International Classification and Codification of Watersheds and River Basins

Watersheds and river basins, referred to as hydrologic units (HUs) are independent of territorial boundaries, and therefore compel the partners representing all the nations or other administrative units within an HU to adopt a holistic approach to resource management. A basic requirement for the holistic approach is a comprehensive hydrologic unit database (HUD) developed under a common framework of classification with a uniform nomenclature and codification system. Currently, the classification of HUs differs from one country to another, as a result of which, the HU boundaries drawn by different HU partners fail to match with each other at the territorial boundaries, causing inconsistency in the HUD. Conventions for uniform classification and codification of HUs are suggested to develop a comprehensive HUD and a framework of concepts and strategies for different levels of HUs. The suggested conventions will help in the development of a global hydrologic unit database and assignment of unique global hydrologic unit codes to each HU identified on the globe. The proposed code will work as a tool to develop a Web site for a global resource information system.