ABSTRACT

Many computerized tools have been used for the groundwater assessment, development and overall management in the world. The Geographic Information System (GIS) user-friendly decision support tool for the monitoring and management of spatially distributed groundwater arsenic contamination intensity and water quality promises to provide an appropriate information systems on thana census blocks in respect to depths in the groundwater reservoir of Bangladesh. Digitized map features of thana census blocks with longitude-latitude coordinates stored available information of groundwater arsenic contamination intensity and water quality. Mapinfo Professional database has structured format defining fields (Columns) and records (Rows) data repository. MapBasic provides powerful database-access tools. Linking database with the user-interface helps to understand about the overall pictures of country's groundwater arsenic contamination levels and water quality. It gives a more vivid search method and shares graphics, database, and offers a convenient tool to process the information stored in its database and to present the spatially analyzed results on a geographical map. The desktop mapping software package MapInfo for Windows (MapInfo Cor., 1997) was selected as appropriate software to demonstrate the concepts and MapBasic Programming Language for the developing user-interface tools. The main menu of Groundwater appears directly in the Menu bar of MapInfo. It comprises three main menus (Arsenic Contamination, Water Quality and About) and sub menu items. This tool is devoted to the monitoring of the present situation of groundwater arsenic contamination levels and water quality for the thana census blocks of Bangladesh, individual divisions and districts, respectively. The dialog windows are activated in the MapInfo window when user clicks on Sub-menu item Arsenic Intensity and water Quality individually. These windows propose to view the country's groundwater arsenic contamination intensity and water quality, respectively, when user clicks on a particular CheckBox dialog and/or any number of dialogs. CheckBox dialogs are directly linked with programming modules and instantly display output within the MapInfo window when dialog window is terminated. OKButton and CancelButton dialogs control the dialog window. By clicking on a sub-menu item Exit, instant message appears to inform the user that the application is going to terminate. It gives dialog message during operation period and user will be able to know how to get information for specific query from dialog window. The spatially analyzed results for the various depths on the thana census blocks are rapidly displayed allowing the policy makers to view more comprehensible information in color coded maps, tables and graphs, giving adequate time to make proper decision as to monitoring and management progresses. The study result would be of much concerned to the decision-makers to support action program for current hazard and future tubewells installation of the country.