ITS4.2/ERE1.11

Check dam plays a crucial role in controlling soil erosion on the Loess Plateau and reducing sediment loads in the Yellow River. Moreover, sediment deposition in check dams also provides valuable information for understanding of soil erosion on the Loess Plateau. Study on the influence of rainfall patterns on sediment yield in small catchments scale is significant for the reasonable arrangement of soil and water conservation measures, particularly for complex environments such as the wind-water erosion crisscross region. This study estimated sediment yield trapped by the check dam in Laoyeman catchment based on deposited flood couplets formed in erosion rainfall events during the period 1978-2010. All erosive rainfall were divided into three rainfall patterns according to the precipitation, rainfall duration and rainfall erosivity, and the correspondence analysis between sediment yield and rainfall pattern was analyzed. Results showed that there were 1.1´10⁵ t sediment deposited in the dam filed during the trapping history of the check dam as a whole. It has three obvious change stages, which had sediment yield of 4.53´10⁴ t during 1978-1988, 4.48´10⁴ t during 1988-1997, and 1.68´10⁴ t during 1997-2010, respectively. The stage 1989-1997 had the fastest annual deposition rate of 4.98×10³ t·year^-1, 20.9% and 286% faster than stage 1978-1988 and stage 1998-2010. For similar rainfall pattern in these three stages, sediment yield and the characteristic of flood couplet change were closely related to both rainfall erosivity and land use types. This was also approved by the significant decrease of sediment yield on condition of similar rainfall pattern in a decade before and after the implementation of Grain for Green project indicated that this project made a great contribution to the control of soil erosion on the Loess Plateau. The impact of rainfall pattern on sediment yield indicated that the largest sediment yield is initiated under short duration and high intensity rainfall events, while the sediment in the reservoir area is mainly deposited under the rainfall pattern of moderate precipitation, erosivity and duration. That is the reason for the wettest year (1995) had relatively low sediment deposition, while the year (1982) had strong rainfall erosivity had the maximum annual sediment yield (1.68´10⁴ t).

How to cite: Yin, M. and Zhang, J.: Influence of rainfall patterns on sediment yield in flood couplets of a check dam on the Chinese Loess Plateau, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3322, https://doi.org/10.5194/egusphere-egu22-3322, 2022.

An increasing world population and change in consumer preferences necessitate the need to increase food production to meet the demand of a changing world. Intensified agriculture and an accelerated climate crisis with increasing weather extremes threaten the resource base needed to improve crop production. Maize yield obtained by farmers in the guinea savannah zone of Ghana is generally low due to low soil fertility status resulting from continuous cropping coupled with low use of external inputs. Integrated Soil Fertility Management (ISFM) practices have proven to sustainably increase maize yield. However, majority of the farmers practicing ISFM till their land conventionally, potentially resulting in substantial greenhouse gases (GHG) emissions that contribute to global climate change. However, there is dearth of information on GHG emissions regarding crop production systems in sub-Saharan Africa in general and Ghana in particular. Hence, within a field trial we seek to investigate the impact of different tillage practices and ISFM applied to sustain maize yield, on net CO₂ or ecosystem exchange (NEE) and net carbon (C) balance (NECB). The field trial was established at the Council for Scientific and Industrial Research-Savanna Agricultural Research Institute in Northern region of Ghana. A split plot design was used with the main plot treatments being conventional tillage and reduced tillage and the subplot treatments being factorial combination of organic and inorganic fertilizers at three levels each. To determine NEE and thereon based estimates of NECB, an innovative, customized, low-cost manual, dynamic closed chamber system was used. The system consists of transparent (V: 0.37 m³, A: 0.196 m²; for NEE measurements) and opaque chambers (for ecosystem respiration (R_eco) measurements) of the same size. Diurnal regimes of R_eco and NEE fluxes were measured twice a month by repeatedly deploying chambers for 5 to 10min on the 3 repetitive measurement plots (PVC frames inserted 5 cm deep into the soil as collars) per treatment. CO₂ concentration increase and decrease over chamber deployment time was detected by portable, inexpensive Arduino based CO₂ logging systems, consisting of a battery powered microcontroller (Arduino Uno) and data logging unit (3 sec frequency) connected to an NDIR-CO₂ sensor (SCD30; ± 30 ppm accuracy), air temperature and humidity (DHT-22) as well as air pressure sensor (BMP280). Measured CO₂ fluxes were subsequently gap-filled to obtain seasonal NEE. C import and export were further on added to NEE to determine the NECB for each treatment. In parallel to CO₂ exchange measurement campaigns, agronomic and crop growth indices such as the normalized difference vegetation index (NDVI) were performed biweekly at all plots. Here we present NEE and NECB balances for the first crop growth period.

Keywords: Tillage, Integrated soil fertility management, CO₂ emission, Zea mays, net ecosystem carbon balance (NECB)

How to cite: Asante, M., Naab, J., Agyei Frimpong, K., Traore, K., Augustin, J., and Hoffmann, M.: Effect of soil management practices on soil carbon dynamics under maize cultivation, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-6317, https://doi.org/10.5194/egusphere-egu22-6317, 2022.

Agricultural ecosystems provide essential services mainly through food, feed, fiber and consequently income but they also contribute cultural, supporting and regulating services. In turn, farming can adversely affect ecosystem services, especially those from natural ecosystems, if farming practices are unsustainable.

Recently, a Sustainable Agriculture Matrix (SAM; https://doi.org/10.1016/j.oneear.2021.08.015) of indicators across environmental, economic, and social dimensions has been developed by an international research team to coherently quantify the sustainability of countries’ farming systems globally. The focus was on indicators that can be tracked over time and relate to performance to facilitate analyzes of synergies and trade-offs. At present, this indicator system is being co-evaluated with stakeholders in ten countries within an international consortium including Austria, to elicit stakeholders’ appraisal of the framework’s applicability in their specific geographical and socioeconomic context and eventually co-design a revised matrix based on stakeholders’ requirements.

A first workshop has shown that most indicators from the environmental dimension are useful for stakeholders in the Austrian context, but some need further refinements. Biodiversity, for example, is only considered via land cover change whereas threats to (agro-)biodiversity in Austria and the EU foremost occur in-situ. The economic dimension is ranking second in its usefulness for Austrian stakeholders with few indicators such as food loss being of little relevance. The indicators presently included in the social dimension are least relevant as they cover aspects such as land rights, undernourishment, and rural poverty, which do not pose major issues in Austria and more broadly the EU.

General concerns of stakeholders are the directionality of indicator ratings and their scope which is in part considered too narrow. E.g., high government expenditure for agriculture is considered positive in the matrix regardless of its purpose and may cause dependencies. Human nutrition is only included via undernourishment and soil nutrient status solely as surplus, whereas in both cases also the other extreme may be adverse. Accordingly, a bell-shaped indicator and rating would be favored in such cases. A general requirement was expressed for an additional context dimension. Governance arrangements and the overall socioeconomic situation are so far deliberately not included due to the focus on performance in the existing SAM. Yet, indicators describing such framework conditions can be essential to interpret synergies and trade-offs and the effectiveness of policy measures aiming at achieving SDGs. Beyond the evaluation of existing indicators, the stakeholder process yielded comprehensive suggestions for additional indicators, covering biodiversity, research and education, self-sufficiency, as well as various aspects of resilience and stability. Overall, the co-evaluation with stakeholders highlights that only few globally defined indicators are readily applicable in a regional context where consideration of local conditions and specifics is vital.

The proposed revisions are now being matched with available data across geographic scales to revise the matrix and perform further analyses on trade-offs and synergies. This will also include further context information to facilitate the evaluation of policies, ultimately allowing for improved policy-making to attain agricultural sustainability. Results will be further co-evaluated iteratively with stakeholders to eventually produce a globally applicable indicator system.

How to cite: Folberth, C., Sinabell, F., Schinko, T., and Hanger-Kopp, S.: Co-evaluating and -designing a Sustainable Agriculture Matrix for Austria in an international context, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9474, https://doi.org/10.5194/egusphere-egu22-9474, 2022.

PHUSICOS platform aims at gathering nature-based solutions (NBS) relevant to reduce hydro-geological risks in mountain landscapes. The platform can be accessed directly through a web portal. It is based on an Open Source CMS website, including a filter to store documents and a map server to bring ergonomic and powerful access.

To design the platform, an in-depth review of 11 existing platforms has been performed.  Furthermore, a list of metadata has been proposed to structure the information. These metadata have provided the baseline for database. The PHUSICOS platform currently references 176 NBS cases and 83 documents of interest (review articles, assessment papers…). It is continuously enriched through the contribution of NBS community.

For that, a questionnaire based on relevant data, necessary for the definition and identification of the NBS (metadata, to be used for searching the NBSs within the platform) has been defined to enter new entries. A preliminary analysis of the cases has been realized. To characterize and analyse the current 152 solutions, we have worked on the following four categories: The nature of impacted ecosystems, The hazard(s) concerned, The other challenges treated by the NBS, The type of exposed assets.

The platform also proposes a qualitative assessment of the NBSs collected according to 15 criteria related with five ambits: disaster risk reduction, technical and economical feasibility, environment, society, and local economy. The criteria level is sufficiently general to be analysed for the entire PHUSICOS platform NBSs whatever the type of work, the realized approaches, the problematic or the spatial or temporal scale.

The structure of the platform and a first analysis of the qualitative NBS assessment are presented in this work.

How to cite: Bernardie, S., Baills, A., and Garçin, M.: PHUSICOS platform, dedicated to Nature-Based Solutions for Risk Reduction and Environmental Issues in Hilly and Mountainous Lands : presentation and qualitative NBS assessment, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7664, https://doi.org/10.5194/egusphere-egu22-7664, 2022.

An adequate strategy for water quality improvement in developing countries must consider the economic scarcity of water, the external factors that affect its quality, and the participation of multisectoral stakeholders in water management decisions. In addition, stronger links to nature can be established through methods inspired from nature to clean the water, such as artificial floating islands (AFI). Restoration of aquatic ecosystems with AFIs occurs as water passes beneath the floating mat and the roots of macrophytes take up metals and nutrients. In this context, we utilized Fuzzy Cognitive Maps (FCMs) to identify the principal concepts that affect water quality from different perspectives: political, economic, social, technological, environmental, and legal (PESTEL). We also theoretically explore the use of AFIs combined with different policies, to find the strategy that best adapts the local water situation.

By applying the principles of FCMs, different sources of knowledge can predict the effects of policy, and problems can be identified using the centrality index of the underlying graph theory. Thus, a two-step approach was implemented for our analysis: First, from 40 literature-based PESTEL concepts related to water quality deterioration, local experts in water management were invited to identify the most influential concepts and to include additional ones regarding the local water situation and policies to support the improvement of water quality. Second, workshops were organized, inviting members of communities to discuss the degree of cause-effect influence of the identified concepts, and also to include a water management policy, considering AFIs as one solution.

Three Ecuadorian communities distributed to cover representative ecosystems from the Pacific coast, Andean mountains, and Amazon floodplain were selected for this research, i.e. the community of Mogollón dominated by mangroves land cover, Chilla chico by páramos, and Awayaku by rainforest. According to the FCMs, 21 PESTEL concepts affect water quality in the páramos community and most of them are related to politics (23%) and the environment (23%). Community workshop at the same community identify that the major problem is related to natural water pollutants. For the mangrove community, 23 concepts were identified mainly driven (47%) by environmental concepts, whereas the communities see the major water quality issue in view of human exposure to environmental pollutants. In the case of the rainforest community, 19 concepts were recognized with 40% related to economics, whereas the communities identify the principal concern being the violation of environmental legislation. Regarding the potential implementation of AFIs, the páramos community concludes that AFIs should be implemented and coupled with environmental education programs. Additionally, water-related governmental institutions should be involved during realization. The mangrove community shows interest in AFIs, when combined with payment for ecosystem services. Finally, the rainforest community do not consider AFIs as a primary solution. Instead they propose the creation of a committee to denounce violations of water quality laws and to improve the educational level of community members. In conclusion, the FCM is a powerful tool to bring together the knowledge of multisectoral stakeholders and to analyse suitable strategies for the local improvement of water quality.

How to cite: Fonseca, K., Correa, A., and Breuer, L.: Using the fuzzy cognitive map approach to promote nature-based solutions as a strategy to improve water quality in Ecuadorian communities, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8395, https://doi.org/10.5194/egusphere-egu22-8395, 2022.

Social learning is increasingly used to address environmental challenges including sustainable farming. How sustainable agricultural knowledge is co-produced, shared and used between farmers, scientists and government is important for building capacity and trust for sustainability in stressed socio-ecological communities worldwide. However, such understanding is largely lacking in developing economies. This research presents the findings from analysis of smallholder farmers’ social learning in three agricultural regions in China. Combining an existing social capital framework with questionnaires (Q) and interviews (I) with farmers (Q n=632; I n=30) and officials (Q n=77, I n=64), we demonstrate how farmers access and share farming knowledge through bonding, bridging and linking networks. In two regions, family bonding was the dominant learning pathway while linking networks to access ‘formal knowledge’ from government (or scientists) were limited. However, in the third region, government played a more important role in farmers’ knowledge sharing and acquisition processes. In all regions, learning from researchers was largely absent. Key suggestions about ways to enhance use of multiple forms of knowledge are provided. First, this study highlights the need for a more locally and socially embedded approach to facilitate enhanced farmers’ knowledge exchange and learning, to then build trust and capacity to help better address pressing local environmental challenges. Second, we show how social dynamics research can usefully inform knowledge exchange plans for collaborative, international development science, so that it can be best suited to local contexts, to optimise research impacts, capacity building and avoiding of mismatches. 

How to cite: Zheng, Y., Naylor, L. A., Wang, W., Stanton, A., Oliver, D., Munro, N., Chng, N. R., Waldron, S., and Peng, T.: Social capital in stressed social-ecological systems: understanding social learning in agricultural communities in China to aid environmental policy and practice, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-12354, https://doi.org/10.5194/egusphere-egu22-12354, 2022.

When assessing strategies for implementation of Nature-Based Solutions (NBS) it is fundamental to quantify all benefits for securing better, informed decision making. Particularly relevant is the quantification of their multiple co-benefits for communities and the environment. One of the most widespread techniques to quantify these values is to use contingent valuation (CV) methods, such as the Willingness-To-Pay (WTP) approach. Within the CV method, questionnaires are the main tool used to elicit the value attributed to a specific good by the respondents. However, many studies focus on site-specific economic valuation, whereby transferability to other locations is jeopardized. We therefore created a survey to explore how the valuation of an NBS is shaped by its relationship with the users (e.g. frequency and length of visits), and how these responses are linked to both the respondents and the sites’ characteristics (e.g. socio-economic status, size of the NBS, etc.).

We applied this method to a case study comprised of two distinct areas located in Aarhus, Denmark, asking users to explore their perception of the two NBS sites with different features. Both NBS sites have as overarching goals to (i) prevent flooding from cloudburst or water bodies, (ii) improve the biodiversity in the area, and (iii) benefit the local population, e.g. by providing more recreational areas. Despite these common goals, the two sites differ by a number of characteristics, i.e. size, location, and time passed since construction. One NBS involves a large artificial lake in a peri-urban setting, while the other is a small urban park. Respondents were allowed the option of either expressing a value for only one, or for both of the sites. 

We analyzed both responses that stated a WTP and protest votes, that is, responses that rejected the valuation scenario altogether. We found that older citizens are more likely to protest, as well as those not visiting the sites. For the respondents who accepted to state a WTP, their bids significantly increased when the improvement of nature and biodiversity was mentioned in the valuation scenario. Comparing the value given to the two different sites, the characteristics of the NBS seem to play a role in the respondents’ perception and use of the sites, which in turn enhances valuation. In our case study, people’s perception of the site and their relationship with it appear to have a stronger link with the WTP than their socio-economic characteristics. Specifically, frequency and length of visits, and interest in a good quality of nature were mostly related to a positive WTP.

The inclusion of people-NBS relational variables in benefit quantifications appears to be an essential tool to realize a more realistic economic valuation, as well as correctly design NBS in order to achieve the desired impacts. Understanding the underlying synergies between the multiple co-benefits of NBS, their features and the users’ perception is decisive for maximizing these strategies’ potential and avoiding missing opportunities.

How to cite: Viti, M., Löwe, R., Sørup, H. J. D., Mcknight, U. S., and Arnbjerg-Nielsen, K.: Assessing the interconnections between the characteristics, perception, and valuation of Nature-Based Solutions: A case study from Aarhus, Denmark, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3784, https://doi.org/10.5194/egusphere-egu22-3784, 2022.

Sustainable river management frameworks are based on the connection between citizens and nature. So far, though, the relationship between rivers and local populations has played a marginal role in river management. We present a blueprint questionnaire to characterize the perception of cultural ecosystem services and flood risk by locals, and how preferences change across the river landscape. We investigate how locals value the river and whether their preferences are affected by characteristics such as place of residence, age, frequency of visits and relation to the river. The approach is tested on the Tagliamento river, the last major free-flowing river in the Alps, which is characterized by debates on flood protection, flood management and ecological conservation. The questionnaire was filled in by more than 4000 respondents, demonstrating huge interest and willingness to contribute with their opinion on this topic. A participatory map of favorite places shows that most of the river is valued/appreciated by locals, with a high preference for the landscape of the braided middle course. River conservation is the main priority for most respondents across different stakeholder groups, highlighting the need for nature-based solutions in flood-risk management and demonstrating the mismatch between management choices and citizens´ values and priorities. Land-use planning is identified as a factor that can increase flood risk. The results highlight the necessity to tackle conservation, risk management and land-use planning together in order to develop risk-oriented river management strategies. More generally, this work points out that any river intervention should be pondered carefully accounting for its environmental impact also in terms of loss of cultural ecosystem services.

How to cite: Scaini, C., Stritih, A., Brouillet, C., and Scaini, A.: What locals want: (mapping) citizen preferences and priorities for an alpine river landscape, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-2049, https://doi.org/10.5194/egusphere-egu22-2049, 2022.

Fire regimes form an integral part of terrestrial biomes in the Mediterranean region as they provide essential disturbances which change the structure and function of plants that favour Mediterranean type climates. Fire is inextricably linked to such ecosystems and cannot be excluded from them. However, the intensification of human activities in Greece, coupled with increasingly unpredictable wildfires has created huge imbalances and jeopardised the ecological integrity of ecosystems. Expansions into the wildland urban interface, rural abandonment, and the focus on fire suppression are increasing the vulnerability and flammability of the Greek environment. The duality of fire is delicate, both at local and national level, catastrophic wildfires singe deeply on landscapes and economies, social burns can take just as long to heal. In Greece, this is further exacerbated by the burgeoning socio-economic and political complexities that have catalysed the current ineffective and unsustainable fire management strategies. Damages from wildfires affect ecosystem services which can lead to a reduction in human wellbeing. Understanding the interactions between ecosystems and humans through environmental valuation is key to implementing effective policy. This study uses economic valuation methods in the form of a choice experiment to elicit public preference for a wildfire management policy in Crete. A survey was deployed around the island, with respondents asked about their preferences between different management strategies. The policies outlined in the survey are made up of the following attributes: risk of fire, agricultural production, landscape quality and post-wildfire damage mitigation. Results from this study indicate a positive preference by the public for a new proposed policy. The findings from this study can be used for decision making in Crete and other similar southern European environments by providing metrics for appropriate wildfire management.

How to cite: Misal, H., Kountouris, I., Voulgarakis, A., and Rovithakis, A.: Eliciting public preferences for wildfire management policies in Crete, Greece, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9542, https://doi.org/10.5194/egusphere-egu22-9542, 2022.