SOIL MOISTURE SENSING WITH AIRCRAFT OBSERVATIONS OF THE DIURNAL RANGE OF SURFACE TEMPERATURE1

ABSTRACT: Aircraft Observations of the surface temperature were made by measurements of the thermal emission in the 8-14 μm band over agricultural fields around Phoenix, Arizona. The diuranal range of these surface temperature measurnments were well correlated with the ground measurment of soil moisture in the 0-2 cm layer. The surface temperature indicating no moisture stress. These results indicate that for clear atmospheric conditions remoteley sensed sufrace temperatures can be a reliable indicator of soil moisture conditions and crop status.     

THERMAL MAPPING OF STREAMS FROM AIRBORNE RADIOMETRIC SCANNING1

This paper begins with a brief review of radiation theory as applied to water temperature determinations. Errors introduced in “radiant” temperature measurements due to nonblackness of the water surface and the effects of the atmosphere are included in this discussion. The airborne scanner system is described. Analysis and display of scanner data using the Laboratory for Applications of Remote Sensing (LARS) display system are discussed. Thermal maps of four sections of the Wabash River are included and points of interest of each map are discussed in the text.     

Monitoring Parks Through Remote Sensing: Studies in Nepal and Honduras

The effectiveness of parks as management regimes is hotly contested. Much of the current discussion centered around comparisons of management regimes can be traced to a dearth of cross-site quantitative evaluations. Remote sensing provides a particularly effective tool for this purpose, yet analysis of remotely sensed data requires fieldwork to interpret human activities and the socioeconomic and political contexts that relate to land cover change. This paper examines the effect of establishment of the Celaque National Park, Honduras, and the Royal Chitwan National Park buffer zone, Nepal, on limiting deforestation. In Celaque, the park itself has been largely successful in maintaining forest cover. However, recent changes in land use patterns have led to increasing pressure on the park boundaries, exacerbated by the lack of involvement of local residents. In the Royal Chitwan National Park, in contrast, participatory approaches towards co-management have been implemented over the past decade in the park buffer zone. With significant incomes derived from ecotourism, complete protection of the buffer zone forest has been adopted, leading to significant regrowth of tree cover. However, local decision-making power is limited, and buffer zone management has largely proven successful due to the investment and support provided by international donor agencies. These two case studies demonstrate the utility of remote sensing and Geographical Information Systems analysis in providing a spatiotemporal perspective for assessing management policies. They also demonstrate the importance of fieldwork to provide a nuanced understanding of the socioeconomic and institutional conditions affecting the outcomes of forest management regimes.     

Forest Cover Change,Physiography, Local Economy,and Institutions in a Mountain Watershed in Nepal

This study assessed changes in forest cover in a mountain watershed in central Nepal between 1976 and 2000 by comparing classified satellite images coupled by GIS analyses, and examined the association of forest change with major physiographic, economic, and local forest governance parameters. The results showed an increase in forested area (forest plus shrublands) by 7.6% during 1976–2000. Forest dynamism (changes including improvement, deterioration, gain, and loss) was highest in low-elevation, south-facing and less-steep slopes that were closer to roads. Proportionately the highest net improvement and gain to forested area also took place in those locations. Forest degradation occurred at twice the rate of improvement in high elevation areas (> 2300 m). Forests located in urban and semiurban areas (i.e., a market-oriented economy) experienced a proportionately higher amount of net improvement and gain than forests in rural areas (i.e., a subsistence economy). Among the three governance arrangements, proportionately the highest net improvement and gain took place in semigovernment forests (forested area legally under the forest department but with de facto control and claim of ownership by local communities and/or municipality) followed by formalized community forests (including leasehold). Government forests, which were mostly found in the southern high mountains and had virtually open access, remained relatively stable during the study period. Over 50% of the watershed forests have not come under community-based management despite favorable policy and more than two decades of government intervention with continuous donor support. The findings indicate that the present one size fits all approach of community forest handover policy in Nepal needs rethinking to accommodate biophysical and socioeconomic variations across the country.     

基于GIS的芜湖市城市用地扩展规律

利用芜湖市1990年、2000年两个时相的遥感影像进行城市土地利用解译,提取城市新、旧建成区区块用地,通过GIS软件提供的空间统计分析功能,对城市用地空间分布进行定量分析与描述,从而揭示城市用地及其扩展规律.研究结果表明,芜湖市用地扩展呈现明显中心圈层式蔓延和轴向集中性扩展规律的模式.作者提出了城市用地扩展中应注意解决的问题.     

多源土地利用地学知识的获取与应用

土地利用地学知识可应用于LIS智能化分析及辅助遥感影像解译,是国土信息化工程建设中值得深入研究的重要技术环节之一.明确了土地利用地学知识概念,构建了多数据源的土地利用地学知识体系,针对不同数据源分析了土地利用地学知识的获取及表达,并着重对土地利用地学知识辅助遥感影像解译进行了阐述,指出采用知识辅助高分辨率遥感影像解译是亟待深入开展研究的课题.     

STORM RUNOFF PREDICTION BASED ON A SPATIALLY DISTRIBUTED TRAVEL TIME METHOD UTILIZING REMOTE SENSING AND GIS1

ABSTRACT: In this study, remotely sensed data and geographic information system (GIS) tools were used to estimate storm runoff response for Simms Creek watershed in the Etonia basin in northeast Florida. Land cover information from digital orthophoto quarter quadrangles (DOQQ), and enhanced thematic mapper plus (ETM+) were analyzed for the years 1990, 1995, and 2000. The corresponding infiltration excess runoff response of the study area was estimated using the U.S. Department of Agriculture (USDA), Natural Resources Conservation Service Curve Number (NRCS‐CN) method. A digital elevation model (DEM)/GIS technique was developed to predict stream response to runoff events based on the travel time from each grid cell to the watershed outlet. A comparison of predicted to observed stream response shows that the model predicts the total runoff volume with an efficiency of 0.98, the peak flow rate at an efficiency of 0.85, and the full direct runoff hydrograph with an average efficiency of 0.65. The DEM/GIS travel time model can be used to predict the runoff response of ungaged watersheds and is useful for predicting runoff hydrographs resulting from proposed large scale changes in the land use.     

全国洪涝灾害警戒水域遥感数据库的研制

由于以往对发生的洪涝灾情没有形成统一的、客观的评价标准,而不同来源的各种数据往往大相径庭,使有关部门难以了解实际灾情。为此,提出了“警戒水域”的概念,利用TM和NOAA／AVHRR图像数据建立了我国七大江河地区洪涝灾害易发区的警戒水域遥感数据库,并用以指导洪涝灾情的监测与评估,为防洪救灾决策提供科学的、可靠的、时效性强的信息。该数据库的建立在我国的抗洪救灾中发挥了重要的作用。文章对其研究方法与其关键技术进行了介绍．     

遥感与地理信息系统一体化技术在重大自然灾害监测与评估中的应用

本文结合国家“八五”科技攻关的实例，阐述了遥感和地理信息系统技术在重大突发性自然灾害监测与评估中的作用和良好效益，并提出今后着重的三个方面：建立国家自然灾害监测与评估中心；解决关键性的技术问题，牢固用户观点。