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  • 2006 Volume 8 Issue 1
    Published: 25 March 2006
      

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  • ARTICLES
    UN Hui, SHAO Yun, YANG Limin
    2006, 8(1): 7-11.
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    The impacts of cloud, fog, and rain greatly increase the complexity of data acquisition for earth observation, which has resulted in the lack of remote sensing data in multi-sphere monitoring, in particular the continuity, currency, accuracy, and usability of those data. In the history of the Earth observation system, the cloudy and rainy environment has been the bottle-neck for monitoring the land and ocean surface. Only after implementing the all-weather and continual observation on the cloudy and rainy areas, our country can form a real comprehensive system of remote sensing applications. In this paper we propose the concept of cloud-prone and rainy areas remote sensing (CARRS) and introduce the progress in related studies in this field in order to encourage inter-disciplinary research to tackle the "bottle-neck" problem and to advance new theories and methods on the Earth observation system for cloudy and rainy areas.
  • ARTICLES
    SU Fenzhen, DU Yunyan, PEI Xiangbin, YANG Xiaomei, ZHOU Chenghu
    2006, 8(1): 12-15,20.
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    The wave of "Digital Earth" drives the related research, including those in the field of oceanography. With the development of capacity to acquire the marine spatial data with time serial, Geographical Information System shows its potential in Oceanography because its functions are powerful in spatial data management, spatial analysis and graph or image mapping. Based on the character of marine, a prototype of Digital Sea of China (PDSC) has been constructed with the datum of coastal line of China. With the foundation of PDSC, this paper emphasizes on the problems with their resolutions, which differ from other space digital fields, especially on the data organization and manipulation with the datum of coastal line, the structure of "Digital Sea" and the integration method, the logic computation and the visualization method.
  • ARTICLES
    GE Yong
    2006, 8(1): 16-20.
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    How to integrate quantitative data, qualitative data, empirical data and knowledge-based data and then make decision is one of the important issues in spatial data analysis. In this paper, two methods for spatial integration and decision making are discussed. One is fuzzy weights of evidence, and the other is weighted logistic regression. Compared with the traditional methods such as discriminate analysis and multivariate regression analysis, these two methods can give more reasonable results when explanatory variables are a mixed mode of continuous and category data.
  • ARTICLES
    WANG Zhiqiang ZHANG Bai, XU Zhenhua, ZHANG Shuqing
    2006, 8(1): 21-25,29.
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    Wetland is a kind of key natureal resources and is an important environment for human survival. Because of natural and anthropogenic disturbances, wetland has been shrinking in large scale. The function of wetland has been lost. All these endangered the sustanable development of human beings. Taken Naoli River Basin as a case study, the spatio-temperal dynamics of the wetlands in the study area and its driving forces from 1954 to 2000 were analyzed. The results show that the wetland area were reduced from 519 917.96 hm2 in 1954 to 105 008 hm2 in 2000 with the areal percentage reduced from 61.27% to 12.39%. The wetland acreage in 2000 is only 1/4 as much as that in 1954. While arable land acreage increased from 223 173.54 hm2 to 597156.25 hm2. The acreage percentage increased from 25.31% to 70.45%. And the predominant driving force for wetland shrinkage in Naoli River Basin is the reclamation activities by human beings.
  • ARTICLES
    LI Jianxin
    2006, 8(1): 26-29.
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    The university degree program for Cartography and Geographic Information System (GIS) is one of the three degree programs in geography, but the sphere of influence of GIS is not limited within geography or geosciences. In 2005 there are 114 universities offering bachelor's programs for Cartography and GIS (31 from teachers' universities, 27 from universities, 25 from universities of technology, 8 from agricultural universities, 6 from geological universities, 5 from forestry universities, 3 from universities of transportation studies, 3 from achitectural universities, 2 from universities of posts and communications, 1 from hydrologic university and 1 from economic university), and 16 universities and academies offering doctoral programs for Cartography and GIS (6 from universities, 5 from teachers' universities, 1 from university of ocean studies, 4 from the Chinese Academy of Sciences (CAS)). In 2004 there are 54 universities and academies offering master's programs for Cartography and GIS (18 from teachers' universities, 16 from universities, 3 from universities of technology, 3 from agricultural universities, 3 from geological universities, 1 from forestry university, 1 from university of information studies, 1 from university of ocean studies and 8 from CAS), spreading all over the country except Hainan, Xizang (Tibet), Ningxia and Qinghai, mostly concentrating in Beijing, Jilin, Jiangsu and Hubei in geographical and geo-scientific departments. There are 281 research directions in the master's programs (only 26 for cartography) and 126 research directions in the doctoral programs concentrating in science and technology (only 1 for cartography, 1 for economy and 1 for tourism).
  • ARTICLES
    YUE Jianwei, ZHONG Ershun, ZHANG Qiuyi, YAO Min, FANG Li
    2006, 8(1): 30-34.
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    Current research on land information systems mainly focuses on particular projects, thus causing a great lack of reusable components in the land management field. This is unfavorable to the development of land information systems. Besides, research on metadata is mainly concentrated on metadata standards, ways of metadata expression, metadata management and metadata contents. Research on and development of metadata applications in land information systems are quite inadequate. This paper introduces metadata technology into the development of components. It adopts metadata to define business rules and drives the running of components through metadata. When business changes, it only needs to change the definition of business rules in the metadata base and use components to meet the needs of business changes. This will improve the reusability of business components, expand the scope of metadata applications and lay a foundation for the rapid development of land information systems.
  • ARTICLES
    WU Liang, LU Feng, LIU Xingquan, SHEN Paiwei
    2006, 8(1): 35-38.
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    It is an important task in GIS research to efficiently access and manipulate the spatial data stored in database management systems. The author introduces the spatial data storage methods in database management systems, then puts forward a method accessing and manipulating geometric objects with LibPQ, which is provided by PostgreSQL DBMS. This method allows users to expand userdefined geometric models with inheritance from system geometric model. Moreover, the method can make full use of an expanded userdefined geometric model to process spatial operators. As a kind of open source database management system, PostgreSQL DBMS can provide users with conveniently operated procedures at a price lower than the non-open source database management systems. Users can code inside the database management system to solve some problems which can not be dealt using the non-open source database management systems.
  • ARTICLES
    SHEN Paiwei, LU Feng
    2006, 8(1): 39-44.
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    In a distributed spatial database system, spatial data is currently shared with a snapshot-based mechanism. This method is charcateristic of maintaining copies of remote spatial datasets in local databases, and thus inevitably results in great data srorage redundancy and difficulty in preserving data consistency. In this paper, however, a view-based sharing method is put forward to solve this problem. Firstly, a local view is created corresponding to a remote spatial table, then an 'instead-of trigger for modifying each row is set up on the view to enable it modifiable. So local access to remote spatial data in a distributed database environment can be implemented with the extended view-modifying functions and view-selecting functions directly from Database Management System (DBMS). A case based on an Oracle 9i database management system validates the feasibility of this view-based data sharing mechanism, with a satisfactory result.
  • ARTICLES
    HUANG Binghu, ZHANG Hong, LV Guonian, JIANG Wenming
    2006, 8(1): 45-49.
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    This paper analyses the structure of ArcIMS 9 software at first, the importance of ArcXML is found, but the ArcIMS software has shortcoming in building the ArcXML request information and parsing the ArcXML response information. In order to make up the above disadvantage, a method is described which is built in the Microsoft .Net developing environment. Then the MVC design mode is adopted by this method to the design of the WebGIS control, every component ' s function of the MVC is described in detail. The control tie' s function is to build ArcXML request information and parse the response information, the main classes' relationship diagram of the control tie is showed and the every component' s function is explained. Finally, it summarizes the advantage of this method which integrates the advantages of the MVC design module, .Net developing environment and ArcIMS function. By using the above control to build the WebGIS system will save time for program developers.
  • ARTICLES
    CHENG Jieliang, YE He, LI Hongyi, SHI Zhou, YANG Dazhi
    2006, 8(1): 50-54.
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    As a consequence of industrialization and urbanization, a large amount of pollutants are spread in the agricultural soils: solid materials and aerosols which contain organic matters as well as inorganic harmful materials, toxic elements and heavy metals contamination of soils has become increasingly serious, the safety of the farm produce is being paid more and more attention by people. This paper is about combining Visual Basic 6.0 with a set of components of map software developed by ESRI-MapObjects 2.0 to program farm produce safety management system in Zhejiang province. The provincial 1:250000 spatial database and regional 1:50000 remote sensing imagery were established and combined with the attribute database of crop sampling sites and the standard database of farm produce safety to realize some functions and operations for sampling sites distribution map of provincial scale and some important counties scale such as zooming,roaming,labeling,consultation and statistics etc., the system can not only display specially the attributes of soil and crop samples and their operation results, it can also update the correlative information. This study provides a rational and efficient platform for the information management of farm produce safety in Zhejiang province.
  • ARTICLES
    ZHANG Zhong, HAN Jiafu, LIU Yue
    2006, 8(1): 55-60,139.
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    As the largest freshwater lake in China, the environment characteristic of Poyang Lake is very special, hence it is very significant to carry out research by means of integrating multi-source spatial data in order to improve our scientific understanding about this area. This article introduced the step of constructing the Poyang Lake spatial information system and virtual environment viewing system. The system consists of a series of theme spatial database and basic GIS database. With the help of the VR-Map software, it is possible to realize the virtual 3D visualization of the terrain. And with the help of the ArcGIS software, it is possible to generate all kinds of theme maps, such as DOM (digital orthodox map), land use maps, population distribution maps and so on. Maps of good quality are very important to the research work. These maps can be updated immediately when the basic data are updated.
  • ARTICLES
    FU Wei, XING Guangzhong
    2006, 8(1): 61-66,78.
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    This paper presents design principle and realizable approach for Intellectual Data Structure of Geographic Expert System. With the frame network structure of knowledge, the author describes the entity units of geo-environment, and links the expression of expert knowledge at different levels with the pointer so that it becomes the frame network from knowledge to semantics. Also, the author expresses expert knowledge with extended R-F relational model based on intelligence, and discusses organization structure of knowledge base in the system and design principle of inference engine. The data structure can be used to realize an integrated description for geographic entities and their interrelations, and the knowledge base of the system can be operated simply and easily with the model, and therefore, the inference mechanism can be assuredly realized. Taking U-rumqi river basin as a test region, the author expounds expression approach of expert knowledge for planning and decision expert system of land rational use in the watershed, as well as the basic rules of expert knowledge expression and the organization models of expert knowledge in the system. Furthermore, the author also discusses the design principles and organization method of inference rules and the inference algorithms of inference engine in the system.
  • ARTICLES
    JIA Zelu, LIU Yaolin
    2006, 8(1): 67-72.
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    With the establishment of market economic system and the practice of using land institution, integrated evaluation of the quality grade of agricultural land has been a very important task in land administration at present and in the future. Classifying and grading of agricultural land is a very comprehensive task, the results of it not only connect with many natural factors, but also relate to the economic factors, society factors and many other factors. Moreover, in practice it involves analysis and handling huge amount of data and pictures, so the calculation task is very gigantic. Agricultural Land Classifying & Grading is a problem, which can not be described with mathematics completely, but needs to be resolved with experience and knowledge. Using a great deal of data accumulated in the past reasonably and integrating the expert knowledge adequately to classify & grade agricultural land, setting up Agricultural Land Classifying & Grading Expert Information System (ALCGEIS) with intellectualized analysis and decision function to improve the precision of classifying and grading results of agricultural land and to raise the efficiency of work are very necessary. Building a system based on Artificial Intelligence (AI) is also the goal and developing orientation in the future research. This paper presents knowledge acquisition and design approaches and principles of inference engine for Expert System (ES), and probes basic structure of ALCGEIS, knowledge classification, knowledge acquisition and algorithms of program realization, basic control strategies of inference engine and algorithms of program realization as well as search strategies of reasoning knowledge. In addition, the author designs the inference engine of ALCGEIS. And taking the structure of inference engine as an example, the author designs methods of reasoning rules as well as reasoning algorithms, and elaborates organization structures of reasoning knowledge.
  • ARTICLES
    YAO Yonghui, ZHANG Baiping, LUO Yang, ZHU Jun, CEN Gang
    2006, 8(1): 73-78.
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    Both grid mapping and grid computing are effective methods to describe, analyze and virtualize regional geographic phenomena and their applications to the analysis of the spatial pattern are quite promising. The grid mapping of landscape describes not only the spatial distribution of landscapes but also their respective capacity of occupying the ecological space of them. Meanwhile the grid mapping can be used to realize the quantitative, specialized and visualized description of the spatial heterogeneity. Moreover, on the basis of grid mapping and grid analyzing, some spatial analytic methods such as the spatial autocorrelation analysis and semivirogram analysis can be used to further study the characteristics of spatial patterns.
  • ARTICLES
    ZHANG Wei, LU Zi, WANG Ran
    2006, 8(1): 79-83,96.
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    Country is a basic unit in international scale and the relations among countries need the support of telecommunication flows.Telecommunication flows constitute a space which reflects human communication activity while the size of telecommunications flows is the main basis reflecting a national economic development level and utilization of ICTs technology. This paper reviewed the investigation result and development process of country -to -country telecommunication flows since 1970, and eight kinds of explanatory variables (telecommunication equipment, economic development, international trade, international travel, country relationships, government advance, cultural relationships, and spatial structure) which affected telecommunication flows are identified. We can see the change of the factor index system affected by the telecommunication flows in the process of modelling. This article uses the mathematics method to analyse the factor index and arrange them in order by taking Western Pacific as an example. The functions of various kinds of material flows to telecommunication flows can be categorized into four, namely, the strengthening function, thesubstituting function, coordinating function and deriving function.
  • ARTICLES
    WANG Yang, LU Zi, SUN Zhongwei, SUN Jingyi
    2006, 8(1): 84-90.
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    Taking Leyou outdoor sports club website as a case, this paper explores the members' communication model of the "self-relying" small-medium outdoor sports websites and the guiding function of information flow to people flow. It considers that this guiding function was produced by three processes: information -obtaining, knowledge -conversing, cognizing and decision making. It was completed via four platforms of website communication media: information, gathering, communication and organization. As far as the people are concerned, information flow in network space cannot displace human communication in geographical space in the circulative process of information flow and people flow in this kind of the "self-relying" websites. At present, most of the small-medium outdoor sports websites still regard the local customers group as their main target, so the space concept of geographical distance meaning is still very significant in their virtual communities. This paper also confirms the influencing factors about decision concerned with the guiding function of information flow to people flow. The four factors can be considered to play important roles to the operation of club websites, like plan, capital, members and sponsors' media. Through study of the virtual-reality organization features from the angles of the users of websites, many issues of the development of human geography in information society can be found.
  • ARTICLES
    U Yanli, LU Zi
    2006, 8(1): 91-96.
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    In accordance with the cooperation trend appearing in regional tourism informationization, this paper draws lessons from all kinds of cooperation modes in the domestic and international tourism informationization or other industries informationization and identifies five different cooperation modes -unite -alliance cooperation mode, industrial chain cooperation mode, dot type cooperation mode, ladder type cooperation mode and two waves superposing cooperation mode. Aiming at the best choice question about the cooperation mode of regional tourism information, this paper offers a method of suitability measuring. Based upon which it carries on the positive selection of cooperation modes- taking Beijing, Tianjin and Hebei as examples, and analyses the dot type cooperation modes-PPP project dots mode, 4 cooperation fields mode and 5+2 bases mode.
  • ARTICLES
    MA Shengnan, YUE Tianxiang
    2006, 8(1): 97-102,142,143.
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    The term ' Ecological diversity' is a combination of richness and evenness of an investigation object, as species and ecotope. The concept includes HLZ ecosystem diversity, ecotope diversity and species diversity. The challenge comes in multi -scale measuring and simulating such a broad concept in ways that are useful. Many studies shed light on the scaling ecological diversity index that is theoretical sound to simulate ecological diversity on different scales. Based on the remotely sensed database and land-use spatial database of the end of 1980s, the midterm of 1990s and the end of 1990s, we simulate ecotope diversity of western China on different scales using the scaling index. The result shows that: ①The ecotope diversity of western China reduces from the end of 1980s to the midterm of 1990s and increases from the midterm of 1990s to the end of 1990s, and the e-cotope diversity of the eastern part is greater than the western part in western China, ②On scale of provinces (cities and regions), Shaanxi is the province with the highest simulated ecotope diversity, while Xinjiang Uygur Autonomous Region and Tibet Autonomous Region are two regions with the lowest simulated ecotope diversity, and Tibet Autonomous Region is with the most obvious variation of simulated ecotope diversity during the three periods, while Gansu and Chongqing are with the least change; ③On scale of counties, there are 11 ecotope diversity key areas in western China; ④The simulated ecotope diversity of western China is bigger than the provinces, and the simulated ecotope diversity of each province is bigger than the counties inside. The comparison between scales indicates that the scaling index is applicable to simulate ecological diversity on multi-scales.
  • ARTICLES
    MING Dongping, LUO Jiancheng, ZHOU Chenghu, WANG Jing
    2006, 8(1): 103-109.
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    Image segmentation is a key technique in image processing and computer vision field. From the point of view of geo-processing and application of remote sensing images, this paper emphasizes the importance of image segmentation for information extraction and targets recognition from remote sensing images and sets a classification system of common remote sensing image segmentation methods. In addition, this paper states the thoughts of high resolution RS image segmentation methods evaluation and tests it by evaluating four typical image segmentation algorithms based on features with six images qualitatively and quantitatively. The four typical image segmentation algorithms are Max-Entropy (ME), Split&Merge (SM), improved Gauss Markov Random Field(GMRF) and Orientation&Phase(OP). In the qualitative evaluation, this paper analyses these algorithms in terms of their rationale and gets a rough evaluation. In the quantitative evaluation, image complexity is taken into account firstly and five measures are employed. The five measures are removed region rumber, non uniformity within region measure, contrast across region measure, variance contrast across region measure and edge gradient measure. The qualitatively and quantitatively evaluation results are important to perform the optimal selection of segmentation algorithm in practical work. In the end, this paper draws some conclusions about high resolution remote sensing image segmentation and enumerates the flaws of image segmentation methods evaluation, especially it concludes the application prospect of high resolution RS image segmentation.
  • ARTICLES
    WEI Yuchun, HUANG Jiazhu
    2006, 8(1): 110-113,126.
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    In this paper, the gains and biases (G/B) of landsat-5 image data are summed up according to the USGS document and parameters in the head file of image, and the difference of G/B and its effects on the planetary reflectance is discussed. Planetary reflectance is calculated based on the image with a path of 119 and a row of 38, obtained on 26 July, 2004. Four kinds of G/B are used: 1) ENVI4.0 parameters dated 1986; 2) head file provided by L5 image; 3)the USGS document parameter dated after 2003; and 4) the USGS document parameter dated before 2003. The result shows that it is difficult to compare planetary reflectance value when the source of G/B is different. Taking the results of calculation by USGS parameter after 2003 as a standard, the reflectance of band 3 in terms of error distribution of other bands has the lowest relative error, and that of bands 1,5 and 7 have the highest relative error which may be greater than 20%. In order to make the TM application intercomparable, the planetary reflectance calculated using the G/B parameters provided by the USGS document may be a better choice.
  • ARTICLES
    LAN Zhangren, ZHANG Dongshui, QIU Rongzu, CHEN Henglin
    2006, 8(1): 114-120.
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    The dynamic change measurement, transferring matrix of the dynamic change, and its spatial distribution indication of the landscape in Minjiang River Estuary wetland are critical issues for study on the dynamic change pattern of the wetland in different periods of time. Classification and information extraction of the wetlands in the present research are resulted from the remote sensed TM imagery in the imaging years of 1986, 1994 and 2000 respectively. In this paper, dynamic change for each classified type of wetlands is measured in terms of area; transferring matrix of the dynamic changes is formulated and model of transferring probability based on it is established; and applying the fragmentation index, mean landscape fractal dimension, and landscape diversity index, the spatial distribution structure of the wetlands is figured out. Combining these issues above, the dynamic change process of Minjiang River Estuary wetland has been analyzed for the periods of 1986 to 1994 and 1994 to 2000. The results indicate that the dynamic change pattern of the wetland in two periods are different due to the human activities imposed on it, which is highly associated with the local economic development level from time to time. It comes to conclusion that the wetland conservation plan in Minjiang River Estuary should take into consideration of the human activities affected on it in the progress of urbanization.
  • ARTICLES
    YANG Lin, LV Guonian, SHENG Yehua, PEI Anping, BI Shuoben, SUN Yiqing, CHEN Jimin
    2006, 8(1): 121-126.
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    This article introduces the design and implementation of Mapping Information System for Field Archaeology. Based on close -range digital photogrammetry and GIS software, we designed three mapping methods: photogrammetric mapping, electronic mapping and scanning mapping which are used to directly get all kinds of plot maps. Photogrammetric mapping is about calibrating the images achieved by digital camera to the orthophotos which is used to directly get all kinds of plot maps; scanning mapping is the same to the former in the basic principle; and electronic mapping is a mapping method with enough known field data based on GIS platform. At the same time, the field manipulating criterion and flow are given. The application proved to be simpler and more convenient in transforming traditional mapping on the paper to the electronic one and had good accuracy as well. The application of the system is worthy of popularizing widely.
  • ARTICLES
    CHENG Changxiu, LU Feng, NIU Fangqu
    2006, 8(1): 127-130.
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    This paper reviewed the related work on map information measures and introduced the Wu's raster-based map information measurement. Out of the cord of Shannon' entropy, this method regards the sum of all pixels' information that is the difference between every pixel and its context as map information amount. It is difficult to testify the validity of this method in mathematics, so this paper uses some vector data at 1:400 scale and an ECW image to verify raster-based map information measurement. Two experiments indicated that these map view information amounts calculated by raster-based map information measures are linearly related with the view information accepted by human beings.
  • ARTICLES
    JIANG Yan, ZHOU Chenghu, CHENG Weiming
    2006, 8(1): 131-138.
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    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.