Knickpoints are fundamental for understanding local erosion basis and the evolution of fluvial landforms. To extract the knickpoints, Digital Elevation Model (DEM) is widely adopted as the basic data in literatures. However, the accuracy of the extraction is greatly influenced by the DEM resolution. In this paper, to explore the influence of DEM resolution on the extraction of knickpoints, we analyzed the gradient of the fluvial longitudinal profiles to extract the knickpoints in Mount Lu area based on DEM and Digital Line Graphic (DLG). Firstly, the longitudinal profiles of the 16 streams with elevations are derived from 5 m DEM, from which the potential knickpoints are extracted from an empirical gradient domain. Secondly, to find a suitable gradient domain, a field investigation of four typical rivers, including Three-Step Spring and Crane Ravine, is carried out to collect the spatial positions of 30 knickpoints with GPS. Thirdly, multiple resolutions of DEM data are generated by wavelet transformation based on the 5 m DEM. The knickpoints in each scale are extracted in the same way from the corresponding DEM. Finally, the influence of the DEM resolution on the accuracy of knickpoints is discussed. The experiment results reveal that the suitable threshold of gradient domain for 5 m DEM is 0.6, by which the knickpoints’ altitude differences are greater than 5 m. The number of knickpoints is subject to a power function of the DEM resolution. As the DEM resolution coarsens, the number of knickpoints decreases. To verify this power function, the ASTER GDEM and SRTM DEM data are used, which reveals the consistency between the extracted knickpoints from the DEMs and the predicted ones from the function.

Integrity authentication is proved to be the prerequisite of remote sensing image applications. In other words, an image with poor integrity would have little value in further utilizations. The special nature of the authentication process is not taken into account in conventional authentication technologies, which makes it difficult for all users to be authorized to discriminate whether the images have been destabilized. Moreover, traditional authentication technologies are based on the binary data, which can not meet the requirements of content authentication for remote sensing image. According to the actual requirements of remote sensing image authentication, a multi-level authorization method for remote sensing image based on perceptual hashing and one-way function is proposed from the perspective of content authentication. Perceptual hash technology is different from the cryptographic hash function, that it can express the content of remote sensing image with little information, at the same time, it can keep the robustness for operations that do not change the content of image. Multi-level authorization management is realized by establishing a key vector corresponding to the permission vector. So the higher privileged users can calculate the keys of users with lower priorities, based on their own keys. First, the key vector was produced for multi-level authorization management based on one-way function. Second, the image is partitioned into regions with different sensitivity levels according to the contained objects. Then, the perceptual hash values of the regions are generated and used for authentication, and are encrypted with hierarchical keys. Users with different priorities can authenticate the corresponding contents with relevant sensitivity levels from the remote sensing image, after decrypting the perceptual hash values. The experiment results show that the proposed approach effectively achieved the multi-level authentication for remote sensing images with high computing efficiency and confidentiality.

Modeling spatial relations and their scale changes has been one of the important topics in GIS science. This paper discussed the geometric-based and relational-based representation of geographic information. The first representation aims to store, manage, and analyze geometric data with coordinates, and concentrates on the geometric locations, shapes and distributions of spatial objects, thus it is termed as geometric representation. The latter uses symbols to qualitatively represent, communicate and infer spatial relationships between spatial objects based on people’s cognition and understanding, thus it is termed as relational representation. This paper mainly focused on summarizing the latest progress in theories, methods and applications about the relational representation. First, the above-mentioned two representations were compared and their scale changes were highlighted. It is discovered that the geometric representations of same geographic entities vary at different spatial scales, so do the relational representations vary between geographic entities. This type of changes in relational representations strongly associates with cartographic generalization operators, which affects the changes of shapes, sizes and structures of spatial objects. Second, the influences of the generalization operators, which include shape simplification, merging of areal objects, attribute induction and spatial dimension reduction, on spatial relations were analyzed, and related methods were presented for deriving and modeling the scale changes of topological and directional relations which was caused by the four operators. Third, combined with multi-scale spatial relations, a technological framework for analyzing multi-scale datasets was presented. We also illustrated the concepts and solutions for detecting the consistency of multi-scale data, and tested them practically with case studies to demonstrate their efficiency. Finally, it can be concluded that the generalization operators and modeling methods play important roles in analyzing and understanding multi-scale spatial datasets.

There are many image fusion methods developed in recent years with the development of multi sensor, multi-temporal and multi -spectral remote sensing technologies. Of these, the HIS, PCS, HPF, SFIM, SVR, Wavelet and Brovey fusion methods are widely used. However, the traditional image fusion is a technology that usually merges the images with the same temporal or near temporal data to increase the image spatial resolution and multi -spectral resolution. The fusion image can largely improve the image visualization and increase the classification accuracy when using appropriate image merging technique. However, this paper proposes a merging method that uses different time serial TM/ETM+ images to do image fusion. After this process we can apply the unsupervised classification method and the second principal component method on the resultant fusion image to detect and extract land cover change areas. To evaluate accuracy of the methods, we use post-classification method to classify TM image of 1986 and ETM+ image of 2000, and then extract land cover change areas. After this, the detected results of unsupervised classification and the second component analysis were compared with that detected using the post-classification method. The comparison reveals that the two methods used in this study have much higher accuracy than the post-classification method. The study indicates that these two methods can quickly and efficiently detect land cover changes.

The Catalogue and Archive System, a basic work and important research task, is crucial for searching and browsing data in the remote sensing satellite application. In the first part of this paper, the characteristics of remote sensing satellite data catalogue are introduced. Then the actual status and remaining problems in some Catalogue and Archive Systems are analyzed. And the reasons why the operation is not efficient enough in these systems are pointed out. After discussion on the topic of the necessity of researching Catalogue and Archive System, several critical outlines of implementing a new type of Catalogue and Archive System, which are based on the new development of GIS and computer technology and being achieved by China Remote Sensing Satellite Ground Station, are described. These outlines include: (1) Integration oriented storage method is adopted for remote sensing satellite data archiving in order to maintain its integrity and consistency. (2) Time-dividing storage method is used for system's high availability, high performance and easy maintainability, which are very important to mass storage system. (3) Hybrid storage mode is introduced in integration oriented storage method for spatial data management and application. (4) Based on consideration of the characteristics of remote sensing satellite data catalogue, some advices on how to design the database of Catalogue and Archive System are also given.

Terrain structure lines are the skeleton lines of the physiognomy and they mainly include ridge lines and valley lines. Terrain structure lines do not directly exist in the original contour data, but they can be derived from the original contour data. In a sense, they are more important than contours in Geographical Information System (GIS) because terrain structure lines can play an important role in the cartographic generalization, processing of terrain sensing digital image, construction of precise digital elevation model (DEM), hydrographic analysis, mineral deposition, land erosion and extension, the other functions of GIS etc. With the rapid development of GIS, terrain analysis has attracted more attention of the researchers in this field. And the automatic extraction of terrain structure line is a very important problem in terrain analysis. The automatic extraction of terrain structure line usually includes two steps, namely, confirming feature points and linking the feature points to create the terrain structure lines. The first step is decisive for the eventual result and the method is different when using different algorithms. But the second step is always the same. An algorithm for confirming feature points on contours is presented in this paper and the process to confirm all feature points in the whole studied region is improved: according to the difference of the local landscape feature, the feature points in each local region are confirmed using different thresholds which are only adaptive to the local region instead of confirming all the feature points in the whole region using the same threshold. This improvement is very rational because the variation of the landscape is taken into account. Then, based on the established mathematical model, the terrain structure lines are acquired by matching all the feature points confirmed in the whole studied region. In order to make the extracted terrain structure lines more useful, all the terrain structure lines are organized in the form of tree structure and the grade of each branch is available. Because of the complexity and multiplicity of the terrain, few errors are likely to exist in the automatically extracted terrain structure lines, so few manual editing is sometimes necessary to correct these errors. Many experiments proved that the presented method adapts to all the different landscapes, furthermore, the terrain structure lines extracted by this method are integrated and precise.

The spatial variability of rainfall is a major problem in its description and prediction. Akesu river basin lies in the semi-arid and arid region of northwestern China. The local climate and topographic factors affect the magnitude and distribution of rainfall. Rainfall has very low total magnitude in the southeast region, but in the northwest region comparatively more precipitation events occur. Fifteen representative stations were selected for years to reflect the regional rainfall patterns throughout the region. The study area lies between 40°00'-42°00'N and 76°00'-82°00'E. The network of rainfall gauging stations in the southwest is sparse and the available data are insufficient to characterize the highly variable spatial distribution of rainfall in this mountain area. Therefore, in areas where data are not available, it is necessary to develop methods to estimate rainfall using data from the surrounding measuring stations. The major goal of this study is to characterize the spatial variability of annual rainfall by suitable variogram models, which are then used in the kriging process for assigning values to ungauged locations for compiling mean rainfall isoline map. The multiple-regression model for predicting rainfall results in many prediction errors because this kind of model considers precipitation to be independent without spatial distribution pattern and mutual interdependence. Geostatistics, which is based on the theory of regionalized variables, is increasingly preferred in hydrology and meteorology because it allows one to capitalize on the spatial correlation between neighboring observations to predict attribute values at unsampled locations. More and more cases have shown that the geostatistical prediction technique provides better estimates of rainfall than conventional methods. Kriging is a geostatistical estimation technique for regionalized variables that exhibit an autocorrelation structure. Kriging algorithm, based on unbiased and minimum-variance estimates, involves a linear system of equations to calculate the weights. Such a structure can be described by a semivariogram of the observed data. This paper presents one univariate and two multivariate geostatistical algorithms for the spatial prediction of rainfall: ordinary kriging, ordinary co-kriging and disjunctive co-kriging incorporating elevation for precipitation prediction. The resulting semivariograms are anisotropic and fitted by spherical models. Cross validation is used to compare the prediction performances of the three geostatistical interpolation algorithms. The three geostatistical algorithms outperform the multiple regression, in particular the disjunctive co -kriging which stresses the importance of accounting for spatially dependent rainfall observations in addition to the colocated elevation. Cross validation and validation withhold one or more data samples and then make a prediction to the same data location. If the prediction errors are unbiased, the standardized mean prediction errors should be near zero, small root-mean-square prediction errors, average standard error near root-mean-square prediction errors, and standardized root -mean -square prediction errors near one. The prediction error results of the cross validation demonstrated that disjunctive co -kriging is one of the best approaches to describe the spatial variability of rainfall and the result is used to plot isoline maps of rainfall in Akesu river basin.

The analytic function of GIS and the cartographic function of Computer assisted cartography (CAC) are two aspects of geographic spatial data application. The conflict, which exists between GIS and CAC, comes from several different aspects including spatial positions, attributes and relations of geographical objects, and prevents their data from sharing. It usually makes geographic spatial data recollected and wasted. Beginning with a general method that thinks about data, software system and cartographic symbol database at the same time, this paper basically discusses the strategy and methods of geographic spatial data integration. The result of the research indicates that the traditional integration method based on assistant curve makes it more difficult to build and renew geographic database. In this paper, two main methods are put forward that consist of data integration based cartography and data integration based analysis. Compared with the cartographic style, the analytic style has some advantages, such as easily collecting, mapping and analyzing, simple spatial relation and integrated object entitles, so it is obviously more available for geographic analysis and cartography. The research on the strategies of geographic spatial data integration will help to syncretize GIS and CAC by combining artificial intelligence and expert system with data integration scheme.

Discussing the harmfulness of agricultural non-point pollution to the ecological environment. We introduce the mechanism and the inspecting method in agricultural non-point pollution. As one of the most important research fields of non-point pollution, the agricultural non-point pollution research has been accentuated and developed rapidly. This article introduces and analyzes several representative agricultural non-point pollution models and predicts the development trend of this research. So it is in possession of certain significance for the management and study. There is a very close relationship between non-point source pollution and land use in watershed. On the basis of this fact, the export coefficient modeling approach has got substantially developed. An improved export coefficient method for estimating polluting load of non-point source pollution is proposed.

Based on fractal geometry and GIS technology, this paper describes an algorithm for fractal dimension of spatial structure and pattern of built-up land in Fujian and Taiwan. Remote sensing techniques provide the necessary data rapidly and periodically for the spatial characteristics and evolvement study. The study area including Fujian and Taiwan provinces is cut from ASTER images in 2002 after geometric correction based on the topographic map. GIS is an effective tool to analyse the spatial characteristics and evolvement with the strong spatial analysis functions. Based on GIS, the area and perimeter of built-up land are distilled. The fractal dimension D of spatial pattern denotes its complexity and stability, which can discover the trend of the urban evolvement. It varies from 1 to 2, and the greater the D, the more complex the distribution of towns. If D < 1.5, the shape of the urban system is becoming more simple. If D = 1.5, the stability is worse, and the urban system is in the Brown movement. If D > 1.5, the shape is more complex and instable. If D = 2, one place on the plane is filled by the graph of the town. According to the fractal dimension analyses, some characteristics of the spatial structure and pattern of built-up land in Fujian and Taiwan can be identified, and some suggestions on planning the built-up land are proposed based on the research result.

The spectral information of remote sensing images has integrated and realistic characteristics. It has become an important means of using remote sensing information and GIS technology to estimate forest biomass in global change research area. Firstly,the development of using remote sensing information to estimate forest biomass was summarized in this paper. Then four methods which included the method based on relationship between remote sensing information and biomass, the method based on fusion remote sensing data and process model, the method based on K-Nearest neighbor and the method based on artificial neural network were discussed. Finally the shortcomings of current research and the emphases of future research were given in this paper.

Based on the theories of Geo-information Tupu and supported by the technologies of Geographical Information System and Remote Sensing, this paper, taking the Fujian province as a case, first selects hydro thermal conditions, land cover, topography etc. as the indexes, and calculates their weights using the Analytical Hierachical Process method, so as to workout the synthetic eco-environmental evaluation grade map of Fujian province. It then defines the regional eco-environmental quality index, selects the main geographical spatial elements such as coastal strip, main rivers, main cities, and the main railways etc. to build the buffering zones. Finally it overlays the buffering zone on the synthetic eco-environmental evaluation grade map to result a series of spatial distribution pattern maps of eco-environmental quality index, and applies these maps to constitute the eco-envionmental spatial distribution pattern Tupu of the Fujian province. According to the analysis of the Tupu, this paper draws the following conclusions: most of the economically flourishing regions possess of preferable eco-environments, and few of economically flourishing regions with the worse eco-environment locating in the middle coastal strip, where the vegetation cover rate is low due to human's irrational developments and utilization of land resources. In a word, with the theories of geo-information Tupu, the paper expounds the eco-environmental spatial distribution laws clearly and effectively, and this attempt explores and develops the investigative ideas and methods on eco-environment.

The study of resources and environmental sciences requires greatly the spatialized data sets of socio-economic data which are always obtained from administrative regions at county or province level. The authors integratedly analyze the regional differences of China' s economic development first. An approach to the spatial-ization simulation of China' s gross domestic product (GDP) from original county level statistical data is presented to the 1km gridded database with the standard coordinate system, data format and metadata document. The data used in the paper is land use spatial database derived from Landsat TM at 1: 100 000 scale with 25 classes land use types as well as topographic maps of whole China in 1995. The interactions among GDP structure and different land use patterns are analyzed and simulated. Some key indicators are selected to build the model of GDP spatialization simulation. Based on the hierarchical regions of economic development level, spatial relation model between GDP and land use pattern is developed to extend the county GDP to the 1km grid.

A method based on FCD model is adopted for estimation of vegetation density. FCD model is mainly applied to Landsat-TM imagery until now. So in this paper, the method is developed for SPOT imagery and three indexes are modified: vegetation index(VI), bare soil index (BI), and shadow index (SI). Then the method is implemented in ERDAS software system. In order to verify the estimation accuracy, we did much field work, with the aids of GPS, digital camera, etc. The result shows that the accuracy of this method for vegetation density is more than 80% in all, which indicates that the developed method based on FCD model is efficient, simple and economical and suits to SPOT imagery. The method meets the requirement of macro-scale monitoring vegetation density.

With the rapid development of technologies in computer, digital image, geographical information system and relevant commercial softwares, great progress has been made in the field of automatic classification and mapping of regional landforms since the 1980s. However, two methods have been employed till now. One is visual interpretation using digital images, and the other is the automated extraction of landform characteristics from DEM. Because of the difference in personal visual perceptions, different boundary lines of the same landform unit often appear in two workers' interpretation results. Thus, the results obtained from the first method are difficult for future use. As to the second method, it is difficult to get detailed classifications (for example, to distinguish a valley plain from an open plain) by using DEM alone due to the complex nature in landform characteristics. In fact, DEM and digital image contain different, yet complementary, informations related to landform features. Therefore, a new method to integrate landform information of both DEM and TM image by digitizing signing lines in TM image is presented in this paper. With this approach, six types of basic landforms were successfully classified and mapped automatically in Guyuan county of Hebei province. In addition, the spatial variability of accuracy in classification was also evaluated by an application of fuzzy set theory using the notion of entropy in Guyuan case studies.

Landsat TM has a thermal infrared band (band 6) which can be used to retrieve land surface temperature (LST). So far, three methods have been proposed to retrieve LST from TM6 data, they are Radiative Transfer Equation (RTE), Mono-window Algorithm and Single-channel Method. Due to the complicated process of computation and the general unavailability of in situ atmospheric profile at the satellite pass (especially for the images in the past), it is quite difficult to put the RTE method into real world application. The advent of the other two new algorithms has made it possible to retrieve the real LST from Landsat TM thermal band and with relatively high accuracy. The mono-window algorithm requires two atmospheric parameters (the total atmospheric transmissivity and the atmospheric water vapor content) while the single-channel algorithm only requires one (the atmospheric water vapor content). The land surface emissivity is the common key parameter of these two algorithms. In this paper, we make a comparison between the LSTs retrieved from the mono-window algorithm and the single-channel algorithm over a study area in Fuzhou city, Fujian, China. The Landsat TM image used in this paper is acquired on June 15, 1989. The research results show that: (1) when compared to each other, the retrieved LSTs from these two algorithms have similar overall temperature distributions, but, the LST retrieved from the mono-window algorithm is about 2.45℃ higher than that from the single-channel algorithm; and (2) when compared to the corresponding pixel brightness temperature, a higher difference value is obtained. For the mono-window algorithm, it is about 2.84℃, and for the single-channel algorithm, about 5.28℃.

Two Landsat TM/ETM+ images of 1996/9/6 and 2003/5/29, as well as two SPOT images, have been used for this study. To reveal urban expansion areas in Fuzhou of SE China from 1996 to 2003, the original 7-band TM/ETM+ image was compressed into a 3-band image using the band-dimension compression technique. The 3 new bands were derived from three thematic indices, which are Soil Adjusted Vegetation Index （SAVI）, Modified Normalized Differences Water Index （MNDWI）, and Normalized Differences Built-up Index （NDBI）. A supervised classification was carried out on this new 3-band image and the urban built-up lands were extracted from the classified maps. The results show that the expanded areas are generally coordinated with the Fuzhou City's Planning （1995-2010）..

陈述彭院士最近把他们用英文写成的新著寄赠给本人,余虽身体欠佳(胰腺炎),但粗略拜读一遍,深有所得,即奋笔作评,以表予敬佩之意。此书触及地理学者的思维,处处均有可学习之处。即欲推进地理科学的进展,处处均有用场。亦反映述彭兄对我国地理学界又作了一次重大贡献。

This paper firstly introduces the general condition and characteristics of the regional environment.Then it identifies the classification systems on ecological elements composed of environmental landscapes, such as geology, landform, soil, vegetation, etc. Based on these and two satellite images from Landsat TM/ETM+ in March,2001 in Xiamen city, the contents of the study on the serial integrated remote sensing mapping of eco environment in Xiamen city are defined. Its theoretical foundation, in fact, is a methodology of map deduction which is analyzed and discussed. Its cores or key contents are the synthesis based on the analysis and in the meantime on the analysis under the guidance of the synthesis. After the identified symbols of image interpretation are established, the remote sensing images are interpreted through the naked eyes and the results are corrected by field investigations. The paper further discusses the methods and steps, including confirmation of the outlines of the map and the methods of cartographic generalization, etc. Finally, the detailed processes are described on how to use GIS ArcView software to make the serial integrated remote sensing maps at a scale of 1:100 000 on Xiamen eco-environment, and the latest development tendencies and the view of new century of cartography are also briefly outlined.

The eco-environment is not only the substance base, which the human community depends on, but also a limiting factor that could not be ignored during economic construction and community development. The integrated information TUPU of eco-environment, basing on the investigation and dynamic scout, employs a great deal of digital information of the base of eco-environment and the dynamic database. It' s a kind of method and artifice that use the computer technique of dynamic multi-dimension visualization to reveal the interspace configuration and space-time transformation rule of the eco-environment and its essentials, after the abstract of epitome of graphic thought. It is significative for the study of regional sustainable development. Sustained by GIS technique, using the basic information TUPU of eco-environment in Fujian province, this paper designs a database according to the characteristics of the integrated information TUPU of eco-environment and develops a database system of integrated information TUPU of eco-environment in Fujian province. All of that is on the basis of the merger of various units, the abstract of attribute information and the chosen of rational targets. At the same time, it emphasizes discussion of the mutual query and searches functions of the integrated information TUPU of eco-environment and attribute information, along with displaying the associated query of interspace structure and attribute information under different scales. This research has a guidance effect on the more extensive investigation of the integrated information TUPU of eco-environment in Fujian province.

ASTER image is one of the high spectrum resolution remote sensing images which could serve as new information resources of higher quality. NDBI is derived from the NDVI and is rewritten into the formula of NDBI=(ASTER4-ASTER2)/(ASTER4 + ASTER2). In this study, an ASTER image of Fuzhou City was used to extract the urban land-use information of the research area by NDBI method. The result was testified by comparing to the other two methods: PCA and Unsupervised Classification with the same ASTER image and Supervised Classification with the TM image. The result showed that The interpretation result by NDBI method is better than those by automatically classification method. The NDBI method not only has higher precision, but also can distinguish the old buildings from the new ones.

The plates that make up the earth's crust are from a violent collision that happened between the earth and another planet from outer space. The Pacific Ocean is a giant hollow resulting from a collision and the Atlantic Ocean is a rift valley shaping like a huge "S". The water on the earth is possibly mainly from this collision.

In this paper, rape is selected as an example in Tengchong county of Yunnan province for discussing the characteristics and relation of homogeneous crop in different growth periods and with different overlay degrees, through measurement of typical samples in the open, and processing and analyzing these data. The pilot study indicates that spectrum reflectivity increases from 375nm to 670nm and decreases from 800nm to 1100nm along with the increase of flowers of rape, and the combination scale is close to the spectrum combination scale of rape with full flower and without flower. The spectrum reflectivity decreases and increases with the growth of overlay degree from 368.4nm to 738.2nm and from 741.2nm to 1110.6nm, respectively. The combination scale is close to the spectrum combination scale of oil and rape with 100% overlay degree. This research is of practical significance to the recognition of different growth periods and different overlay degrees.

One of the important research fields of the human settlements,which relates to three levels: macro-scopical, middle-level and microcosmic, is to construct the good city environment. And it is the combination of the physical eco-system and man-made eco-system. During the period to construct the sustainable human settlements, "3S" (RS, GIS, and GPS) can play good roles in spatial and attribute data processing, management, analysis and visiblization as strong tools. This article gives a case of Guiyang city area to discuss the concrete application of human settlements study in the analysis of city eco-environment. The study result can help us bring forward the improvement advice for the existing urban plan of Guiyang, and make this plan to suit the need of constructing the good human settlements environment better.

In the field of computer-assisted cartography, cartographic generalization is one of the basic theories and methods of mapping. It is not only an abstract cognition of objective world, but also an important means of spatial information transformation and an important step of mapping. In digital environment, especially in GIS, all kinds of geographic entities and phenomena on the earth's surface are abstracted as points, lines, and polygons. Point cluster is one of the most important objects in the spatial analysis. In GIS, size, direction and shape of spatial points are not vital, however the holistic spatial configuration of spatial point cluster can represent the overall characteristics of point cluster. Thus, the whole spatial configuration of point cluster must be taken into account in automatic cartographic generalization. For the former methods, the reduction of spatial points is settled commendably, but there are still insufficiencies of maintaining the boundary and spatial structure of spatial points. In this paper, the boundary and the clustering center of point clusters are defined in detail. For the point clusters, the delaunay triangle is built and the points on the boundary are located. Then a method to extract the key points on the boundary is set forth. For the center points, the cluster method is quoted to locate them. Finally, the optimum method to improve the maintenance of the structure of spatial point clusters is identified and the content of this method is designed at length.

Based on the Landsat TM image covering Qinghai Lake district received on June 29 of 1997 and using the fractal dimension arithmetic method for coastline, the length of the shoreline of the Qinghai Lake is measured and computed at different scales. It shows that the fractal dimension of the shoreline of Qinghai Lake is 1.0237. The results of this study indicate that, firstly, fractal dimension is a feasible approach for expressing characteristics of the shoreline. Secondly, remote sensing and GIS supported measurement of shoreline fractal dimension has obvious advantages such as saving considerably amount of work and raising work efficiency, which indicates that remote sensing and GIS techniques have very good application prospect in the measurement of fractal dimension of shoreline.

Loess Plateau is a kind of peculiar relief unit in China and in the world, attracting strong attentions for its various and complex morphologies. This paper firstly presents several traditional methods to express land-forms, and then introduces three main methods to model 3D landforms, namely, the surface modeling, the DEM modeling and the fractal technique, the latter is especially described in detail. Finally, some kinds of landform morphologies of the Loess Plateau are generated with the most commonly used two dimensional midpoint displacement algorithms of fractal technique. The results show that we can acquire a satisfying visual effect.

Geo-informatic Tupu is a methodology for geographic spatio-temporal analyses in the condition of modern information technology, which illustrates the spatial distribution and dynamic process of geographic phenomena. Optimization of land use structure is the integration of distribution and process, and Geo-informatic Tupu is strongly applicable for it. Some aspects of Tupu during optimization of land use structure, such as spatio-temporal scale, scenarios of process, hierarchy, inter-feedback between Tupu and models etc. are discussed in this paper. The Tupu of land use and single index of ecological safety produced in the first stage is counted in sign Tupu. The complex evaluation Tupu of ecological safety and land use in the second stage is counted in diagnosis Tupu. The Tupu of optimization scenarios in the last stage is counted in action Tupu. The type definition and grade classification of Tupu should be systematic and harmonious. The optimization case of Baxiantong in Horqin Sandy Land show that Geo-informatic Tupu in optimization of land use structure can provide series of scenarios for constructing the past, evaluating the present and predicting the future. Furthermore it will offer evidence for land use sustainable development decision-making.

Symbolization of geographic information in GIS is named with geographic information portrayal in ISO/DIS 19117. This International Standard defines a feature-centered rule based portrayal mechanism. Instances of features are portrayed based on rules, which make use of geometry and attribute information. Portrayal information needs to be presented to portray a dataset containing geographic data. The portrayal information is handled as portrayal specifications applied according to specific portrayal rules. The portrayal mechanism makes it possible to portray the same dataset in different ways without altering the dataset itself. The portrayal specifications and portrayal rules are not part of the dataset. The portrayal rules can be stored in a portrayal catalogue. The portrayal specifications can be stored separately and referenced from the portrayal rules. The portrayal rule mechanism can be used to handle portrayal issues that have to be solved as they happen, such as how to automatically place text on maps, and how to specially represent the feature instances according to time of a day, direction or scale. The portrayal rules in the portrayal catalogue can be tested on the attributes of the feature instances in the dataset. A portrayal rule should be applied as a query statement that returns TRUE, or FALSE. New portrayal rules should be applied until one returns TORE. The portrayal specification associated with that particular portrayal rule shall then be applied. If no portrayal rule returns TRUE, then the default portrayal specification shall be used. A portrayal service is used to portray a feature instance or instances. The portrayal rules, in the light of mapping knowledge, match the cartographic specifications with geographic information, and find the symbol in the portrayal specification in order to represent the geographic object. Integrating the portrayal rules and extensible style sheet language (XSLT), we can describe the new model, the portrayal rules based on XSLT, where the portrayal rules are presented by the XSLT markup language. In the experiment, the Geographic Markup Language (GML) is transformed into the MapML by XSLT, where the MapML is the user-defined markup language representing the map-making data. Finally, the MapML is symbolized in the symbols based on SVG. The experimentation indicates that the portrayal rules based on XSLT can satisfy the needs of geographic information portryal.

This paper discusses the difference between the system theory of geographic science and the theory of man-land relationship of previous geography, the different points include the following: ①the geographic science system emphasizes the man-land interactions;②the geographic science system identifies research scope covering the past, present and future;③the geographic science system can be applied either to an individual country and region or to global change study. Meanwhile, it also expounds the significance of geographic science system in modern economic construction.