Geographic information systems and global positioning systems for watershed management

Taipei Water Resource Management Commission (TWMC) is in charge of watershed management in order to provide sustained water for about four millions population in Taipei. Watershed management is not confined to its traditional scope. Almost everything relevant with water quality and water quantity has to be taken care of. House construction permission, garbage collection and management, water and soil conservation engineering, tree plantation, water monitoring and examination, sewerage system management, nonpoint source pollution monitoring, illegal land uses enforcement, special soil and water conservation zoning enforcement are daily operations to be performed. A long-term watershed management has to look all problems into two different watersheds. Geographic information systems have been implemented for more than ten years at TWMC. Different types of maps can be overlay to each other right away on a color monitor such as house site maps, contour maps, sewerage system maps, cadastral maps, township, river, road, and digital orthophoto maps. The GPS device is now giving the key component say, x and y coordinates, for watershed management such that all relevant information for a given position can be examined simultaneously. Watershed management at TWMC can review in different aspects such as the whole township, a small river; and so on