The dictionary of Hydrological Engineering aims at facilitating the transfer of knowledge between hydrologists, engineers, scientists and students involved in the fields of hydrology and sustainable water resources management. It also aims at promoting the use of national idioms by providing equivalent terms little known in the technical domain. You can find in the dictionary, divided into seven parts, a collection of over 2 ooo terms in hydrology and related fields : hydrotechnics, hydrogeology, metrology, hydraulics, water supply, geomorphology and geography. English terms are given in a numbered alphabetical list (reference list), along with their equivalent in other languages. At the end of the dictionary, the user will find an alphabetical list in French, Armenian, Russian, Polish, Romanian and Arabic. Each term is indexed so that it can be found easily throughout the dictionary whatever the language. The dictionary will help to ensure a more sustainable management of water resources by disseminating the basic principles of hydrology and related fields to users in their monther tongue and not only to those who are fluent in one of the main international languages such as English and Russian.