IRRIGATION AND DRAINAGE Irrig. and Drain. 53: 385–395 (2004) Published online in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/ird.141 FLOOD CONTROL AND LAND USE MANAGEMENT IN MENGWA RETENTION AREA, HUAI RIVER BASIN y HAN RUIGUANG 1 *AND F. X. SURYADI 2 1 Huaihe River Water Conservancy Commission, Ministry of Water Resources, Tianjin, China 2 Delft Hydraulics and UNESCO-IHE Delft, the Netherlands ABSTRACT Retention areas have a very important role in flood alleviation in the Huai River Basin. With economic and societal development the former retention areas have been developed and some of them even became very important urban areas. When floods come, there is a lot of damage. The government has realized that the flood control standards in the whole river basin are low and has made a plan to increase flood control standards for the Mengwa retention area. The design water level will be 28.00 mþMSL at Runheji. In light of this the use of the Mengwa retention area needs to be considered. To arrive at decisions that reduce flood damage, one should take into account the following uncertainties: the river discharge, the flood damage given the discharge, the downstream water level given the discharge, and the costs of constructing embankments and dredging the river. By using the DUFLOW model and a GIS model, the present situation and the alternative development options have been analysed. How to use the Mengwa retention area is also discussed. Copyright # 2004 John Wiley & Sons, Ltd. key words: flood control; land use management; retention area RE ´ SUME ´ Les zones d’expansion jouent un ro ˆ le important dans la re ´duction des crues du fleuve Huia. Ces zones ont connu le me ˆme de ´veloppement e ´conomique et social que le reste de la re ´gion, et certaines sont maintenant fortement urbanise ´es. Les crues y provoquent beaucoup de de ´ga ˆts. Le gouvernement a pris conscience que les crite `res pour contro ˆler les crues dans le bassin versant sont insuffisants, et a e ´labore ´ un plan pour ame ´liorer ce contro ˆ le dans l’aire d’e ´pandage de Mengwa. Le niveau d’eau de re ´fe ´rence retenu est a ` la cote 28 m, prise a ` Runheji. Ceci implique de reconside ´rer l’utilisation de la zone d’expansion. Les de ´cisions permettant de re ´duire les de ´ga ˆts dus aux crues ont e ´te ´e ´labore ´es a ` partir des parame `tres suivants: de ´bit du fleuve, relation entre le de ´bit et les de ´ga ˆts dus aux crues, niveau d’eau en aval, cou ˆts de renforcement des digues, cou ˆ t du dragage. La situation actuelle et les possibilite ´s d’ame ´lioration ont e ´te ´ analyse ´es avec le mode `le DUFLOW et un SIG. L’utilisation de la zone d’expansion de Mwenga est examine ´e e ´galement. Copyright # 2004 John Wiley & Sons, Ltd. mots cle ´s: Contro ˆle des crues; gestion de l’occupation du sol; aire d’e ´pandage Received 1 January 2003 Revised 16 March 2004 Copyright # 2004 John Wiley & Sons, Ltd. Accepted 13 May 2004 *Correspondence to: Han Ruiguang, Huaihe River Water Conservancy Commission, Ministry of Water Resources, 15 Longtan Road, Hedong District, Tianjin, 300170 China. E-mail: hrg@hwcc.gov.cn y Contro ˆle des crues et gestion de l’occupation des terres dans la zone d’expansion des crues de Mengwa, sur la rivie `re Huai