Simulating Rural Environmentally and Socio-Economically Constrained Multi-Activity and Multi-Decision Societies in a Low-Data Context: A Challenge Through Empirical Agent-Based Modeling

Development issues in developing countries belong to complex situations where society and environment are intricate. However, such sites lack the necessary amount of reliable, checkable data and information, while these very constraining factors determine the populations' evolutions, such as villagers living in Sahelian environments. Beyond a game-theory model that leads to a premature selection of the relevant variables, we build an individual-centered, empirical, KIDS-oriented (Keep It Descriptive & Simple), and multidisciplinary agent-based model focusing on the villagers\' differential accesses to economic and production activities according to social rules and norms, mainly driven by social criteria from which gender and rank within the family are the most important, as they were observed and registered during individual interviews. The purpose of the work is to build a valid and robust model that overcome this lack of data by building a individual specific system of behaviour rules conditioning these differential accesses showing the long-term catalytic effects of small changes of social rules. The model-building methodology is thereby crucial: the interviewing process provided the behaviour rules and criteria while the context, i.e. the economic, demographic and agro-ecological environment is described following published or unpublished literature. Thanks to a sensitivity analysis on several selected parameters, the model appears fairly robust and sensitive enough. The confidence building simulation outputs reasonably reproduces the dynamics of local situations and is consistent with three authors having investigated in our site. Thanks to its empirical approach and its balanced conception between sociology and agro-ecology at the relevant scale, i.e. the individual tied to social relations, limitations and obligations and connected with his/her biophysical and economic environment, the model can be considered as an efficient "trend provider" but not an absolute "figure provider" for simulating rural societies of the Nigrien Sahel and testing scenarios on the same context. Such ABMs can be a useful interface to analyze social stakes in development projects.Rule-Based Modelling, Rural Sahel, Confidence Building, Low-Data Context, Social Criteria

Characteristics and causes of natural and human-induced landslides in a tropical mountainous region: the rift flank west of Lake Kivu (Democratic Republic of the Congo)

Tropical mountainous regions are often identified as landslide hotspots with growing population pressure. Anthropogenic factors are assumed to play a role in the occurrence of landslides in these densely populated regions, yet the relative importance of these human-induced factors remains poorly documented. In this work, we aim to explore the impact of forest cover dynamics, roads and mining activities on the characteristics and causes of landslides in the rift flank west of Lake Kivu in the Democratic Republic of the Congo (DR Congo). To do so, we compile a comprehensive multi-temporal inventory of 2730 landslides. The landslides are of different types and are grouped into five categories that are adapted to study the impact of human activities on slope stability: old (pre-1950s) and recent (post-1950s) deep-seated landslides, shallow landslides, landslides associated with mining and landslides associated with road construction. We analyse the landslides according to this classification protocol via frequency–area statistics, frequency ratio distribution and logistic regression susceptibility assessment. We find that natural factors contributing to the cause of recent and old deep-seated landslides were either different or changed over time. Under similar topographic conditions, shallow landslides are more frequent, but of a smaller size, in areas where deforestation has occurred since the 1950s. We attribute this size reduction to the decrease in regolith cohesion due to forest loss, which allows for a smaller minimum critical area for landsliding. In areas that were already deforested in the 1950s, shallow landslides are less frequent, larger and occur on less steep slopes. This suggests a combined role between regolith availability and soil management practices that influence erosion and water infiltration. Mining activities increase the odds of landsliding. Landslides associated with mining and roads are larger than shallow landslides but smaller than the recent deep-seated instabilities, and they are controlled by environmental factors that are not present under natural conditions. Our analysis demonstrates the role of human activities on the occurrence of landslides in the Lake Kivu region. Overall, it highlights the need to consider this context when studying hillslope instability characteristics and distribution patterns in regions under anthropogenic pressure. Our work also highlights the importance of using landslide classification criteria adapted to the context of the Anthropocene.</p

Framework for assessing sustainability levels in Belgium agricultural systems - SAFE

Sustainability is now regarded as a crucial property of agricultural systems and its evaluation has become a main challenge for scientists, policy makers and farmers. In the last decade, different sets of indicators have been designed both at national and international levels. Meanwhile, more practical environmental impact assessment (EIA) tools have been developed at the farm level . However, none of these indicator sets can be used at both levels. Further, most of these initiatives focus only on environmental aspects of sustainability and do not take socio-economic aspects into consideration. Indicator selection does not always fit in a consistent and comprehensive framework, although there is a strong need to integrate sustainability indicators in order to facilitate comparison and assessment. Finally, few of these works relate to Belgian agriculture, which up til now lacked a tool for assessing the sustainability of its farms. This project aims at providing a framework for assessing sustainability levels in Belgian agricultural systems (SAFE) that overcomes the deficiencies mentioned above. This is achieved by: 1. Considering the concept of agricultural sustainability in a holistic manner – SAFE accounts for all three pillars of sustainability (environmental, economic & social). 2. Developing (a) a consistent approach for defining sustainability principles and criteria and (b) a core list of sustainability indicators identified through a standardized selection procedure. The ‘SAFE selection procedure’ is a flexible scientific process that builts on knowledge and experience of numerous experts. 3. Ensuring that the tool remains as easy as possible to interpret and thus to use, thanks to the integration procedure of sustainability indicators and the graphic expression of the results. 4. Building on a generic methodology. Though the set of selected indicators presented in this report is specific to the Belgian agricultural context, the method developed for the construction of the SAFE tool can be transferred for assessing sustainability levels in other geographical (Europe, world, …) and sectorial contexts. In particular, principles and criteria defined in SAFE have a universal value. 5. Taking action at three spatial levels, depending on the scale of application: (1) parcel (2) farm or (3) watershed for surface water-related issues, landscape/ecosystem for some soil and biodiversity related issues, and administrative units (region, state) for some environmental as well as for some socio-economic issues

Quantifying the direct impacts and risks of large urban gullies in the Democratic Republic of Congo

peer reviewedLarge urban gullies (UGs) cause major infrastructural damages and often claim casualties in many tropical cities of the Global South. Nonetheless, our insight into this new type of geo-hydrological hazard remains limited to some case studies and the overall impacts remain poorly quantified. Here, we aim to bridge this gap by making a first assessment of the number of persons affected by urban gullies at the scale of the Democratic Republic of Congo (DRC). We used Google Earth imagery in combination with local news sources and earlier research to identify 25 cities in DRC where UG occur at a significant scale (at least ten UGs). This list is likely exhaustive. Next, for each of these cities, we used Google Earth imagery and other high resolution satellite images to map all visible UG, evaluate their expansion rate and inventorize detectable damages to houses and roads. In total, >2,000 UGs were mapped across the 25 affected cities. Overall, the problem of UGs in DRC is especially acute in the cities of Kinshasa, Mbujimayi, Kikwit, Tshikapa and Kananga. Over 90% of these gullies were active during the observation period (typically from 2002 to 2020). Next, we assessed the total number of persons that are directly affected, as well as the number of persons currently at risk. Using available high resolution population density data and taking into account the current position of urban gullies, we estimate that around 68,700 people were directly displaced due the formation and expansion of UGs over the last 15 years. This corresponds to an average of ca. 4,300 persons per year. By considering the population that lives in the direct vicinity (<100 m) of an UG, we estimate that around 1.3 million people in D.R. Congo are currently at risk and/or experience significant impacts because of UGs (e.g. reduced land value, problems with trafficability, stress). This number has doubled over the past 10 years (2010-2020) and will likely continue to increase as a result of urban expansion and climate change. Overall, this research shows that urban gullying is a very serious problem in the Democratic Republic of Congo, but likely also in many other countries of the Global South. More research is needed to better understand this processes and, ultimately, to prevent and mitigate its impacts. The results and the database of this study provide an important step towards this

Framework for assessing sustainability levels in Belgium agricultural systems - SAFE

Sustainability is now regarded as a crucial property of agricultural systems and its evaluation has become a main challenge for scientists, policy makers and farmers. In the last decade, different sets of indicators have been designed both at national and international levels. Meanwhile, more practical environmental impact assessment (EIA) tools have been developed at the farm level . However, none of these indicator sets can be used at both levels. Further, most of these initiatives focus only on environmental aspects of sustainability and do not take socio-economic aspects into consideration. Indicator selection does not always fit in a consistent and comprehensive framework, although there is a strong need to integrate sustainability indicators in order to facilitate comparison and assessment. Finally, few of these works relate to Belgian agriculture, which up til now lacked a tool for assessing the sustainability of its farms. This project aims at providing a framework for assessing sustainability levels in Belgian agricultural systems (SAFE) that overcomes the deficiencies mentioned above. This is achieved by: 1. Considering the concept of agricultural sustainability in a holistic manner – SAFE accounts for all three pillars of sustainability (environmental, economic & social). 2. Developing (a) a consistent approach for defining sustainability principles and criteria and (b) a core list of sustainability indicators identified through a standardized selection procedure. The ‘SAFE selection procedure’ is a flexible scientific process that builts on knowledge and experience of numerous experts. 3. Ensuring that the tool remains as easy as possible to interpret and thus to use, thanks to the integration procedure of sustainability indicators and the graphic expression of the results. 4. Building on a generic methodology. Though the set of selected indicators presented in this report is specific to the Belgian agricultural context, the method developed for the construction of the SAFE tool can be transferred for assessing sustainability levels in other geographical (Europe, world, …) and sectorial contexts. In particular, principles and criteria defined in SAFE have a universal value. 5. Taking action at three spatial levels, depending on the scale of application: (1) parcel (2) farm or (3) watershed for surface water-related issues, landscape/ecosystem for some soil and biodiversity related issues, and administrative units (region, state) for some environmental as well as for some socio-economic issues

Using the DSSAT Model to Support Decision Making Regarding Fertilizer Microdosing for Maize Production in the Sub-humid Region of Benin

Fertilizer microdosing is being widely promoted across sub-Saharan Africa, yet all recommendations regarding this technology are derived from short-term studies. Such studies are insufficient to properly assess the production risk caused by climatic variability. To address this issue while avoiding costly long-term experiments, a common and well accepted strategy is to combine results from short-term experiments with validated dynamic crop models. However, there have been few documented attempts so far to model fertilizer microdosing under sub-humid tropical conditions. The objective was therefore to evaluate the potential of the DSSAT model for simulating maize response to fertilizer microdosing, and to use the validated model to assess the effects of inter-annual rainfall variability on maize productivity and economic risk. The model was calibrated and validated against data from a 2-year on-station experiment (2014 and 2015) with 2 levels of hill-placed manure and five mineral fertilization options including broadcast and fertilizer microdosing. Model simulations were in good agreement with the observed grain and biomass yields for conventional broadcast fertilization, with relative RMSE and d-values of 12% and 0.96 for grain and 8% and 0.97 for biomass, respectively. For fertilizer microdosing, the N stress coefficient needed to be adjusted to avoid occurrence of large N stresses during simulation. After optimization, the model adequately reproduced grain yields for fertilizer microdosing, with relative RMSE of 10%. Considering the long-term scenario analysis, the use of the validated model showed that the application of 2 g of NPK15−15−15 fertilizer + 1 g urea per hill (equivalent to 23.8 kg N ha−1, 4.1 kg P ha−1 and 7.8 kg K ha−1) improved both the minimum guaranteed yield and the long-term average without increasing inter-annual variability and the economic risk compared to unfertilized plots. Even though combining microdosing with manure (1–3 t ha−1) was economically slightly riskier than microdosing alone, this risk remained low since a value-cost ratio of 2 could be achieved in almost 100% of the years. Furthermore, combined application consistently reduced the inter-annual yield variability. Considering this as well as the other benefits of manure for soil health, combining microdosing with small quantities of manure would be recommended to increase the sustainability of the system

Measuring, modelling and managing gully erosion at large scales: A state of the art

Soil erosion is generally recognized as the dominant process of land degradation. The formation and expansion of gullies is often a highly significant process of soil erosion. However, our ability to assess and simulate gully erosion and its impacts remains very limited. This is especially so at regional to continental scales. As a result, gullying is often overlooked in policies and land and catchment management strategies. Nevertheless, significant progress has been made over the past decades. Based on a review of >590 scientific articles and policy documents, we provide a state-of-the-art on our ability to monitor, model and manage gully erosion at regional to continental scales. In this review we discuss the relevance and need of assessing gully erosion at regional to continental scales (Section 1); current methods to monitor gully erosion as well as pitfalls and opportunities to apply them at larger scales (section 2); field-based gully erosion research conducted in Europe and European Russia (section 3); model approaches to simulate gully erosion and its contribution to catchment sediment yields at large scales (section 4); data products that can be used for such simulations (section 5); and currently existing policy tools and needs to address the problem of gully erosion (section 6). Section 7 formulates a series of recommendations for further research and policy development, based on this review. While several of these sections have a strong focus on Europe, most of our findings and recommendations are of global significance.info:eu-repo/semantics/publishedVersio

EUSEDcollab: a network of data from European catchments to monitor net soil erosion by water

As a network of researchers we release an open-access database (EUSEDcollab) of water discharge and suspended sediment yield time series records collected in small to medium sized catchments in Europe. EUSEDcollab is compiled to overcome the scarcity of open-access data at relevant spatial scales for studies on runoff, soil loss by water erosion and sediment delivery. Multi-source measurement data from numerous researchers and institutions were harmonised into a common time series and metadata structure. Data reuse is facilitated through accompanying metadata descriptors providing background technical information for each monitoring station setup. Across ten European countries, EUSEDcollab covers over 1600 catchment years of data from 245 catchments at event (11 catchments), daily (22 catchments) and monthly (212 catchments) temporal resolution, and is unique in its focus on small to medium catchment drainage areas (median=43km2, min=0.04km2, max=817km2) with applicability for soil erosion research. We release this database with the aim of uniting people, knowledge and data through the European Union Soil Observatory (EUSO)

Les aménagements et techniques anti-érosifs

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Erosion éolienne dans le Sahel nigérien: perception paysanne, causes et moyens de lutte

En zone sud-sahélienne du Niger, les changements d'occupation du sol et les pratiques agropastorales sont à l'origine de modifications des états de surface qui conduisent à une augmentation du risque d'érosion éolienne. Ce risque est clairement perçu par les paysans sahéliens. Les jachères constituent actuellement encore d'importantes zones tampons sans toutefois empêcher la dégradation des terres cultivées. Différents techniques de lutte contre l'érosion éolienne se sont avérées efficaces mais leur mise en œuvre se heurte au fait que les zones où l'érosion éolienne est la plus active sont aussi celles où la lutte contre ce phénomène est la moins prioritaire pour les populations. L'intégration de la lutte contre l'érosion éolienne dans une approche globale d'amélioration du cadre de vie des populations est donc essentielle. Bibliogr., rés. en français, en anglais et en néerlandais