Satellite-based damage mapping following the 2006 Indonesia earthquake—How accurate was it?     

Norman Kerle 《International Journal of Applied Earth Observation and Geoinformation》2010

The Yogyakarta area in Indonesia suffered a devastating earthquake on 27 May 2006. There was an immediate international response, and the International Charter “Space and Major Disasters” was activated, leading to a rapid production of image-based damage maps and other assistance. Most of the acquired images were processed by UNOSAT and DLR-ZKI, while substantial damage mapping also occurred on the ground. This paper assesses the accuracy and completeness of the damage maps produced based on Charter data, using ground damage information collected during an extensive survey by Yogyakarta's Gadjah Mada University in the weeks following the earthquake and that has recently become available. More than 54,000 buildings or their remains were surveyed, resulting in an exceptional validation database. The UNOSAT damage maps outlining clusters of severe damage are very accurate, while earlier, more detailed results underestimated damage and missed larger areas. Damage maps produced by DLR-ZKI, using a damage-grid approach, were found to underestimate the extent and severity of the devastation. Both mapping results also suffer from limited image coverage and extensive cloud contamination. The ground mapping gives a more accurate picture of the extent of the damage, but also illustrates the challenge of mapping a vast area. The paper concludes with a discussion on ways to improve Charter-based damage maps by integration of local knowledge, and to create a wider impact through generation of customised mapping products using web map services.  相似文献   

有机和常规农业管理方式下的浮游植物群落特征及其影响因素     

杜少娟  王吉毅  国超旋  Jonathan Miles Adams  任明磊  李侃  郭亚平  杜宗军  王建军 《湖泊科学》2022,34(6):1828-1839

为了解不同农业施肥管理方式对水体浮游植物群落的影响,本研究以江苏句容戴庄有机示范村和常规农业管理区池塘浮游植物为对象,分析冬夏两季浮游植物群落特征及相关水环境因子.结果表明：冬季有机和常规农业区域的浮游植物分别检到7门95种和7门111种,夏季分别检到7门102种和6门112种,有机农业区浮游植物由冬季的隐藻—绿藻型向夏季的蓝藻—绿藻型变化,常规农业区从隐藻—绿藻型向蓝藻—硅藻型变化,蓝藻逐渐取代隐藻的优势地位.夏季各池塘浮游植物alpha多样性没有显著的区域差异,但冬季常规农业区浮游植物物种丰富度、蓝藻和裸藻的Shannon-Wiener多样性指数显著较高.指示物种分析显示,谷皮菱形藻(Nitzschia palea)和梅尼小环藻(Cyclotella meneghiniana)为有机农业区指示物种,而梭形裸藻(Euglena acus)、针形纤维藻(Ankistrodesmus acicularis)、肘状针杆藻(Synedra ulna)和狭形纤维藻(Ankistrodesmus angustus)为常规农业区指示物种,此6种藻为中、富营养化藻类,说明水体氮磷营养盐浓度较高,这与...  相似文献   

Archaeological obsidian studies: Method and theory     

Norman Herz 《Geoarchaeology》1999,14(6):591-594

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