基于HJ-1B/CCD地表反照率的估算

地表反照率是入射太阳能被地表反射的比分,决定地表吸收太阳辐射能的多少,是影响地表能量收支的关键参数.该文使用6S大气辐射传输模型对环境星的多光谱CCD数据进行大气纠正,并利用其观测角度信息,分别基于统计模型和BRDF模型估算研究区不同地表覆盖类型的窄波段地表反照率,并实现窄波段向宽波段反照率的转换.将宽波段反照率与MODIS反照率产品数据进行对比分析,对不同的地表覆盖类型选择模型的适宜性做出分析评价:对于水体,基于朗伯面假设采用统计模型效果较好,相对误差为9.2％;对于植被及非植被覆盖区,采用二向反射模型较合适,相对误差分别为4.02％和5.6％,都能够满足应用需求.     

基于环境一号（HJ-1A/1B）卫星图像的浑善达克沙地荒漠化变化检测

本文旨在通过计算浑善达克沙地（北纬43°08′,东经119°38′)2006年～2009年的植被覆盖度,进行变化检测。研究结果表明：研究区西部森林砍伐现象严重,而北部和东北部地区植被恢复良好。该项目表明,新设计的环境卫星在探测荒漠化方面是有效的,而受测试的用于提取森林覆盖面积的植被覆盖度方法,对于绘制研究区域的荒漠化变化是有用的。     

TRMM3B42降水产品在鄱阳湖流域梅川江子流域的精度评价(英文)

在鄱阳湖流域的梅川江子流域,利用52个站点9年(2001-2005及2007-2010)的日降水数据对V6和V7两个版本的TRMM 3B42降水产品进行了精度评价。该评价针对多个时空尺度进行,包括栅格和流域两个空间尺度,日、月和年三个时间尺度。为避免尺度不匹配问题,本文利用泰森多边形方法将点尺度的站点观测数据转换到与TRMM数据相同的栅格尺度。评价结果表明,V6和V7两个版本的TRMM3B42降水产品差别较小,整体上均轻微高估了降水量(偏差均为0.04)。在日尺度,栅格和流域空间尺度上V6和V7TRMM3B42降水产品的精度均较差,相对均方根误差在135%-199%之间。因此,在该地区利用3B42数据进行日尺度的水文分析前需要对其进行校正。在月和年尺度,栅格和流域两个空间尺度上V6和V7两个版本的TRMM 3B42降水产品精度均较高,决定系数达到0.91-0.99,相对均方根误差在4%-23%之间。这表明TRMM 3B42降水产品在该地区月和年尺度的水文分析方面具有很好的应用前景。     

中国地理科学进展与展望——与美国地理学战略方向的比较(英文)

Understanding the Changing Planet: Strategic Directions for the Geographical Sciences(UCP),published by the National Research Council(USA),and its comments in The Professional Geographer propose that uppercase and plural "Geographical Sciences"(GS) is the strategic direction for geography in the next decade for better understanding of our rapidly changing planet. According to these comments,UCP valued technologies and tools excessively("task"),and did not pay much attention to methodology("discipline"). Actually,both"task" and "discipline" are geographical wings,especially in the time of "big science".Enlightenment from UCP and its comments is the strategic direction that should be balanced between "task" and "discipline",GS should be a three-dimensional construct of a disciplinary system,methodology,and technologies and tools,and this system should be scientific humanism based on scientific spirit and directed by humanism. During the last 60 years,Chinese geographers devoted themselves to GS,including practice and theory. Obviously progress and outlook are proposed as interdisciplinary GS,Earth Surface Sciences(ESS) and Geographical Construction(GC). The disciplinary system of GS is very complex,and is composed of such human knowledge domains as sciences,technologies,engineering,and philosophy. The main mission is to research the open,complex,and macro earth system(not only scientifically,but also humanistically),and one significant methodology is "comprehensive integration of qualitative and quantitative means"(CIQQM). At the same time,another changing direction in Chinese geography is Human-Economic Geography(HEG).     

气候变化情景下中国自然生态系统脆弱性研究——一个基于生态地理区域的研究(英文)

Assessment of vulnerability for natural ecosystem to climate change is a hot topic in climate change and ecology, and will support adapting and mitigating climate change. In this study, LPJ model modified according to features of China's natural ecosystems was employed to simulate ecosystem dynamics under A2, B2 and A1B scenarios. Vulnerability of natural ecosystem to climate change was assessed according to the vulnerability assessment model. Based on eco-geographical regions, vulnerability of natural ecosystem to climate change was analyzed. Results suggest that vulnerability for China's natural ecosystems would strengthen in the east and weaken in the west, but the pattern of ecosystem vulnerability would not be altered by climate change, which rises from southeast to northeast gradually. Increase in ecosystem vulnerable degree would mainly concentrate in temperate humid/sub-humid region and warm temperate humid/sub-humid region. Decrease in ecosystem vulnerable degree may emerge in northwestern arid region and Qinghai-Tibet Plateau region. In the near-term scale, natural ecosystem in China would be slightly affected by climate change. However, in mid-term and long-term scales, there would be severely adverse effect, particularly in the east with better water and thermal condition.