Understanding and contextualizing social impacts from the privatization of fisheries: An overview     

Julia Olson 《Ocean & Coastal Management》2011,54(5):353-363

Fisheries management around the world has experimented with regulations to promote privatization, in order to reach such multifaceted goals as ending overfishing and reducing economic inefficiencies. This review surveys a wide range of empirical experiences in different contexts around the world to help provide a fuller picture of potential and sometimes disparate consequences from privatization in general and new ways of organizing around fishing that can follow in the wake of such measures. Looking at the many different participants in the fishing industry—from crew, small-boat owners, to households and communities—as well as the diverse sociocultural contexts in which fishing takes place, enables a better understanding of who and what is impacted, how they are impacted, why and with what further consequences, such that communities come to be seen less oppositional to economy, but rather constituted by multiple scalar processes and by economic relations comprising different motivations and behaviors.  相似文献   

Water vapour periodicities over Indian Ocean during contrasting monsoons from NOAA satellite data     

C. M. Kishtawal  P. K. Pal  M. S. Narayanan 《Journal of Earth System Science》1991,100(4):341-359

The satellite-derived moisture fields during different phases of two normal and poor monsoon years have been studied. Spectral analysis was performed in different zones of the monsoon region to study the nature and modes of intraseasonal fluctuations of lower layer moisture fields. Seasonal mean fields of water vapour at low and middle layers show a dry anomaly over the Arabian subcontinent and a wet anomaly over the Bay of Bengal during good monsoon years, while the anomalies show an opposite trend during the poor monsoon years. The zonal and meridional propagation of low-frequency oscillations of moisture fields has also been examined. The southward movement of low-frequency oscillations seems to be suppressed in good monsoon years as compared to the poor monsoon years, whereas the northward movement of the same shows no particular difference. Fluctuations in the 30–50 day range are found shifted to longer time-period side in the poor monsoon years.  相似文献   

Monitoring the source of trans-national dust storms in north east Asia     

《International Journal of Digital Earth》2013,6(1):119-129

Abstract

The vast expanse of the Gobi desert across the Mongolian plateau experiences frequent dust storms. In this isolated region remote sensing techniques can provide an effective measurement of dust storms. Brightness temperature channels 4, 5 of AVHRR/NOAA satellite data, emissive bands of MODIS/TERRA satellite data and meteorological station measurement data were used and tested for dust and sandstorm mapping in the desert area of Mongolia and northern China. The differences between thermal bands in combination with geographic information system (GIS) layers were used for mapping in this study. The results show that dust and sand storm maps can be achieved from emissive bands for monitoring of dust and sandstorms. Most active dust storm sources can occur in truly remote areas where there is little or no human activity, although many sources are associated with areas where human impacts are well documented. Thus, on a regional scale dust mobilisation appears to be dominated by natural sources.  相似文献   

Documentation and evaluation of the CSE NOAA AVHRR data set     

Gorm Dybkjær  Thomas Theis Nielsen  Kjeld Rasmussen  Michael Schultz Rasmussen  Lars Boye Hansen  Assize Touré 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2013,113(1):125-135

A NOAA AVHRR data set covering Senegal and parts of the surrounding countries during the period from 1987 to present is under construction and improvement in an ongoing collaboration between Centre de Suivi Écologique (CSE). Dakar. Senegal, and Institute of Geography, University of Copenhagen (IGUC). This paper details the entire processing chain from raw images to a properly calibrated, geometrically rectified and cloud-masked time-series tracking a number of well-defined variables. Two vital aspects of this time series, the cloud masking procedure and the geometrical rectification, are evaluated in detail. A two-step, multi-criteria cloud masking procedure requiring a manual input does not consistently improve the quality of the data set compared to the simpler, automated procedure. With respect to geometrical rectification an accuracy on the order of I km is obtained. Finally, suggestions for further improving the data set are forwarded  相似文献   

最小方差算法反演NOAA/AMSU海面大气温度垂直廓线     

王静  赵朝方 《海洋湖沼通报》2008,(2):16-23

利用最小方差算法对NOAA/AMSU(Advanced Microwave Sounding Unit)探测资料在105°E~135°E、0~30°N海域范围内的大气温度垂直廓线进行了反演研究。利用NCEP再分析资料对算法的反演性能进行了验证;并与中国海洋大学卫星地面站SeaSpace/TeraS-can软件系统反演的温度廓线进行了比较。结果表明:该算法在中国区域具有较好的反演精度和适应能力;总体上改善了TeraScan软件的反演结果,尤其提高了对流层大部分区域的反演精度。本研究为地面站ATOVS(Advanced TIROS Operational Vertical Sounder)数据的进一步利用提供了一种较好的理论参考。  相似文献   

基于遥感数据的渤海海冰面积提取订正模型研究          下载免费PDF全文

国巧真  顾卫  孙从容  金会义  李京 《海洋科学》2008,32(8):70-75

为了获取准确的海冰信息，利用高空间分辨率和高时间分辨率数据相结合的方法来测算海冰面积，在假设TM海冰面积是比较准确的前提下，用TM海冰面积来订正MODIS和NOAA／AVHRR海冰面积，以提高这两种高时间分辨率遥感资料对海冰面积的判别精度。选取2003年2月5日的TM、MODIS和NOAA／AVHRR数据，在这3个图像上分别选择20个样本，然后进行了海冰面积的线性回归分析，得到的海冰面积提取订正模型。并分别以此两种模型为基础，对2002年12月8日至2003年2月26日和2005年2月1日至2月11日冬季渤海海冰面积进行修正，并将由MODIS和NOAA／AVHRR提取的海冰面积、用模型订正后和国家海洋环境预报中心给出的海冰面积做了详细的比较。结果表明：线性回归可以提高海冰信息的提取精度。此研究为海冰防灾减灾和海冰资源量估算提供依据。  相似文献   

NOAA卫星图像水体信息神经网络识别方法的探讨   总被引：7，自引：1，他引：7  

梁益同  胡江林 《应用气象学报》2001,12(1):85-90

该文阐述了应用神经网络识别NOAA卫星图像水体信息的基本原理和方法, 并进行了实例分析, 结果表明, 神经网络法比阈值法具有更高的精度和效率.  相似文献   

用NOAA/AVHRR数据估算上海地区水稻种植面积   总被引：17，自引：1，他引：17       下载免费PDF全文

吴健平  杨星卫 《应用气象学报》1996,7(2):190-194

应用模糊监督分类方法对NOAA/AVHRR数据进行象元分解，并估算了上海市10个郊县1992年和1993年两年的水稻种植面积，估算的结果与统计数据比较后表明，全市总的估算精度（采用面积比精度）分别为92.0%和95.4%。  相似文献   

用NOAA卫星可见光和红外资料估算甘肃省东部农田区土壤湿度   总被引：24，自引：1，他引：24       下载免费PDF全文

郭铌  雷建勤 《应用气象学报》1997,8(2):212-218

应用NOAA卫星AVHRR通道1、2计算的植被指数和通道4的亮温、农业气象试验站观测的土壤湿度，并结合气象卫星完成的土地覆盖分类等资料，建立了由植被指数和亮温估算甘肃省东部农田区土壤湿度的方程。结果表明，农田土壤湿度与植被指数和亮温间均存在一定相关关系；用植被指数和亮温可以估计土壤湿度情况，并对干旱进行监测。  相似文献   

基于GIS的中国东北植被综合分类研究   总被引：53，自引：3，他引：50  

刘纪远  庄大方  凌扬荣  Y.Awaya 《遥感学报》1998,2(4):285-291

ＮＯＡＡ／ＡＶＨＲＲ由于运行周期短、覆盖范围大、成本低、波段宽等特点,目前正越来越广泛地受到人们的普遍关注。在大尺度、中尺度植被遥感上,ＮＯＡＡ／ＡＶＨＲＲ具有陆地卫星无法比拟的优势,但在另一方面,ＮＯＡＡＡＶＨＲＲ也存在分辨率低、数据变形较大和几何畸变较严重等问题。这样,在应用ＮＯＡＡＡＶＨＲＲ数据进行大区域植被制图时,植被分类的精度仍待提高。本文从理论上探讨了将地理信息系统提供的地理数据与遥感数据复合的可行性;尝试在ＧＩＳ环境下,将气温、降水、高程３个影响区域植被覆盖的主要指标,按一定的地面网格系统和数学模式进行量化,生成数字地学影像,并使之与经过优化、压缩处理的ＮＯＡＡＡＶＨＲＲ数据进行复合,对复合后的综合影像进行监督分类。分类结果显示,与传统的应用最大似然分类方法对单一遥感图像分类相比,该综合分类方法分类精度提高了１８．３％,该研究方法改变了遥感影像的单一信息结构;丰富了图像的信息含量;完成了地理数据的数字传输、处理、存储及影像化显示。  相似文献