HS8.1.8

EDI
Water scarcity and management in dry regions: from groundwater to the vadose zone

The proper management of blue and green water is vital for sustainable livelihoods in drylands (i.e. hyper—arid, arid, semi—arid and dry sub—humid lands), where any productive activity is structurally and deeply related to the understanding of soil hydrological behaviour. In these areas groundwater is usually the primary source for drinking water supply and irrigation so that water management is critical to the water-food-energy security nexus.
Irrigation, in particular, should be regarded as a fundamental element of any agroecosystem and an effective defence against desertification. This as a consequence of the fact that on one hand traditional irrigation is often a cultural heritage, which requires to be faced with an interdisciplinary approach, while on the other hand incorrect irrigation techniques may lead to soil and groundwater salinization, with dramatic fallout on agricultural productivity.
Also, due to local shifts in climate and in the hydrological cycle, or global changes such as population growth and changes in land use, drylands and regions with high water stress are expected to expand globally: for example, catchments in Central Europe with continental climate and decreasing precipitation in summer periods are likely to be new areas subjected to water stress.

This session welcomes contributions ranging from the understanding of the soil hydrological behaviour and of the mass fluxes through the soil in drylands and environments under stress conditions to the identification of the consequences of a changing environment for better future management, protection, and sustainable use of water resources in drylands.
This includes adapted modelling techniques coupling climate models with hydrological models or with soil water and groundwater models, or studies dealing with groundwater quantity and quality, the interaction between irrigation and soil hydrology, and the design of irrigation systems in arid districts and oases, also involving non—conventional waters (e.g. water harvesting). Particular attention will be given to traditional irrigation techniques as well as to precision irrigation techniques, also with local community involvement.

Due to a frequently associated data scarcity issue in dry regions, methodologies and strategies addressing uncertainty and limited data availability are of interest for this session. Interdisciplinary contributions and contributions from appropriate field observational studies are encouraged as well.

Co-organized by CL3.2
Convener: Martin Sauter | Co-conveners: Noam Weisbrod, Jaime Gómez-Hernández, Mira HaddadECSECS, Marco PeliECSECS
Presentations
| Tue, 24 May, 15:55–18:22 (CEST)
 
Room 2.31

Presentations: Tue, 24 May | Room 2.31

Chairpersons: Mira Haddad, Marco Peli, Lysander Bresinsky
15:55–16:00
16:00–16:07
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EGU22-92
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ECS
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On-site presentation
Shubham Tiwari and Brijesh Kumar Yadav

Aquifer Storage and Recovery (ASR) is one of the most effective ways of artificial groundwater recharge to assure freshwater availability during droughts in arid and semi-arid areas. However, this method of managed aquifer recharge is less prevalent in saline groundwater regions due to low recovery efficiency (RE). The injected freshwater of an ASR scheme in saline regions is decreased due to mixing between fresh-saline water and the upward movement of stored freshwater due to gravity effects. The losses due to mixing, however, can be reduced by managing the operational parameters. This study proposes a solution for reducing losses of injected freshwater due to gravitational within the saline aquifer by introducing multiple partially penetrating well-system (MPPW) in place of a single fully penetrating well-system (SFPW). A variable-density flow (SEAWAT) model is used to simulate and compare the ASR system performance for specific hydrogeological conditions and variable operational parameters for SFPW and MPPW well systems. The results indicate that by using MPPW in place of the SFPW ASR well system, 8 to 15% extra injected freshwater can be recovered. The difference in recovery efficiency due to the use of MPPW in place of SFPW tends to increase with the increasing values of injected freshwater storage duration and the number of successive ASR cycles and decreases with increasing the injection/recovery rates and injection volumes. This research provides the basis for understanding the suitable ASR well type for any specific site for different operational factors.

How to cite: Tiwari, S. and Yadav, B. K.: Improving the performance of Aquifer Storage and Recovery schemes using Multiple Partially Penetrating Wells, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-92, https://doi.org/10.5194/egusphere-egu22-92, 2022.

16:07–16:14
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EGU22-173
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ECS
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Virtual presentation
S. Paolalsiam Vaiphei and K. Rama Mohan

Human modernizations and achievements are at peak but in contrary we ignore facts about the tremendous amount of anthropogenic waste that are exposed directly to atmosphere which later reach groundwater aquifer and contaminate through natural water cycle. So, to limelight man-made sources, Wanaparthy watershed is chosen as it is densely agriculture urban area covering about 1600 km2 were peoples solely get their daily wages from farming. Samples were collected systematically for pre (march-may) and post monsoon (september-december) through gird preparation (5*6 sq.km) to determine the hydrogeochemical characteristics of physicochemical parameters and major analytes concentration to preside the types, quality, permissibility, facies and nitrate health risk of different age groups in groundwater. In short findings are as follows: Major analytes concentration for pre-monsoon, Cl- (8.02%) >HCO3- (3.27%) >SO42-(2.75%) >NO3-(1.09%) >F-(0.02%); Na+(4.08%) >Ca+2(1.71%) >Mg+2 (0.45%) >K+ (0.26%)while post-monsoon, HCO3-(8.94%) >Cl- (6.9%) >SO42- (2.46%) >NO3- (2.42%) >F-(0.02%); Na+(3.28%) >Mg+2(2.14%) >Ca+2(0.75%) >K+(0.28%) respectively. Piper diagram explains the major water types for pre- and post-monsoon as Na-Cl type and Ca-Mg-Cl type. Gibb’s plot shows that in both seasons the dominant environmental facies are influence by rock and evaporation conditions. Water quality index shows deterioration increase at most twice from “poor to unfit class” (36.21% - 60.34%) during pre to post season. Health Quotient evaluation for nitrate indicates “children group” as most effected where HQ value range from 5.40E-03 to 1.23E+01 (72.4 pc) followed by infant group, 5.80E-03 to 1.31E+01 (68.97 pc) and adult 2.10E-03 to 4.68E+00 (32.7pc). And, from spatial distribution maps it is observed that slope and structure have direct response to recharge/discharge as well as aquifer properties.

How to cite: Vaiphei, S. P. and Mohan, K. R.: Characteristics of groundwater quality and its non-carcinogenic health risk assessment through monsoon inputs in Wanaparthy watershed, Telangana, India, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-173, https://doi.org/10.5194/egusphere-egu22-173, 2022.

16:14–16:21
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EGU22-3104
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ECS
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Virtual presentation
Janine de Wit, Marjolein van Huijgevoort, Gé van den Eertwegh, Dion van Deijl, and Ruud Bartholomeus

Sufficient freshwater is needed for water dependent sectors as agriculture, nature, drinking water, and industry. However, even in low-lying, flood prone countries like the Netherlands, climate change, weather extremes, economic growth, urbanization, land subsidence and increased food production will make it more complex to guarantee sufficient freshwater for all sectors. Specifically, the range of weather extremes from extremely dry to extremely wet is expected to increase and extremes are expected to occur more frequently.

Over the last decades, drainage, land consolidation and urbanization resulted in declining groundwater tables. Additionally, the freshwater demand of different sectors caused an increased pressure on the regional groundwater system. As a consequence, the annual groundwater table in the Dutch sandy soil areas dropped over time with the effect that, nowadays, freshwater is becoming scarce in dry periods. Agriculture needs to anticipate on these conditions in order to prevent both drought and waterlogging. However, the current Dutch agricultural water management system is historically focused on water discharge and not designed to anticipate on both weather extremes.

One of the solutions could be to modify the current pipe drainage systems (already existing in 34 % of the agricultural land) to drainage systems with three purposes, called: controlled drainage with subirrigation. First, the drainage systems could discharge water if the risk of waterlogging increases. Second, the drainage system could store water during rainfall in the soil (retain water). Third, (external) water can be actively pumped into the drainage network to raise groundwater tables (recharge water).

We focus on the data and model output of four experimental sites in the Pleistocene uplands of the Netherlands, where controlled drainage with subirrigation is applied. Field data is collected over ± the years 2017-2021, like water supply, groundwater table, soil moisture content. Water balance components as actual transpiration, drainage and downward seepage are modelled with SWAP (Soil-Water-Atmosphere-Plant model). The effects on crop yield and configuration of the management are also quantified with the model.

The construction of controlled drainage with subirrigation, topographical location, and a proper management of these systems are important. First, results show that through subirrigation, water can be stored in the soil instead of discharged. The water storage leads to an increase in groundwater tables of ± 0.70 m during the growing season, leading to higher crop yields. By storing external water at the field scale, fast drainage was prevented, which decreased drought vulnerability. Second, results of the four experimental sites show that effects of subirrigation on the water balance components are strongly site dependent. For example, an impermeable layer at a shallow depth is needed for enough resistance to increase the phreatic groundwater level. Furthermore, ditch levels surrounded by the field are important as a shallow groundwater table with low ditch levels results in lateral drainage, an unfavorable effect. Third, results of the experimental sites show that proper management of these systems is important to prevent clogging of the system.

How to cite: de Wit, J., van Huijgevoort, M., van den Eertwegh, G., van Deijl, D., and Bartholomeus, R.: Controlled drainage with subirrigation: a water management measure to discharge, retain and recharge freshwater , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3104, https://doi.org/10.5194/egusphere-egu22-3104, 2022.

16:21–16:28
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EGU22-4147
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ECS
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On-site presentation
Mimi Peng, Zhong Lu, Chaoying Zhao, Mahdi Motagh, Lin Bai, and Brian D. Conway

The Willcox Basin, located in southeast of Arizona, USA, covers an area of approximately 4,950 km2 and is essentially a closed broad alluvial valley basin. The basin measures approximately 15 km to 45 km in width and is 160 km long. Long-term excessive groundwater exploitation for agricultural, domestic and stock applications has resulted in substantial ground subsidence in the Willcox Groundwater Basin. The land subsidence rate of the Willcox Basin has not declined but has rather increased in recent years, posing a threat to infrastructure, aquifer systems, and ecological environments.

In this study, an integrated analysis of remote sensing and in-situ groundwater observations is made to assess characteristics of land subsidence and response of the aquifer skeletal system to the change in hydraulic head in Willcox Basin. L-band ALOS and C-band Sentinel-1 SAR data acquired from 2006 to 2020 are analyzed using multi-temporal interferometric approach to derive subsidence deformation. We show that the overall deformation patterns are characterized by two major zones of subsidence, with the mean subsidence rate increasing with time from 2006 to 2020. This study also suggests that subsidence here is a result of human-induced compaction of sediments due to massive pumping in the deep aquifer system and groundwater depletion. 

Independent component analysis (ICA) a leading method for blind source separation to isolate signals without knowing a priori information about the signal sources, which was adopted to separate the mixed InSAR time series signal into a set of independent signals. On the one hand, the application of ICA filtered the residual errors in InSAR observations to enhance the deformation time series, and the deformation accuracy is improved by more than 13%. On the other hand, it also revealed that two different spatiotemporal deformation features exist in this area, indicating hydrogeological properties of aquifer systems are spatially variable in this basin.

In addition, the relationship between the observed land subsidence variations and the hydraulic head changes in a confined aquifer is analyzed. Using InSAR measurements and groundwater level data, the response of the aquifer skeletal system to the change in hydraulic head was quantified, and the hydromechanical properties of the aquifer system is characterized. The estimated storage coefficients, ranging from 6.0×10-4 to 0.02 during 2006-2011 and from 2.3×10-5 to 0.087 during 2015-2020, signify an irreversible and unrecoverable deformation of the aquifer system in the Willcox Basin. The reduced average storage coefficient (from 0.008 to 0.005) indicates that long-term overdraft has already degraded the storage ability of the aquifer system and that groundwater pumping activities are unsustainable in the Willcox Basin. Historical spatiotemporal storage loss from 1990 to 2020 was also estimated using InSAR measurements, hydraulic head and estimated skeletal storativity. The estimated cumulative groundwater storage depletion was 3.7×108 m3 from 1990 to 2006. 

Understanding the characteristics of land surface deformation and quantifying the response of aquifer systems in the Willcox Basin and other groundwater basins elsewhere are important in managing groundwater exploitation to sustain the mechanical health and integrity of aquifer systems.

How to cite: Peng, M., Lu, Z., Zhao, C., Motagh, M., Bai, L., and Conway, B. D.: Use of satellite remote sensing and independent component analysis to assess land subsidence and aquifer system properties over the Willcox Basin, USA, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4147, https://doi.org/10.5194/egusphere-egu22-4147, 2022.

16:28–16:35
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EGU22-4617
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Virtual presentation
Juan C. Santamarta, Noelia Cruz-Pérez, Jesica Rodríguez-Martín, Miguel Ángel Marazuela, Rosana Álvarez-Vázquez, and Alejandro García-Gil

The outermost regions of Europe are nine: Guadeloupe, French Guiana, Martinique, Mayotte, Reunion and Saint Martin (France), the Canary Islands (Spain), the Azores and Madeira (Portugal). These regions enrich the EU economically, culturally and geographically, hosting 80% of its biodiversity. However, due to their remoteness and other unique features, they pose challenges for their development. The particular case of the Canary Islands will be developed in the framework of the European H2020 project Arsinoe, where the hydrological cycle and agriculture in the Canary archipelago will be studied in El Hierro and La Palma. These two islands have been selected for the following reasons: i) El Hierro is a pioneer in presenting a self-sufficient energy model (La Gorona del Viento project) and is rich in groundwater, this being the most used water resource on the island; ii) La Palma has been selected because it is an island rich in groundwater (in fact, it is the only island in the Canary archipelago that does not have desalination plants) and where agriculture is very important (especially tropical crops such as banana, mango, avocado, etc.) and, due to the volcanic eruption that began in September 2021, the situation of the aquifer is uncertain, something that is worrying since La Palma depends on groundwater resources to guarantee the water demand of agriculture, local population and tourism. The effect of the eruption on the vulnerability of the aquifer of La Palma is still unknown, so it is desired to study in depth the effects on the aquifer in quantitative and qualitative terms therefore, ARSINOE will focus on the ecological transition and vulnerability of aquifers in volcanic islands and will put further efforts to the primary production including agriculture, forestry, fisheries and aquaculture, water management and clean energy infrastructure. ARSINOE will take into account the interdependence between water and agriculture. The agricultural sector is the largest water user in the Canary Islands, where wine, potatoes and tomatoes are the main exports. Therefore, greater sustainability within the water sector (through the water footprint and the carbon footprint) will positively affect the agricultural sector and, therefore, the water and energy situation of the archipelago. But aquifers of both islands are also at risk due to other circumstances, specifically those derived from climate change: greater saline intrusion (due to rising sea levels), losses in freshwater inputs (due to decreased rainfall), changes in physic-chemical conditions of all water bodies… All these effects will be studied on both islands, through the ARSINOE Project, and from a local point of view. 

How to cite: Santamarta, J. C., Cruz-Pérez, N., Rodríguez-Martín, J., Marazuela, M. Á., Álvarez-Vázquez, R., and García-Gil, A.: Vulnerability of aquifers on volcanic islands: the case of La Palma and El Hierro (Canary Islands, Spain) , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4617, https://doi.org/10.5194/egusphere-egu22-4617, 2022.

Coffee break
Chairpersons: Marco Peli, Mira Haddad, Lysander Bresinsky
17:00–17:07
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EGU22-5856
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ECS
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Virtual presentation
Soroush Zarghami Dastjerdi, Ehsan Sharifi, Bahram Saghafian, and Andreas Güntner

Climate change, urbanization, and growing population have led to the rapid increase in the use of groundwater. Therefore, monitoring the groundwater (GW) changes is essential for water management and decision-makers. Due to frequent lack of reliable and sufficient in-situ information, remote sensing and hydrological models can be counted as the alternative sources for assessing GW storage changes on a regional and global scale. Here, we test such an approach for Qazvin Plain in Iran, one of the regions that recently have been facing severe drought conditions. The main purpose of this study is to downscale GW storage anomaly (GWSA) of the WaterGAP Global Hydrology Model (WGHM) from a coarse (0.5-degree) to a finer spatial resolution (0.1-degree) using fine spatial resolution auxiliary datasets (0.1-degree) such as the evaporation, surface and subsurface runoff, snow depth, volumetric soil water, and soil temperature from the ERA5-Land model and precipitation from integrated multi-satellite retrievals for global precipitation measurement (IMERG). Different regression models were tested for the GWSA downscaling. Moreover, since different water budget components such as precipitation or storage are known to have temporal lead or lag relative to each other, the approach also includes a time shift factor among the components. The most suitable regression model with the highest skill score during the validation test was selected and applied to predict the 0.1-degree GWSA. The downscaled results showed a high agreement with the in-situ groundwater levels for Qazvin Plain in both interannual and monthly scales, with a correlation coefficient of 0.99 and 0.65, respectively. Moreover, the downscaled product clearly proves that the developed downscaling technique is able to learn from high-resolution auxiliary data to capture GWSA features at higher spatial resolution. The major benefit of this method is in utilizing only the auxiliary data that are available with global coverage and free of cost, and that this method does not need in-situ GW records for training. Therefore, the proposed downscaling technique can potentially be applied to a global scale, other geographical regions, or aquifers.

This study has received funding from the European Union’s Horizon 2020 research and innovation programme for G3P (Global Gravity-based Groundwater Product) under grant agreement nº 870353.

How to cite: Zarghami Dastjerdi, S., Sharifi, E., Saghafian, B., and Güntner, A.: Downscaling WGHM-Based Groundwater Storage Data Using Regression Method: A Regional Study over Qazvin Plain, Iran, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5856, https://doi.org/10.5194/egusphere-egu22-5856, 2022.

17:07–17:14
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EGU22-6881
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ECS
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Virtual presentation
Neetu Singh, Ian Cartwright, and Pennan Chinnasamy

Arid and semi-arid areas characterised by low precipitation and high evaporation rates are highly vulnerable to alterations in precipitation regimes, leading to water deficiency and an increase in dependence on groundwater resources. Flash floods have become more frequent in several semi-arid regions due to changing climatic conditions. Thus, an efficient water management system is needed for these regions to manage flash floods and support groundwater recharge. A coupled surface water-groundwater model is an advanced tool for simulating large-scale hydrologic processes and quantifying factors influencing floods and drought. To accommodate the high variability and heterogeneous spatial distribution of surface and groundwater resources, distributed modelling tools are essential. However, scarce monitoring networks may lead to the unavailability of spatio-temporal input data and limit the applicability of these models. Advances in remote sensing (RS) techniques for monitoring hydrological parameters like precipitation, soil moisture, evapotranspiration, and groundwater depth can mitigate this problem.

This study analyses the remote sensing product MOD11A1.006 of Moderate Resolution Imaging Spectroradiometer (MODIS), which provides daily day and night land surface temperature (LST) at a spatial resolution of 1000 m, facilitating the analysis of surface water-groundwater interactions through distributed hydrological modelling in the semi-arid Banas River basin (~6800 km2). Remotely sensed LST data allowed air surface temperature (Ta), which is crucial for estimating reference evapotranspiration, to be retrieved. While Ta at weather stations 2 m above the ground are more accurate, those data have limited spatial coverage. The Banas River basin contains five weather stations located primarily in the central region. To improve the spatial distribution of reference evapotranspiration, which is a significant input of the hydrological models, a linear regression model using Ta observed at the weather stations of Banas basin, along with LST, elevation, Normalized Difference Vegetation Index (NDVI), latitude, and longitude of the pixels coinciding with the location of weather stations was developed to estimate the air surface temperature for the whole basin.

A multiple linear regression model was built by stepwise linear regression (SLR) method using the OLSRR package of R. Calibration using day LST, latitude and longitude provided the best estimate of maximum Ta, with an adjusted R2 value of 0.60, Pearson correlation coefficient (r) of 0.72, and Root Mean Square Error (RMSE) of 3.2o C. While calibration using night LST and elevation data provided the best estimate of minimum Ta with an adjusted R2 value of 0.81, r of 0.84 and RMSE of 3.02o C. The daily LST data and daily Ta data have shown a good agreement. This research improves the understanding of the spatial distribution of daily day and night air temperature in the Banas River basin. It opens a new methodological perspective for groundwater and surface water management through hydrological modelling with a spatial resolution greater than that of the existing monitoring networks.

How to cite: Singh, N., Cartwright, I., and Chinnasamy, P.: Estimation of air surface temperature using MODIS land surface temperature over data-scarce Banas River basin, Western India, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-6881, https://doi.org/10.5194/egusphere-egu22-6881, 2022.

17:14–17:21
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EGU22-8221
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ECS
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On-site presentation
Lysander Bresinsky, Jannes Kordilla, Irina Engelhardt, Yakov Livshitz, and Martin Sauter

Climate simulations indicate that the Mediterranean region will be severely affected by climate change and is often referred to as the most prominent climate change hotspot (Gao and Giorgi, 2008). This study addresses the combined effects of climate change and three groundwater consumption scenarios on the water availability of the Western Mountain Aquifer (WMA) in Israel and the West Bank. Generally applied methods to quantify recharge and water resources rely on linear regressions or simplified models, such as data-driven approaches (i.e., lumped-parameter and black-box approaches). However, they are unfit to assess climate change impacts because the predictive power of data-driven approaches is low, should the variability of, e.g., precipitation expand beyond historically observed fluctuations, such as expected from climate change effects. Furthermore,  they do not honor the physics of flow. Therefore, assessing the impact of climate change requires the application of distributed process-based numerical models that incorporate as many relevant physical flow processes as feasible. For example, when karstified vadose zones measure several hundreds of meters, such as in the case of the WMA, variably saturated flow is a highly relevant flow process controlling vadose storage at large timescales and altering recharge flux at the “control plane” groundwater table.
We simulate the complex dynamics of the dual-domain infiltration and partitioning of the precipitation input signal by employing HydroGeoSphere (HGS) for transient variably saturated water flow. Flow in the limestone rock matrix and secondary high porosity system (i.e., conduits and fractures) is modeled by overlapping individual continua based on the bulk effective Richards’ equation with van Genuchten (VG) parameterization. The model input of this study stems from two coherent dynamically downscaled high-resolution regional climate projections (daily, 3km, and 8km resolution) until the year 2070, assuming the IPCC RCP4.5 climate change scenario. The results indicate that long-term average recharge quantities will decrease by circa 10 % compared to the reduction in average precipitation by 30 %. The mitigated impact on recharge is an effect of the pronounced heterogeneity of karstic flow (i.e., preferential recharge along with karst dissolution features) and increased intensity of individual rainfall events, emphasizing the need to apply spatiotemporally resolved climate models with daily precipitation values as input to the recharge assessment. However, despite the comparatively moderate decrease in recharge, the length and severity of consecutive drought years with low recharge values are likely to increase while freshwater demand is believed to increase during these periods, emphasizing the need to adjust the current management practices to climate change. Finally, the model is used to simulate managed aquifer recharge applications to mitigate the effects of more extended drought periods by strategic freshwater reserves. 

How to cite: Bresinsky, L., Kordilla, J., Engelhardt, I., Livshitz, Y., and Sauter, M.: Impact of climate change and groundwater consumption scenarios on a major transboundary karst water resource - The Western Mountain Aquifer in Israel and the West Bank, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8221, https://doi.org/10.5194/egusphere-egu22-8221, 2022.

17:21–17:28
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EGU22-8732
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ECS
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Virtual presentation
Thyago Anthony Soares Lima and Paulo de Tarso Amorim Castro

The source of the Grande river and its tributaries on the left bank are located in a tropical region adjacent to the humid valley of the Tocantins river, with rainfall that favors the continuity of the rivers. In the middle and east part of the basin, the predominance is of the semi-arid climate, as well as typical of the middle São Francisco basin, with irregular rainfall that does not contribute to the supply of the rivers. It is noteworthy that most of the tributaries of the hydrographic basin are intermittent. The Grande river basin is part of two important hydrogeological systems, the Group Bambuí system and the Urucuia system (SAU), which is the most important system in the western region of Bahia, as well as one of the most important in the São Francisco river basin, as well as the entire brazilian Northeast region, in addition to being one of the most relevant in the country, since it is a strategic source of water. Such hydrogeological systems are directly responsible for supplying the hydrographic basin in its dry periods. The Brazilian semi-arid region, with its limited water resources, is currently classified as a critical dry and water-poor area. This study aims to identify potential areas of groundwater in the aforementioned hydrographic basin, located in the middle eastern portion of the São Francisco river basin, in the State of Bahia. Integrating geological and hydrogeological analyses, remote sensing, geographic information systems (GIS) and multicriteria statistical evaluation (AHP) techniques. It is intended to create thematic layers in a GIS where values will be assigned using appropriate weights and classifications in relation to their relative contribution to the occurrence of groundwater through multicriteria assessment techniques. These layers include lithology, geomorphology, lineament density, drainage density, soil texture, precipitation, and slope. The final groundwater potential map is composed of five classes of groundwater potential: very high, high, moderate, low and very low. The validity of the results of this GIS-based model was performed by superimposing existing wells, analyzing the statistical probability of the existence of groundwater. The single parameter sensitivity test was performed to evaluate the influence of the signaled weights on the groundwater potential model, and new effective weights will be derived after the analysis, as a way to calibrate the model, and the ROC analysis was applied to validate the model

Keywords :Groundwater, Grande River Basin, AHP, Prospecting, Statistical probability, GIS

 

How to cite: Soares Lima, T. A. and Amorim Castro, P. D. T.: Prospecting Potential Groundwater Zones through Geotechnology and Statistics Techniques in the Grande River Basin, Bahia,Brazil, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8732, https://doi.org/10.5194/egusphere-egu22-8732, 2022.

17:28–17:35
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EGU22-12997
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ECS
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Virtual presentation
Dimitris Papadimitriou, Ioannis Daliakopoulos, Constantinos Constantinopoulos, Thrassyvoulos Manios, and Dimitrios Kosmopoulos

Under salinity stress, plant physiology and yield characteristics deteriorate, showing, among others, symptoms similar to those of water stress. Tomato (Solanum lycopersicum) is moderately sensitive to salinity stress and suffers yield losses of over 15% at irrigation water electrical conductivity (ECw) of  3 dSm-1 (Malash et al., 2008) and over 25% at ECw of 3.5 dSm-1 (Daliakopoulos et al., 2019). As salinity can often buildup in soils and substrates, it can have a creeping effect not readily measurable in irrigation water ECw, therefore it is essential that plant physiology symptoms are spotted early to take corrective action. Here we investigate the potential of multispectral imaging, to detect early symptoms of salinity stress on S.lycopersicum plants (var. Elpida) due to NaCl accumulation in the nutrient solution of a soilless cultivation system. In this context, we established a control (0.5 mM) and five salinity treatments of 5.0, 10.0, 15.0, 20.0 mM NaCl, with three tomato plants (replications) per treatment, resulting in a total number of 18 S.lycopersicum plants. During the experiment, multispectral images (bands 460, 540, 630, 850, and 980 nm) were obtained at three stages of plant development (30, 60, and 90 days after transplant) using a MUSES9-MS sensor. For each multispectral image, four spectral indices (NDVI, OSAVI, LWSI and GOSAVI) were calculated. Although, the statistical analysis of the results reveal low sensitivity to the increasing salinity at early sampling stage (60 DAT), during the third sampling stage (120 DAT) all spectral indicators demonstrate significant sensitivity for treatments over 10.0 mM NaCl.

References

Daliakopoulos, I.N., Apostolakis, A., Wagner, K., Deligianni, A., Koutskoudis, D., Stamatakis, A., Tsanis, I.K., 2019. Effectiveness of Trichoderma harzianum in soil and yield conservation of tomato crops under saline irrigation. Catena 175. https://doi.org/10.1016/j.catena.2018.12.009

Malash, N.M., Ali, F.A., Fatahalla, M.A., A. khatab, E., Hatem, M.K., Tawfic, S., 2008. Response of tomato to irrigation with saline water applied by different irrigation methods and water management stratigies. Int. J. Plant Prod. 2, 101–116.

Acknowledgements
This research has been co-financed by the European Union and Greek national funds through the Operational Program Competitiveness, Entrepreneurship, and Innovation, under the call RESEARCH-CREATE-INNOVATE (project codes: T1EDK-04171)

How to cite: Papadimitriou, D., Daliakopoulos, I., Constantinopoulos, C., Manios, T., and Kosmopoulos, D.: Monitoring Solanum lycopersicum var. Elpida salinity stress using multispectral imaging, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-12997, https://doi.org/10.5194/egusphere-egu22-12997, 2022.

17:35–17:40
17:40–17:47
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EGU22-2492
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Virtual presentation
Muawia Dafalla

 

 

ABSTRACT: Harvesting rain and flood water is a common practice in desert and arid areas. The storage of water is always influenced by hot weather periods where most of the stored water is lost either by evaporation or infiltration of water into very deep aquifers.  Utilizing sand clay liners as barriers for near-surface material can work as an efficient tool for better use of water resources.  In desert areas where groundwater is located at a deep level the cost of retrieving water is high and requires expensive infrastructure and systems. The concept of this study is to create an artificial aquifer enhanced with pumping systems to supply water to shallow-rooted plants in an adjacent zone.  A simplified model consisting of major collection tanks with automatic pumps was used in a project to save irrigation water in the Eastern province of Saudi Arabia. This concept can be expanded to create large deep-seated storage overlain by granular soil to minimize evaporation. Water supply from this aquifer can be transported to nearby fields by gravity if the water level in the aquifer is higher than the planted area or by pumping if water is needed at a higher level. The sand-clay liner can be made up of bentonite of 10% to 15% clay content by dry weight. The work presented in this study includes the characteristics of the material used and the mechanism followed to retain and re-use water multiple times.  5TE Decagon sensors capable of recording moisture content, temperature, and electrical conductivity connected to Em50 data loggers were employed.  Chemical tests and the salinity of water were monitored during the process. Suggested storage geometries are presented for efficient use of the system.

 

 

KEYWORDS: subsurface storage, barriers, sand-clay mixtures, hydraulic conductivity, evaporation.  

How to cite: Dafalla, M.: Intercepting rain and stormwater using clay-sand liners to maximize irrigation to shallow-rooted plants in desert and arid areas, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-2492, https://doi.org/10.5194/egusphere-egu22-2492, 2022.

17:47–17:54
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EGU22-13049
Ioannis Daliakopoulos, Ioannis Louloudakis, Dimitrios Papadimitriou, Michalis Sabathianakis, Ioannis Christoforakis, Theofilos Matsoukas, Nikolaos Zotos, Theocharis Moysiadis, Konstantinos Anastasopoulos, Ioannis Mavrogiannis, and Thrassyvoulos Manios

Population rise and economic growth put additional pressure on global water resources, especially in the Mediterranean Island states that have a long history of aridity and water management challenges. In Crete, Greece, 81.2% of total water consumption is attributed to the agricultural sector, with olive trees covering 64.2% of the total cultivated land. Simulation and applied studies have shown that Irrigation Decision Support Systems (IDSS) can reduce water consumption from 10 (Fotia et al., 2021) to 34% (Phogat et al., 2014). Here we examine the feasibility of optimizing such a IDSS for deficit irrigation while maintaining olive crop yield. Experiments are conducted in the DRIP Project infrastructure (Daliakopoulos et al., 2020; Petousi et al., 2018) including an olive grove of 90 10 year-old trees and 5 20m3 lysimeters planted with olive trees from the same olive grove. The infrastructure includes a precision irrigation system comprised of FDR soil moisture sensors, microclimatic stations, and smart irrigation schedulers. The CROPWAT model (Smith et al., 2002) is calibrated using data from 5 irrigation treatments ranging from overirrigation to rainfed cultivation. Field measurements included stomatal conductance [mmol cm-2 s-1], relative chlorophyl fluorescence [Fv/Fm], leaf relative water content [%], leaf area [%], pruning weight [kg], and yield [kg]. Results clearly highlight the differences in olive tree physiological parameters in deficit irrigation treatments and the lack of significant yield benefit in over-irrigation, while the modeling study can estimate exact irrigation scheduling for incorporation with the IDSS.

Acknowledgments

This research has been co-financed by the European Union and Greek national funds through the Operational Program Competitiveness, Entrepreneurship and Innovation, under the call RESEARCH-CREATE-INNOVATE (project code: T1EDK-03372)

References

Daliakopoulos, I. Ν., Papadimitriou, D., Matsoukas, T., Zotos, N., Moysiadis, H., Anastasopoulos, K., Mavrogiannis, I., & Manios, T. (2020). Development and Preliminary Results from the Testbed Infrastructure of the DRIP Project. Proceedings, 30(1), 64. https://doi.org/10.3390/proceedings2019030064

Doorenbos, J., & Pruitt, W. O. (1975). Guidelines for predicting crop water requirements. Irrigation and Drainage Paper.

Fotia, K., Mehmeti, A., Tsirogiannis, I., Nanos, G., Mamolos, A. P., Malamos, N., Barouchas, P., & Todorovic, M. (2021). Lca-based environmental performance of olive cultivation in northwestern greece: from rainfed to irrigated through conventional and smart crop management practices. Water (Switzerland), 13(14). https://doi.org/10.3390/w13141954

Petousi, I., Daliakopoulos, I. N., Matsoukas, T., Zotos, N., Mavrogiannis, I., & Manios, T. (2018). DRIP: Development of an Advanced Precision Drip Irrigation System for Tree Crops. TERRAENVISION Abstracts, 1, 2018–2. https://terraenvision2018.eu/abstracts/export.php?id=269

Phogat, V., Skewes, M. A., Cox, J. W., Sanderson, G., Alam, J., & Šimůnek, J. (2014). Seasonal simulation of water, salinity and nitrate dynamics under drip irrigated mandarin (Citrus reticulata) and assessing management options for drainage and nitrate leaching. Journal of Hydrology, 513, 504–516. https://doi.org/10.1016/j.jhydrol.2014.04.008

Smith, M., Kivumbi, D., & Heng, L. K. (2002). Use of the FAO CROPWAT model in deficit irrigation studies. In Deficit irrigation practices.

How to cite: Daliakopoulos, I., Louloudakis, I., Papadimitriou, D., Sabathianakis, M., Christoforakis, I., Matsoukas, T., Zotos, N., Moysiadis, T., Anastasopoulos, K., Mavrogiannis, I., and Manios, T.: Optimization of Olive Tree Irrigation Using the DRIP Irrigation Decision Support System, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-13049, https://doi.org/10.5194/egusphere-egu22-13049, 2022.

17:54–18:01
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EGU22-13446
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ECS
Mira Haddad, Geert Sterk, Jasper Goos, Stefan Strohmeier, and Job de Vries

The Jordanian Badia is a desert region that covers roughly 90% of Jordan. Average annual rainfall in the Badia is below 200 mm and is only occurring during the winter months (Nov – Feb). Despite the dry conditions the Badia it is a vital region to the country, especially for ago-pastoralist communities. Over the past decades unsustainable land management and especially overgrazing have resulted in reduced vegetation cover, soil degradation, and loss of biodiversity. Rainwater harvesting structures are used to regenerate soils, improve vegetation cover and allow barley production in local depressions. Two types of water harvesting structures are currently tested in experimental catchments.

The first type is the Vallerani micro water harvesting structure. A Vallerani is constructed along a hillslope contour and consist of a ridge and furrow. The interspace area between two Vallerani’s is the surface runoff collection area. Inside the furrow native shrubs (Atriplex halimus) are planted and provide fodder for livestock. Vallerani structures are simple and cheap to construct, reduce soil erosion, conserve moisture and stimulate vegetation cover. The second type of rainwater harvesting is the Marab, which is a macro-scale water harvesting technique. A Marab consists of a series of earthen dams that are constructed parallel in a local depression. Surface water from a wadi enters at the upstream end in the Marab and is forced to flow in a zig-zag pattern around the constructed dams. The flow speed of the surface water is slowed down which results in enhanced infiltration. The stored water in the soil is used to grow a barley crop in the interspaces between the constructed dams. Apart from conserving moisture, Marabs retain sediments and help to reduce flash floods in the Badia.

When Vallarani’s and a Marab are both constructed in one catchment there is a trade-off between the two structures. The more Vallerani’s are implemented on hillslopes the less water will flow towards the downstream Marab. In this study modelling was used to optimize the location and number of Vallerani structures and quantify the available water running to the Marab in an experimental catchment. The Soil and Water Assessment Tool (SWAT) was used for this purpose. Rainfall, discharge and soil data were collected from the field during the 2018/2019 rainy season. The calibrated model showed good performance for large events but underestimated smaller events. A 30 year run was made, with and without Vallerani structures. Increasing the number and area of Vallerani structures from zero to the maximum decreased the number of significant runoff events by 45.3%, and the total discharge reaching the Marab by 36.2%. Using SWAT, the number and locations of the Vallerani’s were optimized to ensure that the Marab would receive enough water, while maximizing the number of hillslope water harvesting structures. It is concluded that implementation of Vallerani’s in sub-watersheds that produce low amounts of surface runoff results in most vegetation cover on hillslopes, while allowing sufficient barley production in the Marab.

How to cite: Haddad, M., Sterk, G., Goos, J., Strohmeier, S., and de Vries, J.: Water harvesting in the Jordanian Badia: Trade-offs between micro and macro structures, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-13446, https://doi.org/10.5194/egusphere-egu22-13446, 2022.

18:01–18:08
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EGU22-9631
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ECS
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On-site presentation
Johanna Blöcher, Arij Chmeis, and Michal Kuraz

Water resources in arid regions around the world are under a lot of strain due to extremely low precipitation rates and very high evaporation. In addition to water scarcity, irrigation methods can be inefficient. For example, over-irrigation beyond soil saturation can cause many problems, such as an increase in soil salinity and a decrease in productive soil capacity. This research aims to design a water content and soil temperature prediction system for an automated sensor monitoring system installed at the vineyard Ecohumus in San Juan province, Argentina. Short-term predictions of the water balance have the potential in delivering a useful tool to farmers for optimizing their irrigation water consumption.

For modeling soil water dynamics with evaporation and root water uptake losses, we use a coupled water, vapor, and heat flow model implemented in DRUtES software, Kuraz and Blöcher (2020). The model's top boundary condition solves the surface energy balance. For that we use weather forecast data and solar radiation as an input. The weather forecast is obtained from Norwegian meteorological institute (yr.no) using their API for developers which is provided as a free service. The solar radiation is computed based on equations suggested in the FAO Irrigation and Drainage guideline No. 56 and by Saito et al. (2006). Due to the lack of measurement data on the study site, soil hydraulic and thermal properties are estimated. We neglect the effect of soil organic matter in the water retention model and assume a homogeneous type of soil for the thermodynamic model. We establish communication with sensors installed in the soil for estimating initial conditions as well as with weather forecast service for estimating boundary conditions using our R script.

The result is output records that simulate pressure heads and water content distribution across the flow field over the simulated period. We present a system that describes the flow field allowing us to calculate evaporation rate changes with time, thereby optimizing the irrigation process according to soil and plant needs. This can be a helpful decision-making tool for farmers.

How to cite: Blöcher, J., Chmeis, A., and Kuraz, M.: Predicting evaporative loss at an Argentinian vineyard using a coupled water, vapor and heat flow model, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9631, https://doi.org/10.5194/egusphere-egu22-9631, 2022.

18:08–18:15
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EGU22-12385
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ECS
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On-site presentation
Angela Gabriela Morales Santos, Reinhard Nolz, and Margarita García-Vila

In sub-humid areas, supplementary irrigation is often needed to meet crop water requirements and avoid yield reduction. The effect of water scarcity on agriculture is worsened in locations where summer rainfall is decreasing as a consequence of climate change. In order to stabilize crop production through sustainable water management, improvements of irrigation scheduling methods are required. For instance, traditional irrigation scheduling criteria that provided adequate yields in the past, may no longer be appropriate under drier conditions. Models that combine crop physiological and soil hydrological processes can help improving irrigation scheduling to optimize water productivity. The purpose of this study was to evaluate irrigation management approaches traditionally used by farmers in Austria, specifically at a study site located in the largest crop production area of the country (ca. 35 km east from Vienna), by means of a modelling approach. This study also aimed at proposing an irrigation schedule that increases water productivity, thereby aiding water conservation.

AquaCrop is a crop growth model developed by the Food and Agriculture Organization of the United Nations (FAO) that uses an empirical and mechanistic approach to simulate yield response to water for a variety of crops. In this study, AquaCrop was used to simulate crop water requirements of soybeans in a sub-humid environment under different water management practices. The model was validated after adjustments on the non-conservative crop parameters based on field measurements. The experimental field was divided into four plots. One plot was rainfed and the others were irrigated – each of them by means of a different irrigation system. The systems used were sprinklers on a pipe network, drip lines and a hose reel boom. Irrigation was managed by the farmers based on their experience. The collected data included leaf area index to obtain green canopy cover development and soil samples at different depths to characterize the soil. After the validation process, an irrigation schedule that covered the full crop water requirements was automatically generated by the model. Additionally, irrigation schedules for each irrigated plot were generated based on percentage of readily available soil water (RAW) thresholds.

The simulated yields were in good agreement with the observed data, with a model efficiency coefficient (EF) > 0.80 for the four plots. The irrigated plots revealed a certain level of stress during the critical crop growth stage of flowering, even though they were expected to represent well-watered conditions. After simulating net crop water requirements, the resulting potential yield was larger than the observed yields. Furthermore, the irrigation events generated using RAW thresholds also produced larger yields than the observed ones. The results showed that to schedule the irrigation events earlier in the season and distribute the same total irrigation water amount in four events rather than three – as scheduled by the farmers – increased the yield and thus, water productivity. Therefore, AquaCrop model predictions can help improving farmers’ irrigation scheduling strategies for soybeans under this study conditions. This might be helpful for local farmers in situations of increasing pressure on water resources.

How to cite: Morales Santos, A. G., Nolz, R., and García-Vila, M.: Impact of irrigation scheduling on yield and water productivity of soybeans in a sub-humid environment: A modelling approach., EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-12385, https://doi.org/10.5194/egusphere-egu22-12385, 2022.

18:15–18:22
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EGU22-8159
Stefano Barontini, Marco Peli, Cesare Rapuzzi, Paolo Colosio, and Roberto Ranzi

Benfratello's conceptual method, to estimate the irrigation deficit for agricultural districts in semiarid or arid climate, firstly came to light in 1961. The method generalizes previous Thornthwaite (1948) and Thornthwaite and Mather (1955) water balances to assess the irrigation deficit as the difference between the maximum evapotranspiration, exerted by the plant in full irrigation conditions and traditionally estimated with the Thornthwaite formula, and the actual evapotranspiration provided by the available soil water. Since its first appearance, it has been applied to the study of many areas in Southern Italy. Due to its simplicity and to the small number of required parameters, Benfratello's method might be regarded to as an effective tool to assess the effects of climatic, landuse and anthropogenic changes on the soil water balance and on the irrigation deficit.

In the previous General Assembly we presented a GIS based application of Benfratello's method to the case study of the semiarid Capitanata plane (4550 km2, Southern Italy), which is one of the most important agricultural districts in Italy. With this contribution we present a further theoretical development of the method that allows to simply estimate in closed form the uncertainity of the calculated irrigation deficit, once known the uncertainty of the required climatic variables (temperature and precipitation). Our procedure is based on a local linearization of the core—function of Benfratello’s method, which presents the decrease of the available soil water, during the dry season, as a function of the potential soil water loss, given by the difference between the maximum evapotranspiration demand and the precipitation. The maximum evapotranspiration was in this case determined by means of the Hargraves formula, according to FAO procedure in case of limited availability of meteorological data. The estimate of the uncertainty can be easily performed in both the cases in which the field capacity is completely or only partially restored during the wet season. As a test case, the method was then applied to some sites in the Capitanata plane and extended to the whole plane through a GIS application, with fair results if compared with the required water volumes declared by the local irrigation consortium.

How to cite: Barontini, S., Peli, M., Rapuzzi, C., Colosio, P., and Ranzi, R.: A method to assess the uncertainty of Benfratello’s estimate of the irrigation deficit in a semiarid area and its GIS based application for anthropogenic and climate change scenarios, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8159, https://doi.org/10.5194/egusphere-egu22-8159, 2022.