A web-based strategy to reuse grids in geographic modeling

Integrated application of geo-analysis models is critical for geo-process research. Due to the continuity of the real world, the geo-analysis model cannot be applied immediately over the entire space. To date, the method of regrading space as a sequence of computing units (i.e. grid) has been widely used in geographic study. However, the model's variances in division algorithms result in distinct grid data structures. At first, researchers must install and setup the various software to generate the structure-specific grid data required by the models. This method of localized processing is inconvenient and inefficient. Second, in order to integrate the models that use different structural grid data, researchers need to design a specific conversion method based on the integration scenario. Due to difference of researcher’s development habits, it is difficult to reuse the conversion method in another runtime environment. The open and cross-platform character of web services enables users to generate data without the assistance of software programs. It has the potential to revolutionize the present time-consuming process of grid generation and conversion, hence increasing efficiency.

Based on the standardized model encapsulation technology proposed by OpenGMS group, this paper presents a grid-service method tailored to the specific requirements of open geographic model integration applications, and the research work is carried out in the following three areas:

• The basic strategy of grid servitization. The heterogeneity of the grid generation method is a major factor that prevents it from being invoked via a unified way by web services. To reduce the heterogeneous of the grid generation method, this study proposes a standardized description method based on the Model Description Language (MDL).
• Method for constructing a grid data generating service. A unified representation approach for grid data is proposed in order to standardize the description of heterogeneous grid data; an encapsulation method for grid generating algorithms is proposed; and grid-service is realized by merging the main idea of grid servitization.
• Method for constructing a grid data conversion service . A box-type grid indexing approach is provided to facilitate the retrieval of grid cells with a large data volume; two conversion types, topologically similar and topologically inaccessible grid data conversion, are summarized, along with the related conversion procedures. On this foundation, a grid conversion engine is built using the grid service-based strategy as a theoretical guide and integrated with the grid conversion strategy.

Based on the grid service approach proposed in this paper, researchers can generate and converse grid data without tedious steps for downloading and installing programs. Thus, there are more time spend on geography problem solving, hence increasing efficiency.