On the Management of Nature-Based Solutions in Open-Air Laboratories: New Insights and Future Perspectives

The adoption of Nature-Based Solutions (NBSs) represents a novel means to mitigate natural hazards. In the framework of the OPERANDUM project, this study introduces a methodology to assess the efficiency of the NBSs and a series of Open-Air Laboratories (OALs) regarded as a proof-of-concept for the wider uptake of NBSs. The OALs are located in Finland, Greece, UK, Italy, and Ireland. The methodology is based on a wide modeling activity, incorporated in the context of future climate scenarios. Herein, we present a series of models’ chains able to estimate the efficiency of the NBSs. While the presented models are mainly well-established, their coupling represents a first fundamental step in the study of the long-term efficacy and impact of the NBSs. In the selected sites, NBSs are utilized to cope with distinct natural hazards: floods, droughts, landslides, salt intrusion, and nutrient and sediment loading. The study of the efficacy of NBSs to mitigate these hazards belongs to a series of works devoted to the implementation of NBSs for environmental purposes. Our findings prove that land management plays a crucial role in the process. Specifically, the selected NBSs include intensive forestry; the conversion of urban areas to grassland; dunes; marine seagrass; water retention ponds; live cribwalls; and high-density plantations of woody vegetation and deep-rooted herbaceous vegetation. The management of natural resources should eventually consider the effect of NBSs on urban and rural areas, as their employment is becoming widespread.

The Open-Air Laboratory Italy

<p>The Open-Air Laboratory is a novel concept developed by the EU-funded Operandum project (OPEn-air laboRAtories for Nature baseD solutions to Manage Environmental risk) to co-design, implement and assess the effectiveness of Nature-Based Solutions (NBSs). </p><p>In this work we present the Open-Air Laboratory Italy (OAL-Italy) and discuss the application of the OAL as a framework for the development of innovative NBSs to mitigate the impact of hydro-meteorological hazards in present and future climate.  By combining consolidated practices in an original multidisciplinary frame, the OAL-Italy deploys novel modelling strategies, laboratory measurements and targeted monitoring open-field campaigns. In three operational sites, the NBSs are implemented via a co-design, co-development  and co-deployment approach based on a thorough interaction with key stakeholders. By describing the structure and the approach of the OAL we illustrate salient features of the methodology developed in Operandum that are instrumental for the replicability and the upscaling of the NBSs. </p><p>Presented results address the use of the NBSs to mitigate a range of hydrometeorological hazards such as coastal erosion, flooding, storm surge and salt wedge intrusion. Innovative NBSs tested and developed by the OAL include: deep-rooted plants installed on a river embankment to prevent levee failures, special plants that can live in high salt concentration and remove salt from the river mouth water, an artificial dune and marine seagrass to mitigate the impact of storm surges and coastal erosion. We argue that the OAL constitutes an unprecedented holistic effort towards sustainable land management, adaptation to climate change and the acceptance of Nature-Based Solutions. </p>

Evaluating nature-based solutions in a non-stationary climate with changing risk of flooding

<p><strong>Abstract</strong></p><p>Under climate change scenarios, it is important to evaluate the changes in recent behavior of heavy precipitation events, the resulting flood risk, and the detrimental impacts of the peak flow of water on human well-being, properties, infrastructure, and the natural environment. Normally, flood risk is estimated using the stationary flood frequency analysis technique. However, a site’s hydroclimate can shift beyond the range of historical observations considering continuing global warming. Therefore, flood-like distributions capable of accounting for changes in the parameters over time should be considered. The main objective of this study is to apply non-stationary flood frequency models using the generalized extreme value (GEV) distribution to model the changes in flood risk under two scenarios: (1) without nature-based solutions (NBS) in place and; (2) with NBS i.e. wetlands, retention ponds and weir/low head dam implemented. In the GEV model, the first two moments i.e. location and scale parameters of the distribution were allowed to change as a function of time-variable covariates, estimated by maximum likelihood. The methodology is applied to OPEn-air laboRAtories for Nature baseD solUtions to Manage hydro-meteo risks, which is in Europe. The time-dependent 100-year design quantiles were estimated for both the scenarios. We obtained daily precipitation data of climate models from the EURO-CORDEX project dataset for 1951–2020 and 2022–2100 representing historical and future simulations, respectively. The hydrologic model, HEC-HMS was used to simulate discharges/flood hydrograph without and with NBS in place for these two periods: historical (1951-2020) and future (2022-2100). The results showed that the corresponding time-dependent 100-year floods were remarkably high for the without NBS scenario in both the periods. Particularly, the high emission scenario (RCP 8.5) resulted in dramatically increased flood risks in the future. The simulation without NBS also showed that flooded area is projected to increase by 25% and 40% for inundation depth between 1.5 and 3.5 m under RCP 4.5 and RCP 8.5 scenarios, respectively. For inundation depth above 3.5 m, the flooded area is anticipated to rise by 30% and 55% in both periods respectively. With the implementation of NBS, the flood risk was projected to decrease by 20% (2022–2050) and 45% (2071–2100) with a significant decrease under RCP 4.5 and RCP 8.5 scenarios. This study can help improve existing methods to adapt to the uncertainties in a changing environment, which is critical to develop climate-proof NBS and improve NBS planning, implementation, and effectiveness assessment.</p><p><strong>Keywords</strong>: Nature-based solutions; flood frequency analysis; climate change; wetlands; GEV model</p><p><strong>Acknowledgments</strong></p><p>This work has been carried out under the framework of OPERANDUM (OPEn-air laboRAtories for Nature baseD solUtions to Manage hydro-meteo risks) project, which is funded by the European Union's Horizon 2020 research and innovation programme under the Grant Agreement No: 776848.</p>

Supporting co-development phase of Nature Based Solution by combined use of Earth Observation and modeling

<p>A protected natural area in the Emilia Romagna region, Northern Italy is threatened by hydro-meteorological hazards, particularly sea storms. In the last 50 years the northern part of the Bellocchio Park (Sacca Bellocchio II Nature Reserve, Site code EUAPP0072 - Ferrara, Italy)  was interested by an intensive urbanization (Lido di Spina) with the realization of infrastructures, e.g. roads and residential settlements. This land use change led to the construction of embankments and to the conversion of wetlands. These modifications, in combination to even more frequent storm surge events increased coastal erosion. In addition, inland flooding caused by storm surges acts with the reduction of the lagoon and the increase of soil salinity. As an example, the last event occurred in December 2020  eroded a large portion of the Bellocchio beach.   </p><p>Co-design, co-development and deployment of NBS solutions to reduce storm surge risk in the Bellocchio Park is one of the objectives of the H2020 project OPEn-air laboRAtories for Nature baseD solUtions to Manage environmental risks (OPERANDUM). BellocchioBellochio park is in fact one of the 10 Open Air Laboratories (OAL) where the evidence of mitigation of hydro-meteorological risk by NBS will be demonstrated by the combination of different models, approaches and data.</p><p>During the co-design process in the Bellocchio park, potential deployment locations of sand dunes have been identified in collaboration with local authorities devoted to the management of the natural area and to the coast defense (CB and ARSTePC-RER) and an environmental engineering consultant assisting Arpae (IRIS sas). Field visits were devoted to the analysis of the environmental features, strengths and weaknesses of candidate sites.</p><p>This work aims to explore the usefulness of the combined use of multisource remote sensing and modeling in decision making during the co-design process of a NBS. The impacts of the most intense extreme storm surge events in the last 30 years have been documented by delineating flooded areas along the coast using Synthetic Aperture Radar and Multispectral image data. Coastal erosion has been also described by means of change detection analysis and very high resolution multispectral EO data. This screening has given a picture of areas at the risk, i.e. the area most likely to be affected by storm-surge events. Auxiliary data like Digital Terrain Models has been assimilated in a dedicated model to produce flood maps under different scenarios, i.e. different locations and size of NBS and different intensities of storm surge.  </p><p>The integrated analysis was helpful in defining the priority sites, among the ones defined by the stakeholders and engineers, in term of effectiveness for storm surge risk reduction.</p>

Co-design and co-deployment of nature based solutions for river flooding mitigation in northern Italy river embankments

<p>Po valley in the Emilia Romagna region, Northern Italy, is threatened by hydro-meteorological hazards, such as river flooding. In the last 50 years this area was interested by an intensive urbanization (with cities that span from the size of a village to metropolitan urban areas such as Bologna) with the realization of infrastructures, e.g. roads and residential settlements near rivers. In addition, the strengthening and expansion of the embankment system led to the development of the areas prone to floods located nearby the rivers. These modifications, in combination with the occurrence of high flood peaks recently experienced in this area have increased the impacts and thus, the attention, on riverine floods. The last event occurred in December 2020, where Panaro river, a tributary of the Po river, broke its banks near Modena causing large flooded area.</p><p>Co-design and co-deployment of nature based solutions (NBS) to reduce flooding risk in the Panaro river is one of the objective of the H2020 project OPEn-air laboRAtories for Nature baseD solUtions to Manage environmental risks (OPERANDUM). A portion of the Panaro river embankment is one of the Open Air Laboratories (OAL) where special deep rooted plants were implemented to evidence the mitigation of hydro-meteorological risks by NBS.</p><p>In this work, a combined approach between Earth Observation (EO) data and multi-scale modelling is shown, to support the co-design process of the NBS. Synthetic Aperture Radar (SAR) and optical EO data were used to identify areas at risk, i.e. the area most likely to be affected by severe flooding events.  A thresholding method was applied to the SAR and optical images available during past extreme events to identify size and location of the floods. The remote sensing analysis allowed the definition of specific portions of the Panaro river where NBS can be more effective for flood risk reduction. In a second step, a multi-scale modelling approach, based on the characterisation of deep-rooted plants by laboratory experiments and in-field measurements, is used to determine the response of the identified portions of Panaro river to flooding events and to evaluate the effectiveness of possible NBS.</p><p>Remote sensing analysis indicates that the area between Secchia and Panaro rivers, delimited to the north by the town of Bomporto and to the South by the town of Albareto has been most frequently inundated in the recent extreme events. The integrated analysis leads to the identification of potential sites, along the Panaro river, where NBS could be effective for river flooding risk reduction, contributing to the definition of the priority sites among the ones defined by the stakeholders and engineers.</p>

How Effective Are Citizen Scientists at Contributing to Government Tree Health Public Engagement and Surveillance Needs—An Analysis of the UK Open Air Laboratories (OPAL) Survey Model

The incidence of tree disease has been increasing in the UK in recent years as a result of a range of alien tree pests and pathogens new to the country. In the early 2010s government staff resources to monitor, identify and eradicate these pathogens were limited, so we tested the efficacy of “citizen scientists” to support these needs. The Open Air Laboratories (OPAL) is a successful citizen science programme launched in 2007, which at that time of launch involved over 650 thousand people in a range of environmental surveys. In 2012–2013, the Food and Environment Research Agency (Fera) and Forest Research staff worked with OPAL and its partners to launch a citizen science tree health survey in Great Britain and this was extended to cover Northern Ireland until it closed in 2019. Over 2800 surveys were completed including records on more than 4500 trees, the majority from urban areas. This paper discusses the results of the survey and their value for the assessment of tree health. It also considers the implications of engagement with the general public for the future of tree health surveillance. Recommendations are made for further development of the OPAL “model” and more generally for the role of citizen science in this important area.

Modelling the effect of Nature Based Solutions on slope instability

<p>In the framework of the OPERANDUM (OPEn-air laboRAtories for Nature baseD solUtions to Manage environmental risks) project, modelling the effect of the Nature Based Solutions (NBS) on selected open-air laboratories plays a determinant role. In this work, we focus the attention on the Vögelsberg (Tyrol, Austria) landslide case study, located in the municipality of Wattens. The 0.25 km<sup>2</sup> active part of the slope shows annual movement rates in the order of 3.5-6 cm/a. Recent studies provided evidence that the motion is mainly driven by variations of the groundwater level. The latter are related to prolonged moist periods during which excessive rainfall or snow melt water can infiltrate and act on the geo-hydrological system. With the aim of enhancing the slope stability employing NBS, a detailed analysis of the hydrogeology and the slope characteristics have been carried out, obtaining the required technical parameters describing the involved soil material. Furthermore, a slope stability analysis by means of different numerical models has been performed. Results prove that variations of the groundwater level in the range of 1-2 m can strongly affect the stability of the slope. Thus, specific NBS should aim at reducing the amount of infiltrating water. Examples of such NBS include the adaptation of forest management and land use planning, the introduction and re-activation of drainage channels and the sealing of leaky streams and channels. Beside the effects of the variation of the groundwater level, results have proved that the slope could fail under the action of a moderate seismic load. In this scenario, it is likely that the effects of the NBS would be insufficient to maintain the slope intact.</p>

Operationalising nature-based solutions for mitigating hydro-meteorological hazards

<p><strong>Operationalising nature-based solutions for mitigating hydro-meteorological hazards</strong></p><p><strong> </strong><strong>Prashant Kumar<sup>1,*</sup>, Sisay Debele<sup>1</sup>, Jeetendra Sahani<sup>1</sup>, Silvana Di Sabatino<sup>2</sup></strong></p><p><strong><sup> </sup></strong><sup>1</sup>Global Centre for Clean Air Research (GCARE), Department of Civil and Environmental Engineering, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH, United Kingdom</p><p><sup>2</sup>Department of Physics and Astronomy, University of Bologna, Viale Berti Pichat 6/2, 40127, Bologna, Italy</p><p><sup>*</sup>Presenting author. Email: [email protected]</p><p><strong>Abstract </strong></p><p>The impact of weather- and climate-related hydro-meteorological hazards (HMHs) is amongst the greatest global challenges society is facing today. The concept of nature-based solution (NBS) is becoming popular for HMH management but the lack of knowledge on NBS designing and effectiveness is hindering its wider acceptance. This work discusses HMH risk analysis, relevant data, the role of NBS and its operationalisation by bringing co-design concept and testing them in OPERANDUM project’s open-air laboratories (OALs). HMH risk assessment employs different methodologies with respect to exposure, vulnerability and adaptation interaction of the elements at risk. The classification and effectiveness of any NBS depend on its location, design, typology and environmental conditions. OALs, via the collaboration of researchers and end-users, can foster increasing uptake, upscaling, replication and implementation of NBS projects as compared to traditional grey infrastructure approach. Multi-hazard risk analysis and inclusion of NBS into policy plans can foster NBS operationalisation processes across all sectors and at levels by fostering participatory processes such as co-design, co-creation and co-management among municipalities, researches, policy-makers, funding agencies and other stakeholders; and can inspire more effective use of skills, knowledge, manpower, as well as economic, social and cultural resources. NBS data monitoring, its standardisation, accessible storage and compliance with existing standard metadata is needed. The monitoring and evaluation manuals and guidelines are needed to decrease uncertainty about performance and overall cost-effectiveness of NBS and overcome potential hurdles to create long-term stability and enhance the wider uptake of NBS.   </p><p>Keywords: Hydro-meteorological hazards, nature-based solution, climate change, policy, co-design, co-creation, operationalisation </p><p><strong>Acknowledgement</strong><strong>s</strong>: This work is carried out under the framework of OPERANDUM (OPEn-air laboRAtories for Nature baseD solUtions to Manage hydro-meteo risks) project, which is funded by the Horizon 2020 under the Grant Agreement No: 776848. We thank OPERANDUM collaborators (Laura Leo, Francesca Barisanid, Bidroha Basu, Edoardo Bucchignani,  Nikos Charizopoulosg, Alessio Domeneghetti,  Albert Sorolla Edo, Leena Finér, Glauco Gallotti,  Sanne Juch, Michael Loupis, Slobodan B. Mickovski, Depy Panga, Irina Pavlova, Francesco Pilla, Adrian Löchner Prat, Fabrice G. Renaud, Martin Rutzinges,  Arunima Sarkar, Mohammad Aminur Rahman Shah, Katriina Soini, Maria Stefanopoulou, Elena Toth, Liisa Ukonmaanaho, Sasa Vranic, Thomas Zieher, for their contributions.</p>