Putting the Dominican Republic on the map
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CTA. 2003. Putting the Dominican Republic on the map. ICT Update Issue 12. CTA, Wageningen, The Netherlands
Permanent link to this item: http://hdl.handle.net/10568/57624
by Christopher Neale Geographical Information Systems (GIS) form the basis of a new database that maps all irrigation water users on the Caribbean island and will improve water management practices.
A water user database is an important tool for the successful management of irrigation systems in many ACP countries. With up-to-date information about the location of irrigated areas and water users, it is possible to accurately estimate irrigation water demand and supply in a specific area, or even country. A water user database allows the staff of local irrigation districts and water user associations to organize irrigation water distribution and schedule maintenance activities, as well as to set water tariffs and assign water rights for the use of public water resources. In the Dominican Republic, the Instituto Nacional de Recursos Hidráulicos (INDRHI), the national water resources development agency, is in the process of decentralizing the operation and management of the island´s irrigation systems to local water user associations. To implement the policy, INDRHI has set up the Programme for the Management of Irrigation Systems by Water Users (PROMASIR), with funding from the Inter-American Development Bank and technical support from Utah State University (USU). As a first step, PROMASIR has had to create a national water user database from scratch using a geographical information system (GIS) and aerial photographs. In the first phase, the project produced digital orthophoto quads (DOQs) at a scale of 1:5,000 for approximately 4,400 km2 of irrigated areas in the country. DOQs are digital maps that combine the geometric information of a regular map with the detail of an aerial photograph. The aerial photos are scanned and the digital images are corrected to remove the distortion caused by perspective, camera tilt and terrain relief. The DOQs served as the basis for defining property boundaries in the irrigated areas, as well as for delineating the irrigation canal and drain systems, which were then verified by field crews. Their information was used to produce the digital cadastral maps, with additional attributes such as the names of the property owners and/or water users, cultivated crops, salinity and drainage problems. These data were divided into several ´layers´ or query categories using ARC-INFO GIS software, thus completing the database. Project staff subsequently developed a Visual Basic application to provide a user-friendly interface in Spanish to enable water users to search the database. With this application, users can search for individual water users and properties, and can obtain graphical representations of property boundary changes, monthly crop statistics and estimates of daily, weekly or monthly irrigation water demand in specified areas. Within INDRHI, USU has established a Geomatics Laboratory to compile the digital products generated by the project and to manage information for the institution. The USU support also includes short- and medium-term training for local lab personnel and technology transfer. The laboratory is equipped with the latest computer workstations, with image processing and GIS software and peripherals. Training is provided for lab personnel in maintaining the water user database by modifying the cadastral layer, as well as for the operations and accounting staff of the water user associations in the use of the software, and keeping the information system updated. Changes in property ownership are reported by the farmers to the water user association personnel, who modify the database locally. More complex property boundary changes are compiled digitally and passed on to the INDRHI Geomatics Lab for permanent changes in the GIS cadastral layer. The use of this modern database has increased the water user associations´ revenues, which will result in more efficient system operation and maintenance. Overall, the irrigation systems that have been transferred to the water user associations are now better managed, with fewer water conflicts than those still operated by government agencies. For more information, visit www.engineering.usu.edu/bie/rssl/drproject www.engineering.usu.edu/bie/rssl/drproject mailto:firstname.lastname@example.org Christopher M.U. Neale is a professor at the Department of Biological and Irrigation Engineering, Utah State University.