slack water period meaning in English

平潮期

After analyzing , the author got the basic character of tidal flat hydrodynamic : the time of flooding on bare flat and ebbing is basically the same and the time of flooding on pioneer zone of salt marsh is a little short ; the process curve of current speed on bare flat did not appear peak value on the beginning of flooding and at the end of ebbing but presented double peak , that is , it presented double peak in winter and spring and ebbing peak value disappeared in summer and autumn , salt marsh presented single peak character in a year and the process curve in tidal creek presented double peak ; all current direction on every spot presented gyration current and the current speed changed rapidly during the high water level without obvious slack water period
分析得到了潮滩水动力基本特征：光滩水位涨潮和落潮时间基本相等，而盐沼前缘带水位涨潮时间略短；光滩流速过程线在涨潮初和落潮末出现峰值，呈现“双峰型”特征，盐沼前缘带则冬、春季节呈现“双峰型” ，夏、秋季节落潮峰值消失，盐沼带四季呈现单峰特征，潮沟内过程线为“双峰型” ；各测点流向均呈现回转流特征，在高水位时流向迅速改变，不存在明显的憩流。