Topographic mapping in El Salvador is the responsibility of the Instituto Geográfico Nacional ‘Ingeniero Pablo Guzman’ (IGNES), located at Ciudad Delgado. The organization was founded as the Oficina de Mapa, in 1946. Modern topographical mapping was carried out in collaboration with the Inter-American Geodetic Survey (IAGS) from the early 1950s, following acquisition of a complete 1:40,000-scale air photo cover in 1949 and again in 1954 at scales of 1:30,000 and 1:60,000. The main printed series is the 1:50,000 scale topographic map in 54 sheets, issued since 1955. This five-color map is on a Lambert conformal conical projection, Clarke 1866 ellipsoid, and has a 20 m contour interval. Sheets each cover an area of 10 minutes of latitude by 15 minutes of longitude. The first edition was completed in 1969 and currently all but a few sheets are in a third edition, based on photography obtained in 1981.
A basic map series at 1:20,000 scale (1:30,000 in mountainous areas) was also undertaken using the 1954 air photography, and all 196 sheets were completed in 1969. These sheets are issued as dye-lines, and have a 10 m contour interval. Priority is now given to a new basic map of the country at 1:25,000 scale which is nearing completion in about 200 sheets, and will supersede the earlier series.
A six-sheet 1:100,000 scale series was published in 1974. It is on a Lambert conformal conic projection and has a 50 m contour interval.
Soviet military topographic mapping of El Salvador is available at the following scales: 1:1,000,000 (2 sheets, complete coverage, published 1969-1990); 1:500,000 (3 sheets, complete coverage, published 1985-1988); 1:200,000 (1 sheets, southern coverage, published in 1984) and city (1:10,000 to 1:25,000) topographic map of San Salvador published in 1980. These products are available in print, digital raster and digital vector GIS formats from East View Geospatial.
Geological mapping was undertaken in the 1970s by the West German Geological Mission to El Salvador in collaboration with the Centro de Investigaciones Geotécnicas (CIG), San Salvador, and a series of six 1:100,000 scale geological sheets was published by Bundesanstalt fϋr Geowissenschaften und Rohstoffe (BfGR), together with a single sheet 1:500,000 scale map of the whole country.
A number of small-scale resources maps of the country were produced in the 1970s. Dirección General de Recursos Naturales Renovables (DGRNR) undertook fieldwork for a series of 1:200,000 scale agro-ecological maps and a six-sheet soil and agricultural land use series at 1:100,000 scale. From 1994-98, a project supported by the Food and Agriculture Organization (FAO) and the Dutch government was undertaken by the Centro Nacional de Tecnología Agropecuaria y Forestal (CENTA) (Projecto CENTA-FAO-Holanda). This focused on the problems of sustainable agriculture in mountainous areas, and the development of participatory planning for soil and water conservation. Landscape, watershed, and soil mapping, together with other environmental information prepared for this project, has been incorporated in a digital Land Information System (Sistema de Información de Tierra). Digital elevation data have also been captured from 100 m contours. Proposals were in hand in 1998 to extend the CENTA project.
Cadastral mapping has been completed for many urban areas at 1:5,000 scale and at 1:10,000 scale for rural areas. The registration of land is in need of a complete overhaul, and with the more settled political situation in the country, a program has been initiated to modernize the cadastre, and establish a digital land parcel database for the whole country. A Centro Nacional de Registros was created in 1994 to proceed with this mission, and there were plans to establish a new geodetic network adjusted to WGS 84 Datum, using GPS software.
Good, recent general maps of the country are published by International Travel Maps (ITM) and by the Banco Agricola y Comercial, San Salvador, with cartography by Allan Cartography in the United States.
Mapping for the demographic censuses is undertaken by the Dirección General de Estadística y Censo (DGEC). New photography of urban areas was obtained in 1988 for this purpose.