洪涝监测遥感图像识别及数据转换   总被引：3，自引：0，他引：3  

冯锐  张玉书 《南京气象学院学报》2003,26(1):141-144

利用NOAA／AVHRR资料监测的洪涝共域显示图，通过文件格式的转换，在地理信息系统ArcView3.1平台上，进行基于地理信息系统洪涝区内各类下垫面面积评估。主要技术包括：用边缘检测法进行洪涝区域的识别；麦卡托投影经纬度坐标转换成高斯－克吕格投影公里网格坐标；阐述写Shapefile文件的注意问题，并以1995年8月4日辽宁洪涝灾害为例进行了说明。  相似文献   

Monitoring hydrological controls on dust emissions: preliminary observations from Etosha Pan, Namibia     

Robert G Bryant 《The Geographical journal》2003,169(2):131-141

Atmospheric dust loadings have a significant influence on global climate by affecting air temperatures through the absorption and scattering of solar radiation. Many dryland basins are significant sources of aeolian dust, but our knowledge of how dust emissions from these systems are affected by ephemeral wetting events is either limited or poor. This research uses synergistic data sets (Total Ozone Mapping Spectrometer (TOMS) and Advanced Very High Resolution Radiometer (AVHRR)) in order to identify possible hydrological controls on aeolian dust emissions from the Etosha Basin, Namibia. Data suggest that individual inundation events (detected by AVHRR) within this basin have a marked effect on immediate and subsequent dust emissions (detected by TOMS). This study also outlines the contribution of dust emissions from both the pan surface and from the ephemeral oshanas region to the north of the Etosha Basin to the persistent dust plume, and highlights the complexity of the interactions between hydrology, land use and dust emissions within ephemeral basins.  相似文献   

Assessment of waterlogging risk in Lixiahe region of Jiangsu Province based on AVHRR and MODIS image   总被引：3，自引：0，他引：3  

Dapeng Huang  Chuang Liu  Huajun Fang  Shunfeng Peng 《中国地理科学(英文版)》2008,18(2):178-183

Four images of 1991 AVHRR, 2003 and 2007 MODIS were used to extract waterlogging inundated water of three years, and three inundated water maps were overlaid to estimate waterlogging affected frequency. Based on waterlogging affected frequency, waterlogging hazard of pixel scale was assessed. According to the weighed score of area percentage of different waterlogging affected frequency in 13 counties/cities of Lixiahe region, waterlogging hazard rank of every county/city was assessed. Waterlogging affected frequency map and 1 km× 1 km grid landuse map were used to assess waterlogging risk of pixel scale; and then waterlogging risk rank of every county/city was assessed by the similar method by which waterlogging hazard rank of every county/city was assessed. High risk region is located mainly in core zone of Lixiahe hinterland, medium risk region is adjacent to high risk region, and low risk region is located in the most outlying area of risk zone and mainly in south to middle part of Lixiahe region. Xinghua and Gaoyou belong to high risk city, Jiangyan belongs to medium risk city, and the other counties/cities have low or lower waterlogging risk. The method of assessing waterlogging risk in this paper is simple and applicable. This paper can provide guidance for the waterlogging risk analysis in broader area of Huaihe River Basin.  相似文献   

基于MODIS冬小麦长势监测研究   总被引：3，自引：2，他引：3       下载免费PDF全文

刘惠敏  黄勇  荀尚培 《气象科学》2007,27(2):187-195

本文在对比分析MODIS NDVI与AVHRR NDVI的系统误差基础上,以MODIS/AVHRR卫星资料、地面农情观测资料为主要数据源,开发出淮北平原冬小麦长势监测旬、月MODIS NDVI比较模型和MODIS NDVI半定量监测指标模型,该模型在2005年检验应用中得到与实际较一致结果。  相似文献   

NOAA/AVHRR与EOS/MODIS遥感产品NDVI序列的对比及其校正   总被引：2，自引：1，他引：2  

张杰  郭铌  王介民 《高原气象》2007,26(5):1097-1104

利用Terra、Aqua两颗卫星的MODIS资料、NOAA-16和17的AVHRR资料,通过对太阳和卫星天顶角及方位角等引起的大气效应订正、大气气溶胶等粒子的散射订正以及NOAA系列卫星信号的衰减订正,得到以上四颗卫星一系列的NDVI产品;对比分析了上午星Terra和NOAA-17,下午星Aqua和NOAA-16两组不同卫星传感器NDVI的差异及其与光谱响应函数的关系。结果表明,Terra和Aqua卫星NDVI随卫星观测角度的不同差异较大,平均NDVI是一种更适合的MODIS/NDVI产品算法,它代表了观测角为±30°之间的NDVI值的分布,在大气和角度的订正基础上,本研究采用了三阶多项式再次订正了观测角引起的NDVI变化;NOAA-16和17所获得的NDVI值较MODIS得到的NDVI值小很多,以MODIS的NDVI产品为标准,应用光谱响应函数将NOAA系列NDVI进行归一化处理,所得的结果基本与MODIS所得的NDVI相当;该方法基本能实现NDVI产品序列的延伸,其资料序列有时空可比性。  相似文献   

利用NOAA/AVHRR监测青海省草地生产力变化的研究   总被引：5，自引：3，他引：5  

王江山  殷青军  杨英莲 《高原气象》2005,24(1):117-122

青海省地处青藏高原，生态环境脆弱。近20年来，由于气候变化和人类活动的共同影响，生态环境，特别是草地资源发生了较大的变化。利用美国地球资源观测系统数据中心探路者数据库(Pathfinder Data Sets)1981-1999年间的NOAA／AVHRR NDVI资料序列，分析了青海省近20年来草地生产力变化的时间特征及地区差异性。  相似文献   

中红外和热红外在测算水稻种植面积上的应用   总被引：6，自引：1，他引：5  

邱新法  曾燕 《南京气象学院学报》2000,23(1):24-28

在利用ＡＶＨＲＲ数据测算水稻种值面积中,对ＡＶＨＲＲ各通道数据进行统计特征分析和影象线性拉伸处理,发现其中红外（ＣＨ３）和热红外（ＣＨ４）通道信息量丰富,且在中红外和热红外拉伸影象上存在稻田的这温较旱地低－“稻区低温”现象。因此,在测算水稻种植面积时,半加了第３、４两通道－中红外和热红外通道。实际应用证明：增加两红外通道非常有助于水稻鉴别。  相似文献   

树木年轮研究的扫描图像分析方法及其在环境演变中的应用   总被引：28，自引：0，他引：28  

谢昆青  李志尧 《第四纪研究》2000,20(3):270-281

本文主要探讨用普通扫描仪作为获取树轮信息手段的有效途径,以及研究将图像分析和数字处理技术应用于树木年轮学的方法。通过对树轮图像的分布特征和噪声变化规律的统计分析,本文设计出一套图像分割、信息提取算法和相应的处理程序。从实际的应用效果以及与其它树轮研究方法所作的对比分析结果表明,这种扫描图像处理方法不仅可行,而且高效、准确,拓宽了树木年轮学方法在环境演变研究中的应用途径。  相似文献   

A-HIGHERS—The System to Produce the High Spatial Resolution Sea Surface Temperature Maps of the Western North Pacific Using the AVHRR/NOAA   总被引：1，自引：0，他引：1  

Futoki Sakaida  Jun-ichi Kudoh  Hiroshi Kawamura 《Journal of Oceanography》2000,56(6):707-716

To study on the oceanic variations in the western North Pacific, we developed a system to produce a high spatial resolution sea surface temperature (SST) map from the data obtained by the Advanced Very High Resolution Radiometer (AVHRR) aboard the National Oceanic and Atmospheric Administration (NOAA) satellites. As the system has been improved on the HIGHERS (Sakaida and Kawamura, 1996), it is called the Advanced-HIGHERS (A-HIGHERS). The A-HIGHERS has been developed on the super computer in the Tohoku University, which is favorable for handling of a large volume of data. Mainly because of improvements in the cloud detection algorithm, the A-HIGHERS can deal with the data obtained at dawn and dusk around the year, and at daytime in summer more effectively. The A-HIGHERS are used to produce SST maps spanning from (60°N, 120°E) to (20°N, 160°E) with a grid size of 0.01 degree.  相似文献   

西北太平洋海表温度变化主成分分析   总被引：1，自引：0，他引：1  

吴凡  方明强  管磊 《中国海洋大学学报(自然科学版)》2014,44(3)

对西北太平洋1982—2010年NOAA系列卫星海表温度(Sea Surface Temperature,SST)产品进行月平均等处理,采用Reynolds SST月平均场对数据进行质量控制、数据融合等处理,建立高空间覆盖、长时间序列的SST场数据集。对月距平场进行经验正交函数(EOF)分解,分析时空模态特征,并将第一模态时间序列与相关气候时间序列进行比较。主成分分析结果显示西北太平洋SST存在显著的约13a周期的年代际模态和2~5a的类厄尔尼诺模态,年代际变化和西太平洋暖池的年代际振荡相似;类厄尔尼诺模态与Ni珘no-3.4区SST周期变化较为相关,并相对于厄尔尼诺具有约10个月的滞后。本研究显示,西北太平洋可能在多种不同时间尺度气候机制的控制之下。  相似文献