Changes in active eolian sand at northern Coachella Valley, California

Climate variability and rapid urbanization have influenced the sand environments in the northern Coachella Valley throughout the late 20th century. This paper addresses changes in the spatial relationships among different sand deposits at northern Coachella Valley between two recent time periods by using satellite data acquired from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). The approach employed here, involving multispectral thermal infrared (TIR) data and spectral mixture analysis, has shown that the major sand deposits can be spatially modeled at northern Coachella Valley. The “coarse-grained (quartz-rich) sand” deposit is associated with active eolian sand, and the “mixed sandy soil” and “fine-grained (quartz-rich) sand” deposits are associated with inactive eolian sand. The fractional abundance images showed a significant decrease between 2000 and 2006 in the percentage of active sand in the major depositional area for fluvial sediment, the Whitewater River, but also in two downwind areas: the Whitewater and Willow Hole Reserves. The pattern of the active sand appears to be related to variations in annual precipitation (wet and dry years) and river discharge in the northern Coachella Valley. We suggest here that recent human modifications to the major watercourses that supply sand affect the capability of fluvial deposition areas to restore sediments over time and consequently the responses of the sand transport system to climate change, becoming more sensitive to dry years where areas of active sand may shrink, degrade, and/or stabilize faster. The approach utilized in this study can be advantageous for future monitoring of sand in the northern Coachella Valley for management of these and similar environments.     

海南岛西部土地利用变化及其景观格局动态分析

利用1986年、1996年和2003年的3期TM数据,在GIS和FRAGSTAT景观格局分析软件支持下,定量地分析海南岛西部的土地利用类型变化及其景观格局动态特征。结果表明：17 a来各种土地类型变化及其相互之间的转化频率十分频繁。没有发生变化的林地占76.88％、耕地占60.38％、建设用地占52.11％、沙地、水体和草地分别仅占32.64％、28.72％和2.7％。岛西各种土地利用类型的空间格局变化显著,景观异质性增强,破碎度降低而连通性增加。近10多年来,岛西土地利用变化及景观格局动态主要是受自然条件和人为活动干扰共同作用的结果。     

遥感技术和地理信息系统在神府-东胜地区环境综合评价中的应用

简要介绍了遥感和地理信息系统在神府—东胜地区环境综合评价中的应用方法。针对这一地区的环境特点,建立了以遥感信息为基础的环境综合评价体系。该体系包括环境压力负荷、环境问题和环境潜力等3个方面的10个因子,运用层次分析法结合专家知识,实现了全部因子的权重排序。以GIS为技术支撑,对各专题进行了时空变化分析,建立环境质量综合评价模型。详细客观地评价了该区的环境质量情况.     

高光谱遥感技术在岩石识别中的应用

依据不同岩石的光谱特征,通过图像处理方法,对各种岩石类型信息进行提取,使高光谱遥感技术在地学领域的应用由定性分析到定量识别。     

遥感技术在鲁南地区水资源综合开发利用中的应用

以水量平衡理论为依据,采用不同时相的TM图像数据及多元信息复合技术对鲁南地区沂源、沂水、沂南三县(简称“三沂”)的地下水资源、地表水拦蓄条件进行调查分析,在此基础上,提出了区域水资源综合开发利用配置方案。     

世界航天遥感技术现状、发展趋势及油气遥感应用方向

世界航天遥感技术发展迅速,掌握卫星发射技术和具备卫星发射能力的国家越来越多,其中,高分辨率小型商业卫星和雷达卫星已经成为重要的遥感信息源;高光谱分辨率遥感将是现今和下个世纪的发展方向。本文总结了世界航天遥感技术现状,分析了今后的发展趋势,提出了油气遥感应用的研究方向     

遥感影像的Web发布研究与实现

随着互联网络的迅猛发展和Ｗｅｂ在网络信息集成中起到越来越大的作用。地理信息系统已经从桌面向网络方向发展,出现了对于ＷｅｂＧＩＳ的研究。针对ＷｅｂＧＩＳ中的影像发布,根据当前影像及ｉｎｔｅｒｎｅｔ的特点,系统地研究了遥感影像Ｗｅｂ发布中的体系结构与技术问题,实现了遥感影像Ｗｅｂ发布系统,并讨论了它与ＷｅｂＧＩＳ的集成。     

厦门市植被变化的遥感动态分析

本文利用美国LandsatTM/ETM+卫星影像,通过变化检测和信息提取等分析了福建省厦门市从1989～2000年的植被变化。它们包含了一部分不是由植被变化所引起的伪变化信息。对此,依次采用了阈值法和掩膜法将伪变化信息剔除,最后获得了准确的植被变化信息。研究结果表明,厦门市11年中,植被面积由于城市扩展绿地面积有了明显的减少。从1995～2000年植被减少的面积明显要比1989～1995年期间的少得多,这与厦门市近年来逐渐重视保护植被和生态环境有密切的关系。     

Land Cover Change and its Environmental Significance in the Herbert River Catchment,North-east Queensland

There has been considerable recent concern over the amount of vegetation clearance in the wet tropics of northern Australia. This paper reports on the results of a case study undertaken in the lower Herbert River catchment in north-east Queensland, which utilised remote sensing and Geographic Information Systems (GIS) to assess both spatial and temporal changes in land cover since European settlement in the mid-nineteenth century. We demonstrate that since European settlement there has been a substantial reduction in the area of Melaleuca, rainforest, and eucalyptus-dominated land-cover patterns. We also provide a range of quantitative measures to show that the landscape diversity, integrity and quality of these ecosystems have also declined between the 1860s and 1996. We conclude that reform is required at policy, planning and enterprise levels if the ecological, economic and social values of these systems are to be maintained in the future.     

深圳市土地利用变化机制分析

利用１９８０、１９８８、１９９４年的遥感影像,通过应用最大似然法和概率松弛法对深圳市土地利用进行了测量。在此基础上,运用分类结果求得研究区土地利用变化的转移矩阵,据此分析了深圳上１５年来土地利用变化的空间过程。结果表明：深圳市土地利用纺要表现为原有农田、果园用地显著减少,城镇用地沿海岸和主要公路干线迅速增加。这一土地利用变化的驱动力主要是深圳经济特区的开放政策、城镇人口迅速增长、外资大量涌入和以房