结合我国河流环境保护与灾害防御的现实背景，提出亟待研究的3个问题，即溃坝洪水灾害、山洪灾害和修建水库所诱发的水华等河流环境问题。建议尽快组织实施相关科学问题的研究，为有效地防御洪水灾害、维护河流健康提供科学基础。

With respect to the current state of river environment protection and disaster defense in China, this paper presents a brief review of research on three major themes, i.e., dam-break flooding, flash flooding, and phytoplankton bloom in reservoirs due to large dams. The identified issues highlight the need for concerted and substantially extended investigations, which should provide the scientific base for more effective fluvial flood defense and environmental rehabilitation.