Research on Digital Information System for Agriculture Ecological Environment in Western Jilin Province
|Keywords||Digital Information System Agro-ecological Environment System Spatial Databases EIS-GIS Coupling GIS Components Development Digital Earth Agricultural Resources Sustainable Utilization the West of Jilin Province|
Jilin is an agricultural province, but also is an economically underdeveloped province.Agricultural equipment and technical level are relatively backward. The contradiction ofresource utilization and allocation is extrusive. Over the past 50 years, especially the last 20years, with the global warm increasing,land desertification became worse and ecologicalenvironment situation was very grim in west part of Jilin under the common effect ofnatural and man. In the past people have done considerable researches on ecologicalenvironment in the west of Jilin and gained a lot of research results, but mostly researcheswere confined to a single subject, a single technical means or methods. Due to lack ofintegration work platform for acquiring, managing the environmental information andsupporting spatial information, previous studies were one-sidedness and repetitive. Theinformation was small and can’t be shared, thus agricultural eco-environment systemresearches were limited. With the rapid development of ecological environmental science,information technology, computer technology and 3S technologies , the traditionalagro-ecological environmental research model has too many problems to deal with thecomplex ecological environment issues and significant information management.Depending on the advanced information technologies and scientific methods,empoldering and utilizing of information resources efficiently have become the era theme ofthe world scientific progress and economic development. In the field of ecological research,the application of multi-source data has brought the rapid expansion of information. How tointegrate multi-source data and to achieve the management, analysis and application ofsignificant spatial information are the urgent requests for comprehensive study onagro-ecological environment in the new era.Research on the development, integration and utilization of space information resourcesdeveloped constantly. It was a process from the geospatial information science rise in 1950sof the 20th Century to the "information superhighway" plan in1980s, and then to put forwardthe concept "digital earth" in 1998. the process expressed the strong desire to use new theories,technologies from a higher level, a systematic and integrated approach to compound andapply earth information resources The concept of "Digital Earth" provided guidelines andeffective way for the more interdisciplinary and multi-technology integration. "Digital Earth"also provided new perspectives and ideas for agro-ecological environment research. On thetheoretical basis of "digital earth", in conjunction with the ecological environment of thespecific scientific research methods, this thesis built the regional agro-ecological environmentof the digital information system in Jilin western ( AEDIS for short). The research improvedthe efficiency and quality of using the agricultural ecological environment information, andenhanced the research scope, depth and level of the agricultural ecological environment. Theresearch also achieved the digitization informationization modeling and visualization of theecological environment research. It has important significance to ensure the regionalsustainable development of agriculture.Before AEDIS structural design, the author summed up the historical formation processof "digital earth", composition and the core technology firstly, and then cleared the AEDISstructural framework. The author selected the western of Jilin as the research and serviceclient for AEDIS.The agro-ecological environmental system was labored. The concept modelof agro-ecological environmental system was built. The character of agro-ecologicalenvironmental system was analyzed. The main agro-ecological environment problems weresummed up. From the perspective of information, the author analyzed the informationcomposition character and circulation of the agro-ecological environment in western Jilin, andestablishes the agro-ecological environment information system models. The functions of thedatabase system module, the graphics module, environment models module and informationsharing module were identified. Then from the perspective of the information acquisitiontransaction and using, the author analyzed the technical composition and characteristics aboutthe acquisition and updating of information, information storage and management,information sharing and information transmission and information development andapplication. The design of the agro-ecological digital information system plot out into threemain stages ,which were the data preparation stage, technical preparatory stage and the systemintegration stage.When the author carried on the database module construction, he determined thestructure and the function of the database system which were divided into four parts the basicdatabase, the spatial database, Yuan database and the special index base. The core ofconstruction is the spatial database. The author has established three time series agricultureecological environment space database in 1989, in 1996 and in 2001 through the analysis tothe spatial data organization and the memory, the spatial data index as well as the spatial dataanalysissitus relational model. The base contained the land use, the vegetation coverage, thevegetation Net Primary Productivity, the soil type, the ground elevation, the populationdensity, the annual accumulated temperature, each kind of disaster index, the Irrigation WaterUse, GDP per capita as well as 74 index, which can provide the important spatial dataresources for developing the agriculture ecological environment comprehensively. In spatialdatabase foundation, combined the environment imitation special topic, the author hasestablished 6 big kinds of 20 special target systems including the ecological environmentquality, the ecology security, the ecological environment vulnerability, sustainable, theecosystem health as well as the environment capacity .and designed the index system tomanage the index information. Under the support of ArcCatolog software, the agricultureecological environment Yuan database was established according to the standard foundationand the management way. The establishment of Yuan database is advantageous to the spatialdata searches, transformation, maintenance and application, but also provides the importantcondition for spatial information sharing.During the graph base module design, the author analyzed the function and structure ofthe graph base, and cleared about the classification storage, spatial analysis, atlas managementand function expansion of the graph base. Then through the secondary development of GISmethods, the visual graphic operation interface was established. The operations of graphicsclassification search, visualization, spatial analysis and graphic output and GIS functionsexpansion were achieved. The author used Visual Basic and MapObjects components toachieve the basic functions of graph base management. The main menu included spaceenquiries, attributes classification, coordinate transformation, database match and thematicmaps output. The author used Visual Basic and ArcObjects components to achieve the GISfunctions expansion modules, which achieved geographic document generation, documentconversion, Spatial overlay, 3D visualization geographic grids and remote sensing processing.On the basis of the special index system, the character, status, quality and movementpatterns of agro-ecological environment were revealed based on a variety of environmentalmodels. The author summed up the development trends of environmental assessment,environmental prediction (early warning), optimization and simulation. The author analyzedthe principles, advantages and disadvantages of each model and established the dictionarymodels base and documents models base to ensure the normal operation of model base.Through the analysis on organizational structure and data share of model base, the sharing-filecoupled approach was established between model system and spatial database system. At last,through the analysis on model the data flow and programming on modeling database interface,the Client-orientation management module of environmental model base was established,which achieved the management to model dictionary, model documents, model parametersand model transfer.On the basis of these digital information modules, the system needed to be builtinternationally. AEDIS was integrated by uniting the "platform integration" and "dataintegration". The attribute data and spatial data information sharing interface was built byADO data connectivity and spatial data engine. Under a unified user interface, the basicdatabase, the spatial database, Yuan database and the special index base of AEDIS weremanaged. Under theory and technical guidance of "digital earth", from the informationperspective, AEDIS was established according to structural characteristics of regionalagricultural eco-environment system. AEDIS was integrative information system whichcan be used to input,transmit,store, transform,analyze and apply the information. Thesystem had the functions of enormous spatial data management, GIS functions expansion, theecological environment metadata management, topical index system management andenvironmental imitation. The system conquered the deficiency and limitation of the traditionaleco-environment research model, so the systems had very strong applicability and promotedvalue. The enormous spatial data management, topical index system management andGIS-EIS coupling are the main feature of the thesis. The reports on information systems offunctional integration have not yet found through literature search.In AEDIS, the various eco-environmental imitation studies may be expanded accordingto the different index system included in index base or from space database. When the authordid the evaluation, forecasting and imitation optimization studies, the space attributes datacame from AEDIS topical index base. At the same time, under the integrative user interface,the environmental imitation results were returned to the space data base by standardizedattributes during the information input and output in environmental imitation models.Compared with the traditional ecological research, to apply the AEDIS can reduce therepetitive work to data standardization and index system establishment and the workefficiency and quality increased. The protection mechanisms of information sharing andtransmission enhanced the automatization and integration of eco-environmental studies. Toapply AEDIS can revise and expand the many kinds of eco-environment information, indicesand environmental imitation models. So the request for different research purposes, differentstudies in depth and the requirements of different research areas can be met. To apply AEDIScan carry on systematic research on agricultural eco-environment evaluation, forecast andoptimization control. The traditional ecological model can’t incompared with the powerfulscalability, portability and continuity of AEDIS. The author chose the topic of agriculturalresources sustainable utilization to carry on the comprehensive study in the west of Jilin.The data from agricultural sustainable resources evaluation indices system were input tothe environmental imitation base. The author calculated the data by the weights set linkedmodel and grey associated model. The results were plotted into five levels, strong sustainabledevelopment, general sustainable development, critical sustainable development,unsustainable development and highly unsustainable development. So the agriculturalresources sustainable utilization grading space database was established in 1989, 1996 and2001 in the west of Jilin. The statistical analysis showed that the overall sustainability ofagricultural resources in the western Jilin was in the downward trend. The weak sustainabledevelopment had turned into critical sustainable development. During the 12 years, thesustainability upward regions were only 17.51% of the study area, but the sustainabilitydownward regions were as high as 47.43% of the regional area. Changling, Zhenlai,Ningjiang, Tongyu and Daan were the most serious. The author regrouped agriculturalsustainable resources forecast indices, and used multiple linear regression and grey GM (1, 1)to forecast. The forecast results indicated that the agricultural resources utilization was incritical sustainable development. The state had turned to unsustainable development fromcritical sustainable development. The sustainability of agricultural resources utilization inTaobei, qianguo and Fuyu were better, and the other cities and counties declined in differentdegree. Taonan, Qianan and Western Changling were the most obvious. On the basis ofassessment and prediction, the author focused on the agriculture economic benefits,agricultural resources conservation, agricultural inputs improvement and overall coordination.And the author brought forward the regulation and control scheme for agricultural resourcesutilization. The value of variables and interrelationship were input to vensim 5 model inmodel base. The per capita grain outputs, agriculture net value of output and resourceabundance were chosen as the basis for agricultural resources utilization best scheme. Theagricultural resources utilization best scheme in western Jilin was the "integrated andcoordinated type" .The agro-ecological environment system was comprehensive analyzed from theperspective of information input, transmission, conversion and output. The information modelfor agro-ecological environment system was composed by many kinds of digital informationmodules. The author applied the object-oriented software development methods to establishAEDIS, which had core functions of spatial data management, multi-source data integrationand sharing and environmental imitation analysis. The agro-ecological environmentalassessment, prediction, control and optimization can be accomplished under the integrativeplatform. With the continuous expansion of data sources and constant improvement offunctional module, AEDIS will have greater application and promoted value.