东北典型丘陵漫岗区沟谷侵蚀动态及空间分析

以黑龙江省克山县为例,分析1954年和2000年侵蚀沟密度变化,探讨研究区土壤侵蚀的时空动态变化,并以侵蚀沟密度变化值为依据进行不同分区侵蚀因素的耦合分析。结果表明:过去46年间,克山县东南部侵蚀沟密度趋于减少,西北部侵蚀沟密度增大。1954～2000年侵蚀沟密度变化值在侵蚀减弱区与高程和坡度呈负相关,在侵蚀增强区呈正相关。随着坡长增加,侵蚀沟密度变化量呈增加趋势。侵蚀沟变化与坡长相关性最大,R²达0.9743,其次为高程,R²为0.6893,与坡度的相关性最小,R²为0.3437。结果表明,高程和坡度不是东北丘陵漫岗地区土壤流失的主要影响因子,坡长是该区侵蚀的一个重要影响因子。土地利用结构变化与土壤侵蚀强度变化密切相关,耕地面积大幅度增加与草地面积明显减少加速侵蚀沟发育。     

On Relativistic Equations of Motion of an Earth Satellite

For numerical integration of the geocentric equations of motion of Earth satellites in the general relativity framework one may choose now between rather simple equations involving in their relativistic dynamical part only the Earth-induced terms and very complicated equations taking into account the relativistic third-body action. However, it is possible quite easily to take into account the relativistic indirect third-body perturbations and to neglect much lesser direct third-body perturbations. Such approach is based on the use of the Newtonian third-body perturbations in geocentric variables with expressing them in the relativistic manner in terms of the barycentric arguments. Together with it, to extend the known results for the spheroid model of the Earth, the Earth-induced terms are treated in great detail by including the non-spin part of the Earth vector-potential and the Earth triaxial non-sphericity.This revised version was published online in October 2005 with corrections to the Cover Date.     

The Beach Crowding Index: A Tool for Assessing Social Carrying Capacity of Vulnerable Beaches

The aim of this article is to introduce the Beach Crowding Index (BCI), a procedure to assess the social carrying capacity of vulnerable beaches. The study uses the people at one time (PAOT) approach and data gathered weekly throughout the bathing season regarding the number of beachgoers in 100 m² cells of the beach to assess how many beachgoers it can comfortably hold. The procedure is based on fieldwork, interviews with beachgoers, and geographic information system (GIS) analysis and has been tested on four beaches in protected areas on the Spanish Mediterranean coast. On a scale from 0 to 4, minimum scores throughout the bathing season are 0.7 and maximum 3.7, although results showed wide variation between the beaches, the section of the beach, and the time of day. This study suggests that determining the location of beachgoers and collecting a long-term series of data is fundamental to assessing social carrying capacity and that the BCI procedure can be used for a large number of applications.     

巴基斯坦城镇体系特征及其影响因素

基于人口普查数据、自然环境、经济产业及交通路网等公开数据,运用城镇体系金字塔、城镇规模基尼系数以及核密度分析等方法,对巴基斯坦城镇体系特征及其影响因素进行分析,发现:1)规模结构方面,城镇规模分布较集中,表现为"大城市化"与"小城市化"并重的特征,中间级别城市发展滞后,城镇人口金字塔大致呈现沙漏形态;空间结构方面,整体...     

山东省主体功能区划分研究

根据山东省区域发展情况,参照"十一五"规划《纲要》提出的主体功能区划分基本思路,尝试建立由资源环境承载力、开发密度和发展潜力等因素构成的指标体系,并以山东省17个地市为基本空间单元,运用状态空间法划定山东省主体功能区。结果表明:除依法设立的各类自然保护区散布在各地市外,重点开发区和优化开发区主要分布在中东部地区,限制开发区集中在西部地区。该研究以期为山东省制定差别化区域政策、统筹区域可持续发展提供战略指导,并为我国主体功能区划分提供理论参考。     

Developing a comprehensive evaluation method for Interconnected River System Network assessment: A case study in Tangxun Lake group

Journal of Geographical Sciences - The Interconnected River System Network (IRSN) plays a crucial role in water resource allocation, water ecological restoration and water quality improvement. It...     

Simulations for the Original Distribution of KBOs

Using the N-body dynamical model that includes the sun, the 8 planets, Pluto, UB313 and massless particles, we simulate the orbital evolution of 551 Kuiper Belt Objects (KBOs) with known parameters. The initial conditions of the simulations are the currently observed orbital parameters. The integration backtracks from now to -10×10⁸ yr. The results show that about 10×10⁸ years ago, more than 1/3 of the presently observed KBOs resided in the region of the present Kuiper main belt, a few were located inside the Neptune orbit, and the rest were beyond 50AU; and that about 4.5×10⁸ years ago, all the objects in the Kuiper main belt exhibited a rather good normal distribution, without so many objects concentrated in the Neptune's 3:2 resonance region, as at present time.     

云GIS下智慧城市地理空间信息共享平台构建

目前,我国数字城市已走向面向云服务的智慧城市地理平台时代。云GIS服务平台为政府部门及公众提供了可定制、弹性化的一站式地理信息服务。本文在研究云GIS下地理空间数据的整合模型、服务体系架构,以及部署方式的基础上,深入分析了Arc GIS云平台特点并设计了一套基于云平台的智慧城市地理空间信息服务共享平台——"兰州市城关区数字化社会管理与服务平台"。该平台通过地理云服务集成了虚拟化、网络化、智能化等关键技术,创建了智慧城市社会管理与服务新模式,提高了社会管理效能和质量。     

空间信息要素模型可视化的设计模式与应用

GIS系统的实现是一个相当复杂的过程,分层次模块化的方法被广泛采用,同时应用设计模式更加简单方便地重复使用成功的设计和体系结构,更有利于GIS系统的开发和重构。本文通过对描述地理信息系统空间信息模型中要素模型的几何体结构分析,充分运用和组合各种设计模式,在要素可视化设计和实现中,探讨要素组织采用组合模式与访问者模式相结合的形式,实现异构几何体的聚集访问;要素可视化的实现总体上采用合成模式与绘制采用策略模式相结合的形式,实现要素与绘制的有机分离及各种绘制形式的充分支持。这种结构的好处在于不但能很方便地实现Open GIS中有关要素几何体的抽象规范和相应的实现规范,而且能使系统结构清晰、模块分明,组织自然,有利于系统的开发、维护和扩展。     

干旱区典型流域近30年土地利用/土地覆被变化的分形特征分析——以玛纳斯河流域为例

利用1976、1989、2005年三期遥感影像,运用GIS和分形理论研究干旱区典型流域——玛纳斯河流域近30年的土地利用/土地覆被变化的复杂性和稳定性。结果表明:玛纳斯河流域各时段的土地利用/土地覆被类型分布具有分形结构,土地利用/土地覆被类型形状复杂性和斑块的稳定性波动变化,1976、1989、2005年三时期的各种土地利用/土地覆被类型总平均分维值分别为1.394 0、1.363 4和1.389 9。总平均稳定性指数分别为0.606 0、0.636 6、0.610 1。三期土地利用/覆被类型平均稳定性排序为:沙地>未利用土地>居民点工矿用地>水域>林地>草地>耕地>盐碱地。耕地、林地、草地、盐碱地稳定性相对较差。通过对流域土地利用/土地覆被类型变化复杂性和稳定性的研究,可以为政府协调水土开发和调整土地利用结构提供支持。