欧亚大陆冬季雪盖同四川夏季旱涝的关系

本文利用1966年～1983年冬季雪盖资料研究了欧亚大陆冬季(12～2月)雪盖面积同后期四川月平均气温和月降雨量之间的关系。研究表明:欧亚大陆冬季雪盖面积对四川省夏季月平均气温为负相关,同月降雨量为正相关。这种关系说明冬季雪盖面积对夏季气温和降雨量有重要的滞后影响,尤其是对川东伏旱地区的作用更为显著。还说明冬季雪盖面积大,夏季月平均气温比多年平均值偏低,月降雨量比多年平均值偏多,高温伏旱轻;相反 冬季雪盖面积小时,夏季月平均气温比多年平均值偏高,月降雨量比多年平均值偏少,高温伏旱严重。     

THE FEATURES OF SEA-ICE COVER, SNOW DISTRIBUTION AND ITS DENSIFICATION IN THE CENTRAL ARCTIC OCEAN

I.INTKODUCTIONTheArcticOcean,withanareaofapproximately9.5X106krnZ,ispredominantlysea--icecoveredthroughouttheyearinitscentralarea,whilethesouthedgeofmarginalicezone(MIZ)variesseasonally.ThemaxinltlmofIcecoverextentoccursbetweenFebruaryandMarch,whilethemininlunlisbetweenAugustandseptember.Placingtheiceedgeto8%iceconcentration(percentarealcoveragesofseaice)isopleths,variationofextentofsea--icecoveroftheArcticOceanisI)etween9X106--16X106kmZIbytheobservationofasatellite--bornescanningm…     

浙江省土地利用与土地覆被遥感综合调查研究

本文从土地利用/土地覆被的国内外研究现状与趋势出发,在总结与分析本地区土地利用与土地覆被已开展工作基础上,根据本次浙江省遥感综合调查的目标与任务 ,基于现代遥感与信息技术 ,建立了土地利用与土地覆被现状调查的技术路线与方法,为今后开展同类研究提供了借鉴     

模糊类别制图的空间统计学方法

类别地图是地理信息系统（ＧＩＳ）应用中所利用的重要数据类别。这类数据可以从摄影测量和遥感技术得到。用摄影测量方法（影像判读）制作的类别地图常以点、线和多边形的离散目标形式描述,而遥感图像分类方法输出的类别地图以连通光栅块形式表达。不论哪一种情况,在每一个多边形或者光栅块（即制图单元）中仅允许单一类别,边界内部非均匀性和模糊形已经被“过滤”了。这样的类别地图沿用了古曲脆集合论,因为每个制图单元只允许     

遥感影像的全模糊监督分类

设计了一个基于神经元网络的全模糊训练、分类和精度评估方法,并成功地应用于一个城郊型土地覆盖分类。结果表明,该方法灵活、适应性强,并能取得较好的分类精度。     

机房沟变质核杂岩构造基本特征

１：５万区调中,于大黑山条垒北段机房沟地区发现四楞山碱长花岗岩北东、南西两侧的早古生代中酸性火山岩及碎屑岩中广泛发育了向外倾斜的中－深层次的顺层韧性变形带、剥离断层及二叠纪哲斯组构成的沉积盖层。总体反映为北东－南西拉伸作用形成的机房沟变质核杂岩构造。     

No peace for the forest: Rapid,widespread land changes in the Andes-Amazon region following the Colombian civil war

Negative environmental impacts of violent conflict have been observed worldwide. Whether or not active global conflicts are declining in number remains hotly debated, the number of countries entering post-conflict periods is on the rise, and the impact of this transition on land cover changes remains poorly understood. In Colombia, though large-scale armed conflict has concluded, the post-conflict period represents an ongoing threat to forest conservation, putting at risk commitments to meet global conservation goals and even those stipulated in the peace accord. This paper aims to assess land cover change associated with the Colombian conflict in the Andes-Amazon region between 1988 and 2019. First, we use the Landsat archive to map land cover and characterize the spatial patterns of change at the regional level. Second, to empirically identify the effect of conflict on land cover change, we employ a difference-in-difference approach using local conflict events data. During conflict (1988–2011), land cover in the Andes-Amazon remained relatively stable, however during the post-conflict period (2012–2019), the conversion from forest to agriculture increased by 40%. We find that forest cover surrounding conflict events (1 km radius) decreased significantly, on average by ~ 19% during conflict, which accelerated to ~ 30% in the post-conflict period. Similarly, agriculture expansion is most substantial during the post-conflict period, but exclusively in municipalities with population below the 50th percentile. Landscape metrics show that in peripheral municipalities (<50th), agriculture occurs in clumped distributions during the conflict period. Meanwhile, during the post-conflict period, this expansion happens more quickly, with significantly greater agricultural patch sizes than during the conflict period. We conclude that a slow implementation of conservation governance, the emergence of illegal land markets, and illicit land uses (i.e., coca and illegal cattle ranching) may accelerate land cover change in the coming years.     

基于FY-3号气象卫星的中国典型积雪覆盖区的时空动态研究

基于风云三号(FY-3)气象卫星的积雪产品数据(snow cover),提出了基于经验模态分解的趋势提取方法,探讨了2010—2019年中国积雪时空动态变化趋势。结果表明:1)中国积雪覆盖频率(Snow Cover Frequency,SCF)具有显著的季节性特征,呈现先增加后减少的特点,每年2月、3月SCF达到当年最大;东北的SCF呈显著下降的年际变化趋势,其他地区变化不大。2)中国整体的积雪覆盖率(Snow Cover Rate,SCR)下降了约1.2％,内蒙古和西藏的SCR下降了约1.5％,其他地区的SCR变化不显著;主要积雪覆盖区的SCR均在2016年发生由增加到减少的转变。     

Protected areas as a double edge sword: An analysis of factors driving urbanisation in their surroundings

Protected areas (PAs) are the most effective tools to protect biodiversity and ecosystem services. They have proven to be effective in stopping extensive land use conversion in well-conserved terrestrial ecosystems. However, land cover changes around PAs threaten biodiversity and ecosystem services within their limits and reduce ecological connectivity. In this study, we analysed the urban sprawls on the boundaries of 159 PAs (national, regional, and natural parks) in Spain, using 2.5 and 5 km non-protected buffer zones from 1990 to 2018. We clustered PAs based on biophysical and socio-economic characteristics and modelled urban sprawl in different buffers and periods. Hierarchical clustering revealed three groups of PAs: (a) proximate urban parks, (b) mountainous parks, and (c) parks in the Madrid autonomous region. We found that urbanisation in the surroundings of PAs in Spain has nearly doubled since 1990. General linear models explained a significant proportion of the urbanisation trends observed, with the number of municipalities in the boundary of the PA, the distance to a main road, and the distance to a big city acting as the most important drivers of urban sprawl. Our results also show that some PAs exert significant effects on urbanisation trends in their surroundings through the park-view effect. Finally, we highlight three coexisting phenomena that might explain the observed urban sprawl processes: (a) PAs attracting urbanisation in their surroundings due to the park-view effect, (b) PAs as a deterrent for urban sprawl within their limits, and (c) PAs occupying residual areas among previously urbanised lands.     

中分辨率遥感图像土地利用与覆被分类的方法及精度评价

利用TM、SPOT及CBERS-1等中分辨率卫星图像,对土地覆被的专家系统分类方法、居民地的决策树提取方法以及水体的迭代混合提取方法进行了试验,其总体精度达到87.89%,与常用的监督分类方法相比精度可提高7.86%.专家系统分类的结果叠合居民地、水体等易于混分专题信息,可以形成精度较高的土地利用与覆被分类结果。