基于项目驱动的藉河流域土地利用时空变化动态分析

根据1997年、2001年和2005年三期TM影像资料,运用遥感非监督分类的方法提取土地利用信息。利用地理信息系统空间分析和数据统计的方法,分析藉河流域1997~2005年间土地利用数量变化和空间变化特征,研究该地区主要土地利用类型数量变化、空间变化以及在不同坡度的动态变化特征。结果表明:耕地、林地和草地三种主要土地利用类型占该研究区土地利用面积的97%以上,是该研究区主要的土地利用类型。以1997年为基数,到2001年和2005年耕地减少幅度分别为1.2%和11.1%,因此1997~2001年的退耕程度小于2001~2005年;在不同坡度上,土地利用变化主要发生在5°~40°,而且在15°~25°之间变化最大。

基于等高线的黄土高原小流域地形虚拟

黄土高原地形三维虚拟是"数字黄土高原"的基础,可为区域水土保持生态建设提供科技支撑。针对直接在地理信息系统软件中观察三维场景存在的控制交互能力不足问题,提出综合利用地理信息系统软件的地形插值算法,基于MFC框架下的OpenGL程序设计的思路,实现地形的真实感三维虚拟。以黄土丘陵沟壑区康家沟小流域为例,等高线数据在AutoCAD和ArcView软件中处理,生成ASCII格式的规则网格DEM数据,依据它们绘制三角形带,采用加权平均法求得各点的法向量,设置光照与材质模式,添加动态天空背景,实现了该流域地形的真实感三维虚拟,并增加交互能力,完成自由漫游与多角度观察。

云南西北部四县林地的分布和受威胁程度评价以及该地区鸡形目鸟类的保护状况分析

横断山区拥有独特的生物区系和丰富的生物多样性，成为研究生物和地学许 多重大理论问题的关键性区域。然而该地区复杂的高山峡谷地形不利于大范围实 地考察工作的开展，而传统的调查方法也较难直接地获取野生动物及其生境的一 些量化数据，如某种或某类生物元素的分布、变化情况以及保护状况等，因此长 期以来对于该地区保护网络的规划和管理效果一直缺乏系统地评价，保护工作的 进一步开展依然面临很多难题。近年来地理信息系统（Geographic Information System, GIS）和遥感技术（Remote Sensing, RS）已经广泛应用于野生动物及其 生境保护的各个方面，为横断山区的保护工作拓展了新的研究思路和方法借鉴。 本研究以位于云南西北部横断山区的四个县（德钦、维西、丽江、香格里拉） 作为核心研究地区，以野生动物的主要栖息地——林地为对象，借助RS 和GIS 手段研究该地区内林地的分布、变化以及受威胁程度；并针对鸡形目鸟类的保护 状况进行了分析，为该地区林地和鸡形目鸟类的保护及评价提供科学的方法指导 和建议。具体如下： （1）林地分布以及针叶林的进一步细分。在地面真实数据的辅助下，通过 对Landsat TM/TM+影像的预处理、分类、分类后处理等过程，将研究地区中的 林地与非林地进行划分；针对暖温性针叶林和寒温性针叶林这两种较难区分的类 别，采用导引聚类（guided clustering）的分类方法，进一步对针叶林进行细分。 精度评估的结果显示，林地与非林地的划分总体精度为94.3%，而针叶林细分为 暖温性针叶林和寒温性针叶林的总体精度为74.8%。该方法可以较为准确地划分 该地区不同的生境类型，为野生动物及其生境的保护奠定基础。（2）林地的受威胁程度评价。通过分析研究地区中的林地在40 多年时间跨 度里（1958-2001 年）的变化情况和保护现状，从而评价其受威胁程度，结果反 映出每个县的林地面积都有不同程度的减少，丽江和香格里拉这两个县的林地受 威胁程度相对较高。进一步对丽江和香格里拉两县在不同海拔带的林地分布和变 化情况进行分析，结果表明，丽江的林地主要分布于2000-3500 米的海拔范围内 （占该县全部林地面积的89.7%），而在香格里拉则主要分布于2500 米以上（占 该县全部林地面积的95.2%）；在这两个林地分布较为集中的区域内，都是低海 拔地区林地面积减少程度较高，意味着在开展保护工作时应重点关注这两个县的 低海拔林地。本研究方法可供整个横断山区乃至其他高山峡谷地区借鉴，为保护 网络的完善提供快速的量化参考。 （3）鸡形目鸟类的保护状况分析。借助RS 和GIS 手段描绘研究地区中当 前林地（2001 年左右）以及早期林地（1958 年前后）的分布，针对那些主要以 林地为生境的鸡形目鸟类，在相应限制因子（例如海拔数据）的辅助下对它们当 前和过去的潜在生境进行预测，从而分析它们的保护现状和生境的变化情况。结 果表明研究地区中现有的保护区对这些鸟类的保护尚不完善，并且在过去40 多 年的时间跨度里它们的潜在生境都有不同程度的退化。建议将来的保护工作优先 考虑那些在当前未被充分保护的物种以及潜在生境退化程度相对较高的物种。针 对这些物种，提出在将来的进一步保护工作中的一些建议，为整个横断山区鸡形 目鸟类乃至其他野生动物类群的保护提供参考。

基于.NET的四层结构及其在综合信息系统中的应用

阐述应用程序开发的三层结构的基本组织形式及存在的问题,提出了基于四层结构的应用程序开发模型及其带来的好处.结合七里村采油厂综合信息系统开发实例,对基于.NET的四层结构的应用程序开发技术进行了研究,实现了基于.NET的四层结构的部署,阐述了基于四层结构的具体实现策略,并在此基础上给出了基于四层结构的应用程序设计与开发的关键技术.

若尔盖自然保护区高原林蛙(Rana kukunoris)扩散模型与景观连接分析

揭示水体中繁殖的两栖动物在异质性景观中的空间扩散特点，探讨景观面积丧失和破碎化对于两栖动物的影响，为两栖动物的保护提供理论依据。本文以四川西北部若尔盖湿地自然保护区的高原林蛙(Rana kukunoris)为研究对象，通过运用地理信息系统及建立景观模型等方法，在分析若尔盖湿地自然保护区范围内现有景观格局的基础上，建立了高原林蛙的景观扩散模型，并模拟了“沼泽→草甸”的湿地逆演化过程下高原林蛙的空间分布与景观连接的变化特点。主要结果是： 1．若尔盖湿地自然保护区呈典型的沼泽—草甸式斑块—基质景观格局。草甸面积占整个景观面积的79.42%，景观蔓延度指数（CONTAG）为79.00远离最小值0而更趋向于最大值100，面积和景观蔓延度指数表明草甸是整个景观中面积占绝对优势且景观连接好的类型，构成了景观的基质，对景观的动态格局演变起主导作用。沼泽面积仅占整个景观面积的18.08%，但却是整个景观中斑块数目最多的单元，占所有斑块数的82.9%。因此沼泽斑块与草甸基质之间的动态结构对高原林蛙的扩散起着决定性的作用。 2．空间扩散模型表明，其它类型的景观不但扩展了高原林蛙的活动范围，而且也为高原林蛙在不同沼泽斑块间的连接提供了通道。高原林蛙的空间扩散区域使得彼此间成斑块化隔离状分布的沼泽形成了潜在景观功能连接，促进了不同斑块间物种的交流。小型沼泽作为垫脚石（stepping-stone），使得整个景观中的相隔距离较远的大型斑块联结为一个功能整体，促进了高原林蛙在整个景观中的相互动态联系。 3．模拟“沼泽→草甸”的湿地逆演化过程表明，大量小型沼泽湿地的消失将会 对在沼泽中繁殖并扩散到其它景观类型中去的高原林蛙造成潜在影响。逆演化过程不仅使沼泽斑块的分布范围，沼泽源斑块的面积和空间扩散面积减少，而且对景观连接也有很大影响。小型沼泽的消失，将使得景观斑块的功能连接变小，使得依靠小型沼泽作为跳板的动物在沼泽斑块之间的移动将变得更加困难。 本文是对生境丧失与破碎化影响下两栖动物的行为反应的一种尝试。影响模型的因素很多，包括动物对各种类型景观的偏好程度，地理数据的精度，及模型的可靠程度都是制约模型准确度的因素。 The spatial diffusion of water—breeding amphibian through heterogeneous landscape and the effects of landscape losing and fragmentation to amphibian were the core theory of the landscape ecology of amphibian. Geographical information system (GIS) and landscape model were used to model the diffused area of Rana kukunoris in Zoige Wetland Natural Reserve. Model was also used to analysis the spatial distribution variation of R. kukunoris and the change of landscape connectivity when simulated the retrogressive succession of landscape. The main results are below: 1. There was peatland—meadow pattern which was typical patch—matrix landscape pattern in Zoige Natural Reserve. The meadow area occupied 79.42% of the entire landscape area, contagion index (CONTAG) was 79.00 which was far away the minimum value (0) but tend to the maximum value (100). Both of these showed that meadow was the largest part and the most continue units. It was shown that meadow was matrix of the landscape, which evolved the leading role to the landscape dynamic pattern. Though their area only occupies 18.08% of entire landscape area, peatlands were according to 82.9% of the total patches. Dynamic of the pattern between peatlands and meadows decided the spatial diffusion of R. kukunoris. 2．The model indicated that the other types of landscape not only expanded diffusion of R. kukunoris, but also have provided the potential channels for frog's connections among different peatlands. The spatial diffusion zone of R. kukunoris forced isolated patch peatlands to be potential landscape functional connectivity. The small peatlands, as stepping-stone, made the large peatlands connect as a functional one and promoted the integrated and dynamic connectivity of R. kukunoris in the whole landscape. 3. The simulation of “peatlands→meadows”retrogressive succession process indicated that the decrease of small peatlands will have potential effect to R. kukunoris because they must bred in peatlands and diffuse to other type of the landscape. Retrogressive succession process not only made the decrease of distribution of peatlands, patches number of peatlands and diffused area of R. kukunoris, but also reduced the connectivity among source patches. As stepping-stone, the disappearance of small peatlands will made the migration of R. kukunoris among patches more difficult. The model was an experiment of the amphibian behavior reaction to habitat losing and fragmentation. There were many factors that could influence the accuracy of model, such as the preference of animals to each type of landscape, the geographical data precision, reliable degree of model.

浑太流域洪涝灾害及其治理方略

Hunhe, Taizihe rivers originating from the east mountain areas of Liaoning Province are the biggest tributaries of the left bank of Liaohe River. From the initial stage of New China to the early 1990s, the frequency of flood damage had decreased, but recently the disasters have upgraded and changed from trunk stream to tributary basins. In July 1995, Dongzhouhe, a tributary of Hunhe River, suffered from a heaviest flood since establishing the document of floods in Hunhe basin. Meanwhile, a peak discharge, almost beyond double defending ability, occurred at Dadongshanpu Station of Beishahe River, a tributary of Taizihe River. Besides the continued heavy rainstorm, no controllable water conservancy projects and ecological damages caused by quickly decreasing forest cover and water and soil loss are the two main causes of flood damage. In addition, the low flood protection standard is also one of causes. According to the above analyses, some strategies of synthetic controlling for flood damages were put forward: 1) Establishing the system of ecological engineering to defend floods and reduce disasters; 2)Setting up storage and detention areas; 3) Establishing flood controlling information system; 4) Improving the accuracy of media short period and short period rainstorm forecast and flood forecast; 5) Insurance of flood protection.

土地资源动态监测信息系统——以延安/安塞七乡镇为例

土地资源动态监测信息系统是在计算机软硬件支持下 ,对土地资源采集、输入、编辑、存储和综合分析应用的技术系统 ,它是土地资源动态监测、土地评价、土地利用规划和管理的有力工具。本文以延安 /安塞七乡镇为例 ,启用 ARC/INFO和 Arcview软件 ,建立土地资源动态监测系统 ,并对监测结果初步分析 ,为区域土地资源管理和合理利用提供服务

黄土丘陵区小流域表层土壤的有机碳密度及其空间分布

通过野外调查和室内分析,采用多元线性逐步回归和地理信息系统(GIS)相结合的方法,研究了黄土丘陵区燕沟流域表层(0~20 cm)土壤的有机碳密度、空间分布及其与土地利用类型和地形因子等的关系。结果表明,流域表层土壤有机碳密度平均为1.72 kg/m2,变幅为0.97~2.93 kg/m2;土地利用类型是影响土壤有机碳密度变化的首要因子;流域土壤有机碳密度呈镶嵌的树枝状和条带状空间分布格局,其高值斑块区与乔木林地和灌木林地的分布一致,中值斑块区与草地和川坝地的分布一致,低值斑块区与梯田、果园、坡耕地、疏林地和未成林地的分布一致。流域表层土壤有机碳总储量为76.81×103t。

基于网络环境的地理信息系统-WebGIS

Web GIS作为一门新兴的技术学科 ,依托互联网的环境和 Internet实用技术 ,成为地理信息系统理论研究和技术创新的增长点。随着网络技术和应用市场的不断发展和扩大 ,将促进 GIS新兴信息产业的形成。本文结合工作实践 ,论述了 Web GIS的技术背景与发展 ,以及系统功能等基础理论 ,重点讨论了 Web GIS的体系结构、实现策略和技术方法

JCA适配器基础开发框架的设计与实现

针对当前JCA适配器开发难度大、效率低问题,提出一种JCA资源适配器的基础开发框架。该框架运用良好的设计模式,抽取并实现JCA规范中的系统契约和应用契约的核心部分,从而使开发人员只需实现和具体企业信息系统密切相关的功能特性,给出一套基于该基础框架的开发工具进行适配器的开发。实验结果表明,该框架能够有效地提高适配器的开发效率和质量。

Digital regionalization of geomorphology in Xinjiang

National Natural Science Foundation of China [40871177]; Project of State Key Lab of Resources and Environmental Information System [088RA304SA]; CAS Knowledge Innovation Project

DECODE: a new method for discovering clusters of different densities in spatial data

National Key Basic Research and Development Program of China [2006CB701305]; State Key Laboratory of Resource and Environment Information System [088RA400SA]; Chinese Academy of Sciences

Surface modelling of soil pH

In addition to classical methods, namely kriging, Inverse Distance Weighting (IDW) and splines, which have been frequently used for interpolating the spatial patterns of soil properties, a relatively more accurate surface modelling technique is being developed in recent years, namely high accuracy surface modelling (HASM). It has been used in the numerical tests, DEM construction and the interpolation of climate and ecosystem changes. In this paper, HASM was applied to interpolate soil pH for assessing its feasibility of soil property interpolation in a red soil region of Jiangxi Province, China. Soil pH was measured on 150 samples of topsoil (0-20 cm) for the interpolation and comparing the performance of HASM, kriging. IDW and splines. The mean errors (MEs) of interpolations indicate little bias of interpolation for soil pH by the four techniques. HASM has less mean absolute error (MAE) and root mean square error (RMSE) than kriging, IDW and splines. HASM is still the most accurate one when we use the mean rank and the standard deviation of the ranks to avoid the outlier effects in assessing the prediction performance of the four methods. Therefore, HASM can be considered as an alternative and accurate method for interpolating soil properties. Further researches of HASM are needed to combine HASM with ancillary variables to improve the interpolation performance and develop a user-friendly algorithm that can be implemented in a GIS package. (C) 2009 Elsevier B.V. All rights reserved.

VGIS-COLLIDE: an effective collision detection algorithm for

Collision detection is an important component in simulation applications which are based on virtual geographic information system (VGIS). In this paper, an effective collision detection algorithm for multiple objects in VGIS, VGIS-COLLIDE, is presented. The algorithm firstly integrates existing quadtree, which is the global hierarchical structure of VGIS, with axis-aligned bounding box of object to perform the broad-phase of collision detection. After that, exact collision detection between two objects which have passed the broad-phase of collision detection is performed. The algorithm makes no assumption about input primitives or object's motion and is directly applicable to all triangulated models. It can be applicable to both rigid and deformable objects without preprocessing. The performance of the algorithm has been demonstrated in several environments consisting of a high number of objects with hundreds of thousands of triangles.