The global rainforest mapping project JERS-1:a paradigm of international collaboration for monitoring land cover change

The Global Rainforest Mapping (GRFM) project was initiated in 1995 and, through a dedicated data acquisition policy by the National Space Development Agency of Japan (NASDA), data acquisitions could be completed within a 1.5-year period, resulting in a spatially and temporally homogeneous coverage to contain the entire Amazon Basin from the Atlantic to the Pacific; Central America up to the Yucatan Peninsular in Mexico; equatorial Africa from Madagascar and Kenya in the east to Sierra Leone in the west; and Southeast Asia, including Papua New Guinea. To some extent, GRFM project is an international endeavor led by NASDA, with the goal of producing spatially and temporally contiguous Synthetic Aperture Radar (SAR) data sets over the tropical belt on the Earth by use of the JERS-1 L-band SAR, through the generation of semi-continental, 100m resolution, image mosaics. The GRFM project relies on extensive collaboration with the National Aeronautics and Space Administration (NASA), the Joint Research Center of the European Commission (JRC) and the Japanese Ministry of International Trade and Industry (MITI) for data acquisition, processing, validation and product generation. A science program is underway in parallel with product generation. This involves the agencies mentioned above, as well as a large number of international organizations, universities and individuals to perform field activities and data analysis at different levels.     

Wetland vegetation biomass estimation and mapping from Landsat ETM data:a case study of Poyang Lake

Poyang Lake is the largest freshwater lake in China. This paper conducted a digital and rapid investigation of the lake’s wetland vegetation biomass using Landsat ETM data acquired on April 16, 2000. First, utilizing the false color composite derived from the ETM data as one of the main references, the authors designed a reasonable sampling route for field measurement of the biomass, and carried it out on April 18-28, 2000. Then after both the sampling data and the ETM data were geometrically corrected to an equal-area projection of Albers, linear relationships among the sampling data and some transformed data derived from the ETM data and the ETM 4 were calculated. The results show that the sampling data is best relative to the band 4 data with a high correlation coefficient of 0.86, followed by the DVI and NDVI data with 0.83 and 0.80 respectively. Therefore, a linear regression model, which was based on the field data and band 4 data, was used to estimate the total biomass of entire Poyang Lake, and then the map of the biomass distribution was compiled.     

GIS专题数据综合的研究

随着GIS技术在各种应用领域的推广使用，各领域的专业数据与G1S的空间数据相结合，形成描述特定地理现象的各种专题数据。与GIS空间数据一样，专题数据的应用也由微观的、较为详细地描述小区域地理现象特征，转向宏观的、较为概略地描述较大范围地理现象特征，这是专题数据综合的主要任务。该文在讨论GIS专题数据类型及特征的基础上，着重分析了专题数据综合的基本类型，并提出了专题数据综合的概念模型，为GIS专题数据自动综合的实施提供理论依据和实施方案。     

空间数据库数据约束系统及其实现

空间数据库模型是构造地理信息系统的关键，如何在空间数据库中定义和实现空间实体间的约束关系直接影响到空间数据的完整性和一致性，是实现通用空间数据库约束系统的关键技术。该文讨论了传统GIS空间数据约束关系实现方法的局限性，提出了一个可扩展的空间数据约束描述和数据更新规则系统，并实现了系统原型。这一可扩展的约束系统将有利于解决GIS的多用户同步操作机制及分布式事务处理的实现问题。     

水土流失评价数据库建立中的数据标准化研究--以中国潜在水土流失评价数据库为例

在水土流失评价数据库的建立研究中，涉及到数据的标准化问题。该研究以中国潜在水土流失评价数据库建立过程中的数据标准化研究为例，探讨建立适合水土流失评价数据标准化的方法。研究包括了水土流失数据标准化建设中的评价数据库的设计、数据的标准化。其中，数据的标准化包括数据的收集与分析、数据的录入、投影变换、其它格式向ARC/INFO格式的转换、补充编制专题文档等。     

Interviewing in 'place': the socio-spatial construction of interview data

The intersubjective dialogic exercise through which identities and knowledge are constructed exists in a dialectic relation with the 'place' of the interview. The in situ nature of interviewing should not be overlooked. Two case studies of interviews conducted with older people in Britain about their social network and support are used to illuminate two aspects of the socio-spatial construction of interview data. First, interview sites can yield important information about the way participants construct their individual and social identities. Second, such identities can influence interviewer–interviewee dynamics.     

面向对象的GIS数据模型与实现

介绍了面向对象数据模型的基本概念，重点讨论了面向对象数据模型在地理信息系统中的应用及具体实现途径。     

台湾地面沉降现状与防治对策

台湾地面沉降始于20世纪50年代初期的台北地区。随着地下水开发利用的普及与养殖渔业和相关耗水产业的移入，西部沿海平原区地面沉降现象普遍，尤以彰化、云林、嘉义、屏东等地显著，总沉降面积达1165km^2。约占台湾平原区的1／100其中屏东地区1970—2001年的累积沉降量达3．20m，最大沉降速率曾超过40cm／a(1979-1981年)。目前彰化地区的沉降速率最大，2000—2001年达17．6cm/a。其它绝大部分地区沉降速率在5cm/a以下。台湾地面沉降的主要原因系开采地下水引起的。仅屏东地区就有4000余口深井，地下水年均开采量1．65亿m^3，最高达3．2亿m^3以上。该岛第四纪地层厚800—1000m，沉降主要发生在60-300m土层内。目前沉降发展态势可分为暂时稳定、渐趋稳定、显著沉降和潜在沉降4类。台湾目前采用一等水准测量、GPS及一孔多标感应分层监测技术进行地面沉降监测。在主要沉降区均设有多处GPS固定站实行自动化监测，一孔多标土层分层监测共有19组。采用数值模拟对地面沉降进行分析与预测。通过用水规划的制定、督导和实施地面沉降的控制与管理。1995—2000年实施第一期地面沉降防治执行方案，2001-2004年实施第二期，针对不同地区沉降发展的不同态势采取相应对策，已取得良好的社会成效。     

辽宁省抚顺市区地质灾害监测系统设计方案

抚顺市地质灾害监测系统，由5方面工作内容组成：(1)建立统一可靠的城市高程起算基准；(2)扩展现有的沉降监测网，使分散的监测点联合形成全面、统一的监测网；(3)对浑河断裂带主断层实施监测；(4)对西露天采坑北坡滑坡重点区和采煤沉陷重点区实施水平位移监测；(5)利用计算机技术和地理信息系统(GIS)技术，建立抚顺市地质灾害信患系统。该系统是城市地质灾害防治的基础工程。系统应用了先进的监测手段及数据处理技术。文章介绍了系统的设计方案。     

声波扫描成像在灾害防治及环境保护中的应用

利用超声波扫描成像测井技术，在地质灾害的预防与环境保护中可以检测由于采矿而形成的冒落带、裂隙带、离层带、洞穴及软弱层的存在状况及部位，测定基岩风化蚀变程度及深度，在地质灾害与环境保护的治理时可以监测治理的质量，提供了直观精确可靠的基础资料。