Research On The Grid Service Method For The Integrated Application Of Open Geographical Models

The integrated application of open geographic models is an important research method for comprehensive simulation of geographic processes.In the simulation process,due to the continuity of the real world,the numerical geographic analysis model is difficult to directly apply to the continuous research space.Therefore,it is necessary to divide the continuous space into a series of small calculation units(grid units)to form grid data,and construct numerical equations on the grid units so that the numerical geographic analysis model can perform accurate calculations.However,due to the different spatial division methods used by different models,there are differences in the types of grid data used.Researchers need to install and configure corresponding software programs to generate grid data according to model requirements.In addition,in view of the situation that the grid data used between the integrated models do not directly match,it is necessary to design a corresponding conversion algorithm to convert the grid data to assist the internal mechanism of the model for organic integration.This localized grid data processing method is cumbersome,inefficient and difficult to reuse.With its openness and cross-platform characteristics,Web services allow users to interact with data without relying on related program software.Using Web services to provide grid data for open model integration applications can change the current cumbersome grid generation and transformation work methods and improve work efficiency.Therefore,how to provide a grid service method in the process of open integrated modeling application is a basic and important work.Based on the actual needs of the integrated application of the open geographic model,this paper starts from combing the characteristics of grid data,and studies the basic strategy of grid service.On this basis,a service method of heterogeneous grid generation algorithm and a construction method of grid data conversion service are proposed to meet the requirements of open geographic model integration applications for grid data.The main research contents and results of this paper are as follows:(1)Research on the basic strategy of grid service oriented to the integrated application of open geographic model.Summarized the grid data characteristics in the integrated application of open geographic model.On this basis,the basic strategy of grid service oriented to the integrated application of geographic model is proposed.By adopting Model Description Language(MDL),the heterogeneous grid generation algorithm is standardized and described,which reduces the heterogeneity of the algorithm and provides basic technical support for the research of grid servicing methods.(2)Research on the service method of heterogeneous grid generation algorithm.The service requirements of heterogeneous grid generation algorithms are analyzed,and the key issues in the service research are put forward.Based on this,a unified expression method for grid data is designed to realize a unified description of heterogeneous grid data;a grid generation algorithm packaging method is proposed,combined with the basic strategy of grid service,to realize the service generation of grid data.It provides basic grid data support for open geographic model integration application research.(3)Research on the construction method of grid data conversion service.From the perspective of grid data conversion in geographic model integration application scenarios,the requirements for grid data service-oriented conversion are sorted out.The box grid index method is designed to realize the rapid retrieval of large-data-volume grid cells;two conversion modes of grid data conversion with the same topology and grid data conversion with topology incompatible are summarized,and corresponding conversion strategies are proposed.On this basis,with the basic strategy of grid serviceization as the theoretical guide,combined with the grid conversion strategy,a grid conversion engine is constructed,and the service conversion of grid data is realized through the service packaging of the grid conversion engine.(4)Grid service-oriented prototype system construction and experimental verification.On the basis of integrating heterogeneous grid generation algorithm service method and grid data conversion service construction method,by constructing a prototype system,the grid data service generation and conversion are realized.Through the integration of application cases in the SWAT model and Hex Watershed model,the grid servicing method is verified to prove its feasibility and practicability.