空间分析基本问题与主要内容的探讨

空间分析是地理信息系统的核心之一,是当前研究的热点.在回顾空间分析起源的基础上,从几个角度给出空间分析内涵的理解;指出空间分析涉及的几个基本问题,包括地理空间性、空间自相关、空间尺度与空间抽样.在此基础上,论述了空间分析的主要研究内容,即空间位置分析、空间自相关、空间插值、空间回归分析及空间分析中的模型与模拟研究.最后展望了空间分析下一步发展,认为空间分析不仅需要在强化基础理论研究,亦当在地理信息服务的过程中,充分结合地理信息系统技术、数据挖掘技术及空间决策支持系统研究,为人口、资源、环境及公共健康等重大问题的决策提供科技支撑.

Spatial patterns of interprovincial mountain geographical names in China and implications for regional governance

Suffering from fragile environment, poor accessibility and infrastructure, as well as social,political and economic marginality, the interprovincial mountain geographical entities are difficult areas for the regional governance in China.By analyzing the spatial patterns and the influencing factors of the interprovincial mountain geographical names(IMGNs), the goal of this research is to clarify the geographical features of IMGNs and offer alternatives for the management of interprovincial mountain regions in China. The spatial visualization,the analysis of spatial agglomeration and the influencing factors of IMGNs were all implemented under a geographical information system. Results showed that there were 6869 IMGNs in China according to the database of "China's Second National Survey of Geographical Names(2014-2018)",including 4209 mountain geographical names, 1684 mountain peak geographical names and 976 the other mountain geographical names. Hunan Province had the largest number of names while Shanghai had the smallest number of names. In addition, the spatial variance of the mountain peak names and the mountain names were larger than that of the other mountain geographical names, and the IMGNs showed a significant clustering phenomenon in the southern part of China. The relative elevation and the population had an impact on the distribution of the IMGNs. The largest number of the names occurred where the relative elevation was between 1000-2000 m and where the population was between 40-50 million. Density of unnamed interprovincial mountain geographical entities declined from west to east in China. The analysis of generic names of different types of IMGNs implied that the naming of IMGNs is inconsistent. Based on these analyses, it is suggested that the government should take the IMGNs as management units, strengthen the naming of unnamed interprovincial mountain geographical entities, standardize the generic names of IMGNs and identify areas of poverty based on the survey of IMGNs.

Digital Watermark-based Security Technology for Geo-spatial Graphics Data

The paper presents a set of techniques of digital watermarking by which copyright and user rights messages are hidden into geo-spatial graphics data,as well as techniques of compressing and encrypting the watermarked geo-spatial graphics data.The technology aims at tracing and resisting the illegal distribution and duplication of the geo-spatial graphics data product,so as to effectively protect the data producer＇s rights as well as to facilitate the secure sharing of geo-spatial graphics data.So far in the CIS field throughout the world,few researches have been made on digital watermarking.The research is a novel exploration both in the field of security management of geo-spatial graphics data and in the applications of digital watermarking technique.An application software employing the proposed technology has been developed.A number of experimental tests on the 1：500,000 digital bathymetric chart of the South China Sea and 1：10,000 digital topographic map of Jiangsu Province have been conducted to verify the feasibility of the proposed technology.

Spatial Distribution of Soil Erosion Sensitivity on the Tibet Plateau

The Tibet Plateau, occupying the main part of Qinghai-Tibet Plateau and having an average altitude of 4 500 m, has geomorphological features that are unique in the world, with soil erosion being one of the main ecological problems. Thus the main objectives of the present research were to set up an efficient and simple way of evaluating spatial distribution of soil erosion sensitivity in the Tibet Plateau as well as the responses of soil erosion to changes of natural environmental conditions, and to indicate key regions where soil erosion should be preferentially controlled. Based on the Universal Soil Loss Equation (USLE), the study applied geographic information system (GIS) technology to develop a methodological reference framework, from which soil erosion sensitivity could be evaluated. The impact of precipitation, soil, topography and vegetation on soil erosion was divided into classes of extreme sensitivity, high sensitivity, medium sensitivity, low sensitivity and no sensitivity. With the aid of GIS, the resultant map from overlaying various factors showed that soil erosion sensitivity had great discrepancy in different parts of the region. In the southeastern part of the Tibet Plateau there were mainly three classes of sensitivity, namely, extreme, high and medium sensitivity. However, the other two classes, low and no sensitivity, were dominant in the northwestern part.

Stable response of axisymmetric two-phase water-saturated soil

Biot's dynamic consolidation equations and Hankel transform were used to derive the integral solutions of stress and displacement for axisymmetric harmonic excitations in the two-phase saturated soil with subjacent rock-stratum. The influence of the coefficient of permeability and loading frequency on the soil displacement at the ground surface were studied. The results showed that higher loading frequency led to more dynamic characteristics; and that the effect of the soil permeability was more obvious at higher frequencies.

A GIS Model for Analyzing Airspace Obstructions and Safety near Airports

The purpose of Federal Aviation Regulations Part 77, entitled ＂Objects Affecting Navigable Airspace＂, is to identify potential hazards and prevent adverse impacts to the safe and efficient use of navigable airspace. The OIS （obstruction identification surfaces） represent these regulations, identify objects that penetrate these imaginary surfaces, evaluate hazardous effects, and ensure safe separations of aircraft from obstructions. The OIS evaluation is often used for selecting airfield locations and runway orientations. More importantly, the OIS evaluation is an airport＇s safeguard against flawed urban development, especially for airports near rapidly expanding cities. Without accurate analysis tools, hand-calculation errors on the OIS can occur and cause adverse impacts to airport safety. Applying the GIS （geographic information system） features of geospatial data and 3D formats, this paper proposes a model named GIS Obstruction Model which is capable of precisely calculating maximum allowable heights and creating visual imagery of penetrating obstructions. The special features of the model include web-based design, adaptability to any airport, user-friendly multiple inquiry methods, quick response to online inquiries, and response with 3D visual reality. The proposed G1S Obstruction Model is useful for airport planning, architecture design, safety management or civil engineering permit review.

Tourist Route Model Formulation Method Considering Spatial Reproducibility

This study aims to gradually reflect information concerning tourists and to propose tourist route model formulation techniques that take spatial reproducibility into account using GIS （geographic information systems）. The conclusions can be summarized into the following three points： （1） Kawagoe city in Saitama Prefecture was selected as the area targeted by this study. All types of data about Kawagoe city and tourists was collected and processed, and a tourist route model formulation method that considered spatial reproducibility using GIS was proposed, （2） 3-stage scenarios were created with the presence or absence of Kawagoe city tourist policies set as standards and this was used to develop tourist route models. It is POSsible to expect synergy in the encouragement of the use of sightseeing buses and the same traffic regulations as the traffic pilot program, and （3） It is considered that it is possible to apply the tourist route model formulation method proposed by this study to other tourist destinations without being limited by spatiotemporal differences or the particular issues of each tourist destinations as spatial reproducibility was confirmed.

Instruments of Urban Planning in Algerian City： Reality and Challenges

The year 1990 marks a line of rupture in the history of Algeria in general by the fundamental changes that have occurred, especially in the fields of urbanism and the land use planning, which has an important impact on space of the city and its environment. However, the absence of directives based on the reality of upstream territories and sometimes the conflict and the weakness of the instruments created at different levels： national, regional and local, have accelerated the galloping development of urbanization （the irrational consumption of land reserves inside and around the city）, often at the expense of the agricultural land. On the other hand, the involvement of new actors in the production of the framework built in the Algerian town was made without compliance with the rules of architecture and urbanism contained in the build permit and in the MPU （Master Plan of Land Use and Urbanism） and the SOP （Soil Occupation Plan） approved. The analyses conducted in the cities such as the capital Algiers and Setif illustrate this situation well. This article presents these situations of paradox, identifies their causes and suggests the recommendations to implement in the framework of studies and actions to take, to correct and regulate their mutations.

Effects of Wetland Utilization Change on Spatial Distribution of Soil Nematodes in Heihe River Basin, Northwest China

The first account of the effects of wetland reclamation on soil nematode assemblages were provided, three sites in Heihe River Basin of Northwest China, that is grass wetland(GW), Tamarix chinensis wetland(TW) and crop wetland(CW) treatments, were compared. Results showed that the majority of soil nematodes were presented in the 0–20 cm soil layers in CW treatments, followed by in the 20–40 cm and 40–60 cm layers in GW treatments. Plant-feeding nametodes were the most abundant trophic groups in each treatment, where GW(91.0%) > TW(88.1%) > CW(53.5%). Generic richness(GR) was lower in the TW(16) than that in GW(23) and CW(25). The combination of enrichment index(EI) and structure index(SI) showed that the soil food web in GW was more structured, and those in TW was stressed, while the enrichment soil food web was presented in the CW treatment. Several ecological indices which reflected soil community structure, diversity, Shannon-Weaver diversity(H′), Evenness(J′), Richness(GR) and modified maturity index(MMI) were found to be effective for assessing the response of soil namatode communities to soil of saline wetland reclamation. Furthermore, saline wetland reclamation also exerted great influence on the soil physical and chemical properties(p H, Electric conductivity(EC), Total organic carbon(TOC), Total nitrogen(Total-N) and Nitrate Nitrogen(N-NO3–)). These results indicated that the wetland reclamation had significantly effects on soil nematode community structure and soil properties in this study.

Solar Radiation Climatology Calculation in China

The Angstrom-Prescott formula is commonly used in climatological calculation methods of solar radiation simulation. Fitting the coefficients is carried out using linear regression and in recent years it has been found that these coefifcients have obvious spatial variability. A common solution is to divide the study area into several subregions and ift the coefifcients one by one. Here, we use ground observation data for sunshine hours and solar radiation from 1961 to 2010. Adopting extraterrestrial radiation as the initial value, Angstrom-Prescott coefifcients are obtained by Geographically Weighted Regression at a national scale. The surfaces of solar radiation are obtained on the basis of the surfaces of sunshine hours interpolated by high accuracy surface modeling and astronomical radiation;results from spatial y nonstationary and error comparison tests show that Angstrom-Prescott coefifcients have signiifcant spatial nonstationarity. Compared to existing research methods, the method presented here achieves a better simulation effect.

Spatial Distribution of Soil Organic Matter Using Geostatistics: A Key Indicator to Assess Soil Degradation Status in Central Italy

Soil organic matter (SOM) content is one of the main factors to be considered in the evaluation of soil health and fertility. As timing, human and monetary resources often limit the amount of available data, geostatistical techniques provide a valid scientific approach to cope with spatial variability, to interpolate existing data and to predict values at unsampled locations for accurate SOM status survey. Using geostatistical and geographic information system (GIS) approaches, the spatial variability of some physical and chemical soil parameters was investigated under Mediterranean climatic condition in the Abruzzo region of central Italy, where soil erosion processes accelerated by human induced factors are the main causes of soil degradation associated with low SOM content. Experimental semivariograms were established to determine the spatial dependence of the soil variables under investigation. The results of 250 soil sampling point data were interpolated by means of ordinary kriging coupled with a GIS to produce contour maps distribution of soil texture, SOM content related to texture, and C/N ratio. The resulting spatial interpolation of the dataset highlighted a low content of SOM in relation with soil texture in most of the surveyed area (87%) and an optimal C/N ratio for only half of the investigated surface area. Spatial location of degraded area and the assessment of its magnitude can provide decision makers with an accurate support to design appropriate soil conservation strategies and then facilitate a regional planning of agri-environmental measures in the framework of the European Common Agricultural Policy.

Urban Expansion and Spatiotemporal Relationships with Driving Factors Revealed by Geographically Weighted Logistic Regression

Urbanization improves our lives but also threatens human health and sustainable development. Revealing the spatiotemporal pattern of urban expansion and spatiotemporal relationships with driving forces, especially in terms of the ubiquitous and fast growing small city, is a crucial prerequisite to solving these problems and realizing sustainable development. Kunshan, China was used as a case study here. Eleven variables from four aspects covering physical, socioeconomic, accessibility and neighborhood were selected, and logistic regression and geographically weighted logistic regression modeling were employed to explore spatiotemporal relationships from 1991-2014. Results reveal that urban expansion in Kunshan shows an accelerating tendency with annual expansion from 2000-2014 four times higher than for 1991-2000. More importantly, the annual expansion rate of Kunshan of 28.42% in 2000-2014 is higher than that of a large city. Urban expansion and related factors have spatiotemporal varying relationships. From a global perspective, the closer to a city, town, main road and the higher the GDP, the more likely a region will undergo urbanization. Interestingly, the effect of population on urban expansion is decreasing, especially in developed areas, and the effect of distance to lake is enhanced. From a local perspective, the magnitude and even the sign of the coefficients vary across the study area. However, the range of the coefficient of GWLR is around that of the corresponding variable in LR, and the sign of most variables in GWLR is consistent with that of corresponding variables in LR. GWLR surpasses LR with the same explanatory variables in revealing regional differences and improving model reliability. Based on these findings, more attention should be given to small cities in China. Promoting the connotation of city culture and public services to realize New-type Urbanization and regional diversity policy in order to manage urban expansion scientifically are also recommended.

Using Weights of Evidence in the Spatial Relation Between Infected Snails and Geographic Factors

Schistosomiasis is a serious public health problem in the middle-lower Yangtze River Basin in China. Study of spatial variation of snail distribution that is related to microgeographic factors can help to choose pertinent measures for snail extinguishment and environment rebuilding. This paper studied the theoretical architecture of weights-of-evidence approach. The case study was made for spatial relation between the occurrence of infected snails and geographic factor combinations in Waijiazhou marshland of Poyang Lake region in China. The multievidence data came from the geographical factor combinations by crossing operation of vegetation coverage grade layer, cattle route distance grade layer, and special environment layer (181 combinations in total) in GIS. The calculation of weight contrast index shows that high vegetation coverage, cattle route distance of <45 meters, and special geographic factor "ground depression" had direct spatial relation with the occurrence of infected snails. The verification by crossing operation in GIS indicated 72.45% of the infected snails concentrated on the areas of positive weight contrast index (sequenced in an order of weight contrast index from high to low), demonstrating the high efficiency of the model established in finding infected snails according to the geographic factor combinations that can be explicitly discerned in the study area.

A Novel Method to Solve Nonlinear Klein-Gordon Equation Arising in Quantum Field Theory Based on Bessel Functions and Jacobian Free Newton-Krylov Sub-Space Methods

The Klein-Cordon equation arises in many scientific areas of quantum mechanics and quantum field theory. In this paper a novel method based on spectral method and Jacobian free Newton method composed by generalized minimum residual （JFNGMRes） method with adaptive preconditioner will be introduced to solve nonlinear Klein-Gordon equation. In this work the nonlinear Klein-Gordon equation has been converted to a nonlinear system of algebraic equations using collocation method based on Bessel functions without any linearization, discretization and getting help of any other methods. Finally, by using JFNGMRes, solution of the nonlinear algebraic system will be achieved. To illustrate the reliability and efficiency of the proposed method, we solve some examples of the Klein-Gordon equation and compare our results with other methods.