Displays

While depicted as a major global threat, water insecurity usually affects the most disadvantaged and marginalized people. Current definitions of water insecurity still fail to address this injustice as they either over-simplify and disconnect human-water dynamics or disregard the politics thereof. In light of this critique, this paper aims to contribute to reconceptualise water insecurity by integrating examinations of socio-political processes in analyses of chronic water insecurity and extreme drought events. To this end, we draw on sociohydrology and critical political ecology as a way to retrace the mutual shaping of hydrological flows and power dynamics that over time produce uneven geographies of water insecurity. We do so in the face of extreme droughts to understand to what extent these events intersect with the production and distribution of water insecurity. This paper draws on empirical work on the severe drought which affected Cape Town in 2015-17 and escalated into a water crisis also known as Day Zero. Despite being portrayed as a middle-class crisis, our study found that the marginalized people were the most affected while the wealthier elite were able to water secure themselves. This unequal picture sharply reflects the same water insecurities which existed long before Day Zero. We, thus, argue that they are a legacy of the spatial and economic segregation which has shaped Cape Town since colonial times. More than producing it, the drought has accelerated a pre-existing water crisis and exacerbated the level of water insecurity of every Capetonian. Proving that water insecurity is a sociohydrological phenomenon, we believe that such politically aware conceptualization is key to address its root causes and prevent the resulting injustices. Our analysis contributes to advance understanding of water insecurity by incorporating questions of uneven distribution and sociohydrological justice.

How to cite: Savelli, E., Rusca, M., Di Baldassarre, G., and Cloke, H.: Don't blame the rain: Explaining sociohydrological (in)security in Cape Town, South Africa, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-697, https://doi.org/10.5194/egusphere-egu2020-697, 2020.

Drought affects more people than any other hazard today, and its impact is likely to further increase. Yet, means to induce, aggravate or alleviate drought are also in human hands. People’s use of water, water management, and trade have consequences for spatiotemporal patterns of drought. For example, technologies for managing water supply and demand may create new vulnerabilities or interrupt supplies elsewhere. To manage drought better, human influences on drought must be better understood. Current frameworks for drought monitoring and water accounting focus on the natural boundary conditions and therefore offer little help in distilling human influences on drought. Therefore this project combines insights from socio-hydrology and water management to produce an entirely new approach, incorporating the study of water-related human dimensions, socio-hydrological dynamics, and the structuring of dialogues among actors. Tools based on the knowledge generated will empower actors to take timely and informed actions for anticipating and responding to drought. As such, lessons learnt from past droughts will be used to promote sustainable water management, enhance food security, and foster inclusive development. From 2019 a team of experts is working together in this 4-year project to make the urgently required progress by developing tools to adequately deal with drought and water scarcity. The project develops and tests the integrated, participatory 3D Drought Diagnosis (3DDD) toolbox. We investigate nested scale levels, related to local water resources and virtual-water transfers together with actor networks of users, managers, traders, and policymakers. Test case is the poor, drought-affected north-east of Brazil. The 3DDD toolbox should eventually enable existing drought monitors to provide contextualized information in drought-affected regions worldwide. Our interdisciplinary approach is innovative in three ways:

1) The innovative downstreamness concept (Van Oel et al. 2018) is used to evaluate spatiotemporal variations in drought impacts and the spatiotemporally-explicit effects of human activities. The downstreamness concept depicts the distribution of resources or activities in a river basin over space and time. The current project will further develop the downstreamness concept, to evaluate the effects of adoption of new technologies (solar pumps for irrigation, low-cost drip technologies, and artificial recharge of aquifers) on drought and its socioeconomic impacts with regard to the equitable distribution of prosperity and well-being.

2) We will evaluate basin-scale drought evolution using empirical agent-based modelling. Since contextual relativism is regarded critically, model parameterization, calibration, and validation will benefit from our participatory modelling

3) Rather than developing these important innovations in isolation, we will integrate them to yield actionable knowledge for marginalized groups, farmers, water managers, supply-chain actors, and others.

References
Van Oel, Pieter R., Eduardo S. P. R. Martins, Alexandre C. Costa, Niko Wanders, and Henny A. J. Van Lanen. 2018. 'Diagnosing drought using the downstreamness concept: the effect of reservoir networks on drought evolution', Hydrological Sciences Journal, 63: 979-90

How to cite: van Oel, P., Kchouk, S., Ribeiro Neto, G., Cavalcante, L., de Sousa Filho, F., Gondim, R., Melsen, L., Dewulf, A., and Martins, E.: Diagnosing drought for dealing with drought in 3D: Toolbox for increasing drought preparedness in north-east Brazil, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-15109, https://doi.org/10.5194/egusphere-egu2020-15109, 2020.

To clarify the nonlinear and intertwined dynamics in coupled human-water systems, we developed a stylized model that combines simple hydrological and social dynamics. In this model, neither too much nor too little water is good (think floods and droughts, respectively; this is a feature absent in previous models) and the population self-organizes to respond to relative benefits they derive from the water system and outside opportunities. Despite its simplicity, the model richly yields 6 different regimes. A closer look at the conditions giving rise to these different regimes sheds light on the design of policies and adaptation strategies for the coupled human-water system under different social-hydrological settings. Advantages and limitations of this modeling approach will also be discussed.

How to cite: Muneepeerakul, R. and Homayounfar, M.: On coupled dynamics and regime shifts in coupled human-water systems, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-3142, https://doi.org/10.5194/egusphere-egu2020-3142, 2020.

Water and environmental resources exist in complex and deeply uncertain systems of social-economic and environmental components.  As such, natural resource systems are impacted simultaneously by the diverse effects of many interacting human-environmental components. While conventional environmental planning commonly stresses estimation and prediction, preferring top-down initiatives and technocratic solutions, this approach often overlooks socio-economic impacts and interactions, leading to unexpected long-term outcomes. In response, it is now widely acknowledged that frameworks capturing the complex dynamics of society and the environment are needed to develop more sustainable environmental and water resources management strategies. Moreover, for robust policy-making, the performances of potential policies must be considered under multiple plausible conditions to enhance the chances of desired outcomes and limit the risk of undesirable results. This research addresses these challenges by considering deep uncertainty in coupled socio-economic and environmental systems.  In this study, a computational model-based approach to support adaptive decision-making under deep uncertainty is developed and applied to adaptive policy-making of sustainable water resources management for human-water systems in developing countries. The Rechna Doab region of Pakistan is considered as a case study. Qualitative-quantitative participatory exploratory modeling is performed by incorporating a physical-socioeconomic system dynamics model, a systematic scenario selection method and a scenario discovery approach.  The Driver-Pressure-State-Impact-Response (DPSIR) model is used through storytelling approaches to identify vulnerabilities in policy options in the coupled socio-economic and environmental system by considering its response to drivers, pressures, states, and impacts. Storytelling methods are used to develop qualitative storylines in order to support a detailed and stakeholder-led description of future adaptive management policies. The proposed methodology is used for systematic scenario discovery to uncover vulnerabilities across a range of possible futures and test the performance of stakeholder proposed policies. Also, the tradeoffs between water resources management alternatives, in terms of stakeholder objectives, and their robustness to deep uncertainty are assessed. The proposed approach simulates qualitative and quantitative cause-effect relationships between the environmental system and socio-economic interactions to assess candidate policies, their vulnerabilities and associated adaptive strategies.

How to cite: Alizadeh, M., Adamowski, J., Malard, J., and Inam, A.: Participatory-Exploratory Modeling of Coupled Socio-Economic and Environmental Systems for Adaptive Management of Water Resources, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-12418, https://doi.org/10.5194/egusphere-egu2020-12418, 2020.

Floodplains are important locations for agricultural production in many regions of the world. In monsoon-dominated regions with a pronounced rainy season, the floodplains are often used seasonally, which can improve food security and the income of poor households in particular. Alluvial farming benefits from fertile sediment deposits, residual moisture in the soil and good access to water from the river or groundwater. At the same time, farmers have to deal with flood risks and highly dynamic hydromorphological and hydrological conditions.
Agriculture is the main economic activity in Myanmar and accounts for 38% of the Gross domestic product. The most important production areas are the central drying zone (CDZ) and the Ayeyarwady Delta. The CDZ, however, is particularly characterized by irregular rainfall, significantly rising temperatures, droughts, a shift in the onset of the rainy season and extreme flood events, which makes agricultural production very challenging and difficult.
By using the Plural Water Research framework the physical and human boundary conditions of a research area in a floodplain in the CDZ were studied in order to identify relevant components which are shaping this complex human-water system. With the help of satellite images, hydrological data, on-site mapping and surveying farmers, the spatio-temporal dynamics of the alluvial farming system was examined and the interactions between hydrological variabilities and extremes and the handling of farmers within this complex system were examined and adaptation strategies were identified.

How to cite: Evers, P. M., Taft, L., Zülich, M., and Almoradie, A.: Alluvial farming in Ayeyarwady floodplains. Spatio-temporal dynamics of a complex human-water system , EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-19473, https://doi.org/10.5194/egusphere-egu2020-19473, 2020.

Supplemental irrigation is critical to ensure high and stable crop yields in many regions. Water needs for irrigation will increase in the future, because of higher demands for food, feed and biofuels, and warmer, more extreme, climates. Water withdrawals for irrigation has led to plummeting water tables in many aquifers. Water harvesting like on-farm ponds can be a more sustainable approach to meet water requirements for irrigation. Nevertheless, whether groundwater or on-farm pond is the most suitable source of irrigation water for a single farmer and the whole community depends not only on the crop water demands and the unpredictability of rainfall, but also on the farmers’ preferences, in terms of risk aversion and long/short-view orientation and how they evolve in time. Here we couple the dynamics of crop development to that of soil water availability and water stored in on-farm ponds and aquifers. For a community of farmers, we also consider each farmer’s short/long-view orientation, and how it evolves in time. While general, the model is applied to the case of the Lower Mississippi River Basin, in the south-eastern USA, where irrigation has already led to a significant decline in groundwater levels. Results show that, for a single farmer, production maximization and risk of low yield minimization are often irreconcilable criteria when sizing the on-farm pond. Moreover, on farm ponds as source of irrigation can be more advantageous as source of water for the community, leading to a higher and more stable income. Yet, this choice is beneficial for the individual farmer only under extreme climates and in communities where the use of on-farm ponds is common.

How to cite: Vico, G., Tamburino, L., Rigby, J. R., and Di Baldassarre, G.: Defining the most suitable source of irrigation water for farmers and communities: a socio-agricultural model, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-10850, https://doi.org/10.5194/egusphere-egu2020-10850, 2020.

In aquifers managed with quotas, water agencies are facing conflicting objectives between ensuring minimum environmental flows for the preservation of groundwater-dependent ecosystems and satisfying the water claims of the farmers to irrigate their crops. Handling the potential conflict between economic and environmental objectives is a major concern to achieve sustainability. This paper analyses the existing trade-off between these objectives as a problem of constraints fulfillment and uses the viability method to adress this conflict.

Hydroeconomic models are generally developed as constraint optimization problems with environmental constraints represented by minimum flow requirements. At each period, the dynamics of an aquifer depend on the balance between the natural recharge, the natural discharge and the amount of extracted water. The natural discharge consists in water flows which sustain groundwater dependent-ecosystems. This natural discharge is assumed to be an affine function of the water table. It allows to defined a critical boundary value of the water table for which the natural discharge is nil. A first requirement of a sustainable management is then to keep the water table above this critical value.

The allocation of water quotas to farmers is also a problem of constraint. The use of market-based instruments such as tradable permits has been proposed as a promising way to replenish an aquifer or to efficiently manage groundwater aquifers for irrigated agriculture. Tradable permits ensure that water will be used by farmers with maximum efficiency. However like all "cap and trade" systems, the way the "cap" which consists in the available amount of water for users is set, remains a difficult issue. A second requirement of a sustainable management is then to implement relevant strategies in the allocation of water quotas for every farmer by a regulating agency.

To deal with these two requirements which take the form of constraints, the use of the viability approach has shown to be well-adapted. This paper developped a dynamic hydro-economic model in discrete-time using the viability approach. The viability kernel that defines the states of the resource yielding intertemporal feasible paths able to satisfy the set of constraints over time is analytically identified. The associated set of viable quota policies and the trade-off between food production and ecosystem conservation objectives are characterized.

The theoretical results of the paper are illustrated with numerical simulations based on the Western La Mancha aquifer in Spain.

How to cite: pereau, J. C.: Managing conflicting objectives in hydro-economic models: A viability approach, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-1666, https://doi.org/10.5194/egusphere-egu2020-1666, 2020.

Over the last few years, several socio-hydrological studies have investigated the dynamics of risk generated by feedback mechanisms and interactions between floods and societies, with a focus on either changing reservoir operation rules or raising levees. In this study, we propose a new socio-hydrological model of human-flood interactions that represents both changes in the operating rules of reservoirs and updating of the levee system. Our model is applied to simulate three prototypes of floodplain management strategies: green systems, in which societies cope with flood risk by resettling outside the flood-prone area; technological systems, in which societies cope with flood risk also via structural measures, such as levees; and green-to-techno systems, in which societies shift from green to technological approaches. Floodplain dynamics are explored simulating future scenarios in the city of Brisbane, Australia. Results show that flood risk is strongly influenced by the flood memory of reservoir operators and their risk-awareness levels control the development of communities. Furthermore, scenarios of more frequent and higher magnitude events prove to enhance social preparedness levels in green systems, while technological systems experience much higher losses.

How to cite: Albertini, C., Mazzoleni, M., Totaro, V., Iacobellis, V., and Di Baldassarre, G.: Socio-hydrological modelling: the influence of reservoir management and societal responses on flood impacts, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-673, https://doi.org/10.5194/egusphere-egu2020-673, 2020.

Water resources are essential for human life and closely related to various social and economic factors (e.g. land use, population, economic development, environment, etc). Also, such human activities affect hydrological environment conversely. Thus, socio-hydrology interdisciplinary studies that consider both hydro-engineering and socio-economic behavior are needed. Multi-purpose dam is a large water infrastructure mitigating water-related disasters by flood control and stable water supply. However, the effectiveness of multi-purpose dam besides the disaster mitigation has not been well analyzed, such as the social and economic influence to downstream area. This study aims to understand the relationship between the socio- and hydrology-sectors and quantitatively analyze the effects of the multi-purpose dam in target area. The representative components of socio-sector are population, land use, GRDP (gross regional domestic product), and flood/drought damages, and the hydrology-sector includes dam inflow/outflow, precipitation, and water demand. A causal loop was developed to identify the causal relationship between the socio- and hydrology-components, and a socio-hydrology system model was constructed using a system-dynamics technique. Various climate and socio-economic scenarios were applied to analyze the future effects of the multi-purpose dam on the population, regional economy, water supply, and flood damage prevention of the target area. The constructed socio-hydrology model can be used in decision-making for efficient water management and water facility planning.

Keywords: Climate change, Multi-purpose dam, Socio-hydrology, System-dynamics modeling

Acknowledgment: This study is supported by Korea Ministry of Environment (MOE) as “Graduate School specialized in Climate Change”.

How to cite: Lee, S. and Kang, D.: Effectiveness Analysis of Multi-purpose Dam: Socio-hydrology Modeling Approach, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-1990, https://doi.org/10.5194/egusphere-egu2020-1990, 2020.

The North East of Brazil is characterized by a high spatial, seasonal and inter-annual variability of rainfall. The climate is semiarid with pronounced wet and dry seasons. In the federal state of Ceará, water supply for the dry season is ensured by the construction of reservoirs of various sizes. However, most of these reservoirs were built without documentation by the water management authorities. Thus, there is no complete state-wide inventory of reservoirs in Ceará. Using the satellite based global surface water dataset (GSW), this study aimed at investigating (i) the location, (ii) size, (iii) commissioning and decommissioning year as well as (iv) spatio-temporal dynamics of reservoirs in Ceará for the period 1984 - 2018.

Based on the maximum water extent of the GSW dataset, 17 919 reservoirs larger than 90 x 90 m were detected in Ceará (ii), which could be confirmed with an accuracy of 87 % for a validation dataset including 157 reservoirs regularly monitored by the State Agency for Meteorology and Water Resources in Ceará (FUNCEME). Thereby, reservoirs with a maximum water extent < 2.05 ha (category 1) form the largest and reservoirs with a maximum water extent > 50 ha (category 6) the smallest share in number of all detected reservoirs (i). In turn, reservoirs of category 6 contribute most to the water storage capacity while category 1 reservoirs contribute least. For the estimation of (de-)commissioning years (iii), the GSW monthly water history dataset was used. The years of commissioning and decommissioning were determined as the first and last year, respectively, of water being detected. The calculated commissioning years were validated against the FUNCEME dataset, whereas to date there is no validation data to confirm the decommissioning of reservoirs. The analysis of spatio-temporal dynamics of reservoir commissioning and decommissioning (iv) indicate a spatially variable increase of reservoirs until approximately 2010, followed by an intensive decrease until 2015 (analysis of extended study period currently ongoing).

Deviations in terms of commissioning years are mainly small and can be attributed to uncertainties inherent to satellite observations. Up to 2010, the detected spatio-temporal variability can be largely attributed to droughts which occurred in most parts of the state in several years and particularly severe since 2012. However, the maximum rate of large strategic reservoir construction by the public sector (for which records exist) decreased since the 1990’s, which is attributed to a shift in the adaptation strategy to water scarcity, from structural measures (construction of dams) to governance measures (water management and control). From the data presented here, it seems that this trend likewise occurred on the level of small reservoirs for which no records existed so far.

How to cite: Brosinsky, A., Timmke, S., Foerster, S., Francke, T., Medeiros, P., and de Araújo, J. C.: Spatio-temporal dynamics of reservoir (de-)commissioning in Ceará, NE Brazil, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-8068, https://doi.org/10.5194/egusphere-egu2020-8068, 2020.

Cooperation in transboundary river basins can make water resources systems more efficient and benefit riparian stakeholders. However, in a basin with upstream and downstream stakeholders that have different interests, non-cooperative outcomes have often been observed. These can be described by a one shot prisoners’ dilemma game where non-cooperation (defection) is a dominant equilibrium strategy. However, cooperative outcomes have also been observed in several transboundary settings, such as the Lancang-Mekong River Basin (LMRB) in Asia. Such cooperation motivates our research effort to refine relevant game theoretic descriptions to account for the evolution of players’ behaviors, from conflict to cooperation. In this study, a repeated game model is proposed to analyze evolutionary transboundary cooperation. A generalized evolutionary cooperation pattern with four stages is summarized, starting with non-cooperation and ending with in-depth cooperation. The LMRB and three other typical transboundary river management case studies are chosen to validate our theoretical findings. Upstream and downstream stakeholder behaviors are analyzed for these case studies, in accordance with a game payoff matrix that accounts for incentives to cooperate. The results indicate that patience and incremental benefits can lead stakeholders to adopt a cooperative equilibrium strategy if appropriate institutional mechanisms are in place. Such mechanisms can be developed through negotiations that recognize the wide range of stakeholder interests that may influence the decision to cooperate. Our analysis suggests that game theory can provide useful insights into the conditions and institutional mechanisms that foster cooperative strategies for managing transboundary water resources.

How to cite: Yu, Y., Tang, P., Zhao, J., Liu, B., and Mclaughlin, D.: Evolutionary cooperation in transboundary river basins, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-1363, https://doi.org/10.5194/egusphere-egu2020-1363, 2020.

The transboundary Lancang-Mekong River Basin has experienced both cooperation and conflict over the past several decades. Downstream countries (Thailand, Cambodia and Vietnam) rely on Mekong River for fisheries and agriculture, while upstream countries including China and Laos have been constructing dams to generate hydropower. The construction and operation of dams in upstream countries has changed the seasonality of streamflow in downstream countries, affecting their agriculture and fishery benefits. More recently, cooperation between upstream and downstream countries has led to benefit sharing and improved international relations throughout the river basin. In this presentation, we introduce a socio-hydrological model that simulates the hydrological changes in downstream countries resulting from upstream dam operation, based on collection of hydrological, economic and social data in Lancang-Mekong river basin. Our model captures the cooperation and conflict feedback loops which impacts the operation rules of upstream dams. In this way, our study generates understanding of the connections between water resources management and hydro-political dynamics underpinning cooperation and conflicts mechanism in this transboundary river basin.

How to cite: Lu, Y., Borzi, I., Guo, L., Patil, R., Zhang, Y., Liu, D., Wei, J., and Tian, F.: Socio-Hydrological Modelling of Cooperation and Conflict in the Transboundary Lancang-Mekong River, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-4121, https://doi.org/10.5194/egusphere-egu2020-4121, 2020.

In water scarce basins, the agricultural economics modeling literature predicts water demand and supply curves with significant inelastic intervals, which limit the cost-effectiveness of charges and water reacquisitions in reallocating water to the environment, respectively. Such models typically rely on yield point predictions that are obtained as an average of past observations, while water input application per crop is assumed constant on a per hectare basis. Yield point predictions allow modeling irrigator’s adaptation at the extensive (land reallocation towards less water-intensive crops) and super-extensive margins (land reallocation towards rainfed crops); yet, they are not suitable for modeling adaptation at the intensive margin, which involves decremental water input application through deficit irrigation -an increasingly frequent response to water scarcity in arid and semi-arid basins. This paper introduces agronomic calibrated production functions into a multi-attribute positive calibrated model to simulate adaptation at the intensive, extensive and super-extensive margins. The model is illustrated with an application to the El-Salobral-Los Llanos irrigated area in the Mancha Oriental (Spain). Agronomic production functions are calibrated for the main crops in the area, namely wheat, barley, corn, alfalfa and onion, which represent 78% of agricultural land use. Results for a hypothetical policy that increases charges from 0 to 100 Eurocents/m³ suggests a relevant role for intensive margin adaptation in the case of cereal crops; while farmers prefer to fully irrigate more profitable horticultural crops (onion). As a result, introducing adaptation at the intensive margin results in a significantly more elastic water demand curve. For example, at a charge increase of 20 Eurocents/m3, the model using agronomic production functions predicts a water conservation of 3855 m3/ha; as compared to 3123 m3/ha in the model relying on yield point predictions (a non-negligible difference of 18.97%).

How to cite: Sapino, F., Pérez-Blanco, C. D., Gutiérrez-Martín, C., Pulido-Velazquez, M., and García-Prats, A.: Influence of crop-water production functions on the performance of economic instruments for water conservation, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-5425, https://doi.org/10.5194/egusphere-egu2020-5425, 2020.

In dry environments, society has long implemented infrastructure to adapt to water scarcity, but unanticipated feedbacks have threatened the supply-demand balance. For instance, construction of dams increases the water residence time in highly impounded basins, causing sediment and nutrient accumulation in water supply reservoirs. Reuse of reservoirs’ sediment as fertilizer sustainably benefits agricultural and water systems by: replacing fine particles and nutrients to soils, previously lost by erosion; recovering water quantity and quality by the removal of nutrient-enriched sediments from reservoirs. In the last 5 years we have assessed the potential of the sediment reuse technique for soil fertilization and water conservation in the semiarid Ceará State (149 000 km²), Brazil, where there is a dense network of more than 20 000 dams with considerable silting and eutrophication. Our previous studies demonstrated that:

• Local features contribute to the adoption of the proposed technique: (i) small reservoirs fall dry frequently, exposing the sediments for excavation without the need for dredging; (ii) in general, soils present nutritional deficit and, under natural conditions, crop production is limited to patches of fertile soils; (iii) small scale agriculture plays a major role for livelihood of the rural population;
• Recycling of nutrients from sediments is technically feasible: an experiment with a mixture of soil and sediment as substrate produced statistically higher growth and enzymes’ activity of sunflower plants, compared to the cultivation directly in the soil or with addition of synthetic fertilizers;
• Sediment reuse is economically feasible: soil fertilization through sediments for maize cultivation may reduce costs by up to 29 % compared to traditional fertilization;
• Removal of sediment from reservoirs may improve the water quality: simulation of annual removal of sediments when a reservoir of the study region is completely empty indicates a change on the trophic level, from eutrophic or higher to mesotrophic or lower, in 10 % of the time.

In spite of the recent advances, sediment recycling must go through some phases in order to be included in the public policy agenda. Our ongoing and planned studies focus on the generation of basic data, real-scale testing, simulations under diverse environmental contexts, elaboration of guidelines and disclosure. Spectroscopy has been successfully applied to characterize sediment and soil properties and reduce the costly laboratory analysis. Additionally, data acquisition will be supported by remote sensing approaches based on hyperspectral satellite images that will become available in the near future (Prisma, EnMAP). Such data will be used to estimate nutrient availability in sediments and deficit in the soils to generate a map of the sediment reuse potential in Ceará. Field scale growth experiments are to be conducted for the main crops cultivated in the study region, in contrast to the indoor controlled conditions of our previous assessment. Furthermore, we are developing a modelling tool to quantify the impacts of the sediment reuse practice on water quality, enabling us to expand our previous study to other reservoirs and to test its effectiveness to water conservation.

How to cite: Medeiros, P., Braga, B., Lira, C., Brosinsky, A., Foerster, S., Gondim, F., and de Araújo, J. C.: Potential of sediment reuse for soil fertilization and water conservation in drylands, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-10199, https://doi.org/10.5194/egusphere-egu2020-10199, 2020.

Effective use of water resources has been identified as a means to improve resilience to drought, particularly in the agricultural sector. In recent decades, the idea of shifting to more efficient irrigation systems (e.g., sprinkler irrigation systems) has received increasing attention to reduce the amount of water loss by traditional irrigation systems (e.g., flood irrigation systems), requiring considerable capital investments. However, there are indications that such investments do not lead to a reduction in water use in the long-run, which may even increase paradoxically; a phenomenon known as the rebound phenomenon or Jevon’s paradox. One of the fundamental information gaps concerns an explicit evaluation of coevolutionary dynamics and the interactions among socio-economic factors in the rebound phenomenon in agriculture, which calls for the application of systems-based methodologies such as global sensitivity (GSA) analysis methods to look at time-dynamical aspects of the coevolutionary dynamics between various factors influencing rebound phenomenon. In this study, we use a previously calibrated and validated Agent-Based Agricultural Water Demand (ABAD) model applied to the Bow River Basin in Alberta, Canada - home  to extensive irrigated farmlands with a history of drought experience. We perform a time dependent variance-based GSA on the ABAD model to examine the direct impact of factors as well as their joint influence due to interactions on rebound phenomenon. The overall findings show that the economic factors are the most important elements, which has an upward trend in the simulation time, in the rebound phenomenon. This finding is supported by the local observation as the net income of irrigated land has an upward trend in this time period. In addition, although the individual effect of the factor representing the social interaction among farmers is less important compared to the irrigation expansion factor, its total-order effect (i.e., the total contribution of a single factor including interactions with all other factors) becomes more important indicating the significant interactions among model factors. This analysis provides a deeper understanding of the coevolutionary dynamics of the rebound phenomenon and paves the way for better management of water resources.

How to cite: Ghoreishi, M., Sheikholeslami, R., Razavi, S., and Elshorbagy, A.: A New Way of Understanding Rebound Phenomenon in Agriculture Water Demand Using A Global Sensitivity Analysis Approach, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-11846, https://doi.org/10.5194/egusphere-egu2020-11846, 2020.

We present a “web-enabled” sociohydrological model that can help us to better understand the system dynamics of a smallholder farmer. It couples the dynamics of the six main assets of a typical smallholder farmer: water storage capacity, capital, livestock, soil fertility, grazing access, and labor. The hydroclimatic variability, which is a main driver and source of uncertainty of the smallholder system, is accounted for at subannual scale. The model incorporates rule-based adaptation mechanisms of smallholders (for example, adjusting expenditures on food and fertilizers and selling livestocks) when farmers face adverse sociohydrological conditions, such as low annual rainfall, occurrence of dry spells, or variability of input or commodity prices.

The novelty presented is that the model has been enabled with remote access to the relevant modelled information through the world wide web, making it accessible to anyone with access to the internet without dealing with the complexity of installing or running models on one’s own machine. We present the sociohydrological model along with a first set up of the webserver, which is written in python (Django), to demonstrate how we envision sociohydrology to be brought to the people - literally at their fingertips.

How to cite: Diederen, D. and Pande, S.: A “web-enabled” sociohydrological model on the system dynamics of a smallholder farmer, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-15882, https://doi.org/10.5194/egusphere-egu2020-15882, 2020.

Climate change, drought, overuse of water from surface(-ground) water resources has caused major problems in endorheic basins across the world. One such basin is Bakhtegan Lake Basin, southwest of Iran. The water entering Bakhtegan Lake has decreased, which has led to a decrease in the water level of this lake. Secondly, groundwater level has decreased in the Bakhtegan aquifer. These problems occurred in the Bakhtegan basin as a result of neglecting human roles as theactive agency within the hydrology of the region. In this study, we present a sociohydrological model in order to simulate dynamic relationship between community sensitivity, which responds to environmental well-being, and water use state variables as key to understanding the competition between water allocation between agriculture and the environment in the basin. Furthermore, agriculture in this basin plays a key role in the economic livelihoods which in turns plays a major role in the competition of water allocation between agriculture and environment in the Bakhtegan area.

The sociohydrological model is developed by coupling water demand and balance based WEAP (Water Evaluation And Planning) model with community sensitivity dynamic equations of the sociohydrological model by Roobavannan et al. (2017). The unique aspect of this model is that the six parameters of the community sensitivity related equations are calibrated, while being coupled to WEAP, using Elitist Non-Dominated Sorting Genetic (NSGAII) Algorithm on observed annual streamflow at three gauges within the basin.

The results demonstrate that the calibrated coupled model is able to simulate past allocations of water to agriculture and the environment in the basin, which we compare with available records. Further, we provide non-dominated pareto set of parameters, that demonstrate equifinality in pareto superior parameters of community sensitivity.

References:

Roobavannan, M., Kandasamy, J., Pande, S., Vigneswaran, S., & Sivapalan, M. (2017). Role of sectoral transformation in the evolution of water management norms in agricultural catchments: A sociohydrologic modeling analysis. Water Resources Research, 53, 8344–8365. https://doi.org/10.1002/2017WR020671

How to cite: Amirkhani, M., Zarei, H., Radmanesh, F., and Pande, S.: An operational sociohydrological model to understand the feedbacks between community sensitivity and environmental flows for an endorheic lake basin, Lake Bakhtegan Iran, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-15107, https://doi.org/10.5194/egusphere-egu2020-15107, 2020.

In several developing cities flooding has become an annual occurrence which threatens lives, livelihoods and homes. However, the exposure of urban populations to climate risks such as flooding is highly heterogeneous, with the effects of climate variability felt disproportionately by the poor. Rapid urbanisation and population growth, combined with systemic factors such as complex land tenure arrangements, inadequate transportation and weak governance, has led to the proliferation of unplanned urban settlements which lack basic infrastructure and are frequently situated on marginal, flood-prone land. While the immediate effects of floods can cause physical, economic and social devestation, floods also have multiple long-lasting effects which may increase vulnerability and exacerbate inequalities. Here, we adapt an existing socio-hydrological model of human-flood interactions (Di Baldassarre et al. 2013; Viglione et al. 2014) to explicitly account for a stratified society consisting of the “haves”, who reside in planned settlements with some degree of flood protection, and the “have-nots”, who live in unplanned, informal settlements which are more vulnerable to flooding. Initially, we conduct a sensitivity analysis to identify the parameters in the original model which may be influenced by social inequality. We then introduce a new state variable to represent the transfer of wealth from the “haves” to the “have-nots”, and use this setup to investigate the effects of wealth redistribution on the co-evolution of the coupled system.

References:

• Baldassarre, G. D. et al. (2013). Socio-hydrology: conceptualising human-flood interactions. Hydrology and Earth System Sciences, 17(8), 3295-3303.
• Viglione, A. et al. (2014). Insights from socio-hydrology modelling on dealing with flood risk–roles of collective memory, risk-taking attitude and trust. Journal of Hydrology, 518, 71-82.

How to cite: Moulds, S. and Buytaert, W.: A socio-hydrological model to explore the role of social inequality on human-flood interactions, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-16188, https://doi.org/10.5194/egusphere-egu2020-16188, 2020.

Participatory system dynamics modelling is a useful tool for sociohydrological systems management due to its inclusion of diverse viewpoints and incorporation of feedback dynamics and delays between the human and environmental spheres. We here present a case study from the Lake Atitlán watershed in Guatemala, which is unique due to its endorheic nature, very long retention time, and diversity of human societies around it (Kaqchikel, Tz’utujil and K’iche’, as well as a Hispanic minority). The lake is under pressure from several sources and has become increasingly vulnerable to eutrophication in recent years. The lake is also central to the economy and ecology of the region, with diverse stakeholders including fishers, farmers, both traditional and youth-led Mayan organisations, NGOs, businesses, and municipalities and other levels of government.

While effectively all participating stakeholders agree that the lake is under threat, there exist very differing narratives regarding the most pressing threat (pollution, biodiversity, or water availability) and therefore appropriate policy options. These differences vary significantly according to the ecosystem services each stakeholder obtains from the lake, as well as their own personal experiences and worldviews. Indigenous voices have also unfortunately been historically marginalised and often excluded from decision-making in environmental management.

In this context, we applied a novel methodology incorporating storytelling and narratives coupled with causal loop diagrams to incorporate the points of view of all stakeholders, whether literate or not. The results from these individual interviews were used to compare visions and possible solutions, followed by the development of a coupled human-hydrological systems model as a decision support tool. In the coupled model development process, socioeconomic processes are represented in a system dynamics model, while hydrological processes are eventually "outsourced" to an external hydrological model (such as SWAT+). Using the Tinamït software package, these two models can then be simultaneously executed with data (e.g., land use and water quality) dynamically exchanged between both models at runtime.

While most studies conducted in or on Indigenous regions and their peoples are conducted in European languages that exclude these very people from meaningful decision-making, all team members (both national and international) in this research project were chosen to be functional in at least one of the mutually intelligible Mayan languages spoken in the basin, and these languages were used as the official project language (while also providing services in Spanish for Hispanic stakeholders). This key aspect to our approach ensured that all stakeholders were equally included in the process, and that Indigenous students also had equal opportunities to be hired as part of the (decision-making) research team.

We discuss how this methodology led to unique contributions to the model throughout the research process, from problem definition to identification of key system processes and candidate policy scenarios, and improved the quality of both the participatory and the modelling processes.

How to cite: Malard, J., Bou Nassar, J., Adamowski, J., Ramírez Ramírez, M., and Tuy, H.: Storytelling and participatory system dynamics modelling for water resources management in Lake Atitlán of Tz'olöj Ya' in Mayan Guatemala, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-11483, https://doi.org/10.5194/egusphere-egu2020-11483, 2020.

Cost-benefit analysis (CBA) is often applied at different levels of decision supports. CBA is a systematic approach to estimate the strengths and weaknesses of alternatives for decision makings. In many countries, CBA is required by law and regulation in different fields, including policy-making and public investment. The benefits of practicing the management of watershed conservation also need to be quantified so that decision-makers can understand engineering projects better. Applying CBA in watershed conservation can provide a comparison of total economic gains and losses resulting from practices and reveal impacts on different aspects with economic principles. Nevertheless, to quantify the benefits derived from watershed conservation, an array of technical relationships in various aspects which is still unclear requires to be developed. For this concern, this study examined several perspectives of watershed conservation to propose the framework of CBA in watershed conservation for Taiwan. In this study, we focused on four main kinds of sediment control facilities including check dam, embankment, slope protection, and groundsill work, and described the effect of sediment conservation based on theoretical sediment processes in spatial as well as temporal. We further analyzed their utilities from the perspective of the water supply. In addition to sediment control estimations, this study also determined some economic factors which were not determined in the past. We yielded a demand curve of raw water from the water supplying data and calculated a social discount rate from government bond rates. Also, we suggested adopting a general extreme value method to investigate the benefit under an extreme turbidity event and adopting an alternative costing method to estimate the water quality improvement benefits. This framework is successfully applied in Taiwan for the evaluation of watershed conservation projects. With this framework, engineers could perform economic CBA for reservoir watershed conservations more efficiently, practically, and precisely.

Keywords: Watershed conservation, Economic cost-benefit analysis, Sediment control, Reservoir management

How to cite: Liang, C.-Y. and You, J.-Y.: A Framework for Using Economic Cost-Benefit Analysis in Watershed Conservation, an Experience in Taiwan, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-14382, https://doi.org/10.5194/egusphere-egu2020-14382, 2020.

Recent research has demonstrated the multidimensional and multi-sectoral impacts of climate change, evidencing the need to develop national and sub-national integrated tools and policies for the analysis of impacts and adaptation, especially central to local policy recommendation and implementation. This framework combines an area-based economic optimization model with the hydrological model WEAP, and represents the socio-economic, agronomic, and hydrologic systems in a spatially explicit manner covering dimensions and scales relevant to downscaled climate change impacts.  Simulated scenarios are setup to incorporate climate scenario, prior-historic dependence to adaptation conformity, and two policy-based adaptation scenarios. Preliminary results indicate that climate change may impact severely in rain-fed agricultural area and also to irrigation systems reducing water availability and security and crop yields, and increasing in more efficient irrigation water allocation.  The adaptation strategies analysis based on socio-economic, agronomic, and hydrologic dimensions capitalizes the key role of Thailand supply- and demand-side management policy in facilitating adaptation. The under developing framework is currently anticipated to be a useful tool for supporting water resources and climate change policy making.  It can contribute to improve understanding on potential impacts of climate change, multi-sectoral linkages, multi-scale vulnerability, and adaptation programs.   

How to cite: Putthividhya, A., Bumbudsanpharoke Khamkanya, W., and Prajamwong, S.: A Hydro-Economic Modeling Framework for Climate Change Impacts and Adaptation Assessment in Thailand with Multi-Sectoral Linkages and Multi-Scale Vulnerability , EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-21616, https://doi.org/10.5194/egusphere-egu2020-21616, 2020.

 Diana Carolina Callejas Moncaleano^a , Saket Pande^a and Luuk Rietveld^a

^{d.c.callejasmoncaleano-1@tudelft.nl; s.pande@tudelft.nl; l.c.rietveld@tudelft.nl}

^aDelft University of Technology, Department of Water Management, the Netherlands

Keywords:

Water use efficiency

Human behaviour

Contextual and psychological factors

Every day a large amount of water is extracted from inland surface (rivers, lakes, wetlands, reservoirs) and aquifers for agriculture, domestic, electricity, and industrial purposes. In semi-arid and arid regions, high water demand can lead water scarcity, and in other areas causes rapid depletion of water tables. One reason behind the over extractions and higher demand is the inefficient use of water

Water use efficiency has been a matter of concern to diverse scholars, water managers, and policymakers, as it affects the well-being of society and the economic growth of countries. In many countries, it becomes a priority policy; indeed, increasing water use efficiency is one of the pillars of sustainable development goals (SDG 6.4.1.).However, the slow progress of water efficiency remains, due to the water demand is likely to rise still higher, especially for many developing countries where the degradation of natural resources is critical, economic growth is slow, and there are not strong institutions for coordinate actions. 

Across the spectrum of water users, there are a variety of contextual and psychological factors behind water use inefficiency. Researchers have identified the importance of associated these factors in influencing user's behaviour. The contextual factors investigated are social, economic, environmental, and institutional, and assessments focus on study causes of the water inefficiency, and what are the perceptions and attitudes of water users to adopt water-saving practices, and regulations.  Yet, none of these studies consider a holistic view of these factors in shaping water use behaviour.

The understanding of water inefficiency requires, firstly exploration of connections between factors. Second, understanding how these influence the human behaviour of stakeholders and the decisions that they make as water users or water managers. A comprehensive assessment of these factors and their relationships is needed to provide insights on the causalities of over-extraction, the interdependence between stakeholders, and water use inefficiency. In this regard, a holistic view of a framework that incorporates the effects of know-how, linkages between stakeholders, such as water users, water managers, and institutions on water use efficiency, is absent.

This paper aims to study the gaps in our understanding of human water behaviour underlying water use efficiency from socio-cultural, economic, psychological, and institutional factors. This research proposes a conceptual model that connects contextual and behavioural factors and represents the prior causal- effect relationships between water users and institutions.

How to cite: Callejas Moncaleano, D. C., Pande, S., and Rietveld, L.: Meta-analysis of human water behaviour underlying water use efficiency, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-15269, https://doi.org/10.5194/egusphere-egu2020-15269, 2020.

The water issue, as vital element to be protected, is central in all societies, including those where water may seem plentiful. With the conscience of the fragility of this resource, the need to question the evolution of the perception of water over time, of the various means used to exploit and preserve it, of scientific knowledge, currently appears as an essential aid to the decision for its preservation.

In many countries, XIXs century was the time of major progress in the construction of water supply networks of cities. Particularly in France, this progress was spured by an hygienist discourse in a context of increase city population, inducing a social demand whose national and local governments seized.The autority of the engineers of the « corps des Ponts et Chaussées » who were in charge of the technical realisation of the cities water network was also an important support in this progress, especially because they also participated at the great evolution of the scientific formulation of fluids mechanics applied to groundwater hydraulic like Henry Darcy (1803-1858) or Jules Dupuit (1804-1866). The latter is also well known as an economist. One of his thoughts is to relate the progress of science to an economic perspective. According to him, « The only difference between the [Roman water ] distributions and those which would be made according to a sound theory and with the best practical procedures is entirely in the expenditure.”

In this study, technical, scientific and management aspects of the evolution of the water supply network of La Rochelle (France ) during the XIXs century are investigated from archives documents. The survey of the conditions for setting up the network of a particular city is a gateway to address all the points cited above. This coastal town, which has a long history and whose port is famous, experienced three stages of improvement of its water network, in 1864, 1883 and 1913. The first step coincides with the development of water supply network of many french towns, the second with the discovery of a new aquifer useable for water supply of the city, and the third one, remained at the state of a project due to the first World War, had been planned in response of the increase of water consumption linked both to the growing of the population and to the new ease of access to water.

This historical knowledge is necessary to understand the spatial and time evolution of the customary practice of water and could be used to draw one’s inspiration from the past efficient solutions that have sometimes be forgotten and that could be reemployed.

How to cite: Moreau, F.: Technics, science and management related to the evolution of water supply network of La Rochelle city, France, from 1864 to 1913., EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-14001, https://doi.org/10.5194/egusphere-egu2020-14001, 2020.