Use of GIS in Optimizing Timber Thinning Strategies in the Eastern Sierra Nevada*

This paper demonstrates the use of a Geographic Information System (GIS) to develop timber thinning strategies on the Kyburz Planning Area of the Tahoe National Forest in northeastern California. The primary criteria used in an assessment of selective thinning potential were forest health and fire hazard ratings. By eliminating environmentally sensitive, economically unfeasible, or low fire hazard areas from consideration, the use of GIS reduced the area that was considered appropriate for thinning by approximately 58%. GIS offers considerable potential for improving resource management strategies.     

国家大剧院深基坑地下水控制设计及施工技术

国家大剧院基坑地下水控制是大剧院工程的三大难题之一,也是专家们讨论的焦点。经过水文地质试验和充分论证,确定了地下水控制方案和施工方法,即采用反循环成井工艺施工引渗井,将上层滞水和潜水引渗到第一层承压含水层中消纳,保证第一步基坑开挖至-15 7m;在-15 7m位置采用连续墙阻隔第一层承压水,并使用旋挖钻机在槽内施工降水井,疏干槽内承压含水层并进行越流补给控制,保证基坑开挖至-26m;在歌剧院台仓局部加深部份(-32 5m),采用封闭布设减压井,解决基坑开挖和台仓地下结构施工时基坑突涌的问题;最后采用特殊的封井技术,将井管内高于槽底约10m的承压水头封堵在槽底以下0 5m,安全截断井管,保证了基础施工。     

湖南通道"百里侗文化旅游长廊"开发研究

侗文化是中华民族文化中的一块瑰宝,通道侗族自治县是中国侗文化的典型代表。通道县侗族民居、侗族建筑、侗族民风民俗种类丰富,特色鲜明,保存完整,为通道县发展旅游经济提供了重要的资源基础。文中客观分析了湖南通道"百里侗文化旅游长廊"开发的竞争优势和不利条件,从空间结构、开发定位、开发方向、开发重点、区域合作、侗文化保护等方面,提出了湖南通道"百里侗文化旅游长廊"开发思路。     

Assessing spatial and attribute errors in large national datasets for population distribution models: a case study of Philadelphia county schools

Geospatial technologies and digital data have developed and disseminated rapidly in conjunction with increasing computing efficiency and Internet availability. The ability to store and transmit large datasets has encouraged the development of national infrastructure datasets in geospatial formats. National datasets are used by numerous agencies for analysis and modeling purposes because these datasets are standardized and considered to be of acceptable accuracy for national scale applications. At Oak Ridge National Laboratory a population model has been developed that incorporates national schools data as one of the model inputs. This paper evaluates spatial and attribute inaccuracies present within two national school datasets, Tele Atlas North America and National Center of Education Statistics (NCES). Schools are an important component of the population model, because they are spatially dense clusters of vulnerable populations. It is therefore essential to validate the quality of school input data. Schools were also chosen since a validated schools dataset was produced in geospatial format for Philadelphia County; thereby enabling a comparison between a local dataset and the national datasets. Analyses found the national datasets are not standardized and incomplete, containing 76 to 90 percent of existing schools. The temporal accuracy of updating annual enrollment values resulted in 89 percent inaccuracy for 2003. Spatial rectification was required for 87 percent of NCES points, of which 58 percent of the errors were attributed to the geocoding process. Lastly, it was found that by combining the two national datasets, the resultant dataset provided a more useful and accurate solution.     

National and transnational borderlanders’ attitudes towards the security fence between Israel and the Palestinian Authority

The subject of the security fence between Israel and the Palestinians in the West Bank has become a major issue in Israel and in the world in the last several years. The main aim of this research is to reveal the attitudes and thoughts about the fence held by local residents living in settlements (borderlanders) in the proximity of a part of the security fence that has already been completed. The research concentrates on the western-Israeli side of the fence, as it aspires to delve into and understand the meaning and implications of the security fence on matters such as personal security, safety of property and freedom of movement, the possibility of maintaining social and economic ties between the two sides and feelings about living in the area in the future. Underlying this research is the transformation occurring in the border area as a result of its closure by construction of the security fence, after many years in which it was open partially. This process has many diverse consequences, some of them contradictory, on the two populations residing near the border in Israel: the majority Jewish population (the national borderlanders), and the minority Arab population (the transnational borderlanders).     

Policy and practice in karst landscape protection: Bohol, the Philippines

The karst landscape in the interior of the Philippines' Bohol Province represents one of the world's premier kegelkarst (cone karst) environments. Government efforts to protect some of this karst, exemplified by the establishment of the Rajah Sikatuna National Park and the Chocolate Hills Natural Monument, have proven to be significant catalysts of social conflict. In Bohol there is a long history of traditional land tenure, which has recently been supplanted by a Westernized model. Protected area establishment is a response to deforestation, agricultural exploitation and uncontrolled quarrying. However, the imposition of protective legislation to prevent further degradation has disenfranchized and marginalized many local farmers and residents. The conflict between the obligation of the State to ensure environmental protection and the perceived property rights of landowners and farmers has provoked an escalation in civil unrest and armed conflict.     

中国国家自然地图集Internet版的设计和研制

本文系统阐述了国家自然地图集Ｉｎｔｅｒｎｅｔ版的设计和研制过程中的若干问题,包括系统的概念设计、系统开发中的ＷｅｂＧＩＳ技术和策略,系统的主要功能和特色,以及系统维护和更新方案等。本系统从概念设计来看分为服务器端软件模块、浏览器端软件模块、国家自然地图集数据库支持等几个部分。系统开发中采取的ＷｅｂＧＩＳ技术和策略有:兼顾服务器端和客户端的综合型ＷｅｂＧＩＳ策略,基于Ｊａｖａ Ａｐｐｌｅｔ的 ＷｅｂＧＩＳ浏览器开发技术,基于Ｍａｐ Ｏｂｊｅｃｔ(ＭＯ)的ＷｅｂＧＩＳ服务器开发技术等３个方面。在系统的主要功能特色方面,本文从以下５个方面进行了论述:科学有序的内容结构、清晰精练并带导航的界面、富有特色的信息查询功能、多重表达的地图可视化效果、一定的空间信息分析和制图功能。在系统维护和更新方案上,本文从网络技术、数据更新、功能开发３个方面介绍了计划,并对今后的发展趋势进行了展望。     

Estimation of surface latent heat fluxes from IRS-P4/MSMR satellite data

The brightness temperatures of the Microwave sensor MSMR (Multichannel Scanning Microwave Radiometer) launched in May 1999 onboard Indian Oceansat-1 IRS-P4 are used to develop a direct retrieval method for latent heat flux by multivariate regression technique. The MSMR measures the microwave radiances at 8 channels at frequencies of 6.6, 10.7, 18 and 21 GHz at both vertical and horizontal polarizations. It is found that the surface LHF (Latent Heat Flux) is sensitive to all the channels. The coefficients were derived using the National Centre for Environmental Prediction (NCEP) reanalysis data of three months: July, September, November of 1999. The NCEP daily analyzed latent heat fluxes and brightness temperatures observed by MSMR were used to derive the coefficients. Validity of the derived coefficients was checked within situ observations over the Indian Ocean and with NCEP analyzed LHF for global points. The LHF derived directly from the MSMR brightness temperature (Tb) yielded an accuracy of 35 watt/m². LHF was also computed by applying bulk formula using the geophysical parameters extracted from MSMR. In this case the errors were higher apparently due to the errors involved in derivation of the geophysical parameters.     

我国国家重力网的系统转换

本文分析了我国１９５７年国家重力网的精度和问题，探讨了国家重力网的系统转换模式，利用现有的新旧重力网的重合点实际数据进行了回归分析、方差分析和系统误差检验，结果表明在“５７网”与“８５网”之间，除了—１３．５８ｍｇａｌ的平均基准差之外，并不存在其它明显的系统误差，特别是看不出有尺度系统差的影响，也不存在差值随纬度变化的任何规律。因此认为将“５７网”系统转换成“８５网”系统时，可以不必加“尺度系统差改正”，更不用考虑“非线性系统差改正”，建议一律只加一项“基准系统差改正”，其数值应该采用—１３．５８ｍｇａｌ。     

中国沿海地区国民收入预测的新组合模型

着重讨论一种基于灰色ＧＭ（１，１）模型及国民收入决定函数模型而建立的新组合模型。该模型建模方法简单，组合性强，并且在各模型的拟合精度提高。该模型汲取了灰色ＧＭ（１，１）模型模拟国民收入变化趋势的优点和国民收入决定函数模型模拟国民收入波动的优点，使组合模型不但在趋势上符合国民收入的发展，而且也给出了在波动方面的比较一致的模拟。