文学地理学的研究方法

本文首次将文学地理学的研究方法归纳为五种,即系地法、现地研究法、空间分析法、区域分异法和区域比较法。系地法,就是考证文学事象发生的地点,然后按照形式文学区或功能文学区进行排列;现地研究法,就是把文献研究法和田野调查法这两种方法结合起来;空间分析法,就是对文学作品的地理空间(包括各种空间元素及其结构与功能)进行分析和解读;区域分异法,就是按照文学的区域特征及其差异,把它们分为不同的地理板块;区域比较法,就是把两个以上的不同区域的文学事象进行共时比较或平行研究。

文学地理学的六个研究方法

本文首次将文学地理学的研究方法归纳为六种,即系地法、现地研究法、空间分析法、区域分异法、区域比较法和地理意象研究法。系地法,就是考证文学事象发生的地点,然后按照形式文学区或功能文学区进行排列;现地研究法,就是把文献研究法和田野调查法这两种方法结合起来;空间分析法,就是对文学作品的地理空间（包括各种空间元素及其结构与功能）进行分析和解读;区域分异法,就是按照文学的区域特征及其差异,把它们分为不同的地理板块;区域比较法,就是把两个以上的不同区域的文学事象进行共时比较或平行研究;地理意象研究法,就是准确地描述地理意象的地理特征和文学特征,深入地揭示其文化内涵、历史价值与现实意义。

Distribution Characteristics Comparison of Salix Psammophila Roots under Different Landforms in Mu Us Desert

[Objective] In order to study plant adaptation mechanism under different landforms in drought regions.[Method] Observe soil moisture dynamic of Salix psammophila sample areas on the dune and depression with neutron moisture gauge and research the roots distribution of Salix psammophila sample areas on the dune and depression respectively by digging method.[Result] The quantity of Salix psammophila roots on the dune exponentially decreases while that on the depression decreases by power function in horizontal direction.In vertical direction,Salix psammophila roots on the dune are mainly distributed in 0-30 and 80-120 cm layers as 72% of all,while Salix psammophila roots on the depression are mainly distributed in 0-40 cm layers as 54% of all.[Conclusion] Salix psammophila roots on the dune not only use surface soil water but also use middle-layer groundwater.Salix psammophila roots on the depression primarily use surface soil water.

Optimal path finding algorithms based on SLSD road network model

A solution to compute the optimal path based on a single-line-single-directional（SLSD）road network model is proposed.Unlike the traditional road network model,in the SLSD conceptual model,being single-directional and single-line style,a road is no longer a linkage of road nodes but abstracted as a network node.Similarly,a road node is abstracted as the linkage of two ordered single-directional roads.This model can describe turn restrictions,circular roads,and other real scenarios usually described using a super-graph.Then a computing framework for optimal path finding（OPF）is presented.It is proved that classical Dijkstra and A algorithms can be directly used for OPF computing of any real-world road networks by transferring a super-graph to an SLSD network.Finally,using Singapore road network data,the proposed conceptual model and its corresponding optimal path finding algorithms are validated using a two-step optimal path finding algorithm with a pre-computing strategy based on the SLSD road network.

Dynamic Changes of Land Ecological Carrying Capacity Based on the Ecological Footprint——By the Case Study of Chengdu City

Chengdu City is in the period of rapid urbanization and industrialization, and the disturbance derived from human activities on environment is increasing remarkablely in recent 20 years. The pressure on environment, economy and population is also increasing and land use in Chengdu has changed enormously. As struc- ture and function of land ecological system change obviously, sustainable development of land productivity has been an important goal and strategic task from now on, and it is necessary to systematically research land ecological carrying capacity based on ecological footprint. The ecological footprint of Chengdu City in the past ten years was calculated and analyzed from the spatial and temporal aspects according to statistical data from 1998 to 2008, as per ecological footprint method, ecological carrying capacity and the GIS spatial analysis method, and regression analysis method. The ecological footprint and ecological carrying capacity values from 2009 to 2019 in Chengdu City were predicted through calculation results in the past ten years. The results show that the ecological footprint and ecological deficit of land use from 1998 to 2008 increased in Chengdu City. The ecological deficit of land use within the city center was in high levels in the past ten years, and the ecological footprint kept raising, especially in areas, such as Shuangliu, Chongzhou, Qingyang among 9 city areas, 4 counties and 6 districts in Chengdu City. There is fanlike distribution of ecological deficit of land use. Analysis shows that the social and natural ecological system is uneven distribution, which is not in sustainable de- velopment situation. The results of the study show that the economic, social and natural ecological system in Chengdu City is not sustainable, and the ecological foot- print is uneven distribution. The analysis of the dynamic change of land ecological carrying capacity in Chengdu City is very important for city government in the pro- cess of the vigorous development in new Tianfu Xinqu, and redevelopment in the northern part of this city.

Natural environment suitability for human settlements in China based on GIS

With the degeneration of environment and acceleration of urbanization,human environment has attracted great attention worldwide.This paper sets up the Human Settlements Environment Index(HEI) model and evaluates the natural environment suitability for Human Settlements in China based on GIS technology.The results show that the HEI of China decreases from southeast to northwest in general,HEI is significantly correlated with population density at grid size and the correlation coefficient(r) between them reaches 0.93,which indicates that natural environment suitability for Human Settlements has a significant influence on population distribution.Most people in China mainly concentrate in areas with high natural environment suitability.The total suitable area is 430.47×104 km2,which accounts for nearly 45% of the total land area in China,while the proportion of people living in the area reaches 96.56%.With a population density of 18 people per square kilometer,the critical area is the transitional region for people to live in China.The critical area covers 225.11×104 km2 with a population of 41.12 million.The non-suitable area covers 304.42×104 km2 with a population of only 2.49 million.

A Modified Certainty Coefficient Method(M-CF) for Debris Flow Susceptibility Assessment:A Case Study for the Wenchuan Earthquake Meizoseismal Areas

In the meizoseismal areas hit by the China Wenchuan earthquake on May 12, 2008, the disasterprone environment has changed dramatically, making the susceptibility assessment of debris flow more complex and uncertain. After the earthquake, debris flow hazards occurred frequently and effective susceptibility assessment of debris flow has become extremely important. Shenxi gully in Du Jiangyan city, located in the meizoseismal areas, was selected as the study area. Based on the research of disaster-prone environment and the main factors controlling debris flow, the susceptibility zonations of debris flow were mapped using factor weight method(FW), certainty coefficient method(CF) and geomorphic information entropy method(GI). Through comparative analysis, the study showed that these three methods underestimated susceptible degree of debris flow when used in the meizoseismal areas of Wenchuan earthquake. In order to solve this problem, this paper developed a modified certainty coefficient method(M-CF) to reflect the impact of rich loose materials on the susceptible degree of debris flow. In the modified method, the distribution and area of loose materials were obtained by field investigations and postearthquake remote sensing image, and four data sets, namely, lithology, elevation, slop and aspect, wereused to calculate the CF values. The result of M-CF method is in agreement with field investigations and the accuracy of the method is satisfied. The method has a wide application to the susceptibility assessment of debris flow in the earthquake stricken areas.

Energy dissipation of coal and rock during damage and failure process based on EMR

The physical and mechanical change processes of coal and rock are closely related to energy transformation,and the destruction and failure of coal and rock is an instability phenomena driven by energy change.However,the energy change of large-scale coal rock in the mine site is hardly calculated accurately,making it difficult to monitor coal-rock systematic failure and collapse from the perspective of energy.By the energy dissipation EMR monitoring system,we studied the damage and failure of coal and rock with bursting liability from the energy dissipation point using the geophysical method-EMR,and explored the energy dissipation characteristics during uniaxial compression and their main influencing factors.The results show that under displacement-control loading mode,there are 2 types of energy dissipation trends for both coal and rock with bursting liability.The type Ⅰ trend is a steady increase one during the whole process,therein,the energy dissipation of rock samples is accelerated at the peak load.The type Ⅱ trend energy is a W-shaped fluctuating one containing 6 stages.Under load-control loading mode,there is one energy dissipation trend of shock downward-steady rise.Besides that,rock samples also present a trend of 4 stages.The energy dissipation characteristics of coal and rockduring loading failure process can be used as effective criteria to assess whether they are in a stable or destructive stage.The factors influencing energy dissipation in the loading failure process of coal and rock mainly include strength,homogeneity,and energy input efficiency.

A SPATIAL CLUSTER METHOD SUPPORTED BY GIS FOR URBAN-SUBURBAN-RURAL CLASSIFICATION

This study was undertaken to construct a preliminary spatial analysis method for building an urban-suburban-rural category in the specific sample area of central California and providing distribution characteristics in each category, based on which, some further studies such as regional manners of residential wood burning emission (PM2.5, the term used for a mixture of solid particles and liquid droplets found in the air, refers to particulate matter that is 2.5 mu m or smaller in size) could be carried out for the project of residential wood combustion. Demographic and infrastructure data with spatial characteristics were processed by integrating both Geographic Information System (GIS) and statistics method (Cluster Analysis), and then output to a category map as the result. It approached the quantitative and multi-variables description on the major characteristics variations among the urban, suburban and rural; and perfected the TIGER's urban-rural classification scheme by adding suburban category. Based on the free public GIS data, the spatial analysis method provides an easy and ideal tool for geographic researchers, environmental planners, urban/regional planners and administrators to delineate different categories of regional function on the specific locations and dig out spatial distribution information they wanted. Furthermore, it allows for future adjustment on some parameters as the spatial analysis method is implemented in the different regions or various eco-social models.

Correction on Effect of Earth’s Oblateness in Inversion of GPS Occultation Data

By using observed CHAMP orbit ephemeredes and MSISE90 dry air model and regarding the earth as a sphere and an ellipsoid respectively, phase delays are simulated and the simulated data are retrieved under different schemes. The comparison between the inverted temperature profiles and the model temperature profiles shows that by inverting observed data, we will get temperature results with large errors if the effect of Earth’s oblateness is omitted. The correction method is proved to be effective because the temperature errors decreased obviously with this method.

Comprehensive assessment method for environmental impact of railway based on geographic information system

By integrating the merits of the map overlay method and the geographic information system (GIS), a GIS based map overlay method was developed to analyze comprehensively the environmental vulnerability around railway and its impact on the environment, which is adapted for the comprehensive assessment of railway environmental impact and the optimization of railway alignments. The assessment process of the GIS based map overlay method was presented, which includes deciding the system structure and weights of assessment factors, making environmental vulnerability grade maps, and evaluating the alternative alignments comprehensively to obtain the best one. With the GIS functions of spatial analysis, such as overlay analysis and buffer analysis, and functions of handling attribute data, the GIS based map overlay method overcomes the shortcomings of the existing map overlay method and the conclusion is more reasonable. In the end, a detailed case study was illustrated to verify the efficiency of the method.

Integration of GIS and multimedia information based on ORDBMS

GIS not includes only spatial data and attribute data, but also multimedia information. How to integrate and manage these data effectively is very important. With the development of the technology of Object-Relation DBMS (ORDBMS), it improved the capability of managing complicated information. With ORDBMS, GIS and multimedia information can be integrated together and can speed accessing files by using "buffer".

Optimal Filtering Algorithm for Stochastic 2-D FMM Ⅱ with Multiplicative Noise

A stochastic two dimensional Fornasini Marchesini’s Model Ⅱ (2 D FMM Ⅱ) with multiplicative noise is given, and a filtering algorithm for this model, which is optimal in the sense of linear minimum variance, is developed. The stochastic 2 D FMM Ⅱ with multiplicative noise can be reduced to a 1 D model, and the proposed optimal filtering algorithm for the stochastic 2 D FMM Ⅱ with multiplicative noise is obtained by using the state estimation theory of 1 D systems. An example is given to illustrate the validity of this algorithm.

Safety Evaluation Method of Evacuation Routes in Areas in Case of Earthquake Disasters Using Ant Optimization Algorithm and Geographic Information Systems

The present study aims to propose the method for the quantitative evaluation of safety concerning evacuation routes in case of earthquake disasters in urban areas using ACO （Ant Colony Optimization） algorithm and GIS （Geographic Information Systems）. Regarding the safety evaluation method, firstly, the similarity in safety was focused on while taking into consideration road blockage probability, and after classifying roads by means of the hierarchical cluster analysis, the congestion rates of evacuation routes using ACO simulations were estimated. Based on these results, the multiple evacuation routes extracted were visualized on digital maps by means of GIS, and its safety was evaluated. Furthermore, the selection of safe evacuation routes between evacuation sites, for cases when the possibility of large-scale evacuation after an earthquake disaster is high, is made possible. As the safety evaluation method is based on public information, by obtaining the same geographic information as the present study, it is effective in other areas regardless of whether the information is of the past and future. Therefore, in addition to spatial reproducibility, the safety evaluation method also has high temporal reproducibility. Because safety evaluations are conducted on evacuation routes based on quantified data, highly safe evacuation routes that are selected have been quantitatively evaluated, and thus serve as an effective indicator when selecting evacuation routes.

Problems of Integrated Assessment of Geo-ecosystems of Steppe Zone of Ural River Basin

Methodological approaches to the assessment of natural geo-ecological systems are researched. Analysis of the interaction of natural and anthropogenic components of the geo-ecological systems and their management is based on the consideration of natural-resource potential in the changing spatial and temporal connection. The principles of identifying and mapping of geo-ecological systems of various rank. Structural changes resulting from anthropogenic transformation allow establish the quality of geo-ecosystems and rank according to the degree of self-realization and sustainability.

Study of Fussy Clustering of Engineering Geological Environment with GIS

Based on previous evaluating methods, a new method which combines GIS with Fussy Clustering algorithm is proposed and applied in evaluating the engineering geological environment of the research area of XuZHou City in this paper. By analyzing the characteristics and formation of engineering geological environment,the major problems are discussed, including stability of basement rock, sandy soil liquefaction and cultural stratum.According to effecting factors of these problems, the stability of every engineering geological problem in the worked area is classified into different classes. Then, the Fussy Clustering method is used in assessing all conditions of engineering geological environment. Finally, the evaluation is fulfilled in the whole studied area. The calculating result shows the method is feasible.

QTPV Data Model and Algorithm and Its Application to Geological Exploration Engineering

3D spatial data model and simulating are the core of 3D GIS can be adopted indifferent domains. A data model based on Quasi Tri-Prism Volume (QTPV) has been proposed. QTPVdefinition and its special cases have been discussed. Using QTPV and its special cases, irregularnatural geological bodies and regular subsurface engineering can be described efficiently. Theproposed model is composed of five primitives and six objects. Data structures and topologicalrelationship of the fives primitives and three objects describing stratigraphy are designed indetail. Some schemes are designed for the QTPV modelling of stratigraphy and subsurface engineeringaccording to modelling data. The model manipulation method of QTPV cutting by an arbitrary plane isdiscussed. Using VC^(++)6. 0 programming language integrated with SQL database and OpenGL graphiclibrary under windows environment, a system prototype 3DGeoMV has been developed. The experimentresult shows that the QTPV model is feasible and efficient in modelling subsurface engineering.

Three-dimensional transformation of magnetization direction and magnetic field component at low latitudes based on vertical relationship

The transformation of the magnetization direction and the magnetic fi eld component is one of the important methods in magnetic data processing and transformation,which can be conducted in both wavenumber and spatial domains.The transformation method in the wavenumber domain has simpler processing expression and higher processing effi ciency than in the spatial domain;however,they are unstable at low latitude.In this paper,the conclusion that the sum is 0 of two vertical magnetic fi eld components(magnetization inclinations are also perpendicular)in 2D is used for the 3D transformation of the magnetization direction and the magnetic field component.In addition,the transformation method at low latitudes based on vertical relationship(VMT)is proposed,which is an iterative algorithm that converts the transformation of the magnetization direction and the magnetic field component at the low latitude into the high latitude.This method restrains the instability of transformation of constant and variable magnetization direction and magnetic fi eld components in low latitudes.The accuracy,stability,and practicality are verifi ed from synthetic models and real data.

Dynamic assessment of rainfall-induced shallow landslide hazard

The assessment of rainfall-induced shallow landslide hazards is a significant issue in the Three Gorges Reservoir area in China due to the rapid development of land in the past two decades. In this study, a probabilistic analysis method that combines TRIGRS and the point-estimate method for evaluating the hazards of shallow landslides have been proposed under the condition of rainfall over a large area. TRIGRS provides the transient infiltration model to analyze the pore water pressure during a rainfall. The point-estimate method is used to analyze the uncertainty of the soil parameters, which is performed in the geographic information system(GIS). In this paper, we use this method to evaluate the hazards of shallow landslides in Badong County,Three Gorges Reservoir, under two different types of rainfall intensity, and the results are compared with the field investigation. The results showed that the distribution of the hazard map is consistent with the observed landslides. To some extent, the distributionof the hazard map reflects the spatial and temporal distribution of the shallow landslide caused by rainfall.

Research on location of underground explosion center based on distributed testing system

Distributed testing system has strong applicability in the field of dynamic testing,which can centrally manage the testing equipment in different locations through the local area network,and meet the new requirements of the test.Based on the theory of seismic location,the location of underground explosion center was studied.The applicability of seismic location theory to the location of underground explosion center was verified by simulating the underground explosion with LS-DYNA simulation platform.Combined with distributed testing system theory and weighting method,the optimal distribution method of test points was summarized through data analysis.