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The paper seeks to gain greater water literacy and numeracy in the connections between water and Regenerative Agriculture (RA). By identifying the many roles and quantities of water and soil-water, our paper argues that water is the Achilles Heel of RA.  At a basic level, RA is failing to fully appreciate and incorporate the many varied inputs, processes and outcomes of water. In ‘outcome’ terms, RA intends to improve soil-water properties and catchment hydrology so that, for example, rainfall seeps into soils rather than running off land surfaces.  In ‘process’ terms, RA adopts agricultural practices such as maintaining a protective cover that aims to enhance soil physical fertility (such as bulk density) and soil-water properties such as infiltration and available water holding capacity.  While these outcomes and processes are idealized and laudable, they miss the many ways in which water and RA intersect. For example water and hydrology are not only affected by RA, but water is also an input to RA. The latter is necessary when soil moisture is required to bolster soil organic accumulation and biological activity.  Accordingly, we find two interconnected fault lines. First, the descriptive and quantified roles of soil-water and water in RA are often missing or poorly explained, and secondly, narrative tropes and terms (e.g. ‘net zero’ or ‘net positive’ water) for describing the benefits and aims of RA are, at best, lacking context or, at worst, are misleading and incorrect. We conclude that scientists and decisions-makers should more thoroughly interrogate how RA is being applied in the context of basin water availability and attempt to bring more precision in regards to quantities of water required – and recognize the competition for those resources as well as opportunity costs. How those quantities overlap with local policies, allocations and hydrology, including farmers’ individual views and policy choices, are critical to RA success. 

How to cite: Lankford, B. and Orr, S.: Is Water the Achilles Heel of Regenerative Agriculture?  A critical examination of the roles and omissions of soil-water and water in ‘Regen Ag’, IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-510, https://doi.org/10.5194/iahs2022-510, 2022.

Climate change manifested in Ukraine by rapid (over 0.6^oC in 10 years) increase in average annual air temperature causes a progressive deterioration of natural water supply significantly increasing the need for irrigation to ensure sustainable agriculture.

"Irrigation and Drainage Strategy in Ukraine until 2030" provides for an  increase of irrigated lands area up to 1.5-1.7 million hectares and the corresponding significant increase in water consumption from the current 1.5-1.8 billion m³ to 5-6 billion m³. Given that climate change has a negative impact not only on the state of natural water supply, but also on the state of available water resources, their rational use in irrigation is an important component of sustainable water management.

Effective tools for its implementation in irrigation are decision support systems. Their usage provides a capability to achieve maximum irrigation efficiency when complying with the following provisions:

- Irrigation should maintain root layer moisture content in a narrow range of high values (from 0.8-0.85 of field capacity to field capacity);

- Tensiometric pressure should be used as a criterion of moisture content and moisture availability for plants;

- Water retention curves should be used to determine field capacity, pre-irrigation thresholds, and optimal ranges of moisture available to plants;

- Moisture transfer models for saturated-unsaturated soils stated in terms of pressure can accurately predict irrigation schedules and rates;

- The combined use of several methods for evapotranspiration assessment improves the accuracy of calculations;

- Remote sensing data can be used to tranfer irrigation schedules and rates predictions to the areas not covered by instrumental monitoring tools.

The application of these principles provides for

- an increase in crop yields accompanied by irrigation water volumes reduction;

- irrigation with environmentally friendly rates minimizing water losses for infiltration, and the development of flooding and secondary salinization processes.

The introduction of these principles in practice will increase the sustainability of water management in agriculture in the conditions of climate change, and the use of decision support systems at full scale will ensure the maximal materialization of the potential of crops’ varieties and hybrids.

How to cite: Romashchenko, M., Bohaienko, V., Matiash, T., Shatkovskyi, A., Kolomiets, S., and Danylenko, I.: Conceptual principles of water resources management in irrigated agriculture, IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-551, https://doi.org/10.5194/iahs2022-551, 2022.

Drainage is the water flowing under the roots when the soil's capacity to hold water is exceeded. It is an important term of the crop water budget, controlling soil salinization, potentially impacting downstream ecosystems, and being a strong indicator of water productivity. Estimating this flux at spatial scales relevant to farmers (plot-scale) and to watershed or irrigation district managers (sub-basin-scale) is thus fundamental for a sustainable management of water, soils, and downstream rivers. However, even though it can be measured or estimated locally with lysimeters or physically-based models, respectively, drainage is generally neglected or considered as a residual variable in crop water balance models. Furthermore, many studies have shown the relevance of using remote sensing data to spatialize crop water fluxes. The aim of this work is thus to estimate drainage from the plot-scale to the sub-basin-scale by using a crop water balance model coupled with remote sensing observations. For this, SAMIR, a crop water balance model based on the FAO-56 method using remote sensing data to constrain the modeled vegetation and the soil water status, is used. The approach is tested over the Algerri-Balaguer irrigation district in northeastern Spain where in-situ drainage measurements are available at an integrated (sub-basin) scale. Those data were obtained from a network of drains feeding four outlets where the drainage is continuously measured. Additionally, four lysimeters were installed on two experimental fields of the area. Firstly, the drainage simulated by SAMIR and by a physically-based model (HYDRUS-1D) are compared with the lysimeters measurements. Preliminary results indicate that both models are able to reproduce the drainage amount cumulated over the season given a site-specific calibration. Secondly, the field-scale SAMIR drainage estimates are aggregated over several sub-basins and compared against the drainage measurements at the outlet of the associated sub-basins. A strategy for calibrating SAMIR at the sub-basin-scale is proposed. The obtained results provide a first assessment of the potential of using a satellite-driven crop water balance to retrieve agricultural drainage at multiple spatial scales.

How to cite: Laluet, P., Olivera Guerra, L. E., Altés Gaspar, V., Rivalland, V., Simonneaux, V., Bustillo, V., Bellvert, J., Villar, J. M., and Merlin, O.: Estimating the drainage of irrigated areas: a combined crop water balance modeling and remote sensing approach, IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-232, https://doi.org/10.5194/iahs2022-232, 2022.

The oases of the pre-Saharan basin of Wadi Ferkla in southeastern Morocco receives low and erratic rainfall (average of 141 mm/year and inter-annual standard deviation of 70 mm - Ait-Bouijane rain gauge over the period 1961-2018). From the 70's, surface and groundwater are increasingly used due to the expansion of irrigation, mainly along two wadis, namely Wadis Ferkla and Satt originating in the High-Atlas and the Anti-Atlas Mountains, respectively. Their flows reach the Ferkla’s irrigated perimeters only when the volume of the flood events exceed upstream evaporation, withdrawals and riverbed's infiltration.

Nowadays, these irrigated perimeters exert significant pressure on groundwater resources, through numerous drillings equipped with pumping systems, most of them are powered by solar energy. This unsustainable situation incentivizes individual farmers to design and implement innovative technics to increase water access for their farms. For instance, the spreading of floodwaters - an ancestral and collective irrigation practice in traditional oases - is currently being adopted and adapted by individuals at the farm level. The technique consists on partially diverting flood flows into earthen basins. The stored water either infiltrates to recharge local aquifers, or is pumped for flood irrigation of date palms.

An experimental protocol was set up to characterize groundwater recharge below one of these on-farm basins equipped with a recharge well. Barometric probes were installed in the basin, in the recharge well and in neighboring boreholes to automatically monitor water table levels (10-minute-time-step). Manual measurements were performed regularly to calibrate the monitoring probes. A topographic survey of the monitoring points and of the basin aimed at deriving piezometric levels from water levels measurements and estimating the height-surface-volume curves of the basin. After 7 months of continuous monitoring, 3 flood events were recorded. The establishment of the basin water balance at a fine time-resolution allowed estimating its different components including the infiltration rate influencing groundwater recharge. An Analytical modeling of this process was developed to explore alternative design and management options of the basin. This approach aims to contribute to a broader reflection on securing water management in this fragile oasis ecosystem.

How to cite: Khardi, Y., Lacombe, G., Taky, A., Dewandel, B., Maréchal, J.-C., Hammani, A., and Bouarfa, S.: Managed groundwater recharge at the farm scale in pre-Saharan Morocco, IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-188, https://doi.org/10.5194/iahs2022-188, 2022.

In Tunisia, illicit drilling exists since the 1980s in both southern and central Tunisia. Since 2011, with the weakening of the administration control, farmers and landowners have been drilling in a frantic manner in the various aquifers throughout the country. According to DGRE (Direction Générale des Ressources en Eau), aquifers are in advanced overexploitation, more accentuated in case of drought. It would therefore be relevant to monitor, detect and forecast this phenomenon by combining drought (SPEI and SGI) and remote sensing (NDVI) indices.

The objective of this work is the monitoring, detection and prediction of illicit drilling by the cross-checking and exploitation of hydroclimatic and vegetation indices, derived from remote sensing for Nadhour-Saouaf aquifer. SPEI makes it possible to consider precipitation and evapotranspiration on different time scales which facilitates the analysis of drought impact on water resource demands. The same is true for SGI, which makes it possible to analyse the water table level. As for NDVI calculated on time series, it allows monitoring the state of crops and their development over time.

These different indices have been used in different contexts to detect anomalies that would be interpreted as illicit drilling, since the detection of significant plant cover in drought conditions could indicate the existence of such drilling. We first computed SPEI and SGI from time series of rainfall (series of more than 30 years derived from DGRE Zaghouan database), temperatures and piezometric levels. The analysis allowed to (1) describe, summarizing, and evaluating the data and (2) Fill gaps. Then, we extracted NDVI time series from LANDSAT data. Finally, the multidimensional exploratory analysis of the three indices combined (SPEI, SGI, NDVI) revealed relationships between them.

A robust indicator is currently being constructed to detect the probable existence of illicit drilling. The variation of this indicator will make it possible to detect the over-exploitation of aquifers caused by these drillings, based on DGRE data. This analysis, moreover, considered the social typology of farmers in the study area and was supported by interviews with farmers. This index makes it possible to analyse the socio-spatial and temporal evolution of the study area.

How to cite: Gargouri, E., Slama, F., Khmiri, K., Dakhlaoui, H., and Chakroun, H.: Detection and prediction of illicit drilling by combination of drought indices and NDVI: case of the Nadhour-Saouaf aquifer (Northeast Tunisia), IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-516, https://doi.org/10.5194/iahs2022-516, 2022.

Under climate change conditions, optimizing water resources management in rainfed agricultural production systerms requires the reasonable choice of crops. In this context, the adoption of crops diversification is promoted to increase the agricultural production and the added value per cubic meter of rain water (green water) used by crops. Contributing, therefore, to increase agricultural production and to preserve soil and water resources. The objective of this study is : i) to identify mixed crops within agricultural fields and, ii) to evaluate the biomass production and the water productivity in the Lebna watershed (Cap-Bon, Tunisia) using remote sensing and field measurements. The study area, covering 210 km2, is characterized by a semi-arid Mediterranean climate, the predominant of cereals, legumes and fodder cropping systems, and the degradation of soil resources. The field investigation and experiments allowed the quantification of crop evapotranspiration and the observed biomass production at the agricultural field plots. The use of the sentinel images and the observations at different agricultural fields allowed to produce NDVI maps. The results first confirmed a good correlation between biomass production and NDVI vlaues. The linear relationships showed a values of R² greater than 0.9 and  values of RMSE less than 0.35. The use of sentinel images and GIS allowed to compute water productivity from field to watershed scale.  The results revealed a considerable spatial variation in water productivity values  for different crops. Compared to a single crops, the cereal-legume mixture cropping improved the water productivity. Theses results help to recommed adaptation measures in agricultural production systems to climate change. Ongoing work coupling field experiments, remote sensing and agro-hydrological model aim to develop simulation and evaluate the agri-environmental impacts from field to regional scale.

How to cite: Mekki, I., Zitouna-Chebbi, R., Benyoussef, S., Abdelghaffar, A., Jacob, F., and Albergel, J.: Analysis of rainfed cereal-legume mixture cropping water productivity in Lebna catchment, Cap-Bon, Tunisia., IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-680, https://doi.org/10.5194/iahs2022-680, 2022.

The spatial organization of crops at the landscape scale is a promising solution to be explored within Mediterranean hilly agrosystems, for agroecological transition and adaptation to climate change. In this perspective, it is necessary to ensure the capacity of crop models to simulate a range of agro-hydrological processes within these agrosystems. The objective of this study is to perform a multi-criteria assessment of the FAO AquaCrop model to simulate crop functioning for a diversity of plant and soil combinations, by considering several hydro-climatic years. This multi-criteria assessment includes canopy cover (CC), dry above-ground biomass (biomass), soil water content (SWC), actual evapotranspiration (ETa) and runoff (non-infiltrated rain). The study area is the small rainfed watershed of Kamech located within the Lebna regional watershed, Cap Bon Peninsula, North-eastern Tunisia. The data, collected in the framework of the OMERE Observatory, are derived from ten measurement campaigns between 2001 and 2013 that focus on (1) predominant soils (Cambisols, Luvisols, Vertisols), and (2) representative crops of the region (wheat and barley as grain cereals, oats as fodder and faba bean as legume). Except ETa, which simulations are quite poor (R² of 0.3, RMSE of 0.9 mm/d and NRMSE of 44%), AquaCrop correctly simulates the water transfer within the soil-plant continuum along with crop growth, for the ten aforementioned campaigns. First, CC is correctly simulated (R² of 0.6, RMSE of 3% and NRMSE of 9%), as is runoff (R² of 0.5 and RMSE of 0.7) mm. Second, SWC is well simulated (R² of 0.88, RMSE of 8.34 mm and NRMSE of 2.34%), as is above-ground dry matter (R² of 0.83, RMSE of 0.17 ton/ha and NRMSE of 5.9%). These results indicate that AquaCrop is relevant for characterizing the water use efficiency under the influence of intra-plot runoff.

How to cite: Dhouib, M., Zitouna-Chebbi, R., Mekki, I., Prévot, L., Molénat, J., and Jacob, F.: Multi-criteria evaluation of the AquaCrop model in a Mediterranean rainfall context, IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-154, https://doi.org/10.5194/iahs2022-154, 2022.

Maintaining biodiversity of spontaneous species in agricultural landscapes is a major challenge regarding the bundle of ecosystem services provided by them, such as preservation of water and soil resources. It is possible to increase landscape’s resilience to climate change through their renaturalization with agroecological measures, especially maintenance practices of vegetation cover in agroecological infrastructures. 

In the Mediterranean environment, those infrastructures such as ditches, plot borders or even inter-rows of perennial crops concentrate both biodiversity and flow of matter (water, pollutants, particles), making these landscape elements particularly susceptible to intense rainfall events that contribute to exchange of biodiversity across landscapes. Managing vegetation of these elements is a significant lever for biodiversity maintenance considering impacts of plants on flows of matters, such as water and seeds. Promoting exchanges requires knowledge of the relative importance of the main types of plant dispersal i.e. hydrochory, anemochory and zoochory that affects seed exchange between landscape elements, by making the hypothesis that the hydrochoric dispersion, i.e. by water, is particularly important in the Mediterranean environment. 

To establish the potential of hydrochory to rehabilitate Mediterranean vineyard environments, we proposed a conceptual model of seed exchanges at landscape scale incorporating the levers available to stakeholders (vegetation maintenance in inter-rows, drainage ditches and plot borders), as well as climatic variables and the specific characteristics of each seed present. We will present the first results of seed dispersal experiments after a rainy event on a vineyard plot, as well as manipulations to determine the seed bank, allow us to make a first estimate of seed transport and the rehabilitation potential of Mediterranean vineyard environments. At the end of the experiments, the knowledge obtained will be integrated into a spatially explicit model based on the source-sink principle to simulate the dispersion of seeds by water, this model being considered as a virtual laboratory to co-construct landscape arrangements with stakeholders for maintaining biodiversity.

How to cite: Faucher, M., Bailly, J.-S., and Vinatier, F.: Hydrochory in agricultural landscapes, IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-428, https://doi.org/10.5194/iahs2022-428, 2022.

How to cite: Vandôme, P., Belaud, G., Leauthaud, C., Moinard, S., Mekki, I., Zairi, A., Charron, F., Leconte, J., Ferchichi, I., and Ajmi, T.: Exploring ways to improve agricultural water management on two Mediterranean irrigated systems : promises of wireless low-tech sensor networks, IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-90, https://doi.org/10.5194/iahs2022-90, 2022.

In Africa, groundwater irrigation is considered a reliable and affordable means to increase food security. Areas equipped for groundwater irrigation in Africa have however, developed slowly since 1950 and remain very limited. This study is based on two approaches to locate and quantify this potential. The quantitative hydrological approach is based on the estimation of the current crop irrigation need and available renewable groundwater for irrigation after all other water needs, including environmental, have been satisfied. This approach shows that the potential is 44.6 x 106 ha or 20.5% of the cropland over the continent. The environmental approach redefines the quantitative potential by considering a set of biophysical and socio-economic factors conducive to sustainable development of groundwater irrigation. The potential is then 19.3 x 106 ha and it is reduced mainly from the equatorial regions where the need for irrigation is limited. In fact, without considering the countries of the Maghreb and South Africa where current irrigation by groundwater exceeds the estimated potential, groundwater irrigated areas could be multiplied by 75. The largest areas which are worthwhile to develop are mainly located along a west-east line from Angola to the north of Mozambique and a line south of the Sahel. The dry regions of the Sahel, East Africa and Southern Africa have limited development potential which is more suitable to small-scale agriculture and could greatly improve food security in Africa.

How to cite: Altchenko, Y., Villholth, K., and Ducharne, A.: Mapping sustainable irrigation development potential with renewable groundwater in Africa, IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-27, https://doi.org/10.5194/iahs2022-27, 2022.

Changing climate and expanding irrigated agriculture exert significant pressure on the already limited water resources in many regions of the world. This study is located in a South African strategic water source area called the Koue Bokkeveld (KBV). The area is characterised by a strongly seasonal flow regime, where winter flash flood flows dominate and long dry summer periods are experienced. Numerous small reservoirs have been constructed in the catchment to capture the extreme winter flows. The region is a biodiversity hotspot with a number of endemic species and forms part of the strategic water source area in South Africa (10% of South Africa’s land surface produces 80% of the country’s runoff).

During the long dry summer period, conflicts over water use and allocation among farmers in the study catchment emerge. When this happens, river flows are abstracted without considering ecological reserve (environmental flow) requirements.

This study quantifies the availability of water resources in the KBV catchment to contribute to creating an equitable and more sustainable water management plan that addresses water-related conflicts among farmers and ensures that ecological reserve requirements are met. SWAT+ has been set up for this study as it allows the representation of spatially distributed reservoirs and river diversion points within a catchment. This study also simulates future flow scenarios in the context of changing climate.

The outcomes of this project will be used to support decision-making regarding sustainable water management. This includes being used as input into an Agent-Based Model (ABM) that will be utilised to explore various management scenarios. Furthermore, the modelled current and future water availability information will assist catchment managers in making informed decisions about how water management could be adapted to changes in water availability.

The project is half way through, with SWAT setup complete. A meeting with the farmers in early 2022 will assist with further calibration of the model, in terms of reservoir and irrigation dynamics. The possibility of additional reservoirs will be explored to counter the run of river summer abstraction occurring that is currently negatively impacting the biodiversity.

How to cite: Mabohlo, S., Tanner, J., and Gwapedza, D.: Application of the SWAT hydrological model for water balance assessment in an intensive irrigated agricultural catchment in the Western Cape, South Africa, IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-629, https://doi.org/10.5194/iahs2022-629, 2022.

Agriculture is an essential driving force in the management of water resources in Mediterranean countries as it has a dominant role in sustaining the growth of rural areas and at the same time represents by far the major water consumer. However, detailed assessment of the irrigation water requirements spatial and temporal distribution is challenging in the case of poorly gauged regions and especially in countries characterized by vast spatial and temporal variability like Greece, as water absractions in agriculture are spatially scattered, various water sources are used in each field, and the corresponding monitoring infrastructure is scarce.

This study presents a modelling approach for the assessment of irrigation water requirements spatial and temporal distribution in Greece on the basis of farm structure survey data, annual crop statistics and meteorological data. The proposed methodology is using an entirely spatially distributed, continuous hydrological model, in order to estimate the spatial distribution of the hydrological balance components at every point of the studied region as well as plants water deficit, and irrigation water requirements in a daily time step for the entire country. The developed approach is directly relevant to agricultural water policies design and evaluation. A special algorithm that is able to link each farm parcel polygon (over 6,000,000 polygons) of the spatial database of the Integrated Administration and Control System (IACS) with the nearest corresponding grid cell of the model was also developed. In this way, the developed approach utilizes all the information included in the IACS database (e.g. irrigation system, water source, applied agri-environmental measures) and provides very precise information at farm parcel level facilitating further analysis. Remote sensing data (Sentinel-Copernicus) and methods were also used for the validation of the crop patterns and of the irrigated fields in IACS database. The model was applied for 34 years reference period (1971-2004) at a daily time step. The obtained results were analyzed to identify spatial patterns and relationships, to investigate the temporal variability and the presence of trends and to provide detailed information on the water requirements of various crops and regions providing valuable information concerning agricultural water management.

How to cite: Soulis, K., Tsesmelis, D., and Psomiadis, E.: A modelling approach for the assessment of irrigation water requirements spatial and temporal distribution in Greece, IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-45, https://doi.org/10.5194/iahs2022-45, 2022.

There are 37 hydraulic water catchment pumps installed in the Urubu River hydrographic basin, located in an important agricultural area in the northern region of Brazil. The water is used to irrigate rice, which takes place between November and March, during the rainy season, and soy for seed, in the months of May to September, which include the dry season of the hydrological regime. In 2016, the region went through a water crisis that extended into the following years. The main causes were associated with a climatic extreme, caused by a prolonged dry season, high demand for irrigation and inefficient management of water resources, which resulted in the judicial suspension of water use permits and conflict between irrigators.

The objective of the study was to evaluate the water availability of the Urubu River in face of demand through the use of the Water Evaluation and Planning System (WEAP) model. The analysis period was from July 2018 to June 2019, focusing on the results for the months of July and August. The flow of the Urubu River was modeled in the WEAP using the Rainfall Runoff method. Three demand nodes (D1, D2, D3) were used to represent the water pumped for irrigation along the river. The pumped flow data for irrigation were obtained from the monitoring High Level Management Project (GAN) implemented in all hydraulic pumps.

The result showed that the demand for rice irrigation is compatible with the availability, however for the soybean crop the water demand exceeded the availability at many moments (Figure 1), causing the interruption of the river flow after node D2. The result shows that the high demand for water causes severe environmental impacts. In addition, the observed situation reflects in economic losses to farmers, decrease in the quality of the soy crop and increases conflicts between users.

Figure 1 - Urubu River flow after water demand for irrigation.

This study proves that it is necessary to change the irrigation techniques currently used to obtain a more efficient water management, preventing the environmental impacts caused by the unfavorable water balance from happening again.

How to cite: John Volken, N., Tezini Minoti, R., de Maria Albuquerque Alves, C., and Enrique Vergara Figueroa, F.: Impact of water demand for irrigation on the water availability of the Urubu River in Brazil, IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-299, https://doi.org/10.5194/iahs2022-299, 2022.

Water is a critical resource for food production. Climate change has shown that shifts in precipitation regimes and increases in atmospheric temperature threaten food production worldwide. Therefore, it plays an essential role as a driver in the water-environment-food nexus. Strategies to cope with impacts of climate risk require understanding the relationship between hydro-meteorological extremes and crop yield shortfalls to guide decision-making. The purpose of this paper is to propose a fully data-driven model for predicting the impacts of hydrological extremes on food production for decision-making at the municipal level. We use the Support Vector Machine (SVM) model considering a variety of kernels for predicting crop yields using reanalysis data of water storage (WS) from 0 to 28 cm of soil during the soybean growing season. We used ERA5 WS data for Paraná state in Brazil and official annual soybean crop yields (SBY) at the municipal level. We tuned a SVM radial basis function kernel with sigma and cost parameters for municipalities with significant production of soybean. The SVM model predicted crop yields accurately with R² ranging from 0.12 to 0.85. The use of soil moisture data increased model accuracy from 30 to 95% and reduced error from 5 to 58% in relation to using only SBY, except for one location. These results indicate that the model is better able to depict SBY during drier conditions, reducing prediction accuracy in years with average or above average yields. The model we proposed is useful for estimating crop losses due to water shortage at the municipal level. Our results suggest that using WS data from ERA5 as an additional input to past SBY adds relevant information for several applications such as risk transfer, irrigation planning and farm-level management with data that are made available for most countries. Our model has potential for climate impact studies coupled with projections from Global Circulation Models forced by Shared Socioeconomic Pathways (SPP).

How to cite: Benso, M. R., Silva, R. F., Gesualdo, G. C., Marques, P. A., Delbem, A., Saraiva, A. M., and Mendiondo, E. M.: Artificial intelligence for agricultural drought monitoring based on soil moisture and crop yield under change, IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-407, https://doi.org/10.5194/iahs2022-407, 2022.

Oases of southern Tunisia are located in a hostile arid environment. Despite the environmental situation, oases are the place of specific knowledge developed by indigenous populations. Theses agroecosystems, where date palm tree is the dominant crop, are a characteristic example of Saharan arid climate region. Nowadays, oasis land is threatened by soil and water degradation under salinity risk as well as water scarcity, identified as the most important problem for regional and national socio-economic security. The advancement of technologies that ensure efficient use of irrigation water may be needed. This work is evaluating the bubbler irrigation system in Jemna Oasis (southern Tunisia) for date palm for current and future climate. The objective was to quantify root water uptake, yield production and root zone salinity under current and future climate change. Mid and long term precipitations, temperature and date palm water needs were determined from 2 regional climate models forced by general circulation model (GCM-RCMs) issued from EURO-CORDEX project. Field experiments and modelling approach were developed within this work. Different scenarios regarding irrigation frequencies and quantities were tested using Hydrus-1D model. In context of water scarcity, implementing an irrigation schedule in which crop growth stages and soil salinity are considered is strongly recommended for date palm tree. The bubbler irrigation system using 100 % ETc and T₃ as irrigation schedule could be considered as a save irrigation method under current and future climate change, if water allocated for irrigation do not exceed 3.2 dSm^-1 with crop yield reaching equal to 80% as a mean value and soil salinity about 12dSm^-1. Results indicated that  climate change from 2020 to 2090 would increase temperatures and decrease annual rainfall. An increase in events with rainfall amounts exceeding 100 mm/day is noted. During this future period, using both saline irrigation water (5 and 5.5 dSm^-1) and irrigation lower than 100% ETc, the date palm crop yield is expected to vary from an average value of 81% in 2020 to about 70 % in 2050 and 55% in 2090 and an increase of soil salinity to 20 dSm^-1 will occur.

How to cite: Zemni, N., Slama, F., Bouksila, F., Dakhlaoui, H., Dhaouadi, L., Sidhom, O., and Bouhlila, R.: Assessment of current and future (under climate change) crop water requirement and irrigation strategies under bubbler irrigation system for date palm in Jemna oasis, Southern Tunisia, IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-517, https://doi.org/10.5194/iahs2022-517, 2022.

Soil and water salinization is a major threat to agricultural land and biodiversity in natural areas. Coastal areas are highly sensitive to salinization leading to a deterioration of resources (water, soil and biodiversity) and ecosystem services. The Aude lowland is longstanding facing this issue. The main solution is to bring massive amounts of fresh water to the surface of the fields, in the form of anthropic flooding, associated with drainage for the leaching of salts. Understanding system equilibrium is crucial in the context of global change, less fresh water available, sea level rise, strong and fast landuse evolution.

To achieve this objective, we propose an integrated approach providing links between high resolution water and soil salinity at lowland scale, lato sensu water management practices and winegrowers perception of the actual state and evolution salinity.

Salinity measurement survey consist in three dimensional sampling with more than 1500 samples on the whole study area. Results exhibit high level of salinity, increasing with depth and heterogeneity at short distance and spatially structured at long distance. Closed questions carried out on 27 winegrowers bring an in-depth knowledge on all winegrowing practices related to water management (tillage, weed control practices, irrigation, drainage). Statistical analysis (MCA, HAC) show five groups of practices associated to different salt control strategies. Perception was investigated using open questions and answers were structured in a matrix including six themes (in column) and 27 winegrowers (in row). Main results show three different types for salinity perception.

The cross analysis between perception, practices and measured salinity brings an integrated vision of the salinization and its management in the study area. This allows to better understand how viticulture can still partially persist despite high soil and water salinity levels. The reason is inside the strategies promoting the adaptation of the practices to salty pressure and soil functioning and not only based on unique practice.

How to cite: Marien, L., Crabit, A., Bergé, F., Alexandre, E., and Colin, F.: Soil and water salinization in mediterranean costal area : toward an integrated approach for salinity management - Case study of the Aude lowland, IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-393, https://doi.org/10.5194/iahs2022-393, 2022.

Agriculture is considered today as having major impacts on water quality in river basins. Transition from this situation to a better integration of agricultural practices in their environment is sought by many stakeholders and policy makers, from water, land development and also agriculture sectors. This appears costly when incorporating their various constraints. With the on-going research project ExpEau, the LTSER-FR network aims at (1) raising awareness on the opportunities to handle agricultural sources of water pollution collectively, and (2) comparing them in various watersheds. 
To that end, we are developing a hybrid serious game featuring activities and relations between farmers, municipalities and river basin organization on a virtual river basin, generated from actual datasets for topography, soil properties, and climate. For comparison sake, the game features a framed number of entities and possibilities of action, and the process of transforming actual datasets is standardized. We consider representative small basins (ca. 100 km2) that we discretize into three sub-basins, each of them representing a municipality as the first level for collaboration. Each sub basin counts about 30 hexagons elementary tiles with a single land use for each.
In practice, the game is made of a physical board and playing action cards, as well as a twin on-line version. Farmer players access to the information on their environment and choose cultural practices thanks to a smartphone. Municipality and river basin organisation roles use their time and budget to facilitate collaboration and support more virtuous practices as well as infrastructures to decrease pollution. A local server computes the impacts of these actions in terms of production, collective well-being and contamination, and updates the players’ data. 
During the game session, players can see the virtual watershed, the land use and the infrastructures on the physical board. According to their role, they receive situated information on production, on territorial well-being and water quality and quantity.
Involving students or local stakeholders, each session is followed by a debriefing that could produce (1) a local understanding on the interactions between agriculture and water quality, and (2) socio-ecosystem data to feed a cross LTSER analysis of these interactions.

How to cite: Barreteau, O., Charpentier, I., Elouati, H., Kelhetter, H., Kudriashov, D., Blanchoud, H., Bonnefond, M., Dousset, S., Gouy, V., Piscart, C., Pons, M.-N., Ragueneau, O., and Salvador-Blanes, S.: Exp’Eau, a hybrid serious game to explore pathways towards better water quality in rural catchments, IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-323, https://doi.org/10.5194/iahs2022-323, 2022.

Mediterranean regions are impacted by critical water scarcity, climatic and demographic change, with national institutions and authorities that are called to take prompt and important decisions to support fair allocation of resources, mitigate conflicts and sustain social cohesion. Understanding the interlinkages of the Water-Energy-Food-Ecosystem (WEFE) Nexus components is of fundamental importance for safe and sustainable management of urban, agricultural, and natural ecosystems. Nevertheless, WEFE Nexus knowledge and technology transfer is still falling behind with major technical and non-technical barriers that avoid the transition towards WEFE Nexus approaches. Multi-Sector, Multi-Disciplinary and Multi-Actor cross-cooperation and mutual trust are still lacking, with stakeholders and citizens that are not adequately informed and involved. The NEXUS Nature Ecosystem Society Solution or NEXUS-NESS project - funded by the PRIMA Programme under the 2020 Nexus Innovation Action - seeks to co-demonstrate with stakeholders a science-driven solution to mainstream WEFE Nexus in Mediterranean regions. NEXUS-NESS aims to co-produce and co-test with stakeholders WEFE Nexus management plans for fair and sustainable allocation of resources. NEXUS-NESS will produce trans-disciplinary datasets and scenarios integrating large scale WATNEEDS and river basin scale FREEWAT eco-hydrological models for building an operational NEXUS-NESS Service (NNS) transferring science-driven WEFE Nexus knowledge to address real case issues. NEXUS-NESS will operationalize the adoption of a WEFE Nexus bottom-up approach in four different case studies employing Living Lab and Responsible Research and Innovation (RRI) principles and change management by applying the RRI Roadmap. Four Nexus Ecosystem Labs (NELs) in Italy, Spain, Egypt and Tunisia were set up as preliminary important step to support NEXUS-NESS mission and goals. In the four NELs all stakeholders will be effectively engaged for creating long-lasting Innovation Ecosystems that are based on collaboration among academia, industry, different levels of the public sector and citizens. This contribution illustrates the preliminary insights, observed during the NELs start up, sharing the issues and opportunities that were co-assessed in the four labs of Val di Cornia in coastal Tuscany (Italy), the Duero basin (Spain), the Wadi Naghamish (Egypt) and the Wadi Jir basin (Tunisia).

How to cite: Nardi, F. and the NEXUS-NESS Consortium: Co-design of multidimensional mainstreaming of the WEFE Nexus: preliminary results from the four Mediterranean Nexus-Ness living labs, IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-651, https://doi.org/10.5194/iahs2022-651, 2022.