In order to evaluate the feasibility, development path and blueprint for developing a subsurface environment model, this project collected information on the development and censorship of commonly used subsurface analysis models and composed a handbook and guideline for model selection to enhance the assessment quality of contaminated sites. Based on nine expert advisory meetings and in-depth interviews with 14 experts, this project proposed the “Reference manual on selecting models for the subsurface environment of contaminated sites”. The content of the manual includes basic concepts of models, the process of establishing a model, the timing and principle for model selection, introduction of models and a model screening platform. On the other hand, this project also completed the “Writing guideline of using subsurface environment models on contaminated sites”, which contents include a checking list, reported on the modeling results and the archive format for modeling files. This project proposed an integrated development roadmap of subsurface environment models and formulated different stages of work. The development of a localized model which includes coupling thermal-hydrology-mechanics-chemical transport mechanisms is necessary in order to cope with the heterogeneous hydrogeology and complex contamination characteristics in Taiwan, and to respond to the need for site investigation and remedy evaluation. By screening and evaluating current models, the domestically developed HYDROGEOCHEM(HGC) was selected as the foundation of the model because of its international reputation. The initial stage is based on the 2D HGC 4.1 of variable saturated flow model, coupling thermal and geochemical reaction transport module, and the function extension on the 3D HGC 5.1, along with a completion of the testing for 2 case studies. This project also established the framework of the model platform. The platform integrated modules of grid generation, parameter input interface, batch reaction, parameter data base and visualization of modeling results. For the promotion strategies in the review regulation, the suggestion is to amend the guideline on writing pollution control/ remediation plans, and included the “Reference manual on selecting models for the subsurface environment of contaminated sites” and the“Writing Guidelines of using subsurface environment models on contaminated sites” into the site censorship system.

Subsurface Environment, Modeling Analysis, Review Regulation