Remote sensing water observation for supporting Lake Victoria weed management

This paper aims to assess the suitability of remote sensing for enhancing the management of water body resources and for providing an inexpensive way to gather, on a wide area, weed infestation extent and optical parameter linked to the water body status. Remotely sensed satellite images and ancillary ground true data were used to produce land cover maps, trough classification techniques, and water compounds maps, applying radiative transfer models. The study proposed within the framework of the cooperation between Italian Foreign Affair Ministry (through the University of Rome) and Kenyan Authorities has been carried out on the Kenyan part of the Lake Victoria. This lake is one of the largest freshwater bodies of the world where, over the last few years environmental challenges and human impact have perturbed the ecological balance affecting the biodiversity. The objective of this research study is to define the thematic products, retrievable from satellite images, like weed abundance maps and water compound concentrations. These products, if provided with an appropriate time frequency, are useful to identify the preconditions for the occurrence of hazard events like abnormal macrophyte proliferation and to develop an up-to-date decision support system devoted to an apprised territory, environment and resource management.     

A multi-scale remote sensing approach for monitoring northern peatland hydrology: present possibilities and future challenges

Remote sensing has the potential to provide quantitative spatially explicit hydrological information across northern peatland complexes. This paper details a multi-scale remote sensing approach for assessing the use of Sphagnum mosses as proxy indicators of near-surface hydrology. Several spectral indices developed from the near infra-red (NIR) and shortwave infra-red (SWIR) liquid water absorption bands, as well as a biophysical index can be correlated with measures of near-surface moisture in the laboratory, in the field and from airborne imagery. Data from all platforms revealed similar patterns in the spectral indices in relation to changes in moisture although the strength of correlations was reduced as the spatial scale increased. The rapid collection of temporally and spatially explicit hydrological data means that the technique has potential practical application for environmental managers and peatland scientists at the local scale. The task of up-scaling the technique for use in operational peatland hydrological monitoring to the global scale is challenging but achievable, and requires further investigation into the heterogeneity of near-surface moisture across Sphagnum patches and the application of novel image processing techniques to improve the spatial resolution of currently available satellite imagery.     

内地与香港燃煤电厂大气污染物排放控制政策与标准比较

香港特区与广东省政府联合成立粤港持续发展与环保合作小组,并发表《改善珠江三角洲空气质量的联合声明》（简称＂减排联合声明＂）,同意制定合理的减排方案,共同执行管理计划。总结分析了粤、港地区在治理燃煤电厂大气污染物方面的控制政策,并对大陆与香港特区燃煤电厂大气污染物的排放标准进行比较。     

群体感应抑制剂与磺胺甲恶唑、盐酸强力霉素对大肠杆菌的联合毒性及其机制初探

群体感应抑制剂(QSIs)具有不会产生抗药性的特点,从而被作为抗生素的可能替代品,具有广阔的应用前景,因此其存在着与传统抗生素环境联合暴露的可能,但是目前尚缺乏相关联合效应的研究。本文以大肠杆菌(Escherichia coli)为受试生物,测定了7种QSIs(DL-焦谷氨酸、N-乙烯基吡咯烷酮、呋喃酮乙酸酯、2-甲基四氢呋喃-3-酮、3,4-二溴-2(5H)-呋喃酮、(R)-3-吡咯烷醇、D-脯氨醇)分别与磺胺甲恶唑(SMX)和盐酸强力霉素(DH)的二元联合毒性,并初步探讨了它们的联合作用机制。根据结果分析,前5种QSIs作用于AI-2类信号分子介导的群体感应系统,与AI-2类信号分子竞争结合Lsr B蛋白,此通路与SMX、DH的作用通路互不影响,因此联合效应为相加;后2种QSIs作用于AI-1类信号分子介导的群体感应系统,与AI-1类信号分子竞争结合Sdi A蛋白,而SMX、DH的作用可能刺激Sdi A蛋白的表达,从而需要消耗更多的QSIs与Sdi A结合,因而联合效应为拮抗。本实验研究可为传统抗生素与QSIs联合暴露的生态风险评价提供一定理论基础。     

基于遥感和GIS的华东区域洪涝灾害动态监测系统的研究和建立

以NOAA卫星资料为主要信息源，以地面高程、上地利用等地形地貌资料为辅助信息源，研制了华东区域多重因子空间分析模式，在GIS平台上建立洪涝灾害动态监测和分析系统，从而提高了洪涝灾害判识的准确性和客观性。     

Assessment for Salinized Wasteland Expansion and Land Use Change Using GIS and Remote Sensing in the West Part of Northeast China

Due to human impact under climatic variations, western part of Northeast China has suffered substantial land degradation during past decades. This paper presents an integrated study of expansion process of salinized wasteland in Da’an County, a typical salt-affected area in Northeast China, by using Geographic Information Systems (GIS) and remote sensing. The study explores the temporal and spatial characteristics of salinized wasteland expansion from 1954 to 2004, and land use/cover changes during this period. During the past 50 years, the salinized wasteland in study area have increased by 135,995 ha, and in 2004 covers 32.31% of the total area, in the meantime grassland has decreased by 104,697 ha and in 2004 covers only 13.15% of the study area. Grasslands, croplands and swamplands were found the three main land use types converted into salinized wasteland. Land use/cover changes shows that between 1954 and 2004, 48.6% of grasslands, 42.5% of swamplands, and 14.1% of croplands were transformed into salinized wasteland, respectively. Lastly, the major factors influencing salinized wasteland expansion and land use/cover changes were also explored. In general, climatic factors supplied a potential environment for soil salinization. Human-related factors, such as policy, population, overgrazing, and intensified and unreasonable utilization of land and water resources are the main causes of salinized wasteland expansion.     

Application of Satellite Microwave Images in Estimating Snow Water Equivalent1

Abstract: Flood forecast and water resource management requires reliable estimates of snow pack properties [snow depth and snow water equivalent (SWE)]. This study focuses on application of satellite microwave images to estimate the spatial distribution of snow depth and SWE over the Great Lakes area. To estimate SWE, we have proposed the algorithm which uses microwave brightness temperatures (Tb) measured by the Special Sensor Microwave Imager (SSM/I) radiometer along with information on the Normalized Difference Vegetation Index (NDVI). The algorithm was developed and tested over 19 test sites characterized by different seasonal average snow depth and land cover type. Three spectral signatures derived from SSM/I data, namely T19V‐T37V (GTV), T19H‐T37H (GTH), and T22V‐T85V (SSI), were examined for correlation with the snow depth and SWE. To avoid melting snow conditions, we have used observations taken only during the period from December 1‐February 28. It was found that GTH, and GTV exhibit similar correlation with the snow depth/SWE and are most should be used over deep snowpack. In the same time, SSI is more sensitive to snow depth variations over a shallow snow pack. To account for the effect of dense forests on the scattering signal of snow we established the slope of the regression line between GTV and the snow depth as a function of NDVI. The accuracy of the new technique was evaluated through its comparison with ground‐based measurements and with results of SWE analysis prepared by the National Operational Hydrological Remote Sensing Center (NOHRSC) of the National Weather Service. The proposed algorithm was found to be superior to previously developed global microwave SWE retrieval techniques.     

遥感资料在分析城市布局结构中的应用

本文介绍了应用彩红外航片，黑白航片分析呼和浩特市城市居民区、工业区、商业贸易区布局结构的技术。     

Remote sensing-based neural network mapping of tsunami damage in Aceh, Indonesia

In addition to the loss of human life, the tsunami event of 26 December 2004 caused extensive damage to coastal areas. The scale of the disaster was such that remote sensing may be the only way to determine its effects on the landscape. This paper presents the results of a neural network-based mapping of part of the region of Aceh, Sumatra. Before-and-after satellite imagery, combined with a novel neural network methodology, enabled a characterisation of landscape change. The neural network technique used a threshold of acceptance for identification, in combination with a bootstrapped identification method for identifying problem pixels. Map analysis allowed identification of urban areas that were inaccessible by road, and which aid agencies could therefore only reach by air or sea. The methods used provide a rapid and effective mapping ability and would be a useful tool for aid agencies, insurance underwriters and environmental monitoring.