Determination of minimum flood flow for regeneration of floodplain forest from inundated forest width-stage curve

作     者：Song-hao SHANG Xiao-min MAO 

作者机构：State Key Laboratory of Hydroscience and Engineering Department of Hydraulic Engineering Tsinghua University Beijing 100084 P. R. China College of Water Conservancy and Civil Engineering China Agricultural University Beijing 100083 P. R. China 

出 版 物：《Water Science and Engineering》 (水科学与水工程（英文版）)

年 卷 期：2010年第3卷第3期

页      面：257-268页

核心收录：

学科分类：081504[工学-水利水电工程] 082902[工学-木材科学与技术] 08[工学] 0829[工学-林业工程] 0815[工学-水利工程] 

基　　金：supported by the National Natural Science Foundation of China (Grant No.50879041) the New Century Excellent Talents in University (NCET) Program of the Ministry of Education of China (Grants No. 06-0059 and 07-0814) 

主　　题：floodplain forest regeneration flow minimum flood stage inundated forest width method ideal point method 

摘      要：Floods are essential for the regeneration and growth of floodplain forests in arid and semiarid regions. However, river flows, and especially flood flows, have decreased greatly with the increase of water diversion from rivers and/or reservoir regulation, resulting in severe deterioration of floodplain ecosystems. Estimation of the flood stage that will inundate the floodplain forest is necessary for the forest＇s restoration or protection. To balance water use for economic purposes and floodplain forest protection, the inundated forest width method is proposed for estimating the minimum flood stage for floodplain forests from the inundated forest width-stage curve. The minimum flood stage is defined as the breakpoint of the inundated forest width-stage curve, and is determined directly or analytically from the curve. For the analytical approach, the problem under consideration is described by a multi-objective optimization model, which can be solved by the ideal point method. Then, the flood flow at the minimum flood stage （minimum flood flow）, which is useful for flow regulation, can be calculated from the stage-discharge curve. In order to protect the forest in a river floodplain in a semiarid area in Xinjiang subject to reservoir regulation upstream, the proposed method was used to determine the minimum flood stage and flow for the forest. Field survey of hydrology, topography, and forest distribution was carried out at typical cross sections in the floodplain. Based on the survey results, minimum flood flows for six typical cross sections were estimated to be between 306 m3/s and 393 m3/s. Their maximum, 393 m3/s, was considered the minimum flood flow for the study river reach. This provides an appropriate flood flow for the protection of floodplain forest and can be used in the regulation of the upstream reservoir.