一、概述建国以来,湖南省除了修建大量中小型农田水利工程处,还在江河的中、下游修建了20多处径流式低水头水利水电上程.这些工程一般都兼有发电、通航、灌溉等多种效益.由于河道较宽(一般以坝顶长与最大坝高之比大于 I. Introduction Since the founding of the People’s Republic of China, in addition to constructing a large number of small and medium-sized farmland water conservancy engineering offices, Hunan has also constructed more than 20 runoff low head water conservancy hydropower projects in the middle and lower reaches of the rivers, which generally have power generation, navigation, irrigation, etc. A variety of benefits. As the river is wider (generally the maximum length of the dam and the maximum dam height than