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A methodology for designing nature-based solutions (NBS) and soil and water bioengineering (SWB) works is proposed which includes the main particularities of this type of intervention. The dynamic nature of NBS/SWB works, their most important changes and possible critical scenarios are reflected in the proposed methodology. A clear and practical time framework for design checks is also defined. Existing structural design routines and plant root reinforcement models are integrated into the proposed time staged scheme. Likewise, the connections with the monitoring stage and the possibilities of continuous improvement are incorporated as an essential characteristic of the approach of this type of intervention. The proposed methodology is validated by means of a practical case study example embracing the whole service life of an SWB/NBS intervention. The obtained results are in good agreement with both the accumulated experience within the European SWB sector and the existing data collected in SWB monitoring works. The proposed methodology can be readily implemented in a wide range of nature restoration projects and works.

Soil and water bioengineering (SWB) is a discipline that combines technology with biology, making use of native plants and plant communities as construction material for erosion control in degraded environments. The term engineering refers to the use of technical and scientific data for constructive, stabilization and erosion control purposes and “bio” because these functions are related to living organisms, mainly native plants with biotechnical characteristics and with the purpose of restoring ecosystems and increasing biodiversity. In this approach, native plant communities’ potential is a key factor to achieve the overall objectives of planned interventions. SWB work designs involve both the integration of intrinsic adaptive information processes and legitimate design approaches (i.e. engagement of stakeholders into the project and work strategy). SWB encompass nature-based solutions (NBSs) which offer sustainable solutions in order to mitigate and adapt to climate change and effective restoration approaches suitable for degraded situations. Nowadays there is a rising awareness that nature is a very powerful source of viable solutions that use and deploy the properties of natural ecosystems and services. SWB practice is in accordance with the principles of NBSs “inspired and supported by nature”. Nature-based solutions provide sustainable, cost-effective, multipurpose and flexible alternatives for various objectives: technical, ecological, landscape integration and socioeconomics. In this context, SWB techniques offer interesting synergies with urban green and blue infrastructure strategies.

Climate change means that fire damage and torrential rains are major issues in many parts of the world, stripping watercourses and their ability to attenuate flow in ponds and weirs. Soil bioengineering methods integrate civil engineering techniques with natural materials to obtain fast, effective and economic methods of protecting, restoring and maintaining the natural slowing of water run-off. This study combines both theory and practical installation involving slope instability, erosion, soil hydrology, mountain plant ecology and land-use restoration to protect the slope against erosion and soil mass loss. Using a multidisciplinary approach, the authors explore the exchange of the stabilising role between an initially inert structure and the living material used in a bioengineering work to protect the slope against erosion and soil mass loss. From a case study investigation in Spain, the authors investigate bioengineering structures installed within erosion gullies or on eroded slopes and propose a similar measure for a site in Nepal. The transfer of know-how between eco-engineering works from different geoclimatic conditions is considered where bamboo is not a native species.

Asymmetric root distribution pattern on steep terrain is analysed by combining GPR (Ground Penetrating Radar) image analysis with a theoretical root distribution model and is verified with field investigation data. Root distribution and morphology of a mature deciduous tree were analysed in terms of the plant’s anchorage needs in an asymmetric loading condition scenario. The GPR method was combined with trench profile and root excavation techniques for both the structural and non-structural root data collection. Good correlations between the field analysis, the theoretical model outcome and the GPR output imagery were found. GPR was proven to be an efficient tool for both root lateral distribution characterisation and vertical root cluster distribution. The combination of the GPR output with a theoretical root distribution model seemed to be a viable non-invasive methodology for assessing root system vertical and horizontal distribution.

Soil and water bioengineering works can improve water quality. Soil and water bioengineering works are nature-based methods. Stakeholder inputs can improve soil and water bioengineering works. Case studies in soil and water bioengineering from the Mediterranean. New protocols and a template for soil and water bioengineering work for the Mediterranean.

Eco-engineering techniques involve the use of both plants and inert materials where, in the latter, non-treated wood is usually present. The two different elements will both evolve with time and change their mechanical properties differently. On one hand, the wood will degrade decreasing its effective cross sectional area with time. On the other hand, the live plant material will grow and propagate new roots as time progresses. Both root development and inert material changes must be accounted for in order to realistically simulate a bioengineered slope evolution and design effective eco-engineering solutions. The dynamic nature of a bioengineered work sets different scenarios throughout the slope design life. All these different stages must be taken into account in the work design process. In this work, we propose an adaptation of the existing routines and procedures of both geotechnical practice and civil engineering design scheme in order to closely reflect the inclusion of bioengineering methods in the classic geotechnical engineering problems. A design methodology covering different critical points within the lifecycle of a bioengineered slope is proposed and put into practice into the design stage for a case study in Scotland. By detecting critical points at the design stage the proposed methodology was proven to offer an improved eco-engineering work design scheme. With the use of the proposed method both external and internal stability checks with their corresponding safety factor values increase with time and there are no conflicts between the two evolving processes involved in this kind of works.

Soil loss and erosion is a major environmental problem in the Mediterranean. Soil and water bioengineering uses plants and/or parts of plants along with inert material to create solutions to fulfill soil conservation objectives combined with an ecological rehabilitation approach. The ECOMED project developed novel approaches and tools to specialize the soil and water bioengineering sector within the Mediterranean. The first activity was the Sector Needs Analysis were the responses to an online questionnaire of 110 stakeholders from the region were analyzed. The main conclusion was the need to specialize the soil and water bioengineering sector in the Mediterranean. In addition, 21 soil and water bioengineering case studies in the Mediterranean were reviewed. Many works of this type are implemented in the region, but have flaws because of the lack of training material, design routines, protocols, specific to the region. The second activity developed New Design Routines and Protocols. Specifically, three protocols, one template and one plant database were developed for the region. Finally, in the Training Material activity, six educational modules along with a handbook (that contained modules, protocols, template and case studies) were developed. Overall the ECOMED project generated new and novel material and tools that were lacking in the region to enhance the specialization process of the soil and water bioengineering sector. These should increase the adoption of soil and water bioengineering techniques with better trained and new professionals as well as improve the work performance of these interventions.

The Mediterranean ecoregion is prone to soil loss and degradation; serious problems to the human well-being. The ECOMED project promotes eco-friendly methods to mitigate such problems by generating material and tools on soil bioengineering specific for the ecoregion. Specifically, the know-how transfer within the sector is being reinforced, existing soil bioengineering works are being evaluated, new interactional schemes are being generated and new designs and protocols for the ecoregion are being developed. The current curricula and work practices of the ecoregion have been reviewed, stakeholders have participated in an online questionnaire on soil bioengineering and three protocols and a template for the ecoregion have been developed. These activities provide the information to develop the educational syllabus for the Mediterranean to train the next generation of soil bioengineering specialists. Overall all the material and tools developed will enhance the knowledge and specialisation level and promote soil bioengineering in the Mediterranean.