The existing finite element numerical simulation method of groundwater flow has some defects in the three-dimensional visual spatial analysis and the expression of numerical calculation process and simulation results. In order to solve this issue, the key steps of the finite element analysis process including the conceptual model construction, spatial discretization, hydrogeological parameters extraction and initial condition assignment are taken into consideration respectively. Based on the finite element method and 3D GIS platform, the method and technique framework of the groundwater finite element numerical simulation under 3D GIS are proposed with the supports of GIS spatial analysis algorithms and computer graphics theory. In addition to describe the technique framework, the core algorithms’ implementation details are given and the complete process of 3D GIS groundwater flow simulation is presented. The groundwater simulation example demonstrates that the proposed method and technique framework are capable of simplifying the finite element analysis process and improving the calculation efficiency of the model. The whole technique framework can be integrated into 3D GIS platform, and furthermore the visualization of simulation process and calculation results can be achieved eventually.

The urban built-up area boundary is important basic information for urban studies, and is also the premise of the implementation of urban function space layout, the implementation of boundaries control. Accurate extract urban built-up area for urban construction, management and research has important guiding significance, but also reflects the city's comprehensive economic strength and the level of urbanization, one of the important indicators.The DMSP/OLS night light data has been widely used in the extraction of urban built-up areas. But due to the effects of saturated, diffuse, and low resolution problems, it is still a huge challenge to rely on the DMSP/OLS NTL mapping the urban built-up areas. In order to overcome the limitations of the data source itself, In this study, the application of hierarchical expert knowledge analysis, multi-source data extraction of the thematic information layer by layer into the extraction process, the construction of urban built-up area for the level of expert knowledge model to achieve the city built-area refinement extraction. The urban index （VANUI） was constructed by combining 250 m MODIS NDVI data with 1 km DMSP/OLS data. Based on the administrative boundary, the statistical area of the area is divided into the administrative boundary of each prefecture-level city, and the optimal segmentation threshold of each administrative unit VANUI feature image is calculated according to the regional segmentation method, so as to obtain 250 m urban boundary space information range. Meanwhile, Due to the low spatial resolution of the DMSP/OLS luminous data and the narrow range of light and light values, there is still a large gap between the optimal segmentation threshold and the built-up area. Therefore, this study proposed the maximum autocorrelation double threshold extraction method. The 30m Landsat 5 NDVI data were fused to obtain the maximum autocorrelation quadratic NDVI threshold in each 30m seed region by multi-scale segmentation of the regional threshold segmentation. According to the maximum autocorrelation threshold of each potential built-up area, each potential built-up area is revised one by one, and finally 30m urban built-up area is obtained. This paper takes the Beijing-Tianjin-Hebei region as the research area, the experimental results show that the total precision of extracting urban built-up area by multi-source remote sensing cooperative method is 92.9%, and it has higher validity and reliability in spatial distribution and statistical data. The results show that the results of the urban built-up area extracted by this method are not only the overall accuracy, but also the spatial extent of the visual interpretation, and the relative error of the statistical area in each prefecture-level city is small, which verifies the reliability and validity of the method in spatial distribution and statistical data, and avoids the error caused by subjective threshold selection. DMSP/OLS data can be used not only for urban area extraction, but also for the intensity and scope of human activities. Therefore, in the follow-up study, based on the identification of urban built-up area boundary, combined with the quantitative analysis of luminous data and evaluation of urban development area outside the expansion trend and internal dynamic changes for the DMSP/OLS luminous data to give full play to its effectiveness, Economic and historical values play a positive role in promoting.

Heatwave has become an extreme meteorological disaster which occurred frequently during the summer. Moreover, heatwave could evidently affect the healthy conditions of residents. Thus, study the spatial pattern of heatwave health risk would be helpful for us to prevent from and respond to the impacts of heatwaves. Using the historically meteorological datum of Xiamen, this study built a database of heatwave cases and analyzed the basic characteristics of heatwaves in Xiamen. Taking a heatwave event occurred in 2010 as a case, we analyzed the spatial pattern of heatwave health risk by using both the remote sensing data and the demographic data. It is concluded as the following statements. (1) The intensity of heatwaves in Xiamen is quite low, but its frequency is rather high. An intensive heatwave occurred occasionally. (2) The regions with high health risk are located in Xiamen Island, lying from the northeast toward the southwest. The regions with the highest healthy risk are located in the northern and southeastern Jiangtou sub-district, Huli district, and the most area of Xiagang sub-district and Siming district. (3) The human health risk pattern of Heatwave is associated with the spatial distribution of environmental and demographic factors. Generally, this study promotes and extends the scientific knowledge on the health risk of heatwaves.

This paper discusses the information quality-index of the space governance in digital agriculture.Digital Agriculture space governance originated in agricultural development in the renewal and transformation of land structure,any of the agricultural modernization and transformation planning and implementation,we need space admittance for updating project approval and space management control decision-making evaluation.Based on the evaluation of agricultural modernization and transformation,the establishment of access to space admittance and space management decision-making evaluation index system was realized.Through analysis of the factors affecting data quality,it is designed to the quality index system of the space governance in digital agriculture.

It is very important to study the characteristics of spatial pattern and variation of soil nutrients and analyze the effect of topographical factors on the spatial distribution of soil nutrients for the effective use and management of soil nutrients. In this paper, the combination of GIS and Geostatistics methods were applied to analyze the spatial distribution characteristics and variation pattern of soil nutrients (organic matter, available nitrogen, available phosphors and available potassium) in the agricultural land of southeast hilly area of Fuzhou. We further studied the correlation between soil nutrients content and topographical factors (topography degrees, elevation, topographic wetness index, deposition and transport index and gradient). The results showed that: the range of organic matter, available nitrogen, available phosphors and available potassium contents were between 1.10~89.5 g/kg, 1.00~461 mg/kg, 0.300~298 mg/kg, 4.00~399 mg/kg and the range of variation coefficients were 35.3~99.0%, which belonged to moderate variability. There was obviously different in the spatial abundance of soil nutrients in the cultivated land. In most of the area, the organic matter and available phosphors content were abundant, available nitrogen content was a little above average level and available potassium content was relatively scarce. The nugget coefficient of organic matter, available nitrogen, available phosphors and available potassium were 32.0%, 37.3%,50.0% and 50.0%, respectively. They were medium spatial autocorrelation, indicating that they were controlled by structure and randomness. Spatial autocorrelation scale of organic matter and available nitrogen were large. They change smoothly in each direction (0°, 45°, 90° and 135°) when the step length was less than 0.3 km.and are isotropic. The variation of effective phosphorus and available potassium was small. Their direction of change was complex and they are anisotropy. These results suggested that the government needed to strengthen guidance of fertilization. Nitrogen fertilizer amount should be maintained and the potash should be increased reasonably. The organic fertilizer and phosphate fertilization should be decreased.. In addition, in the subsequent investigation, the setup of sample points should consider density and direction and appropriately increase the sampling of effective phosphorus and available potassium while nitrogen and organic matter and alkali solution sampling can be reduced based on the study.

Multi-source remote sensing data fusion is the development trend of remote sensing technology in depth. This paper analyzes in detail algorithmic application characteristics of multi-source remote sensing data from three levels of pixel-based, feature-based and decision-based fusion processings. Take Fengning County for example, specific applications of remote sensing data fusion methods in information extraction are illuminated. The data used in this study is firstly pre-processed, then the principal components of Landsat TM data in 1999 are analyzed, the first three principal components account for 97.8% of the total information, the resulted image of inversed principal components transformation is clearer and has more abundant levels. To extract information from remote sensing image, we select the fusion image from Landsat TM pan and multi-spectral bands after principal components transformation, color composition scheme of bands 4, 3, 2 and bands 5, 4, 3, and vegetation index and greenness index after tasseled cap transformation are analyzed, the remote sensing image information fusion with DEM and spatial data of GIS database can also improve the accuracy of remote sensing information extraction. Problems to be resolved and future direction of multi-source remote sensing data fusion are put forward.

The paper analyzes three plans on extraction of vegetation cover rate using remote sensing, i.e., experience model plan,vegetation index plan and mix-pix analytical plan and identifies their force, precision and existing problems in actual application. It points out what affects the wide application of precision of vegetation index transform plan abroad is the choose of the maximum NDVI - complete vegetation cover.Based upon this it introduces an improved model of vegetation index transform plan using the maximum NDVI value of the high resolution satellite image as the homogenous pixel's NDVI value to replace the NDVI value of the middle resolution satellite image, set up vegetation cover extraction model so as to develop a method for obtaining large scale vegetation cover with the aid of middle resolution satellite image. Practice proves this method is simple and practical, suitable for large scale macroscopic monitoring by applying middle resolution satellite image.

The high-resolution DEM and DOM data is an accurate description of the topography and geomorphology, and it is also an important source data for landslide information extraction. At first,according to the requirement of landslide information extraction,we use the UAV platform equipped with mini SLR camera combined with the GPS data measured in the field, as the image acquisition method. According to the characteristics of the UAV images, we use the basic principle of photography measurement and computer vision algorithms to obtain the high-resolution DEM and DOM images, which greatly preserves the rich spectral and texture information. Then, with the help of the ESP auxiliary tool we get optimal segmentation scale of the DOM. Based on the fuzzy classification and SVM algorithm to construct a decision tree, which we used to achieve the object oriented classification and information extraction. Finally, according to the spatial feature and distribution of study area we determine the high risk area. By the morphology and texture analysis and accuracy assessment of the landslide area, we show that the producer’s accuracy and user's accuracy of the landslide area are 84.65% , 91.44%. The result proves that the UAV remote sensing has a high value in the field of landslide information extraction.

Because spatial data has the features of spatial position,unstructured,spatial relationship and vast amount etc,memory access performance on spatial data becomes one of the most important indexes for geo-spatial database evaluation.BeyonDB,researched and developed under the support of National "863" Program,is the geo-spatial database system with independent intellectual property rights.Because at present,there is no software supporting performance comparison test of geo-spatial database and in order to objectively assess its performance index,it is necessary to design,research and develop a kind of performance comparison test software of geo-spatial database.Functional objectives of performance comparison test software of geo-spatial database are firstly analyzed in the paper,i.e.to support performance comparison test between BeyonDB and international leading geo-spatial database system,meanwhile,it can simply extend into other geo-spatial database;to support performance test of loading and inquiring of spatial data;to support testing methods of both SQL sentence and test script,and test report should be automatically generated and output based on "Template" method.As to performance comparison test software of geo-spatial database,we adopt object-oriented design philosophy and method,rationally use software design pattern.General framework design of the software and detailed design of main control,function command interface,access interface of spatial data and output of test results etc.are provided in this paper.After completing the design,we put forward methods of realizing functions of the software,development tool,main interface of the software,output interface of test results and other results.At present,the software has been successfully applied to performance comparison test between BeyonDB and Oracle Spatial,BeyonDB and PostGIS,which greatly improves test efficiency and enables test results to be objective and impartial.Finally,future research emphases of the software are defined in the paper.

Spatial-temporal trajectory classification aims at predicting the category of a spatial-temporal trajectory. The classification of spatial-temporal trajectories plays an important role in urban planning, personalized user recommendation and so on. The process of trajectory classification includes three stages: trajectory preprocessing, feature extraction and classification. This paper reviews the recent research progress on trajectory classification. Firstly, we introduce the process of trajectory classification. Then, the trajectory classification algorithms are classified into three categories according to the method of feature extraction, including the trajectory classification algorithm based on motion feature, the trajectory classification algorithm based on classification rule and the trajectory classification algorithm based on image signal analysis. We also discuss the basic ideas, advantages and disadvantages of these algorithms. Thirdly, we compare the existing classification algorithms according to the sensors, feature extraction and classifiers used in these algorithms. Finally, we introduce the challenges of the existing trajectory classification algorithms.

Land use mapping using remote sensing techniques supplies essential datasets for scientific researches including global climate change, regional sustainable development and so on. The evaluation information on the accuracy of the land use mapping determines the integrity, reliability, usability, controllability and shareability of the land use maps obtained by the applications of remote sensing techniques. In this paper, the methods, processes and results of multiple temporal land use mapping for China's coastal zone using remote sensing techniques were overviewed, and the land use maps in 2010 and 2015 were selected for accuracy evaluation. The validation samples were collected based on Google Earth and the confusion matrices were established for the whole coastal zone and its sub-regions, respectively. Then, the overall accuracy and Kappa coefficient were calculated. Main findings are as follows: (1) Results of land use mapping in 2010 and 2015 using remote sensing techniques achieved high accuracy. For the entire coastal zone in China, the overall accuracy came to 95.15% and 93.98%, with the Kappa coefficients of 0.9357 and 0.9229 in 2010 and 2015, respectively. (2) The accuracy of land use mapping in China's coastal zone exhibited obvious regional differences. The best accuracy was found in the coastal area of Jiangsu province in 2010, and very high accuracy were found in the coastal area of Hebei-Tianjin, Shanghai city, Hainan province and Taiwan province in 2015, while the worst accuracy was found in the coastal area of Fujian province in both 2010 and 2015. (3) The accuracy of land use mapping in China's coastal zone exhibited obvious typological differences. The very high accuracy (both producer precision and user precision) were achieved for farmland, forest, grassland and saltwater wetlands, and the high accuracy for built-up, freshwater wetlands and human made saltwater wetland, while the worst accuracy for unused land. (4) The misclassification between cultivated land and forest land, construction land and grassland is quite significant. Inland water bodies were easily misclassified into cultivated land, forest land and construction land. Artificial salt water wetlands were easily misclassified into cultivated land and construction land, and unused land. It was easy to mistakenly classify the unused land as cultivated land. These are the issues that should be paid more attention during the continuous update of the land use maps in the future. This study provides supports for the dynamic monitoring and scientific researches on coastal land use changes.

Energy fixation and organic matter production of forest ecosystem were dominated by plants, which are impacted by their growth environment. The forest ecosystem has the characteristic of long life-span, which makes its research laborious and costly using field experiment. The virtual geographical environment can provide a new way for its research due to its character of trying to exceed the limit of time and space. In order to estimate the biomass and evaluate relationships among tree and environments, an L-systems based functional-structural model was developed for simulating the development of tree architecture, taking into account tree physiology and environment. The L-systems was used to represent the morphological development of tree. The basic growth unit was described in line with the development of young Chinese fir (Cunninghamia lanceolata). LSTree system integrated the photosynthesis, photosynthates allocation and morphogenesis models. The spatial distribution of solar radiation in tree canopy was simulated for calculating photosynthetically active radiation (PAR) of each leaf obtained. PAR is a key parameter for photosynthesis model to estimate biomass. The dynamic growth of an individual 3-to-4-year-old Chinese fir in Fuzhou was simulated in growing season. Based on the 2010 Fuzhou weather and Chinese fir photosynthetic characteristic, net photosynthesis rate and product were calculated for each stage. The amount of photosynthates allocated to the growth of new segments and leaves or branches and leave amplification are based on source-sink theory. The growth of tree is driven by available photosynthetic products after respiration losses were accounted for. The morphogenesis change in the young Chinese fir in response to environment was simulated dynamically in three dimensional representations. The result of net photosynthesis was compared to the previous field observation research, and it showed the simulation result was reasonable. The methodology has promising benefits to depicting the interaction of plant and environment, which will be valuable for estimation of organic matter production too.

The world's largest dam project and Chinese Western Region Development project was implemented in recent decades in the Three Gorge Reservoir Area (TGRA). These human activities lead to and influence widespread cropland change. In this study we used remote sensing data for dynamic monitoring of cropland in TGRA over 15 years before and after the Three Gorges Project and found that cropland plantation index become 0.25 in 2007 in TGRA, cropland of 0.069 hectare per capita in 2007 is lower than 0.089 hectare per capita of critical line based on estimate of the national total cropland control of 18 billion Mu (1.2 billion hectare). Cropland lost 59 655 hectare during the Three Gorges Project construction, that is to say, annual loss of cropland is 3 977 hectare. With the change of cropland, the ratio of the cropland occupied to the cropland reclamation is 26∶1, such an unbalanced situation means a rapid decrease in land capacity. Meanwhile, high-yield cropland accounts for 61% of cropland loss, resulting to a decline in entire cropland quality. It aggravated the deterioration between cropland supply and food requirement. However, the urbanization process decreases rural population and alleviates the pressure of cropland resources per capita. The driving forces of cropland decline included urban development, "Grain for Green" Project, reservoir submergence and orchard plantation, among them urban development is a key factor. The reservoir submergence accounts for 16% of total cropland loss. Up to now, cropland on slopes more than 25 degree accounts for 20% of total cropland area, that means a high risk of serious soil erosion. As for the long run "Grain for Green" Project which aims at improving the ecological environment, there is still many to do in the future.

The gird scale effect is one of the basic issues on population data spatialization.For the demand of all kinds of spatial population data in the fields of resources and environment and global change models,a lot of researches have been done based on remote sensing and GIS technology both at home and abroad.But the models used are mostly on global(such as GPW,1995,5km),national(such as national population database,2000,1km) or provincial scale,and their resolution ranges from 1km to several kilometers.In recent years,there are studies on local distribution of population by using of high-resolution images.For all the researches,both the method of data source selection according to specific application and the analysis on production suitability are deficient.So,many uncertainties exit in population data application,especially in county level and secondary or tertiary rivers.To solve the problems mentioned above,in this article we mainly propose the method of scale effect analysis on population data spatialization.Taking Yiwu City,Zhejiang Province as the study area,using CBERS and IRS-P5 images we extract land use information and build a spatialization model to the statistical population data of rural towns,then get a set of population data gird ranging from 20m to 1km.Moreover,by comparing population data by grid and statistical population data in rural towns,the grid scale effect analysis is made;by comparing population data by grid and statistical population data in villages,the remote sensing data source scale effect analysis is made.The result of scale effect analysis shows: by using CBERS as data source,the suitable grid scale of production is 200m and its precision is 76%;by using P5 as a data source,the suitable grid scale of production is 100m and its precision is 84%.The method of scale effect analysis in spatial distribution of statistical population is argued in this paper and it can provide basic technical solutions and examples to optimum scale selection in the process of humanistic factors(such as population) spatialization.

The spatial distribution of population at fine-scale has increasingly become research hotspot and a difficulty issue in the field of population geography. It has practical application value and scientific significance for relevant researches, such as disaster assessment, resource allocation and construction of smart cities. The population is concentrated in the urban area. Revealing the population distribution difference in this area is the core content of spatializing population data at the fine scale. In this paper, the urban area of Xuanzhou District was selected as the research area. The population distribution vector data at residential building scale was established by proposing a spatialization method based on urban public facility elements. The method classified residential building patches. And it treated residential building patches as population distribution locations in geographical space with community boundary and community-level demographic data as the control unit. A multiple regression model of patch area and population was constructed. The spatialization method used in this study can reveal the detailed information about the population distribution in urban area. Results show that: ① The population distribution data, obtained by adopting urban public facility elements, is proved to be high accurate and reliable. The number of patches with estimated population in a reasonable range is 35.4% of 779 residential building patches. And the proportion of patches with relative errors of ±20% in population estimation is 61.2%. Moreover, the Chengdong community and Sijia community served as accuracy verification units, the absolute relative error of population estimation in these communities is less than 9%; ② Urban public facility elements, especially primary and secondary schools and kindergartens, vegetable markets and fruit shops, are important factors for accurate estimation of population within a residential building. Their estimation accuracy of number of people is high ifor multi-storied building, but lower for moderate high-rise building.

Mountain basal elevation (MBE) is the elevation of the base which mountains uplift from. The variation of MBE affects the redistribution of water and heat conditions in mountain areas, and the structure and distribution of mountain altitudinal belts. But so far, there has been no accurate and scientific concept of MBE and no effective method to quantitatively extract it. This paper discusses the features of MBE, and develops a new quantitative method for MBE extraction based on topographical features. There are several algorithms available for automated extraction of topographical features, including ridge line, valley line and the boundary of mountains, and most of the current approaches are mainly based on regular statistic unit. This paper takes Taiwan mountain areas for experimental zone, and uses ASTER GDEM at resolution of 30m. Firstly, extracting main ridge line and main valley line by terrain analysis and hydrological analysis, and using topographical features to extract the boundary of mountains. Then based on the result of extraction, the distribution and the value of MBE are determined. The results show that the mountain areas of Taiwan can be divided into six MBE areas (0m, 150m, 200m, 600m, 630m, and 650m). The results can represent the distribution of Taiwan mountain basal elevation. This MBE extracting method is based on sophisticated algorithms, so it can improve the efficiency of the extraction process and the accuracy of results. The method could promote the extraction of the world's mountain basal elevation and the quantitative research of mass elevation effect.

The strategy of western exploitation takes science and technology as the first step and IT industry as the breakthrough point, to avoid rough exploitation and reduce environmental pollution. Thus, digital earth could play an important role in it. In addition, the whole environment should be taken into account for the strategy as well as the interaction and coupling among the environmental elements such as atmosphere, hydrosphere and biosphere, considering the background of global change, as well as the change of Eastern Asia continent. That's just the strongpoint of digital earth, which studies the earth as a whole. Thereby,"digital earth" should be applied in the western exploitation, to transform western information resources into increasing knowledge assets through investment of knowledge capital.

陈述彭先生一生笔耕不缀,为我国地理学事业的发展留下了大量宝贵的学术论著。本文就研读陈述彭先生早期地理论述,试从地理区域研究、综合自然区划、景观综合制图、制图综合指标、地学多维图解五个方面,对先生早期地理学术思想进行了分析,并对先生早期地理思想的现代地理学,以及地球信息科学发展的指导意义进行了思考。

《地理信息系统引论》( Introduction to Geographic Infor mation Systems)教材是 GIS入门的好教材。系由美国爱达荷大学张康聪 ( Kang- tsung Chang)教授长期从事地图学与 GIS的教学与研究 ,在积十几年教学经验的基础上悉心编著的。该教材 2 0 0 1年 8月由美国 Mc Graw- Hill高等教育出版公司出版后 ,第一版即售出 60 0 0多册 ,被美国 2 0 0多所大学采用。美国同行教授评价该教材是“第一本通过实例如此透彻地阐明GIS,且对初学者和已有 GIS经验者皆适用的著作”。

Traditionally, tourism itinerary planning is implemented as a spatial arrangement issue, which lacks the consideration of the spatiotemporal coupling and the flexibility for tourists to make choices. In this paper, the understanding of the itinerary planning problem was extended from the perspective of space to the perspective of tourist activities. From the time-space coupling relationship and reconstruction mode of tourism nodes, the multi-dimensional attributes such as time, space, and topic involved in the travel were organically organized, and then the travel's spatiotemporal chain was proposed. The conceptual model and the method of space-time convergence of the stroke elements. The proposed method was applied to the case study of Nanjing, Jiangsu Province of China. Results show that the match between the model and the traditional itinerary design method in terms of node name, number of nodes, and node order exceeds 80%, indicating good methodological reliability. Compared with existing itinerary planning studies, this research took the basic information of the itinerary (such as travel time, cost budget, departure place, destination, etc.) as the precondition, and considered the travel itinerary from the perspective of tourists. Specifically, the spatiotemporal characteristics of the tourist nodes were organically integrated. While satisfying the spatial order of tourist routes, the rationality of the time arrangement of each tourism element was also considered. The proposed algorithm is mainly used to serve independent tourists. Meanwhile, this algorithm has the advantage of arranging route and schedule flexibly. It should be noted that the specific application of the model is still constrained by the basic travel itinerary conditions. The flexibility of the proposed model for meeting tourists' individualized needs is currently not strong. Considering that tourists' demands are in reality often changing during traveling, it is necessary to further optimize the adaptability, flexibility, and stability of the proposed model.

Logistics essentially refers to material entities movement process with distinct spatial measurement and spatial characteristics, where integration and application of spatial information techniques and other modern techniques of logistics management are needed. This is a new interdisciplinary research fields where to extent spatial information services combined with web services and geospatial analysis to the area of logistics management, and then integrate the concept of spatial information services into modern logistics services system to carry out logistics oriented spatial information web services access, integration and application. What's more, the key point to analyze logistics spatial phenomenon from the geographic perspective. Based on OGC web service framework, this paper we have put forward design and built the architecture of logistics spatial information services mainly include the mechanism for service integration, high-efficiency call and service composition and the model of integration based on web services, which clear its inherent elements and the relationship. Besides, we designed and developed the mechanism for service composition based on Net-Petri and Logistics Web of web service engine, which resolved the problems of dynamic access, high-efficiency call and real-time integrate to the logistics spatial information services. This work provided a new way and measure to the spatial information services being further developed and applied in the logistics area. By this way, even though the logistics information system constructors don't have a professional GIS background, they can also call spatial information service in their own programs. According to our study, the means of techniques of integrating and applying the logistics spatial information services, which achieve the dynamically composited and collaboratively integrated effectiveness and the practical experience for logistics spatial information service system construction.

The DEM Terrain Description Error (Et) has a basic fact that even if the elevation sampling errors of DEM grid points are equal to zero, a terrain description error will still exist because of DEM simple matrix data format. With the development of earth observation technology, Et has become the main factor affecting the quality of DEM, especially when the DEM grid resolution is low. Traditional calculation models could not calculate the Et value of random points on terrain surface. A new calculation model of DEM terrain description error is presented in this paper for improving the traditional models. The new Et calculation model of any ground point considers the layout position of DEM grid which is established based on the mechanism of Et production. Statistic indexes of Et based on DEM are firstly presented. Then the layout scheme of DEM grid on different datum mark position is designed. At last, the Et value of any ground point considering the layout position of DEM grid is calculated using the new model of Et. 100 DEMs with 5、15、25、50、75、100 and 150 meters resolution for Loess hilly test area in Shannxi Province. The results show that: (1) the standard deviation, average value, extreme value, extreme difference and other metrics indexes of Et for each ground point in any DEM grid resolution of different physiognomy type areas could be calculated scientifically and effectively; (2) reconstruction methods of terrain surface based on DEM strongly influence the accuracy of Et model. Complete regularized spline function interpolation method based on a 4×4 search circle is tested for the optimal interpolation method.

Ecological restoration is an important way to adjust the structure and function of ecosystem in order to cope with the excessive interference of land use. Scientific mastery of restoration pattern and farmland pattern evolution has a profound significance on the management of regional ecological environment and the conservation of vegetation in Loess Plateau. This study, taking Yan'an City in Loess Plateau as a typical area, explores the spatial differentiation characteristics of farmland variation and restoration status from the overall characteristics of ecological restoration, topographic factors and regional differences since ecological restoration. The results show that the arable land of Yan'an City decreased from 11752.80 km² to 9149.93km² due to the ecology restoration during 2000-2013. The returned farmland is 2756.85 km², and the returned farmland index is 22.15%. The cultivated land was mostly converted to forest and grassland accounting for 95.29% of the total amount. Farmland and the returned farmland area was mainly distributed in slope (6~25°) and the altitude level of II（925~1115 m）, III（1115~1275 m）, IV（1275~1442 m）, which accounted for more than 70% of the area. The degree of farmland returning increased gradually with the increase of slope, with the land reclamation rate decreased gradually with the increase of slope and elevation. The highest degree of ecological restoration is the altitude level of IV, and the least is altitude level of III. The ecological restoration rate of 2005-2013 was higher than that of 2000-2005. The area and extent of restoration in county decreased from north to south. The center of farmland returning and cultivated land is located in the boundary of Ansai county and Baota District which are in the north of Yan’an City. The center of ecological restoration was changing from northeast to southwest while the center of cultivated land was changing from north to south. This study may provide more scientific and reasonable reference for ecological conservation and construction of ecological civilization in Loess Plateau by the analysis of spatial-temporal differentiation characteristics of ecological restoration in Yan'an city.

Land surface temperature (LST) and fractional vegetation coverage （FVC） are important indicators of ecological environment changes. Studying the temporal and spatial variations of LST and FVC as well as their interaction in Fujian Province are of great significance to the evaluation of ecological environment construction and improvement of regional ecological environment. In this study, the temporal and spatial variations of LST in Fujian Province and the interaction between LST and FVC are analyzed, based on the reconstruction time series data of MODIS 11A2 LST and 13Q1 NDVI from 2001-2015. The results showed that: (1) The overall LST in Fujian Province presented a slight downward trend from 2001 to 2015, and the downward trend of LST is more pronounced after 2010. The spatial distribution of LST and FVC had a good negative correlation consistency, which implies the LST value is lower in the higher area while the LST is higher in the lower FVC area. (2) LST is negatively correlated with FVC, DEM and latitude. And their negative correlation was increased or decreased regularly with the change of months in a year .The negative correlation between FVC and LST was higher in summer and became lower in winter with the correlation coefficient reduced from 0.7 to 0.4. (3) The decreasing trend of LST with the increase of FVC is piecewise linear and has an obvious "FVC inflection point". In front and behind "FVC inflection point", the decreasing trends of LST with the increase of FVC are "slowly first and fast afterwards" in summer and "fast followed by slow "in winter. Moreover, the difference of LST decreasing rate with the increase of FVC becomes smaller in spring and autumn. In summer, when FVC is greater than 0.4, the LST can reduce about 0.77 °C with FVC value increase 0.1, and the cooling effect is about twice as much as that when FVC is less than 0.4. Therefore, if we want to effectively reduce LST in summer, we should make the surface vegetation cover more than 40%。Only in this way can vegetation play a better role in cooling. (4) From January to August, the negative correlation of FVC on LST has a lag, and vegetation change has a greater impact on the spatial and temporal distribution of the next month's LST. This study has a certain significance for the construction and evaluation of ecological environment in Fujian Province, and provide an important reference for the development of vegetation to suppress regional high temperature.

The component-based GIS system has enormous advantages in seamless integration and the flexibility of the system.It stands for the development trend of GIS.Applying the ComGIS based technology,a specific GIS system for monitoring and management of the Minjiang River Estuary wetland based on MapObjects and Visual Basic has been developed in this research.The spatial visualization analysis of the wetlands' dynamic change,in turn,can be implemented.

This article estimated the precision of the precipitation simulated by 15 IPCC AR5 (the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, IPCC AR5) GCMs (Global Climate Models) and the multi-model ensemble (MME), based on the observed precipitation from 660 stations in China during 1996 to 2005. We firstly extracted the model simulation value at the corresponding position of the meteorological station, using the bilinear interpolation method, and took the average value of different models at the same station as the multi-model ensemble simulation value, then estimated the precision of the precipitation simulated by 15 IPCC AR5 GCMs and MME based on the observation of meteorological station. There were four evaluation parameters, including Corr (correlation coefficient), Bias, MRE (Mean Relative Error), and RMSE (Root Mean Square Error). Results show that the biases of the average daily precipitations simulated by IPCC AR5 GCMs present a gradually downward trend from northwest to southeast, and the RMSEs show a gradually increasing trend from northwest to southeast, while MREs in the east are less than those in the west. 82.3% of the average daily precipitations simulated by MRI-CGCM3 have relatively small biases, ranging from -0.5 to 0.5. The precisions of average daily precipitations simulated by BNU and MIROC-ESM are lower than that of others. Compared with other models, the MME simulation has the largest percentages of which the correlation coefficients are more than 0.5, MREs are less than 0.5, and RMSEs are less than 4mm, which accounted for 64.8%, 25.8% and 86.4% respectively. And the percentage of the biases ranging from -0.5 to 0.5 is relatively large, which is 56.7%, indicating that the simulation precision of MME is better than that of any other GCMs, and the MME can reduce the uncertainty of a single GCM simulation in future scenarios. Therefore, it is more scientific and reasonable to select the precipitation simulated by MME as the climate change condition, while studying subjects related to climate change.

Terrain position is the basic morphologic feature on the surface of the Earth. The classification and extraction of terrain position have been widely applied in many research fields such as landform evolution, digital soil mapping and landscape ecological mapping. Proposed by Kang X et al. (2016), the multi-scale Geomorphons method maps terrain position by recognizing the morphology of each interest cell in a DEM according to its relative altitudes within the neighboring window. Multi-scale Geomorphons method can avoid the shortnesses of other classificaton methods, which are caused by different terrain attributes and a single analysis scale. However, there are still some drawbacks in the multi-scale Geomorphons method. For example, the classification results are fragmented and the domain of the analysis scale is difficult to determine. To solve the above problems, this paper presents a new method to classify terrain position, which is based on object-oriented segmentation and multi-scale Geomorphons. First of all, we propose an approach of determining the domain of optimal analysis scale of the multi-scale Geomorphons method. Then, the multi-scale segmentation and classification methods are constructed according to the initial terrain position data via the multi-scale Geomorphons method. At last, the presented method is evaluated by the experimental data of the DEM with 5 m resolution in the loess plateau region of northern Shaanxi. The experimental results show that: (1) the method of mean change-point analysis can effectively solve the problem which is difficult to determine the domain of the analysis scale of the multi-scale Geomorphons method. The domain of optimal analysis scale of the sample area is 5×5 to 33×33 cells. (2) The layer of each terrain position type with the value 0 for non-type cells and 255 for type cells is suitable for multi-scale segmentation. The parameters (i.e. scale, weight of shape and weight of compactness) for multi-scale segmentation have deep influence on segmentation results. There is optimal segmentation parameters for a experimental region. There is optimal segmentation parameter for an experimental region. (3) Comparing with the multi-scale Geomorphons method, the classification results of the present approach are more integrity and reasonable in the aspects of morphology correspondence and geological interpretation.

The geosensor networks system of mine ground disaster monitoring is a integrating system implemented by comprehensive application of geomatics technology, that is, satellite remote sensing, geographic information systems, satellite positioning, Georobots, ground based SAR, and sensor networks. It is of great practical significance to predict the mine ground disasters timely and accurately, in order to prevent and reduce the loss of mine ground deformation disaster. The main research contents of the geosensor networks system of mine ground disaster monitoring include data whole processing theory and method, geographic grid and function partition, data fusion, spatial data clustering analysis, disaster effect analysis, intelligent forecasting models and theory, spatial database and service platform system. Using time-series monitoring data of multiphase geosensor networks, the high-resolution satellite remote sensing monitoring data and the function partition data, the dynamic deformation field can be established over mining region based on the research of spatiotemporal variations, so as to evaluate the effectiveness of the dynamic deformation field by measured data and optimize the deformation field model. Finally we can develop the geosensor networks GIS system of mine ground disasters monitoring and realize the integrating management of monitoring data and analyzing for the purpose of mine safety production and ground deformation monitoring and forecasting.

Two basic dimensions for describing the human social development and human cultural phenomena are space and time. Previous humanities research emphasizes much of the attribution of phenomena itself and time dimension because of the technologic limitation and epistemological difference. Sometimes these research ignored the space dimension or retained the attitude of excluding it. Fortunately, more and more scholars have rethought the importance of spatial coordination system and begun to use spatial thinking in their research. These scholars come from the discipline of history, philosophy, literature, economics, sociology, anthropology, archeology, geography, politics, statistics, etc. This article, based on the instructive thought of space and integrated humanities and social science research, intends to take modern geographic information science and methodology and related space technology as a platform, to tentatively discuss the spatio -temporal characteristics of multi-disciplinary humanity and social science research. Emphases are given particularly to the spatial attribute, space distribution, spatially mutual affection and space evolution rule of the economic and cultural phenomena in human society. In this article, the authors put forward the elementary thought of spatially integrated humanities and social science research which includes basic concept, research object, basic methodology and development direction and wish it can promote the discussion.

Bashibulake uranium deposit, which located in the northwest fringe of Tarim basin in Xinjiang Uygur Autonomous Region, was considered to be closely related with oil-reduced fading alteration. However, the evidences about the oil-reduced fading alteration genesis mainly came from the geological and geochemical microscopic researches. In this paper, the enhancement processing of Quickbird high spatial resolution satellite remote sensing data was firstly made on the basis of analyzing the geological characteristics of uranium mineralizing fading alteration sandstone and the band feature of Quickbird data. Through above processing, the ability of Quickbird images to interpret the fading alteration sandstone was further promoted. Secondly, the features about shape, spatial distribution for oil-reduced fading alteration sandstone which exposed on the Bashibulake uranium ore area were analyzed using the enhanced Quickbird images. Analysis included the following three aspects. One was the general distribution for the fading alteration sandstone from the wide scale of the uranium ore area and its around area. The second was the shape feature and spatial distribution characteristics for the purple red sandstone, which was not under subjected of fading alteration, from the scale of the whole uranium mineralization district. The third was the shape and spatial expand feature for the grey yellow fading alteration sandstone that is located in the internal of a large unfading purple red sandstone from the more large scale of the east uranium ore area. Above results provided the macroscopic evidence from both positive and negative aspects to verify the uranium mineralizing fading sandstone was generated by the oil-reduced alteration, rather than the original sediment genesis. In the same time, the idea about whole spatial distribution of the fading alteration sandstone can provide important information for uranium prospect in the outer edge of Bashibulake uranium mineralization area. All above researches fully show the great application potential for Quickbird high spatial resolution satellite remote sensing data on uranium mineralization exploration.