针对北方大多数水库在主汛期由于汛限水位的制约经常发生汛期空库迎汛造成弃水，而汛后又无水可蓄，使得相当一部分雨洪资源不能得到很好利用的矛盾局面。在分析流域水情的基础上，结合水库汛期分期，在考虑水库大坝安全和下游防洪标准的前提下，运用数理统计法和多方案、多层次分析法对动态提高水库汛限水位的风险效益进行分析，最终给出不同汛限水位方案的风险和效益水平。通过对水库进行分期汛限水位研究，可知提高汛限水位在北方缺水地区实现洪水资源化的可行性和必要性。

Restrained by flood limited water level, most reservoirs in North China discharge a substantive amount of water in order to vacate storage at flood season, while leaving little water for storage during post-flood season. As a consequence, a substantial part of storm-flood resources can’t be utilized adequately. Based on analysis of drainage area, this article divides the whole flood season into different stages, and thus conducted risk benefit analysis on dynamically raising the limited elevation of reservoir under the premises of guaranteeing dam body safety and downstream flood control security by mathematical statistics and multi-scheme, multi-level analysis. And finally the risk and benefit level of different limited elevation schemes is provided. Through the study on limited elevation of reservoirs during different stages of the flood season, this paper demonstrates the feasibility and necessity of increasing the limited elevation of reservoirs to resolve the water shortage in North China.