Modeling the potential impact of climate change in northern Mexico using two environmental indicators

Modeling the deterioration of natural resources, especially water and soil that results from the global effects of climate change has become a powerful tool in the search for mitigation and adaptation measures. The objectives of this research were: (1) to model the potential impact of climate change for the period 2010-2039, and (2) to offer advice about future risks based on local radiative forcing or critical areas and taking into account two indicators of environmental quality, the aridity index (AI) and laminar wind erosion (LWE). Evaluation techniques for natural resources, similar to those applied by the Instituto Nacional de Ecología y Cambio Climático (National Institute of Ecology and Climate Change) were used for studies of ecological land use. The inputs include climate information (current and future), soil cover and edaphic properties related to the municipality of Gómez Palacio, Durango, Mexico (25.886° N, 103.476° W). According to calculations estimated from the anomalies for the mean annual rainfall and mean annual temperature, in a future climate change scenario, an average impact of approximately 63% would be caused by LWE, and the AI would change from its historical value of 9.3 to 8.7. It is estimated that the average impact on the AI in the future will be 0.53 ± 0.2.     

基于ArcGIS的城市居住区空间宜居性评价

随着我国居民生活水平的日益提高,人们对城市居住区的选取提出了更高的要求。本文基于ArcGIS的空间分析功能,对不同的居住区进行分析和比较,在分析过程中分别选择一些具有代表性的影响因素,通过这些影响因素对城市居住区宜居性进行空间评价。     

青海虎头崖矽卡岩型多金属矿床蚀变矿化分带特征研究

虎头崖铜铅锌多金属矿床位于东昆仑西段祁漫塔格成矿亚带内.矿化带产于岩体与围岩接触蚀变带、不同岩性地层接触界面或地层中断裂破碎带内,兼有正接触带和外接触带2种蚀变矿化带.由岩体→接触带→碳酸盐岩地层,金属成矿元素分别为W-Mo→Fe-Sn-Cu→Cu-(Pb-Zn) →Pb-Zn-Ag,蚀变类型由岩体自变质的钾化、硅化、云英岩化过渡为正接触带附近的符山石化、绿帘石化、透辉石化,再到外接触带围岩的石榴子石化、透辉石化,以及晚期的绿泥石化、碳酸盐化.主量元素分析结果显示,地层中的CaO等向岩浆岩内扩散,岩体中的SiO2、Al2O3等则向碳酸盐岩扩散,而且,与花岗岩相比,矽卡岩中FeO、MnO、MgO更为富集,这表明接触渗滤作用与接触交代作用同时存在.成矿元素分析结果显示,W、Mo元素在岩体内含量较高,而Fe、Cu、Pb、Zn主要在矽卡岩带内富集,各成矿元素在未蚀变大理岩中的含量均较低.笔者认为,矿化蚀变的明显分带性是岩体和地层成矿差异性及矽卡岩带内微裂隙系统发育的不均匀性所致.     

论滇中砂岩铜矿浅、紫交互带赋矿及其金属硫化物分带之成因与成矿作用演化

康滇古大陆裂谷的发生和演化造就了楚雄盆地,沉积出煤、铜、盐旋回与含矿建造和矿床组合.铜矿的生成(特别是改造富集)与煤(有机质)、盐(热卤水)密切相关.大姚—牟定式砂岩铜矿以其规模最大而具代表性.它的成矿作用的演化是从风化沉积作用到成岩作用、后生作用再到改造作用.作用的结果是分别产生含铜有机质沉积体、成岩矿层、后生矿层和改造富矿体.层状矿体赋存于砂岩浅紫交互带是氧化性流体与还原性流体相汇于斯而发生氧化—还原反应沉积成岩的结果.其金属硫化物的生成顺序与分带是遵循S、O、Fe、Cu热液体系中矿物共生组合规律的,随介质条件、四元素浓度的差异而变化.     

海洋功能区划实施评估方法研究——以《温州市海洋功能区划(2013—2020年)》及2018年修订版为例

海洋功能区划实施评估是监督海洋功能区划实施成效,提升海洋管理水平的重要工具。基于一致性理念,以规划蓝图为依据,从海域用途符合性、环境质量标准符合性、开发利用影响三方面集成构建海域利用现状和海洋功能区划的协调性判别方法即海洋功能区划协调性指数,并以温州市为实例进行验证。研究表明：基于一致性理念与海洋功能区划蓝图构建的评估方法可以有效测度海洋功能区划实施成效。海洋功能区划修订具有显著适应性,能够高效契合区域海洋经济与海洋生态文明建设需求。该方法对未来国土空间规划海洋部分的有效实施和修订具有重要参考价值。     

面向土地用途分区的空间聚类系统设计与实现

传统的土地用途分区方法存在受人为因素影响、效率低下的问题,不利于土地用途分区管制的实施,基于GIS的智能化的土地用途分区系统则可以弥补这一缺陷。本文以GIS相关理论和土地用途分区的需求分析为基础,构建了系统的逻辑框架,研究了数据库、模型库、算法库和知识库的设计方案,提出了土地用途分区过程中的空间数据整合、目标函数和分区模型的选择等问题的解决方案,并实现了面向土地用途分区的空间聚类系统。以典型地区的土地用途分区为例,验证了该空间聚类系统是一种智能、高效、科学的土地用途分区平台。     

Spatial modelling of site suitability assessment for hospitals using geographical information system-based multicriteria approach at Qazvin city,Iran

Due to the population growth and continuous migration of people from rural areas to urban areas, it is important to identify the suitable locations for future development in order to find suitable sites for various kinds of facilities such as schools, hospital and fire stations for new and existing urban areas. Site suitability modelling is a complex process involving various kinds of objectives and issues. Such a complex process includes spatial analysis, use of several decision support tools such as high-spatial resolution remotely sensed data, geographical information system (GIS) and multi criteria analysis (MCA) such as analytical hierarchy process (AHP), and in some cases, prediction techniques like cellular automata (CA) or artificial neural networks (ANN). This paper presents a comparison between the results of AHP and the ordinary least square (OLS) evaluation model, based on various criteria, to select suitable sites for new hospitals in Qazvin city, Iran. Based on the obtained results, proximity to populated areas (0.3) and distance to air polluted areas (0.23–0.26) were the two highest important criteria with high weight value. The results show that these two techniques not only have similarity in size (in m²) for each suitability class but they also have similarity in spatial distribution of each class in the entire study area. Based on calculations of both techniques, 1–2%, 25%, 40–43%, 16–20% and 14% of study areas are assigned as ‘not suitable', ‘less suitable', ‘moderately suitable', ‘suitable' and ‘most suitable' areas for construction of new hospitals. Results revealed that a 75% similarity was found in the distribution of suitability classes in Qazvin city using both techniques. Nineteen per cent (19%) of the study area are assigned as ‘suitable' and ‘most suitable' by both methods, so these areas can be considered as safe or secure areas for clinical purposes. Moreover, almost all (99.8%) suitable areas are located in district 3, because of its higher population, less numbers of existing hospitals and large numbers of barren land plots of acceptable size.     

Finding suitable locations for ecotourism development in Cox’s Bazar using Geographical Information System and Analytical Hierarchy Process

The aim of this study is finding suitable locations for ecotourism development in Cox’s Bazar, Bangladesh. For this, potential ecotourism sites were identified and ranked using Geographical Information System and Analytical Hierarchy Process. Five factors and 15 criteria were identified to evaluate suitability of sites. Factors and criteria were selected based on literature review, local knowledge and experts’ opinions. Considering the national and international contexts and effects of ecotourism, this study proposes treating highly suitable areas more ‘naturally’ and, for conservation programmes, creating tourist facilities in moderately suitable areas by targeting growth centres and protecting agricultural land as well as local primary activities in marginally suitable areas.     

GEO-Environmental Suitability Evaluation of Land for Urban Construction Based on A Back-Propagation Neural Network and GIS: A Case Study of Hangzhou

Evaluating the geo-environmental suitability of land for urban construction is an important step in the analysis of urban land use potential. Using geo-environmental factors and the land use status of Hangzhou, China, a back-propagation (BP) neural network model for the evaluation of the geo-environmental suitability of land for urban construction was established with a geographic information system (GIS) and techniques of grid, geospatial, and BP neural network analysis. Four factor groups, comprising nine separate subfactors of geo-environmental features, were selected for the model: geomorphic type, slope, site soil type, stratum steadiness, Holocene saturated soft soil depth, groundwater abundance, groundwater salinization, geologic hazard type, and geologic hazard degree. With the support of the model, the geo-environmental suitability of Hangzhou land for urban construction was divided into four suitability zones: zone I, suitable for super high-rise and high-rise buildings; zone II, suitable for multi-story buildings; zone III, suitable for low-rise buildings; and zone IV, not suitable for buildings. The results showed that a BP neural network can capture the complex non-linear relationships between the evaluation factors and the suitability level, and these results will support scientific decision-making for urban-construction land planning, management, and rational land use in Hangzhou.     

Sample surveying to estimate the mean of a heterogeneous surface: reducing the error variance through zoning

One of the major sources of uncertainty associated with geographical data in GIS arises when they are the outcome of a sampling process. It is well known that when sampling from a spatially autocorrelated homogeneous surface, stratification reduces the error variance of the estimator of the population mean. In this study, we evaluate the efficiency of different spatial sampling strategies when the surface is not homogeneous. When the surface is first-order heterogeneous (the mean of the surface varies across the map), we examine the effects of stratifying it into first-order homogeneous zones prior to the usual stratification for a systematic or stratified random sample. We investigate the effect of this form of spatial heterogeneity on the performance of different methods for estimating the population mean and its error variance. We do so by distinguishing between the real surface to be surveyed (?), the sampling frame (?) including the choice of zoning, and the statistical estimators (Ψ). The study shows that zoning improves estimator efficiency when sampling a heterogeneous surface. Systematic comparison provides rules of thumb for choice of sample design, sample statistics and uncertainty estimation, based on considering different spatial heterogeneities on real surfaces.