Peak Flow-Based Hydrological Signatures Explained | Annual Maximum Series, POT, and Lag Time

What can the largest flows in a streamflow record tell us about a catchment? Peak-flow-based hydrological signatures focus on the upper end of the streamflow distribution, providing valuable information about the magnitude, frequency, and timing of high-flow events. In this episode of the Hydrological Signatures series, we explore several important indicators used to characterise peak-flow behaviour, including Annual Maximum Series, Peak-Over-Threshold (POT), high-flow quantiles, and peak-flow timing. We also discuss the key strengths and limitations of these signatures and how they can be used in hydrological modelling, flood frequency analysis, infrastructure design, and catchment comparison. ________________________________________ 📌 Chapters 00:00 Introduction 00:30 What Are Peak-Flow-Based Hydrological Signatures? 01:00 Annual Maximum Series 01:50 Peak-Over-Threshold (POT) 02:21 Peak-Flow Quantiles 03:10 Peak-Flow Timing 03:58 Applications in Hydrological Modelling 04:35 Key Takeaways ________________________________________ 🌊 What You'll Learn In this video, you'll learn: • What peak-flow-based hydrological signatures are • How Annual Maximum Series characterises extreme streamflow • What the Peak-Over-Threshold (POT) approach is and why it can be useful for extreme-flow analysis • How high-flow quantiles can describe the upper end of the streamflow distribution • Why peak-flow timing is an important hydrological characteristic • How peak-flow signatures can be applied in hydrological modelling & design ________________________________________ 💧 Part of the Hydrological Signatures Series This video is part of my ongoing Hydrological Signatures series, where I explore different categories of hydrological signatures and their applications in hydrology and water engineering. The series currently covers: Episode 1 — Introduction to Hydrological Signatures Episode 2 — Magnitude-Based Hydrological Signatures Episode 3 — Variability-Based Hydrological Signatures Episode 4 — Regime-Based Hydrological Signatures Episode 5 — Peak-Flow-Based Hydrological Signatures (this episode) Upcoming episodes will explore: 🔹 Water Balance Signatures 🔹 Elasticity Signatures The objective of this series is not simply to calculate hydrological signatures, but to understand what they reveal about catchment behaviour and how they can be used in hydrological modelling. ________________________________________ 🔑 Keywords #flowbasedhydrologicalsignatures #hydrology #annualmaximumseries #AMS #POT #lagtime #hydrologicalmodelling #highflowquantile #floodfrequencyanalysis #catchmenthydrology #civilengineering #floods #peakflow #streamflowanalysis #floodmodelling