# Assessment of Riparian Ecosystems for Sustainable Management in the Face of Climate Change: A Practical and Interdisciplinary Approach

Romain Dopierala, Arnaud Foret, Océane Joët, Pierre-Olivier Mazagol, Florentina Moatar, Antoine Vernay

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## ► To cite this version:

Romain Dopierala, Arnaud Foret, Océane Joët, Pierre-Olivier Mazagol, Florentina Moatar, et al. "Assessment of Riparian Ecosystems for Sustainable Management in the Face of Climate Change: A Practical and Interdisciplinary Approach." Conférence internationale I.S.Rivers 2025, Jun 2025, Lyon, France. 2025. hal-05180762

HAL Id: hal-05180762

https://hal.science/hal-05180762v1

Submitted on 29 Aug 2025

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Distributed under a Creative Commons Attribution 4.0 International License
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# Interdisciplinary multiscale nested framework for riparian zones: a decision-making tool

Study case from the SAGE Loire en Rhône-Alpes

JOET Océane(1,4,7), FORET Arnaud(1,3,6), DOPIERALA Romain(1,2,5)

(1)IWS Master (EUR H2O'Lyon); (2)Université Claude Bernard Lyon 1; (3)Université Lyon 2; (4)Université Jean Monnet; (5)LEHNA; (6)EVS-ISTHME; (7)INRAE

joetoceane5@gmail.com; arnaud.foret1@univ-lyon2.fr; romain.dprl@outlook.fr and master-iws@univ-lyon1.fr

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**Riparian zones**, defined as the vegetation between the river channel and upland forest (or up to 30 m), are key components of hydrosystems, providing **essential ecosystem services**. Increasingly threatened by global change, they remain poorly characterized and unevenly managed. To preserve these services, riparian zones **are high-priority targets** for short- and medium-term restoration. This study integrates specific objectives across three hierarchical spatial scales.

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From developing catchment scale riparian vegetation characterization to propose a prioritization map.

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To sub-catchment scale integration of detailed vegetation data improving hydrological modeling.

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To functional assessment of riparian trees supporting reach scale application.

## Riparian pre-evaluation matrix – catchment scale

Valley bottoms highlight potential areas for riparian vegetation, based on classified LiDAR data. A matrix-based approach retains the most degrading factor over 500-meter stream reaches and is structured using index-based buffer zones (0–10 m, 10–15 m, 15–30 m).

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## Results

* The matrix identified **hotspots** of potential degradation, especially in agricultural and urban interfaces.

* The aggregated result over lines shows potential areas **suited for restoration**.

* Vegetation density extrapolated from LiDAR but not integrated in the matrix due to imprecisions between units (hedges/corridors vs dense forest).

## Shading function of riparian vegetation – sub-catchment scale

Extraction of height and density parameters using Canopy Height Model (CHM), validated with field measurements. Three scenarios tested (scorching day): 0% vegetation, 100% coverage, and 100% coverage on south banks (realistic scenario).

### Results

* Fine integration of **riparian vegetation improves** T-NET and provides an **operational tool** to estimate vegetation height and density.

* **Short discontinuities** (~160 m) can induce **significant** local temperature.

* Realistic **southern bank** vegetation scenario **effectively** lowers water temperature.

## Functional assessment of riparian vegetation – reach scale

Focus on LDMC per IBCR classes for both species for may 2025

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Assessment tools include the Index of Riparian Biodiversity and Connectivity (IBCR – 500 m/10 m), riparian functionality (RipaScan – 150 m/15 m) and land cover analysis.

Functional traits, such as Leaf Dry Matter Content (LDMC), were measured on 10 riparian trees per species - Alders and Ashes - and site.

### Results

* Assessment tools **do not represent** tree functioning.

* Assessment tools provide **heterogeneous descriptions**: land cover lacks sufficient detail, and only 2 out of 5 IBCR status levels align with RipaScan classifications.

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Interdisciplinary, multiscale, hierarchical approach to guide riparian restoration:

* **Pre-evaluation matrix** (on open data) highlights riparian vegetation cover gaps.

* Identify preferential restoration actions to enhance shading. (e.g., filling vegetation gaps, prioritizing southern banks)

* Assessment tools overlook **tree functioning, essential** for restoration outcomes.

Data visualisation:

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Bowler et al., 2012, Environmental Evidence

DOI: 10.1186/2047-2382-1-3

Diamond et al., 2022, LnO DOI: 10.1002/lno.12271

Seyedhashemi et al., 2023, ESSD

DOI: 10.5194/essd-15-2827-2023

McDonald et al., 2018, OFB ISBN: 978-2-37785-019-8

Michez et al., 2017, J of Env. Man.,

DOI: 10.1016/j.jenvman.2017.02.034

Riis et al., 2020, BioScience

DOI:10.1093/biosci/biaa041

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Data gaps hinder coordination

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Sociological and policy survey

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Upscaling methods (e.g., thermal infrared)

Acknowledgments: VERNAY Antoine, MAZAGOL Pierre-Olivier, VALETTE Laurent, MOATAR Florentina, POTIGNON Amélie, STAENTZEL Cybill and HEVIN Guillaume

* All team members contributed to the development and design of the scientific poster

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H2O'Lyon
Université de Lyon

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