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.

前言 人类认识自然经历了漫长的历史过程,地学是人类认识自然的科学。随着探测器从地面→航空→航天高度的增加及观测技术的进步,人类对自然的认识也在经历着一个从局部到整体,从片面到全面,队概念描述到数学物理模型乃至量化表示的过程。技术的发展推动了科学理论的进步,新理论的完善又向技术提出更高的要求,成为技术发展的动力源泉。这种相互促进共同发展将是一种无止境的循环过程。技术是工具,认识是理论,行动是目的。这是不可分割的一个整体,哪个环节出问题都达不到目的。

GML(Geographic Markup Language) is gradually accepted and widely used as an encoding,storage and exchange format for spatial information,and it offers a powful tool for implementing spatial information sharing and WebGIS development. As a graphic file format standard in the network era,SVG(Scalable Vector Graphic) represents graphic transmission development direction on the web,which integrates vector graphic,bitmap image and plain text merits and is naturally compatible with the network environment,so study on GML and SVG-based WebGIS and its application will have extensive practicality and application value. In this paper,GML and SVG are discussed firstly,especially in the role of open WebGIS,then an open WebGIS architecture is put forward which uses GML to store and integrate geographic information and using SVG to implement web display and operation for geographic information. Finally,taking a campus map issuing system as an example,an open WebGIS application system is set up and discussed.

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.

Geographic features change detection has became a vital component of the national geographical information 12th Five-Year-Plan and the national geographic general survey. In web pages, billions of geographic feature changes were contained, especially in government official websites, news homepages, social portals and etc. The web pages of these websites update frequently, which could provide the latest data for geographic infor-mation change detection. Considering the complex characteristics of the web geographic information description, this paper did some valuable achievements. First of all, the geographic information knowledge base was established by summarizing the geographic information words and phrases, which could give the great supports to geographic information semantics change detection. Then, the web geographic information was obtained using two kinds of web crawler technologies. Combining the Google Custom Search crawler and general topic crawler, the web geographic information obtainment could be more complete in both scope and depth. Thirdly, the geographic information was parsed and extracted from the web text, which showed users the related features, place names, times and attributes. Last but not least, the prototype system was finally developed and the results were analyzed. The experiments indicated that the accuracy of related web pages obtainment and features change detection were over 74% and 70% respectively. In addition, the results of geographic information change detection highly relied on the integrity of knowledge base, which need to be completed further. Moreover, the uncertainty and fuzziness of web geographic information also limited the change detection results. Therefore, the web page based geographic information change detection could be a supplementary method of geographic information change detection. Combining the traditional surveying detection and remote-sensing imagery detection methods, it could solve the problems of continuous updating and timely updating of geographic information efficiently.

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.

Flood is a frequently occurred disaster and it causes great harm in China. In order to effectively prevent, reduce and relief disaster, it is necessary to establish a flood event information model to represent and share flood information. By far, many scholars have studied a variety of event information models. However, the existed event information models mainly represent static information, and they are lack of the capability to handle dynamic process information. To solve this problem, a flood event model is proposed in this paper based on the flood emergence management stages and the dynamic process from the perspective of observation. To build up the model, this paper firstly describes the modelling considerations, including flood phases, observation, and ten types of primary elements for modeling. Then, we construct the flood event model as a ten tuple model based on MOF modelling framework with four layers, and encode the model with a method that maps the elements of the model to elements of the Event Pattern Markup Language (EML). Finally, we simulated an experiment for a flood case occurred in the Liangzi Lake in 2010 as an example to test the proposed model. In the experiment, the building process and the results of the proposed model at different emergence management stages are detailed. The experiment results show that the proposed model has following characteristics: (1) it establishes a model from the perspective of observation, since observation plays a decisive role in real-time disaster information acquisition. (2) The flood model was established by four emergence management stages, and the main tasks of each stage are different. (3) The flood model was modelled dynamically. The proposed ten tuple model itself is not dynamic, but the establishing process and its represented information are dynamic. The modelling process is modelled on real-time data streams, and it dynamically updates time-series data. The time series data in this model are generally the latest observations, which reveal the dynamic information of current flood. (4) The model is extensible and adaptable to ensure the suitability. As a conclusion, the model can represent flooding events and model dynamic flood information effectively, as well as provide a good approach to represent and share flood information.

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.

Generalization of road network is one of the focuses in map generalization. Road network generalization can be considered as the combination of two processes. One is selective omission, and the other is the simplification of selected roads. Selective omission is the key process, in which it is hard to maintain the overall and key local structures of original networks. Many solutions have been proposed for road selective omission. But previous solutions cannot maintain these structures in the process of selective omission. It will solve the problem if we can build the hierarchical structure of road networks and make selection based on the structure. This paper presents a novel method for selective omission. The method first builds the hierarchical structure of road networks. It is based on Hierarchical Random Graph (HRG) which transforms a graph into a dendrogram, which is widely used in complex networks. HRG goes beyond simple clustering and provides clustering information at all levels of granularity for visualization. But HRG is over detailed for multi-scale representation as its dendrogram usually contains tens or even more layers. So, after building HRG of road networks, we propose a measure named Accumulated Probability Number (APN) to simply HRG hierarchy. APN reflects the importance of each road in the whole network. It should be noted that we use road ‘strokes' as vertices and the connections between them as edges when transforming a road network into a graph. The proposed approach is validated with case studies of road network generalization. Different patterns of road networks are considered including grid, ring-star-hybrid, grid-star-hybrid, irregular patterns. The corresponding Google Map is used as the reference for evaluation of road selection. The results of APN-based selection match well with the reference.

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.

公共工程业务涉及图形资料繁杂,传统图形资料生产、保管与维护方式显已无法适应实际需要。为提升工程业务之品质及效率,工程图形资讯管理之电脑化乃成不可避免之因应作法之一。本文概要介绍台北市工务局公共工程图形资讯管理系统发展之缘由,架构与现有成果。

Land Use and Land Cover (LULC) classification products play an indispensable role in ecosystem assessment, climate change simulation, national geographical condition monitoring, and macro-control policy analysis at the global scale; consistency analysis is the precondition of applying various LULC classification products. This paper assessed the area consistency and spatial consistency of five LULC classification products - MCD12Q1-2010, GlobCover2009, CCI-LC2010, FROM-GLC2010 and GlobeLand30-2010- in the global coastal zones. The five products were compared in terms of the deviation coefficient, correlation coefficient, error matrix, and spatial confusion of LULC types. The main findings are as follows: (1) The spatial patterns of LULC in five products demonstrate relatively strong overall consistency, but can have significant local inconsistency. (2) The five products are qualitatively consistent yet quantitatively inconsistent in classifying the LULC in the global coastal zones ? in terms of structure, water ranks top one, followed by forest and unused land, next are farmland, grassland and shrubland, and lastly wetland and artificial surface, yet the exact area of each LULC type differs among different products. (3) For the correlation coefficient, overall accuracy and Kappa coefficient, MCD12Q1-2010/GlobCover2009 have the minimum values, 0.8814, 67.46% and 0.5748, respectively; while GlobCover2009/CCI-LC2010 have the maximum values, 0.9869, 81.50% and 0.7505, respectively; it is because GlobCover2009 and CCI-LC2010 obtained from the same production organization have the same classification system, while MCD12Q1-2010 is different from GlobCover2009 in terms of the production organization, data source, classification system, and classification method. (4) For the spatial confusion/misclassification between any two different products, grassland, shrubland, and wetland have the highest mix-up ratios, followed by farmland and artificial surface, and lastly forest, unused land, and water; this difference is because forest, unused land, and water have distinctive spectral characteristics and clear spatial textures, while grassland, shrubland, and wetland have similar spectral characteristics and fuzzy spatial distributions. (5) There are 28.81% land area in the global coastal zones with relatively low consistency, i.e., with severe spatial confusion; specifically, the misclassification of farmland, forest, grassland, shrubland, wetland, and unused land has direct influence on the spatial consistency of the five products. This paper is hoped to serve as a reference of selecting data from the five available LULC products for researching coastal zones.

受省上领导委托,省旅游局组织兰州市有关专家学者中国科学院李吉均院士、兰州大学地理系教授张林源、中科院冰川冻土研究所研究员王宗太、郑本兴,沙漠研究所研究员杨根生,西北民族学院副教授胡孝宏,甘肃城乡规划设计院高级工程师吕元光以及新闻媒体总编、记者多人与东部来兰投资者,在贾笑天局长等陪同下,于2000年10月23～29日赴河西考察可开发的重点旅游资源(图1,2)。在考察中,为丝路古道上的名胜古迹与自然风光所吸引,并为资源与环境保护的重要性所萦怀,即兴书感以共勉。并对河西各地领导的盛情接待及胡孝宏、张林源等先生对诗稿提出的修改意见表示谢意。

Based on the principle of the CLUE-S (the conversion of land use and its effects at small region extent) model, taking Yangzhou City area as an example, we firstly collected the required data, including basic geographic data (vector data and image data) and statistics data, then preprocessed the image data, including ETM images in 2001 and ALOS images in 2007, and took use of object-oriented information extraction method to obtain a land use map for two periods (2001 and 2007). We selected the driving factors and used GIS spatial analysis tools to get a variety of spatial distribution of all the driving factors, set the model parameters, and took the land-use map in 2001 as the model input data to simulate the spatial pattern of land use of 2002-2007 in Yangzhou City area. Finally, we obtained the actual land use map of 2007 in Yangzhou City area by using the object-oriented data extraction method, and tested the simulation results of 2007 in Yangzhou City area and analyzed the applicability of the CLUE-S model. The result shows that the CLUE-S model could simulate preferably the spatial distribution pattern on a small-scale. Therefore, it could provide guidance for small city planning. So the CLUE-S model is one of the land use/land cover change models that worth to be made more widespread.

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.

自然和人为的灾害每年都使远东的中国和她的周边国家蒙受了巨大的经济损失。为了能快速地对这些灾害作出反应以减少损失,有效和及时地从外层空间监测灾害已成为了一项迫切的国家需要。为了改进现行系统的覆盖范围和覆盖周期,曾建议采用地球观测卫星网。然而,常规遥感卫星的高成本至今还使得这项建议难以实施。萨瑞大学的萨瑞卫星技术有限公司(SSTL)已经研制了一套性能高、寿命长的微型卫星,该卫星利用先进的对地观测有效载荷,具有较强的星载处理能力。利用该套卫星就可以极低的成本获得从空中对地球的常规观测。每颗微型卫星只需费用约250万美元,因此,投资不到1800万美元就能构建由7颗卫星组成的卫星网(星座)。微型卫星重量轻、体积小,只需一个小的发射器就可以把整个网发射到低地球轨道中。

Cloud-top height is an important factor in weather forecasting and monitoring. Accurate cloud-top height has important scientific significance for improving the quality of both weather analyses and numerical weather prediction. The geometric method to calculate cloud-top height using stereo image pair obtained from meteorological satellites has been recognized as providing relatively high precision, and has practical importance. However, this method does not fully consider cloud movement and typically assumes ideal ellipsoids in theory. Thus, the calculated cloud-top height still has a relatively large error in practice. In this study, cloud-movement speed was introduced into the collinearity equation of photogrammetry. We established a model to calculate the cloud-top height from the ASTER images (3B and 3N) with digital photogrammetry and remote sensing technology. Firstly, we created a stereo pair from ASTER images obtained on 25^th September 2012. Then, the cloud-movement speed was calculated through matching cloud points. Finally, the cloud-top heights with and without consideration of wind speed were both calculated. Compared with ground control points, the model error is determined to be within two pixels (about 30 meter). We further compared our results with MISR products, and found that the cloud-top height determined without using wind speed is consistent with the height obtained from MISR, the difference between them is about 300 meters. Our cloud-top height determined with wind speed considered, however is about 1400 meters higher than that of MISR without wind considered. Marchand and Naud had identified in their research that the cloud-top height obtained from MISR is about 1000 meters lower than Lidar observation. This implies that our results with consideration of wind speed are closer to the Lidar observations. Due to the fact that our method for determining cloud-top height is dependent on the cloud moving speed, and the results with wind speed included have led to a good estimation of cloud-top height, we conclude that the wind speed should be included in algorithms for cloud-top height determination.

中国地理学会地图学与 GIS专业委员会暨学术会议于 1 0月 2 5～ 2 9日在青岛举行。出席这次会议的代表有 90多位 ,分别来自全国各地 5 0多个单位 ,共收到论文近 60篇。会议围绕着“新世纪地图学与 GIS的开拓与创新”的主题 ,毋河海、杜道生、崔伟宏、池天河、曹桂发、黄杏元、马耀峰等 1 4位教授在大会上作了报告 ,有近 30位专家学者在分组会上作了报告。

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.