Flash flood is one of the major natural hazards in China. It seriously threatens the lives of people and property in mountainous areas. Various methods have been developed for flash flood study, but most of them focused on the past few decades. As one of the effective methods of historical flash flood events reconstruction, dendrogeomorphology has been used worldwide. It can provide hazard information with long temporal scale and high temporal resolution, sometimes at the seasonal level. By comparing tree ring width and other growth characteristics between disturbed and undisturbed trees, growth disturbance signals can be found in the disturbed trees. Using the growth disturbance in tree rings, flash flood events can be dated, and then the frequency, size, and spatial distribution characteristics of flash floods that have no or little documentary records can be reconstructed. The discharge of flash flood can be reconstructed quantitatively according to the height of scars or by using hydraulic models. With the development of dendrogeomorphology, research tends to probe into the meteorological driving mechanism of flash floods and the pattern of flash floods on a larger spatial scale. In the practical application of dendrogeomorphology, more instrumental data and historical records are applied in the studies. This makes the method increasingly more widely used around the world. But work based on dendrogeomorphology has not been reported in China. In this article, we reviewed the development of the study on flash floods based on tree ring, briefly summarized the research progress, and discussed the advantages, limitations, and potential of this approach, so as to provide some reference information for relevant work in China.

The modification of the Turia River’s course in the 1960s marked a pivotal transformation in Valencia’s urban landscape, evolving from a flood protection measure into a hallmark of sustainable urban development. However, recent rainfalls and flooding events produced directly by the phenomenon known as DANA ((Isolated Depression at High Levels) in October 2024 have exposed vulnerabilities in the infrastructure, particularly in the rapidly urbanized southern areas, raising questions about the effectiveness of past solutions in the context of climate change and urban expansion. As a result of this fragility, more than 200 deaths have occurred, along with material losses in 87 municipalities, whose industrial infrastructure accounts for nearly one-third of the economic activity in the Province of Valencia, valued at 479.6 million euros. This paper presents, for the first time, a historical-document-based approach to evaluate the successes and shortcomings of Valencia’s flood management strategies through policy and spatial planning analysis. Also, this paper remarks the ongoing challenges and potential strategies for enhancing Valencia’s urban resilience, emphasizing the need for innovative water management systems, improved drainage infrastructure, and the renaturalization of flood-prone areas. The lessons learned from Valencia’s experience in 1957 and 2024 can inform future urban planning efforts in similar contexts facing the dual pressures of environmental change and urbanization.