| Abstract |
Mexico's geothermal resources are abundant and widely distributed. Most of them are of moderate- to low-temperature (T<200?C), appropriate mainly for direct applications. However, only a small fraction of these resources have been exploited so far, and its utilization has been almost exclusively restricted to balneology, disregarding many other technically possible and potentially profitable applications. One important reason for the prevalence of this unwanted situation is lack of knowledge about these resources. To promote knowledge and exploitation of these valuable indigenous resources our group has been involved the last few years in a project to assess the Mexican medium- to low-temperature resources and its possible applications. In this context we are developing a Geographical Information System (GIS) to integrate, organize and visualize in numerous useful ways, information on these resources. Our system is built on the ArcView 8.2 geographic data visualization, query and mapping GIS platform. It integrates a previously developed relational database, built on the MS Access database management system, which includes location, general characteristics and chemical data on 2,332 hot springs, water wells and other Mexican geothermal localities with temperatures 27?C. The integration process required exporting the original tables to the personal geodatabase format defined in ArcView 8.2. With this conversion ArcView software is able to display all the data stored in MS Access based on its location data. The system also includes a set of thematic layers with information on topography, hydrography (rivers, lakes, etc.), political sub-divisions, infrastructure (roads and railroads), cities and towns, and shaded relief images, and will eventually incorporate geological and economic data. So far our system uses 1:1,000,000 and 1:250,000 scales, for different applications. These scales are appropriate for the size and location of Mexico and for the applications we envision. One important application of our GIS is to automatically estimate the areas and mean coordinates of numerous geothermal systems. This was achieved by defining groups of geothermal localities by superposition of their "areas of influence". We estimated areas of influence by circles of fixed radii. In this way we were able to estimate minimum, maximum and probable areas for the geothermal systems. We used these results as an important input for estimating the heat reserves of these geothermal systems. Another application is to correlate the locations of geothermal localities with regional structures evident in the shaded relief images. This facilitates the interpretation of the data necessary to define geothermal systems. In this paper we describe the current state of development of the system. Our aim is to develop a tool that will facilitate visualization and analysis of the complex datasets necessary to interpret our geothermal data and their relationships with geographic, geological, political and economic information pertaining to our country, to apply these results to estimate its geothermal reserves. We are also aiming to use this tool to recommend particular applications for these reserves, based on technical and socioeconomic local parameters. The system could also be used to help Mexican authorities to legislate and establish proper rules for the exploitation of geothermal resources, and to promote its use in direct applications. |