导弹用材料环境适应性数据库设计

目的 针对材料工艺师需要系统整合导弹环境适应性信息的手段、分析数据变化规律的工具、网络共享的平台,设计并开发导弹用材料环境适应性数据库。方法 数据库软件采用J2ee体系架构搭建,设计虚拟导弹数字化模型,通过建立大量的数据关联,将导弹基本结构信息、导弹整机失效信息、弹用材料基本性能信息、环境适应性信息和环境信息五大类信息整合为一体,供导弹模型调用。设计曲线绘制算法,采用ActionScript脚本语言编程,实现数据规律动态绘制,采用跨库关联建立数据关联查询和数据对比分析。结果 用户可通过鼠标操作,拆分和组装导弹模型,全方位观察导弹的构成。利用导弹模型整合的五大类环境适应性信息,直观反映导弹的构成和材料应用情况。软件能够查询导弹的故障模式、弹用材料环境适应性信息等,跨库关联则增强了的数据对比性。结论 该数据库已经通过软件测评并上线运行,为导弹多个型号的选材和防护设计工作提供帮助,用户反映良好。     

Exploring the determinants for adopting water conservation measures. What is the tendency of landowners when the resource is already at risk?

In Finland, the current water conservation policy sets equal incentives for water conservation, regardless of the environmental condition. Before any policy reform, it is vital to investigate the tendency of landowners to adopt water conservation measures. In this study, we were interested in examining adoption if the soil quality implies a high leaching risk and if the water quality is already poor. By combining survey data with GIS data, we analysed the effect of farm and farmer characteristics and attitudes towards adoption. Our probit models indicated that financial variables were the key determinants of adoption for active farmers, whereas for passive owners, adoption was also explained by attitudes. In contrast to our expectations, adoption in areas under risk was weakly supported by our estimates. Environmental awareness, providing it increases with risk, is not strong enough to motivate adoption. Targeted agri-environmental measures, even though costly, cannot be avoided, and spatially tailored measures can attract adopters in hotspot areas.     

基于GIS的县域耕地地力评价--以云南省云县为例

以云县为评价对象,基于ArcGIS软件的强大空间分析功能,采用层次分析法对耕地地力进行评价。评价结果显示：云县没有1级耕地分布,2~4级耕地有少量分布,占全县耕地8.23%;5~10级耕地分布较广,占全县耕地91.77%,云县耕地质量在国家标准地力等级体系中处于中等偏下水平。     

南京城市扩展的遥感研究

卫星遥感影像为数据源， 以GIS为制图和数据提取的分析手段， 通过引入城市扩展强度、重心坐标、紧凑度、弹性系数等指标，研究了南京城市扩展的时空规律、形态特征以及与人口发展之间的协调关系；并应用回归分析，筛选了能够解释城市扩张的主要社会经济因子。结果表明：①南京城市扩展的时空分异特征明显，江南主城的东北-西南轴向和东南的江宁一带成为城市扩展最活跃的地区；②城市扩展过程中，紧凑度降低，空间形态向着趋于不稳定状态发展；③ 21世纪以来，城市扩展的弹性系数向着逐渐合理化的方向转变，但在1988~2001年，该指数与合理数值有一定差距，城市扩展与人口增长速度之间出现了不和谐现象；④国家和地方相关政策的引导及自然因素的影响对于南京城市扩展起了重要作用，职工年平均工资的增长和非农业人口的增加也是影响南京城市扩展的主要社会经济因子。     

基于电子鼻土壤与地下水污染修复现场TVOC和恶臭的评估

根据上海某土壤与地下水污染修复现场情况,应用自主研发的电子鼻系统(iSA-M1)分别对未修复及修复过程中的土壤和地下水、修复场地上空及周边空气中的VOCs和恶臭类气体进行检测.结合前期研究所得TPI和OPI公式,求得各点的值,并将其用图表示.结果表明:①修复后TVOC和恶臭的浓度总体呈下降趋势;②在土壤和地下水修复过程中,VOCs和恶臭的挥发受气象要素和作业的影响,其浓度在总体下降的过程中伴随着阶段性上升现象;③结合GIS技术,电子鼻能初步用于评估土壤和地下水修复现场造成的空间污染情况及对周围居民产生的影响.但造成影响程度的具体细化分级还需要进一步研究.     

基于网络图论的黄土模拟小流域水系演化研究

河网形态对土壤侵蚀、河流演变等有较大影响。为描述黄土模拟小流域的河网的网络特征,采用人工降雨实验获取的黄土模拟小流域高解析度DEM数据,计算了不同时期沟谷节点平均连接度及网络结构熵,划分了模拟流域的不同发育阶段。研究表明节点平均连接度侧重度量沟谷形态特征,与坡度等因子相关;而结构熵则侧重定量沟谷发育过程,与主沟道纵剖面变化相关。     

GIS技术在滇池流域水环境管理中的应用

针对滇池流域水环境管理现状及特点整合流域信息资源,探讨利用GIS技术开发流域水环境管理可视化平台的可能性,根据流域地理水文等特点,结合ArcGIS系列开发软件和SQL数据库开发技术,以NET为中间件开发平台,完成系统设计与构建,主要实现流域信息数据管理维护、数据搜索查询和可视化决策功能,利用GIS可视化功能反映流域水环境的特点,为滇池流域水环境管理起到辅助决策作用。     

Spatio-temporal modelling of ground vegetation development in mountain spruce forests

More complex models of forest ecosystems are required to understand how land-cover changes can impact vegetation dynamics and spatial pattern. In order to document spatio-temporal modelling abilities, the observations conducted in the declined climax mountain Norway spruce forest during the recovery period (1995-2006) are used for simulation and spatial analysis in the GIS environment. The developed spatio-temporal model is used for simulation of forest vegetation dynamics in a mountain spruce forest in the framework of regeneration processes after stress from air pollution. In order to explore the spatial and temporal phenomena of regeneration processes, the spatio-temporal model is based on a large set of ordinary differential equations that solve dynamic processes in sets of microsites arranged in grids for each ground vegetation species and each age group of Norway spruce seedlings. The spatial extent of the explored site is composed of a set of 50 × 50 microsites. Each microsite is represented by a square with dimensions of 1 m × 1 m. The presented simulation studies are mainly focused on seedlings from the seed year 1992, in order to explore the longest monitored time series of survival. It is based on exponential growth models that are related to the environmental conditions for each microsite. The canopy gaps based on estimates of the local crown projected area, the soil type layer, and the dominant grass density are used to provide case simulation studies. The first case study simulates the influence of microsite positions in relation to the local tree crown projections on the survival of spruce seedlings. It is assumed that the density of the trees is the main factor that determines the light and heat supply to the ground level of the Norway spruce seedlings. The second case study extends the previous study to include terms that determine the growth ratio in dependence on the crown projection area. The third case study provides further extensions in order to simulate growth ratio relations to the local soil type. The fourth case study demonstrates the local influence of the dominant grasses, such as Avenella flexuosa and Calamagrostis villosa, on the natural regeneration of Norway spruce. Starting from the conditions at the sites before the recovery period, the case simulation studies are able to project the short-term succession for a regeneration decade and the approximate long-term development. In addition to the standard simulation procedures based on solution of ordinary differential equations, spatio-temporal modelling in the GIS environment is able to provide spatial data management, analysis and visualization of the data.     

基于情景模拟的上海中心城区居民住宅的暴雨内涝风险评价

内涝是影响上海的主要灾害之一,上海城区居民住宅特别是旧式住宅容易因之受损乃至倒塌。基于情景模拟和指标体系方法,开展了上海中心城区住宅的风险评估。利用上海水务信息中心开发的内涝仿真模型,设置暴雨情景并对该情景下的内涝进行模拟,得到了区域水深分布状况,利用G IS技术求得每座住宅的水深,体现其在内涝中的暴露程度,并构造暴露性评价模型,综合反映区域总体暴露状况。根据旧式住宅较易受到影响的事实,构造脆弱性指数,最终衡量区域住宅面临灾害的整体风险状况,实现区域间居民住宅内涝风险的对比分析。设置了五十年一遇的暴雨内涝情景,针对中心城区各街道开展了实证研究,最终评价结果显示出的危险性、暴露性、脆弱性和风险分布规律,与实际情况基本符合。该方法可以为市政部门提供必要的信息,提高内涝灾害的管理水平。     

基于GIS的城市地震建筑物次生火灾蔓延模型

考虑城市地震次生火灾发生和蔓延的实际情况,以城市内地震破坏下的建筑物为火灾蔓延的主要载体,从工程应用的角度按不同结构类型给出了次生火灾蔓延参数,并建立了不同类型结构蔓延的临界距离等;考虑地震破坏下和不同风速对燃烧参数的影响,建立了以建筑物为对象的城市地震次生火灾蔓延模型。并以地理信息系统为平台,开发了城市地震次生火灾蔓延模拟系统。该模型的建立可为防御和减轻城市地震次生火灾提供辅助决策,同时对城市日常防火也有一定的参考价值。