基于高分辨率遥感影像的设施农业资源信息采集技术研究

结合设施农业空间位置分布规律及其在高分辨率遥感影像上的纹理特征体现,设计了批量设施自动生成算法,并基于GIS组件开发了基于高分辨率遥感影像的设施农业信息采集系统;该系统以高分辨率遥感影像为基础底图,结合批量设施自动生成算法进行数字化,实现了人机交互式半自动化信息采集。     

Passive microwave remote sensing of the historic February 2010 snowstorms in the Middle Atlantic region of the USA

The snowfall in the Baltimore/Washington metropolitan area during the winter of 2009/2010 was unprecedented and caused serious snow‐related disruptions. In February 2010, snowfall totals approached 2 m, and because maximum temperatures were consistently below normal, snow remained on the ground the entire month. One of the biggest contributing factors to the unusually severe winter weather in 2009/2010, throughout much of the middle latitudes, was the Arctic Oscillation. Unusually high pressure at high latitudes and low pressure at middle latitudes forced a persistent exchange of mass from north to south. In this investigation, a concerted effort was made to link remotely sensed falling snow observations to remotely sensed snow cover and snowpack observations in the Baltimore/Washington area. Specifically, the Advanced Microwave Scanning Radiometer onboard the Aqua satellite was used to assess snow water equivalent, and the Advanced Microwave Sounding Unit‐B and Microwave Humidity Sounder were employed to detect falling snow. Advanced Microwave Scanning Radiometer passive microwave signatures in this study are related to both snow on the ground and surface ice layers. In regard to falling snow, signatures indicative of snowfall can be observed in high frequency brightness temperatures of Advanced Microwave Sounding Unit‐B and Microwave Humidity Sounder. Indeed, retrievals show an increase in snow water equivalent after the detection of falling snow. Yet, this work also shows that falling snow intensity and/or the presence of liquid water clouds impacts the ability to reliably detect snow water equivalent. Moreover, changes in the condition of the snowpack, especially in the surface features, negatively affect retrieval performance. Copyright © 2011. This article is a U.S. Government work and is in the public domain in the USA.     

A 200-year precipitation index for the central English Lake District / Un indice de précipitation de 200 ans pour la Région des Lacs en Angleterre

Abstract

Abstract The geographical context and hydroclimatology of the English Lake District means that the region is an important monitor of changes to nationally significant environmental assets. Using monthly rainfall series for sites in and around the central Lake District, a continuous ~200-year precipitation index was constructed for a representative station close to Grasmere. The bridged series shows a significant decline in summer rainfall since the 1960s, offset by increases in winter and spring that are strongly linked to North Atlantic forcing. Over longer time periods, the index exhibits several notable dry (1850s, 1880s, 1890s, 1930s, 1970s) and wet (1820s, 1870s, 1920s, 1940s, 1990s) decades. These patterns are strongly reflected by reservoir inflow series and by indicators of the biological status of the region’s freshwater lakes. It is argued that long-term climate indices will become increasingly important as managers seek to evaluate recent and project environmental changes within the context of long-term natural variability.     

Subduction and back-arc activity at the Hikurangi convergent Margin,New Zealand

The Hikurangi Margin is a region of oblique subduction with northwest-dipping intermediate depth seismicity extending southwest from the Kermadec system to about 42°S. The current episode of subduction is at least 16–20 Ma old. The plate convergence rate varies along the margin from about 60 mm/a at the south end of the Kermadec Trench to about 45 mm/a at 42°S. The age of the Pacific lithosphere adjacent to the Hikurangi Trench is not known.The margin divides at about latitude 39°S into two quite dissimilar parts. The northern part has experienced andesitic volcanism for about 18 Ma, and back-arc extension in the last 4 Ma that has produced a back-arc basin onshore with high heaflow, thin crust and low upper-mantle seismic velocities. The extension appears to have arisen from a seawards migration of the Hikurangi Trench north of 39°S. Here the plate interface is thought to be currently uncoupled, as geodetic data indicate extension of the fore-arc basin, and historic earthquakes have not exceededM _s=7.South of 39°S there is no volcanism and a back-arc basin has been produced by downward flexure of the lithosphere due to strong coupling with the subducting plate. Heatflow in the basin is normal. Evidence for strong coupling comes from historic earthquakes of up to aboutM _s=8 and high rates of uplift on the southeast coast of the North Island.The reason for this division of the margin is not known but may be related to an inferred increase, from northeast to southwest, in the buoyancy of the Pacific lithosphere.     

辽宁及其邻区1900—1949年M≥5级地震参数研究

我们搜集了国际国内地震台网资料、宏观考察资料、地震专题研究报告,对1900—1949年5级以上地震全部进行了核查,重新进行定位处理,并结合宏观考察资料和前人工作成果进行分析研究,得到较为准确的震中位置。通过这项研究,增补了原目录中遗漏的地震,并对目录中的错误进行了修正,从而得到一份较为完整可靠的地震目录。     

Mapping the Geographical Diffusion of a Finnish Smallpox Epidemic from Historical Population Records

Smallpox mortality from an early 19th century epidemic in Finland is mapped at the parish village level. First, geographically referenced historical materials are used to construct a map showing the spread of smallpox mortality among villages. Next, the diffusion of smallpox morbidity is simulated by computer for the same set of villages. These two maps are then compared. Results indicate that at this scale maps of mortality diffusion can show general trends but have no direct spatial correspondence to the underlying pattern of morbidity diffusion. Mortality maps cannot be used as a surrogate measure of infectious contact behavior at micro scales of analysis.     

鲜水河断裂带炉霍县卡扎村大探槽古地震研究

本文测定分析了特殊地区的两种不同饱和状态的干压实土体在不同等级荷栽作用下产生的沉陷量，探讨了施荷时间对沉陷量的影响从而提示了两种干压实土体在荷载作用下沉陷量变化规律，并分析研究了这两种干压实土体的最大压缩模量与饱和度的关系。这一研究成果对干旱特殊地区的公路设计施工具有一定的参考价值。     

川滇交界中段历史强震及其活动特征

本文在详细补充调查和充分整理前人资料基础上，对川滇交界中段的其中６次强震进行了等烈度图编制，并对川滇菱块东界大地震的等烈度线分布特征进行了研究，按照构造孕育与发震扩展的思路，探讨了川滇交界中段的中长期地震危险性。     

干旱地区土地合理利用问题研究：——以新疆阜康县为例

本文以阜康县为例，对干旱地区土地利用的特点，问题进行了探讨，并提出了合理利用途径。