Tracking land cover change along the western edge of the U.S. Corn Belt from 1984 through 2016 using satellite sensor data: observed trends and contributing factors

The Cropland Data Layers (CDL) are high-resolution geo-referenced data products made available by the U.S. Department of Agriculture. However, the CDL lacks in its ability to be employed as a tool to identify the impact of the gradually evolving drivers of land use change, e.g., climate change, due to its limited historical depth. We implement a robust, phenology-based satellite image classification algorithm to identify historical cropland allocation in eastern South Dakota and North Dakota predating the initial CDL by 13 and 22 years, respectively. Five major land covers, i.e., corn, soybeans, wheat, alfalfa and grass (including native grass, hay and pasture) are identified using archived Landsat-5 surface reflectance data, while achieving CDL-like accuracy. The long-term rate of grassland loss during 1985–2011 is found to be significantly lower (26,781 hectares or 1.5% annually) relative to the near-term rate of grassland loss during 2006-’11 (84,545 hectares or 5.2% annually). We find similar discrepancy in regional corn expansion rates. Our value-added raster data provide opportunities for improved identification of land use drivers, whereas relying solely on the CDL’s restricted historical extent may lead to biased land use change estimates and misguide policy.     

利用卫星遥感技术进行干旱监测

利用2003年卫星遥感干旱监测资料和哈尔滨市土壤湿度资料，应用土壤热惯法计算和分析了黑龙江省哈尔滨市旱灾情况，提出了相应的防治措施。研究表明：这种方法在目前对裸地面进行干旱遥感监测中是定量水平较高的，对裸露土壤湿遥感精度可达到60％，根据农业气象观测规范，它可以给出土壤干旱的绝对等级。利用这一方法，计算了哈尔滨市12个县(市)不同级别干旱灾害的分布情况。     

台湾海峡7.3级强震前的热红外增温异常

描述了１９９４年９月１６日台湾海峡７．３级地震前，在震中区附近上空观测到大面积的突发性增温异常带。并对该异常带的形成机理作了探索。     

极轨气象卫星资料在四川的应用前景

本文系统地介绍了极轨气象卫星及其区域性遥感资料处理系统。分析探讨了NOAA/AVHRR资料在四川省各非气象领域应用的可能性。     

USE OF HEMISPHERIC IMAGERY FOR ESTIMATING STREAM SOLAR EXPOSURE1

ABSTRACT: Solar exposure profoundly affects stream processes and species composition. Despite this, prominent stream monitoring protocols focus on canopy closure (obstruction of the sky as a whole) rather than on measures of solar exposure or shading. We identify a candidate set of solar exposure metrics that can be derived from hemispheric images. These metrics enable a more mechanistic evaluation of solar exposure than can be achieved with canopy closure metrics. Data collected from 31 stream reaches in eastern Oregon enable us to quantify and compare metrics of solar exposure from hemispheric images and a metric of canopy closure with a concave densiometer. Repeatability of hemispheric metrics is generally as good as or better than the densiometer closure metric, and variation in the analysis of hemispheric images attributable to differences between analysts is negligibly small. Metrics from the hemispheric images and the densiometer are typically strongly correlated, at the scale of an individual observation and for 150 m stream reaches, but not always in a linear fashion. We quantify the character of the uncertainty in the relationship between the densiometer and the hemispheric metrics. Hemispheric imagery produces repeatable metrics representing an important ecological attribute; thus those researching the effects of solar exposure on stream ecosystems should consider the use of hemispheric imagery.     

卫星云图资料同化中的质量控制及其在暴雨预报中的应用

以1996年7月3—4日发生在江淮流域的暴雨过程为例，依据统计特征分别以常规分析场、正涡度高值区、高低空急流为标准，设计了三套方案对卫星反演湿度场进行质量控制。利用中尺度MM5模式进行的数值试验表明：经质量控制后预报场得到较大改善；质量控制方案的优劣对预报效果有直接影响，选择合理的控制标准是重要的。     

森林火险天气等级预测及火情监测应用

通过对1989-2003年500hPa高空天气形势的分析，给出了冬、春季森林火险戒严期的4种主要天气模型。根据林火气象条件的统计分析，找出了与森林火险天气密切相关的主要气象及物候因素，并对其进行了火险天气指数的等级划分。应用vb6．0软件开发建立了运行稳定、精度较高的未来24～48h森林火险预测平台，采用气象卫星遥感技术对森林火情进行准确定位的实时监测，提出了森林防火的一些安全措施，为森林火险等级预测和林火及时扑救抢险提供积极的气象保障条件。     

Jason-2卫星测高数据在陆地水域水位变化监测中的应用——以南洞庭湖为例

论文在对Jason-2/OSTM GDRs数据特点、湖泊水位计算原理、测高数据编辑与处理过程进行详细阐述的基础上,以地处长江中游的南洞庭湖区为监测实例,对Jason-2卫星测高数据在陆地水域水位变化监测中的应用进行了试验研究。在同监测点距离最近的地面水文站实测水位的对比来看,二者监测结果间存在显著的线性相关关系,相关系数达0.974。表明基于Jason-2/OSTM GDR数据的水位监测结果具有较高的可信度,在陆地水域水位变化卫星监测中具有一定的现实可行性,从而为我国陆地水域水位变化监测提供了一种新的有效技术手段。     

我国人造卫星在环境污染管理中的应用

卫星资料为环境管理部门提供了决策依据,为环境管理部门采取有效的行政措施节省了宝贵时间。环境与灾害监测预报小卫星星座使用后,我国环保部门将拥有自己的专用卫星。可以做更多的环境科研工作,     

盘锦市湿地变化的遥感监测分析

采用1986,1995,2000和2006年美国TM卫星影像,通过人工解译、计算机自动识别以及实地核实等方法,监测盘锦市湿地的变化情况,分析变化原因,得出变化趋势。