Location Matters: A Framework to Investigate the Spatial Characteristics of Distributed Flood Attenuation

Federico Antolini,Eric Tate

doi:10.3390/w13192706

Abstract

Distributed attenuation in flood management relies on small and low-impact runoff attenuating features variously distributed within a catchment. Distributed systems of reservoirs, natural flood management, and green infrastructure are practical examples of distributed attenuation. The effectiveness of attenuating features lies in their ability to work in concert, by reducing and slowing runoff in strategic parts of the catchment, and desynchronizing flows. The spatial distribution of attenuating features plays an essential role in the process. This article proposes a framework to place features in a hydrologic network, group them into spatially distributed systems, and analyze their flood attenuation effects. The framework is applied to study distributed systems of reservoirs in a rural watershed in Iowa, USA. The results show that distributed attenuation can be an effective alternative to a single centralized flood mitigation approach. The different flow peak attenuation of considered distributed systems suggest that the spatial distribution of features significantly influences flood magnitude at the catchment scale. The proposed framework can be applied to examine the effectiveness of distributed attenuation, and its viability as a widespread flood attenuation strategy in different landscapes and at multiple scales.

Highlights

Large reservoirs and levees have long been the traditional engineering response for river flood protection
Distributed attenuation represents a change from the dominant paradigm in flood control
This article presents a framework for analyzing distributed attenuation, in which attenuating features are modeled on a large number of potential locations

Summary

Introduction

Large reservoirs and levees have long been the traditional engineering response for river flood protection. In the United States, the US Army Corps of Engineers estimates that the 715 dams and 4100 miles of levees under their management prevented $348 billion in flood losses in 2019, and an annual average of $138 billion in the decade 2010–2019 [1]. Large reservoirs decrease flow peak magnitude and frequency, and act as barriers to sediment flux and aquatic fauna mobility. Adapting a centralized work, such as a levee or a large reservoir, to changing conditions or to prevent failures [12,13] and unintended behaviors [14] is an onerous process [15,16,17]

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