挖掘图片背后的故事……：湿地

湿地系指天然或人工、常久或暂时之沼泽地、湿原、泥炭地或水域地带，带有静止或流动、咸水或淡水、半咸水或咸水水体，以及海洋和低潮时水深不超过6米的浅海水域。湿地的类型有珊瑚礁、滩涂、红树林、湖泊、河流、河口、沼泽、水库、池塘和水稻田等。湿地表面常年或经常覆盖着水或者充满水，是介于陆地和水体之间的过渡带。湿地在控制污染、调节径流和气候等方面起到重要作用。     

难忘的北大荒经历（二）

嘟噜河测区任务完成后,下一个测区定点在离黑龙江江边五六里地的鸭蛋河南岸,在十万分之一军委图上看,是块方圆不足百米的小地方。搬家那天,我们乘县运输公司一辆嘎斯车,一个分队二十几个人,全部测量工具,一顶帐篷,二十几个行军床和炊事用具,还有从朝鲜屯买的100个鸡蛋,装了两柳条筐。因为新测区是个无人区,基本是沼泽地。不仅没有汽车道,就是人走的小道也没有。     

上海的湿地 您关注过吗？

湿地是陆生生态系统和水生生态系统的过渡地带,按《国际湿地公约》的定义,湿地是指天然的或人工的、长久的或暂时性的沼泽地、湿原、泥炭地或水域地带,带有静止的或流动、或为淡水、半咸的、咸水水体者,包括低潮时水深不超过6m的海域。据调查,上海地区现有湿地599148hm^2,占上海地区海拔5m以上总面积的65．67％。其中天然湿地231268hm^2,人工湿地367880hm^2。     

速读

<正>考古Archaelogy2010年5月/6月封面专题:千年沼泽古尸在西北欧的泥炭沼泽里,保留有数千年前的人类遗骸。由于这些沼泽区域低温、缺氧,酸度高,沼泽地里的尸体得以很好地保存,比如著名的1984年发现     

Integrating TM and ancillary geographical data with classification trees for land cover classification of marsh area

The main objective of this research is to determine the capacity of land cover classification combining spectral and textural features of Landsat TM imagery with ancillary geographical data in wetlands of the Sanjiang Plain, Heilongjiang Province, China. Semi-variograms and Z-test value were calculated to assess the separability of grey-level co-occurrence texture measures to maximize the difference between land cover types. The degree of spatial autocorrelation showed that window sizes of 3×3 pixels and 11×11 pixels were most appropriate for Landsat TM image texture calculations. The texture analysis showed that co-occurrence entropy, dissimilarity, and variance texture measures, derived from the Landsat TM spectrum bands and vegetation indices provided the most significant statistical differentiation between land cover types. Subsequently, a Classification and Regression Tree (CART) algorithm was applied to three different combinations of predictors: 1) TM imagery alone (TM-only); 2) TM imagery plus image texture (TM+TXT model); and 3) all predictors including TM imagery, image texture and additional ancillary GIS information (TM+TXT+GIS model). Compared with traditional Maximum Likelihood Classification (MLC) supervised classification, three classification trees predictive models reduced the overall error rate significantly. Image texture measures and ancillary geographical variables depressed the speckle noise effectively and reduced classification error rate of marsh obviously. For classification trees model making use of all available predictors, omission error rate was 12.90% and commission error rate was 10.99% for marsh. The developed method is portable, relatively easy to implement and should be applicable in other settings and over larger extents.     

基于TM光谱特征的沼泽地定量提取模式研究

要从TM影像上定量提取沼泽地信息就必须首先获取TM数据中的沼泽地波谱信息这个最基本参数。以2000年7月TM数据为数据源,在ERDAS和PCI等遥感软件支持下,运用灰度分析方法分析沼泽地及背景地物光谱特征,并以一条光谱采样剖面线分析沼泽地内部光谱结构。最终,建立了基于前述光谱特征的三个关于沼泽地信息的定量提取模式,定量提取了沼泽地的植被、积水信息以及与水田区别的参数,具有计算机上运算的可行性。     

世界最大湿地:巴西潘塔纳尔沼泽地

<正>目前,世界最大的湿地是位于巴西马托格罗索州 的潘塔纳尔(Pantanal)沼泽地,面积达2500万公顷。沼 泽地内分布着大量河流,湖泊和平原,其中的湿地、草 原、亚马逊和大西洋森林都是南美具有代表性的生态 系统。沼泽地不仅有世界上最大的植物群,还栖息着 1000多种动物,包括650种鸟类、230种鱼类、95种