚模式;采用多元线性回归模型,挖掘城镇化耦合协调性的驱动因子。结果表明：长江上中下游地区城镇化耦合协调度显著差异,呈现出：下游地区＞＞中游地区＞上游地区的格局。城镇化耦合协调度中等协调及以上水平的地级市主要位于长江三角洲、合肥与皖江沿线、武汉城市圈、长沙城市圈、成渝城市群、南昌、贵阳、昆明等地。耦合协调度处于失调水平的地级市主要位于长江源头地区、藏东—川西—滇北横断山区、甘肃陇南、乌蒙山区、武陵山区、南岭地区等地。城镇化耦合协调度的空间集聚模式可划分为热点聚集型、中部发展型、冷点聚集型、边缘游离型4种类型。在此基础上,构建出4种空间集聚类型的拟合模型,决定系数R²均大于0.800。立足于新型城镇化建设,对长江流域人口、土地、经济城镇化的发展提出了针对性的政策建议。     

1997~2005年区域城市土地集约度变化与影响因子分析

城市土地集约利用研究具有非常重要的意义。本文以不同区域内的14 个省会城市为研究对象,从城市承 载力和城市协调度两个方面挑选了20 个指标,采用主成分分析的方法计算得出14 个城市1997—2005 年间的城 市土地集约利用值,得出了重要主成分所含的指标及其在研究期间内的变化与差异;然后从区域城市土地集约利 用的角度出发,分析了不同区域内城市土地集约度变化的一致性和变化趋势;以变化为基础,将影响因子分为自然 导向型、投入导向型、产出导向型和城市容貌导向型四个不同类型,分析了这些类型的影响因子在研究期间内的变 化,同时结合城市土地集约利用度分析了这些类型影响因子的作用。本文一方面全面掌握了区域城市土地集约利 用变化的趋势;另一方面为城市土地集约利用挖潜提供了参考。     

中国人口健康分布的时空变化与影响因素

该文利用最近3次人口普查获得的资料,对我国省级层面的人口健康分布的时空变化特征与影响因素进行分析。结果表明:1)近20年我国居民总体的健康状况得到较大改善,但人均预期寿命存在明显的省际差异,呈现西部较低、中部次之、东部最高的空间梯度特征,差异程度随时间不断降低;2)各地区健康分布并非表现出完全的随机性,而是在总体上呈现出一定的空间集聚趋势,但集聚趋势随时间变化有所弱化;3)地区人均预期寿命的增加速度与初始水平负相关,初始水平较低的地区增速普遍高于初始水平较高的省区,空间收敛趋势明显;4)人均GDP、食物支出占比、森林覆盖率与废水处理达标率等指标较高的地区的预期寿命相对较高,城市化的快速推进与医疗设施禀赋变化对人口健康的净效应总体为负。     

洞庭湖区土地生态系统的服务价值时空变化

采用5期遥感影像数据,在ArcGIS等软件支撑下,运用当量因子法、空间自相关分析法,估算洞庭湖区土地生态系统服务价值,探究其时空变化。结果表明：① 1995—2015年洞庭湖区林地面积持续减少,未利用地面积稳步增加,林地与未利用地面积的增减主导着区域土地利用变化。② 1995—2015年洞庭湖区土地生态系统服务总价值经历1995—2000年的陡增后不断下降,近20年来累计减少21.64亿元,减少幅度为1.06%,林地面积减少是洞庭湖区土地生态系统服务总价值减少的根本原因。③ 从土地生态系统服务价值结构变化来看,1995—2015年洞庭湖区除废物处理价值有小幅增加外,其他各项生态服务价值均有不同程度的下降,但生态环境保育始终是洞庭湖区土地生态系统的主要功能。④ 1995—2015年洞庭湖区土地生态系统服务价值分布的空间自相关性较为显著,格局变化较明显,高值区、低值区趋于集中,高-高类型区在西部的沅江流域常德段有所减少,向东部的汨罗江流域快速扩展,低-低类型区集中在北部、南部、西部的城镇相对密集区并沿城镇发展轴逐步扩张凝结成带片状。     

欧亚大陆冬季雪深的时空演变特征及其影响因子分析

利用美国冰雪资料中心(National Snow and Ice Data Center)提供的前苏联1948~1994年逐日积雪深度资料,定义了冬季雪深增量的概念,探讨了欧亚大陆秋末雪深、冬季雪深、冬季雪深增量的时空演变规律,通过比较分析三者的异常变化特征,揭示了三者之间可能存在的联系。经验正交函数分解(EOF)结果表明:欧亚大陆冬季雪深、冬季雪深增量的第一模态的空间分布特征均为大致以50°N为界的南北反相变化,欧亚大陆北部的积雪深度和冬季雪深增量都呈现出一致性的变化趋势;两者对应的时间序列均反映了显著的年代际变化特征,且年代际转变均发生在20世纪70年代中期前后。第二模态则呈现出欧亚大陆东、西部反相的偶极型空间分布特征。进一步分析表明,欧亚大陆秋末雪深无论从空间分布还是时间演变来看与冬季雪深几乎不存在相关性。欧亚大陆冬季雪深变化主要是冬季雪深增量影响所致,与秋末雪深无关。     

青海省降尘量时空分布及其影响因素分析

大气降尘在生活中随处可见,与人们的生活息息相关。本研究应用青海省8个监测站2004-2010年降尘量资料及气候和社会资料,对青海省降尘量时空分布规律及其影响因素进行灰色关联度和主成分分析。结果表明,青海省降尘量城市大,偏远的瓦里关山小;月降尘量4月峰11月谷;季节降尘量春季＞夏季＞冬季＞秋季;年降尘量玛多和西宁呈下降趋势,共和与平安呈增加趋势,而瓦里关本底台、德令哈、同仁和格尔木降尘量年际间变化趋势不明显。沙尘天气出现频率年际和年代际变化均呈减少趋势。气候因素与降尘量的关联度自青海省东部向西部逐渐增大;社会因素中与降尘量的关联度大于0.900的因子有造林面积、木材采伐量、房屋建筑竣工面积、烟尘排放量、植被盖度综合指数、人口、工业粉尘排放量和农作物播种面积;对与降尘量的灰色关联度大于0.8的19个社会、气候因子进行主成分分析表明,气候因子的载荷值明显高于社会因子,气候因素对降尘量的影响集中而突出,而社会因素影响复杂而分散。     

中国土地利用效益的时空特征研究

基于经济、社会、生态三维视角构建土地利用效益评价指标体系,运用灰色关联方法测度2004—2014年中国土地利用效益水平,并借助于Arc GIS空间分析技术分析其空间异质性及空间演变格局。从时序特征来看,2004—2014年全国土地利用效益波动性提升。从空间特征来看,中国土地利用效益的空间格局存在差异性,但差异日渐缩小;土地利用效益的增减空间分布不均,随着时间的推移,土地利用效益提升省份增加的幅度越来越大,土地利用效益降低省份的下降幅度越来越小;中国土地利用效益空间集聚特征明显,热点主要分布在内蒙古、辽宁和西藏,冷点主要分布在东南沿海地区;土地利用效益的变化也表现出集聚特征,东南沿海与西部地区为中国土地利用效益变化最强烈的集聚区,其土地利用效益变化呈互逆发展态势;中国土地利用效益变化具有明显的政策导向性。     

巴西土地利用/覆盖变化时空格局及驱动因素

土地利用/覆盖变化(LUCC)是全球变化研究的热点问题之一。本文采用人机交互方法基于2005 年基准年的Landsat TM/ETM遥感影像修正欧空局GlobalCover 2005 年土地利用数据,进而采用逆时相目视解译法从1980年基准年的Landsat MSS/TM遥感影像数据提取1980-2005 年土地利用/覆盖变化信息,分析其变化的时空格局及驱动因素。结果表明:1980-2005年的25年间,巴西土地利用/覆盖变化面积达79.43万km²,占土地总面积的9.33%。其中,单纯耕地像元面积增加了20.18 万km²;耕地/自然植被镶嵌混合像元区面积增加了10.70 万km²;林地面积减少了53.12 万km²;灌丛与草地净增加21.10 万km²;水体面积增加0.46 万km²;城乡建设用地面积增加7573.87 km²。由此导致热带和亚热带湿润阔叶林生态地理区、热带和亚热带干旱阔叶林生态地理区、热带及亚热带草原生态地理区、草原和沼泽湿地生态地理区、沙漠和旱生植物生态地理区以及红树林生态地理区内分别呈现不同的土地利用/覆盖变化特征。近25 年间,地形地貌、气候、植被等自然地理条件深刻影响着土地利用的宏观格局,而土地利用政策调控、经济及对外贸易发展、人口增加及空间迁移、道路修建等是导致巴西土地利用变化的主要原因。     

山东省耕地变化趋势及驱动力研究

根据山东省各市、县的统计资料,分析了山东省50年代以来耕地面积变化的总体趋势、空间差异和驱动因子。结果表明:经济发展动态、社会系统压力和农业科技进步是影响山东省耕地数量变化的三类因素。通过建立多元回归模型,预测出2005和2010年的耕地数量,并对研究结果应用GIS进行了空间表达。研究结果和分析结论对山东省农业可持续发展具有重要意义     

Landscape change in the Calakmul Biosphere Reserve,Mexico: Modeling the driving forces of smallholder deforestation in land parcels

This article uses remote sensing and spatial modeling to quantify and analyze land change in Mexico's largest protected area, the Calakmul Biosphere Reserve. Change trajectories are identified within distinct property regimes and between the Reserve's core and buffer zones. A parcel-level spatial econometric model identifies the driving forces of land use change in two communities located along the eastern edge of the Reserve, the locus of increased deforestation in 1987–1996. The study assesses the role of biophysical variables, locational context, household socioeconomics and institutional factors in driving deforestation. The results address the effectiveness of reserves and other state policy instruments in protecting forests.     

近60a三工河流域耕地利用动态变化与驱动力分析

基于近60a耕地利用相关数据,从耕地规模、结构和效益分析三工河流域耕地利用动态变化,并利用回归模型和灰色关联方法对耕地利用变化的驱动机制进行分析.结果表明:(1)三工河流域耕地面积总体呈增加趋势,人均耕地则趋于下降;种植业结构变化趋势与全疆吻合,由以粮食为主向粮食、经济作物并重转变;农作物单位面积产量趋于上升,单位面积...     

Land use and land cover change and its driving forces in Maqu County, China in the past 25 years

Maqu County is located in the northeast Qinghai-Tibetan Plateau, and it is the main watershed for the Yellow River. The ecosystem there is extremely vulnerable and sensitive to climate change and human activities, which have caused significant deterioration of the eco-environment in this region. In order to restore the ecological environment, a government project to restore the grazing areas to grassland was implemented in Maqu County in early 2004. This study evaluates the effects of that restoration project on land use and land cover change (LUCC), and explores the driving forces of LUCC in Maqu County. In the study we used Landsat images obtained in 1989, 2004, 2009, and 2014 to establish databases of land use and land cover. Then we derived LUCC information by overlaying these layers using GIS software. Finally, we analyzed the main forces responsible for LUCC. The results showed that forests, high-coverage grasslands, and marshes experienced the most significant decreases during 1989-2004, by 882.8 ha, 35,250.4 ha, and 2,753.4 ha, respectively. However, moderate- and low-coverage grasslands and sand lands showed the opposite trend, increasing by 12,529.7 ha, 25,491.0 ha, and 577.5 ha, respectively. LUCC in 2004-2009 showed that ecological degradation slowed compared with 1989-2004. During 2009-2014, high- and moderate-coverage grasslands increased obviously, but low-coverage grasslands, marshes, unused lands, sand lands, and water areas showed the opposite trend. These results suggested that the degradation of the eco-environment was obvious before 2009, showing a decrease in the forests, grasslands, and water areas, and an increase in unused lands. The ecological degradation was reversed after 2009, as was mainly evidenced by increases in high- and moderate-coverage grasslands, and the shrinkage rate of marshes decreased obviously. These results showed that the project of restoring grazing lands to grassland had a positive effect on the LUCC. Other major factors that influence the LUCC include increasing temperature, variation in the seasonal frozen soil environment, seasonal overgrazing, and pest and rodent damage.     

Spatial patterns and driving forces of land use change in China during the early 21st century

Land use and land cover change as the core of coupled human-environment systems has become a potential field of land change science (LCS) in the study of global environmental change. Based on remotely sensed data of land use change with a spatial resolution of 1 km × 1 km on national scale among every 5 years, this paper designed a new dynamic regionalization according to the comprehensive characteristics of land use change including regional differentiation, physical, economic, and macro-policy factors as well. Spatial pattern of land use change and its driving forces were investigated in China in the early 21st century. To sum up, land use change pattern of this period was characterized by rapid changes in the whole country. Over the agricultural zones, e.g., Huang-Huai-Hai Plain, the southeast coastal areas and Sichuan Basin, a great proportion of fine arable land were engrossed owing to considerable expansion of the built-up and residential areas, resulting in decrease of paddy land area in southern China. The development of oasis agriculture in Northwest China and the reclamation in Northeast China led to a slight increase in arable land area in northern China. Due to the “Grain for Green” policy, forest area was significantly increased in the middle and western developing regions, where the vegetation coverage was substantially enlarged, likewise. This paper argued the main driving forces as the implementation of the strategy on land use and regional development, such as policies of “Western Development”, “Revitalization of Northeast”, coupled with rapidly economic development during this period.     

21世纪初中国土地利用变化的空间格局与驱动力

Land use and land cover change as the core of coupled human-environment systems has become a potential field of land change science (LCS) in the study of global environmental change. Based on remotely sensed data of land use change with a spatial resolution of 1 km × 1 km on national scale among every 5 years, this paper designed a new dynamic regionalization according to the comprehensive characteristics of land use change including regional differentiation, physical, economic, and macro-policy factors as well. Spatial pattern of land use change and its driving forces were investigated in China in the early 21st century. To sum up, land use change pattern of this period was characterized by rapid changes in the whole country. Over the agricultural zones, e.g., Huang-Huai-Hai Plain, the southeast coastal areas and Sichuan Basin, a great proportion of fine arable land were engrossed owing to considerable expansion of the built-up and residential areas, resulting in decrease of paddy land area in southern China. The development of oasis agriculture in Northwest China and the reclamation in Northeast China led to a slight increase in arable land area in northern China. Due to the Grain for Green policy, forest area was significantly increased in the middle and western developing regions, where the vegetation coverage was substantially enlarged, likewise. This paper argued the main driving forces as the implementation of the strategy on land use and regional development, such as policies of Western Development, Revitalization of Northeast, coupled with rapidly economic development during this period.     

Dynamic trends and driving forces of land use intensification of cultivated land in China

The aim of this study is to establish several important factors representing land use intensification in cultivated land (denoted by CII), using a multi-dimensional approach to achieve realistic and practical cultivated land use policies in China. For this reason, the theoretical framework was first built to explain the changes of land use intensification in the cultivated land, and then the variables and index were further developed for the purpose of characterizing the dynamic trends and driving forces of the land use intensification in the cultivated land at the provincial level. The study results indicate that the extent of CII significantly increased during the period of 1996 to 2008, due to the extensive use of fertilizers, machinery and pesticide, increased labor and capital input, and intensified land use. Moreover, the principal component regression results show that the productivity of cultivated land, economic benefits of cultivated land, labor productivity, and land use conversion are the main factors affecting the village development. The first three factors play a positive role, while the last one has a negative effect on the land use intensification in the cultivated land. According to these results, the main policies for sustainable intensification in cultivated land are proposed. First, the sustainable pathways for intensification should be adopted to reduce the unsustainable uses of chemical fertilizer, agricultural chemicals, etc. Second, the conditions for agricultural production should be further improved to increase the cultivated land productivity. Third, it is very necessary and helpful for improving labor productivity and land use efficiency from the viewpoint of accelerated the cultivated land circulation. The last step is to positively affect the production activities of peasants by means of reforming the subsidy standards.     

江汉平原土地利用的时空变化及其驱动因素分析

采用遥感、GIS一体化技术,利用1989～1990、1995～1996和1999～2000年获取的三期陆地资源卫星图像,对江汉平原土地利用10年变化和以1995～1996年为界的前后两个5年变化的时空特征进行了分析,并探讨了变化的驱动因素。结果表明,该区的土地利用在不同的时间及空间尺度上有明显不同的特点。10年间,耕地减少近5万hm²,其中,前5年的减少量占多数,达6783%。各类建设用地总计增加了156万hm²,其中,前5年的增加量是后5年的2倍。水域面积在10年间增加了达到354万hm²,后5年的增幅不到前期的1/2。土地利用变化最快的区域均处于工业经济较发达、城市化较快的地区如武汉、仙桃,变化最慢的区域在监利、松滋、天门等地。政策、社会经济与科技因素对土地利用随时间尺度的变化有决定性的影响。