TM影像在1∶25万国土资源综合大调查中的应用——新疆博斯坦、西藏聂拉木国土资源调查遥感初译简述

本文简述了作者在对新疆博斯坦、西藏聂拉木地区遥感初步解译过程中的体会 :用专业遥感图像处理系统 ,对TM数据进行相关的处理 ,专题信息提取 ;并根据色调、影纹结构、阴影等各种直接或间接解译标志 ,从地貌、地质构造、生态等方面着手 ,论述了其在TM影像上的特征。为该地区进行 1 :2 5万国土资源大调查做了较为充分的技术准备 ,以及为下一步更好地开展大调查打下了良好的基础     

Groundwater vulnerability and risk mapping for the Basaltic aquifer of the Azraq basin of Jordan using GIS, Remote sensing and DRASTIC

Water consumption in Jordan already exceeds renewable freshwater resources by more than 20% and, after the year 2005, freshwater resources are likely to be fully utilised. Over 50% of supply derives from groundwater and this paper focuses on a small part of the northern Badia region of Jordan that is underlain by the Azraq groundwater basin where it has been estimated that annual abstraction stands at over 100% of the projected safe yield. While water supply is a crucial issue, there is also evidence to suggest that the quality of groundwater supplies is also under threat as a result of salinisation and an increase in the use of agrochemicals. Focusing on this area, this paper attempts to produce groundwater vulnerability and risk maps. These maps are designed to show areas of greatest potential for groundwater contamination on the basis of hydro-geological conditions and human impacts. All of the major geological and hydro-geological factors that affect and control groundwater movement into, through, and out of the study area were incorporated into the DRASTIC model. Parameters included; depth to groundwater, recharge, aquifer media, soil media, topography, and impact of the vadose zone. The hydraulic conductivity of the aquifer was not included in calculating the final DRASTIC index for potential contamination due to a lack of sufficient quantitative data. A Geographical Information System (GIS) was used to create a groundwater vulnerability map by overlaying the available hydro-geological data. The resulting vulnerability map was then integrated with a land use map as an additional parameter in the DRASTIC model to assess the potential risk of groundwater to pollution in the study area. The final DRASTIC model was tested using hydrochemical data from the aquifer. Around 84% of the study area was classified as being at moderate risk while the re mainder was classified as low risk. While the analysis of groundwater chemistry was not conclusive, it was encouraging to find that no well with high nitrate levels was found in the areas classified as being of low risk suggesting that the DRASTIC model for this area provided a conservative estimate of low risk areas. It is recognised that the approach adopted to produce the DRASTIC index was limited by the availability of data. However, in areas with limited secondary data, this index provides important objective information that could be used to inform local decision making.     

重庆市土地利用现状遥感调查与国土资源信息系统应用

应用遥感资料,通过室内遥感信息解译和外业实地调查验证,将土地利用现状遥感解译的作者原图资料和地理、社会经济信息,在统一的软、硬件环境支持下进入国土资源信息系统,利用系统的特有功能,实现了对重庆市土地利用现状与社会经济状况的综合分析.     

镇康芦子园地区遥感和GIS成矿预测示范研究

利用遥感及GIS技术，对云南省重要原矿化集中域－镇康芒子园地区进行成矿预测示范的方法研究，取得重要成果。在GIS平台下，充分利用遥感图像多功能处理成果及遥感地质解译数据，综合地物化遥信息，建立遥感地质成矿模型并类比外推，在芦子园地区进行成矿预测。经对预测靶区进行野外查证，不仅发现已有多个民采点存在，且可望近期会有找矿突破，充分说明遥感和GIS成矿预测的方法技术有效可行。     

青海湖环湖区沙漠化土地的遥感动态研究

青海湖地处青藏高原的东北部 ,近几十年来 ,由于自然环境条件变化和人为活动的综合影响 ,环湖区土地沙漠化趋势日渐加剧。利用遥感和GIS综合手段对环湖区沙漠化土地作了尝试性的动态监测研究 ,结果表明 ,自 1 95 6年航测资料记录以来到 1 972年 ,沙漠化土地面积分别是 45 2 9平方公里、498 4平方公里 ;1 986年TM数据解译结果显示沙漠化土地面积为 75 6 6平方公里 ;到 2 0 0 0年沙漠化土地面积已增加到1 2 47 7966平方公里 ,土地沙漠化处于正过程发展阶段 ,1 95 6～ 2 0 0 0年平均年净增 1 8 0 7平方公里 ,尤其是在2 0世纪 80年代以后扩展速度在加快 ,1 986～ 2 0 0 0年间均净增 3 5 0 8平方公里     

Mapping the spatial and temporal distributions of woody debris in streams of the Greater Yellowstone Ecosystem, USA

The objectives of this study were: (1) to document spatial and temporal distributions of large woody debris (LWD) at watershed scales and investigate some of the controlling processes; and (2) to judge the potential for mapping LWD accumulations with airborne multispectral imagery. Field surveys were conducted on the Snake River, Soda Butte Creek, and Cache Creek in the Greater Yellowstone Ecosystem, USA. The amount of woody debris per kilometer is highest in 2nd order streams, widely variable in 3rd and 4th order streams, and relatively low in the 6th order system. Floods led to increases in woody debris in 2nd order streams. Floods redistributed the wood in 3rd and 4th order streams, removing it from the channel and stranding it on bars, but appeared to generate little change in the total amount of wood throughout the channel system. The movement of woody debris suggests a system that is the reverse of most sediment transport systems in mountains. In 1st and 2nd order tributaries, the wood is too large to be moved and the system is transport-limited, with floods introducing new material through undercutting, but not removing wood through downstream transport. In the intermediate 3rd and 4th order channels, the system displays characteristics of dynamic equilibrium, where the channel is able remove the debris at approximately the same rate that it is introduced. The spatial distribution and quantity of wood in 3rd and 4th order reaches varies widely, however, as wood is alternatively stranded on gravel bars or moved downstream during periods of bar mobilization. In the 6th order and larger channels, the system becomes supply-limited, where almost all material in the main stream can be transported out of the central channel by normal stream flows and deposition occurs primarily on banks or in eddy pool environments. Attempts to map woody debris with 1-m resolution digital four-band imagery were generally unsuccessful, primarily because the imagery could not distinguish the narrow logs within a pixel from the surrounding sand and gravel background and due to problems in precisely coregistering imagery and field maps.     

宁乡煤炭坝外围遥感地质解译及找煤研究

通过卫片地质解译,从遥感角度对该区的构造特征及规律进行了初步的总结,同时,紧密结合生产性的物探、井探及钻探工作,以半隐伏含煤复向斜为找煤影像模式,在本区中、新生界盖层下或断裂构造下圈出含煤预测区7个,预估含煤面积12.8 km~2,预测煤炭储量5473万吨。     

不同施肥条件下玉米的荧光光谱特征及其在遥感中应用的可能性

在田间栽种玉米,并按氮、磷肥的不同施用量分为10种情况处理。在不同生长期进行了生长形态指标测量和活体叶片的荧光光谱与激光诱导荧光光谱测量,并测试了叶片浸出液的荧光光谱。结果表明,不同的施肥条件.不仅使玉米在长势上有所反映,而且还会引起光合作用效率和叶绿素含量等的变化,因而导致了玉米叶片荧光光谱的变化。利用440,550,685nm等处的荧光强度可探测玉米的养分供应状况,当利用它们的比值时,表征更为明显。这就为遥感监测玉米的长势和估产提供了新的途径和可靠依据。从玉米的需肥情况、农时、荧光光谱的差异性以及遥感的可行性来看,在拔节期是遥感监测的最佳时期。     

应用荧光光谱特征作受害植物判别指标的研究

本文讨论了几种植物在正常、受害及衰老状况下的荧光光谱特征及其变化。结果表明,叶绿素两个荧光峰强度的消长与植物受害程度有着内在的联系,利用这种关系可预测植物长势和进行植物生理状态的研究。