PICO
In this study, a new unsteady-state equation is proposed for calculating the drain spacing of subsurface drainage systems.
We consider the one-dimensional Boussinesq equation
(1)
for 0<x<L and t>0, where L is the drain spacing (m) and t the time. Here Z(x,t) is the transient groundwater table, K is the saturated hydraulic conductivity, and S the specific yield for a homogeneous soil.
The Equation (1) is considered together with the following initial and boundary conditions:
(2)
where D describes the distance of the drains (placed at x=0 and x=L) from the impervious layer. The function f(x) can be constant, polynomial or trigonometric (Figure 1).
Figure 1. The geometry of the drainage problem.
Assuming f(x)=m0sin(πx/L) we observe that f(0)=f(L)=0 and f'(L/2)=0 so that the boundary conditions in (2) are satisfied and in addition f (L/2)=m0 resulting in Z(L/2,0)=D+m0.
By linearizing Equation (1) we obtain a linear partial differential equation of the form ∂Z/∂t-α(∂2Z)/(∂x2 )=0 where α=K(D+m0/2)/S.
We propose to solve it using the Variational Iteration Method which provides the solution in a series form and converges after a few iterations.
Performing two iterations, we get the following equation to estimate the spacing L between the drains given the height m decrease in the middle (L/2), for a specific time interval T
(3)
From the two positive solutions of the quadratic Equation (3) for L2, the acceptable solution is given by
(4)
which is valid only if 2m-m0≥0⇒m≥m0/2, meaning the above formula is applicable when the height m in the middle is bigger or equal than its half initial value m0.
The comparison of the proposed equation with the widely used Glover-Dumm equation showed relative error differences smaller than 5%.
How to cite: Kargas, G., Mindrinos, L., and Londra, P.: A new unsteady-state equation for the design of subsurface drainage systems, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10744, https://doi.org/10.5194/egusphere-egu25-10744, 2025.
Open ditches and subsurface drainage are effective measures for improving saline soils. Installations of subsurface drainage are now complementing surface drainage in Northwest China, but their optimisation has not been attempted. Therefore, the drainage and desalination performance of a combined subsurface drainage-open ditch system was analysed using two years of field experiments. The data were then utilised to calibrate and validate a water and salt transport model. The drainage volume in surface drains were 9-fold those in subsurface pipes. Additionally, 25 sets of orthogonal numerical experiments were designed with the subsurface pipe length, depth, and open ditch depth as variables. The results revealed that these three factors significantly affected the desalination efficiency of salinealkaline farmland (P < 0.05). The ditch depth, pipe length, and pipe depth F values were 9.954, 50.286, and 6.557, respectively, and no interactions were observed among these factors. When a single open ditch was used for drainage, the desalination rate initially increased and then decreased as the distance from the open ditch increased. The inflection point varied with the open ditch depth and occurred within a range of 32–43 m when the ditch depth was 180–300 cm. The combination of an open ditch and a subsurface pipe produced a larger desalination area, and its efficiency was 170 % that of a single open ditch. Within the inflection point range, the desalination rate increased with increasing ditch depth. Beyond the inflection point, subsurface drainage played a primary role, and the desalination rate increased as the subsurface drainage depth increased but remained relatively stable along the drainage direction. The optimal installation depth for subsurface pipes was estimated to be 90–110 cm, and the depth of ditches was 180–210 cm in a combined system. The maximum length for full flow in long-distance subsurface drainage was 750–850 m. This study provides references for the optimal application of combined subsurface drainage–open ditch systems in arid Northwest China.
How to cite: Wu, J., Guo, C., Yao, C., and Qin, S.: Evaluation of combined open ditch and subsurface drainage: Experimental data and optimization of specifications in arid Northwest China, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1894, https://doi.org/10.5194/egusphere-egu25-1894, 2025.
The Po Valley, Italy's largest and most economically significant region, heavily relies on intensive irrigation to sustain its very productive agriculture and meet the demand of a variety of high-value food productions. Historically, the region's agricultural success has been driven by widespread traditional surface irrigation systems, which primarily draw water from rivers and deliver it to fields through an extensive network of irrigation canals. These systems, that in many areas have been operational for centuries, not only enhance agricultural productivity but also contribute to groundwater recharge, helping to mitigate river droughts and seasonal fluctuations in surface water availability. In recent years, however, declining surface water availability and increasing reliance on groundwater extraction have already been observed, because of a higher variability of summer precipitation and decreasing winter snow accumulation in the Alps caused by climate change. Consequently, accurately estimating groundwater recharge from irrigation excess has become crucial. Despite its importance, the impact of irrigation on groundwater recharge across the Po Valley remains poorly investigated. This is mainly due to the complexity of the region's hydrological systems characterized by strong interactions between groundwater and surface water, and to the lack of reliable data covering the entire Po Valley.
In the context of MidAS-Po project, a methodological approach has been developed for the preliminary estimation of groundwater recharge through percolation from irrigated areas and seepage from irrigation channels over the whole Po Valley.
This approach involves two main steps. First, the application of a distributed agro-hydrological model, IdrAgra-Po, simulating daily soil water balance terms, including percolation from the agricultural soil layer (1 meter deep) in irrigated fields. The model was implemented over the period 2010–2022, with a spatial resolution of 0.25 km², and incorporates several input datasets: i) agro-meteorological conditions from the E-OBS dataset, produced by the Copernicus Land Monitoring Service of the European Environment Agency; ii) soil hydro-pedological data sourced from four regional databases, processed and harmonized over the study area; iii) land use data provided by the CORINE project and integrated with local information; and iv) depth of the shallow groundwater table. The second step is the estimation of groundwater recharge due to seepage from the irrigation network using a simplified methodology that relies on the data of the national agricultural information system SIGRIAN. This approach estimates channel seepage as the ratio between the measured water volumes allocated upstream of the irrigation districts into which SIGRIAN splits the Po Valley and the irrigation requirements determined by the IdrAgra-Po model for the same districts.
The resulting preliminary estimate of groundwater recharge linked to irrigation practices represents a significant step toward understanding the role of irrigation in the aquifer recharge in Po Valley. However, further investigations should be conducted to improve the quality of the input data, mainly, information on local irrigation methods and practices, land use and irrigation volumes diverted from rivers and withdrawn from aquifers.
Acknowledgment
This contribution is presented in the framework of the MidAS-Po project, funded by Italy's Development and Cohesion Fund - FSC 2014-2020.
How to cite: Gharsallah, O., Cazzaniga, S., Chiaradia, E. A., D'Amico, M. E., Rienzner, M., and Gandolfi, C.: Assessing the Role of Irrigation in Groundwater Recharge in the Po Valley, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3479, https://doi.org/10.5194/egusphere-egu25-3479, 2025.
Brandenburg is one of the driest regions in Germany and heavily relies on groundwater resources for both drinking water supply and irrigated agriculture. The state is already experiencing declining groundwater levels, and climate change is expected to further exacerbate the situation. For sustainable management of groundwater resources, the groundwater recharge rate is a key parameter. However, its quantification remains a challenge since it cannot be directly measured at the field scale.
In this study, we utilize daily data from multiple cosmic-ray neutron sensors (CRNS), which enable non-invasive measurement of soil moisture in the near-surface root zone on a hectare scale to calibrate a soil hydrological model (HYDRUS-1D) and derive downward water flows below the root zone as an approximation of groundwater recharge.
For this purpose, we use a unique dataset collected over more than five years at a highly instrumented agricultural research site near Potsdam, Brandenburg. The ~10 ha site, featuring a variety of agricultural plots, extends along a gentle hillslope towards a lake above a Pleistocene, unconfined aquifer with a groundwater table depth ranging from 1 to 10 meters. Core of the instrumentation is a cluster of eight continuously operated CRNS combined with more than 25 point-scale soil moisture profile probes measuring to depths of up to 1 m. A wide range of additional measurements, including soil texture, hydraulic properties, continuous soil moisture measurements at depth, and groundwater level monitoring, provide a robust foundation for validating the model and capturing the relevant hydrological processes at the site.
In various simulation experiments, we evaluate the added value of using different soil moisture products for model calibration. To evaluate long-term trends and variability in groundwater recharge, we run the calibrated model with over 50 years of historical weather data. We analyze changes in groundwater recharge rates under varying climatic conditions and discuss the associated uncertainties, particularly in the context of the site’s tight water balance.
How to cite: Scheiffele, L., Dimitrova Petrova, K., Munz, M., Francke, T., Heistermann, M., Marret-Sicard, E., and Oswald, S.: Advancing groundwater recharge estimation at the field scale: spatiotemporal dynamics of soil moisture and simulated 1D water fluxes at a cosmic-ray neutron sensing cluster site in northeast Germany, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17305, https://doi.org/10.5194/egusphere-egu25-17305, 2025.
Climatic extremes, such as prolonged periods of summer droughts, alternated with wet winters pose a significant challenge for farmers. Uncertainty in water availability over the growing season forces farmers to make management decisions that are not always favorable for optimized crop yield. Under the EU project FARMWISE, a large variety of management strategies are evaluated that could help farmers mitigate future climatic extremes.
This research focuses on a novel system, consisting of controlled drainage with subirrigation (CD-SI), that allows farmers more control on water drainage and irrigation from their field. The system relies on subterranean drainage lines installed under the agricultural fields. These drainage lines are connected to a control pit, allowing the system to be dual used, for both drainage and irrigation using an external water source. The system is under evaluation at a field site in America in the Netherlands, where soil moisture and groundwater heads are monitored at a field equipped with an CD-SI system and at an adjoining reference field. Previous studies at the field site have shown a positive effect on water availability for crops under irrigation conditions. However, it is uncertain what the overall effectiveness is of the supplied irrigation water. The main aim of this study is to determine the division of supplied irrigation water within the CD-SI system to all parts of the water balance, including root water uptake, evapotranspiration and percolation to deep groundwater, and quantify potential losses.
A physics-based 3D integrated surface-subsurface hydrological is developed and calibrated to simulate the functioning of the CD-SI system using HydroGeoSphere. Preliminary model results show simulated the groundwater dynamics that agree with the observations both at the field with the CD-SI system as well as the reference field, confirming the difference in groundwater dynamics that are observed between the observation and reference field. Research into the overall effectiveness of the supplied irrigation water and division between the various elements of the water balance is ongoing.
How to cite: de Bruin, J., van der Ploeg, M., Bonné, J., Rakonjac, N., Bartholomeus, R., de Wit, J., and Mustafa, S.: Simulating Controlled Drainage with Subirrigation at an Experimental Agricultural Field in the Netherlands to Investigate Irrigation Water Effectiveness, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17423, https://doi.org/10.5194/egusphere-egu25-17423, 2025.
Compacted subsoils affect vegetation growth and soil water balance. Numerical models help quantifying the hydrological impacts of subsoil compaction. These models are useful to evaluate measures that augment groundwater recharge in compacted soils and are important to guide proper water resource management under climate change in these soils. However, vegetation in these models is often parameterized using only limited field measurements or using relations between vegetation parameters and other variables. In this study, we show that uncertainties in vegetation parameters linked to transpiration (leaf area index [LAI]) and water uptake (root depth distribution) can significantly affect modeling outcomes. We used the HYDRUS-1D soil water flow model to simulate the water balance of experimental grass plots on the sandy soil of Belgium’s Campine Region. The compacted case has the compact subsoil at 40- to 55-cm depths while the non-compacted case underwent artificial decompaction. The models for each case were calibrated using soil moisture sensor data at two depths. We calibrated the soil water flow model for the compacted and non-compacted case considering three different vegetation scenarios that represent various reactions of canopy and root growth. Subsequently, we simulated soil water flow for different future climate scenarios.
Our experiments reveal generally higher soil moisture content on the compacted case, suggesting subsoil compact layer’s role of promoting soil water accumulation above it. Moreover, the compacted case had lower LAI while the non-compacted case had deeper roots. Considering these canopy and root growths’ reactions in our models, results show that compaction does not always reduce deep percolation because of enhanced water uptake from the non-compacted case’s deeper roots. Therefore, while soil compaction affects both vegetation growth and soil water balance, this affected vegetation growth can further influence the water balance. Hydrological studies on (de-)compaction should dynamically incorporate vegetation growth above- and belowground under cases with compaction being present or absent. Thus, field evidence of vegetation growth and yield, often far lacking in compaction studies, is vital.
How to cite: Pinza, J. G., Devos Stoffels, O.-A., Debbaut, R., Willems, P., Vanderborght, J., Garré, S., and Staes, J.: Quantifying hydrological impacts of compacted sandy subsoils using soil water flow simulations: the importance of vegetation parameterization, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9199, https://doi.org/10.5194/egusphere-egu25-9199, 2025.
Projected climate changes in arid and semi-arid regions, such as reduced aquifer recharge capacity and altered riverine hydrography, pose significant challenges to water supply, particularly in the Nile River basin in Egypt. Riverbank Filtration (RBF) offers a sustainable, cost-effective water treatment technology that enhances the quality of water abstracted from polluted rivers. By installing abstraction wells along riverbanks, RBF supports agricultural resilience and climate adaptation by providing a stable and reliable water source during extreme events. This study evaluates a full-scale RBF site in Akhmim City, consisting of four vertical wells located 50 meters from the Nile River bank. Samples were collected from both the RBF wells and the Nile River during a period of extreme precipitation in November 2016, which significantly affected the river’s water quality. Key parameters analyzed included turbidity, dissolved oxygen, total suspended solids, total organic carbon, pH, electrical conductivity, bacterial counts, and coliform levels. Results showed that while Nile River turbidity ranged from 5–25 NTU, with potential hundred-fold increases during flash floods, RBF wells consistently maintained turbidity below 5 NTU. Similarly, bacterial counts in Nile water exceeded 55,000 CFU/100 mL during the event, compared to less than 2,100 CFU/100 mL in RBF water. The pH of Nile water was measured at 8.6, compared to 7.5 for RBF filtrate. These findings indicate that RBF significantly improves both physical and microbiological water quality, meeting national irrigation water standards. Moreover, RBF not only enhanced the quality of ambient groundwater but also effectively purified Nile water, making it a viable alternative to conventional surface water treatment plants. This study highlights the cost-effectiveness and reliability of RBF as a treatment solution in the Nile Valley, offering an adaptable and sustainable approach to mitigating the impacts of climate change while supporting agriculture and water security.
Keywords: Climate change, Arid and semi-arid regions, Nile River, Riverbank filtration, Aquifer recharge, Water quality, sustainable water treatment.
How to cite: Ibrahim, M., Gad, A., Ali, O., and Ahmed, A.: Enhancing Water Quality and Agricultural Resilience through Riverbank Filtration: A Case Study from the Nile River, Egypt , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-575, https://doi.org/10.5194/egusphere-egu25-575, 2025.
The Mediterranean climate in general and particularly in Israel, has a typical unsynchronized water supply, with rain during the winter and almost no precipitation during the hot summers. Orchards require extensive water resources, in order to meet the high demand, even at peak transpiration times during summer. While Israeli farming relies on pressurized irrigation with treated wastewater, these reserves deplete during summer, and orchards face critical water shortage, which can become extreme under drought conditions.
Trees can mitigate seasonal water shortages by abiotic resiliency and the capacity to grow roots to deeper soil water horizons. However, on the one hand, the sporadic rain evens in recent years, with their higher intensity and shortening periods, cause for lower infiltration and more water loss via runoff. Therefore, there is less soil water in the spring. On the other hand, current irrigation practices do not utilize tree temporal and spatial hydraulic capabilities that could spare such valuable resources.
We search for irrigation strategies that could mitigate climatic effects by harnessing tree resiliencies and the soil-water storage capacity. We hypothesize that additional water dose during the dormant tree period in winter could sustain trees through spring and summer without waterlogging risks. Therefore, we proposed to fill the root-zone soil profile during winter, by utilizing the drip irrigation system with treated effluent water that are highly available in winter but not in summer.
We present a comparative analysis of soil water status and tree physiology acquired from multiple sensing platforms in the soil-tree-atmosphere system under three irrigation approaches: (i) hydrated, irrigated to match potential ET during summer; (ii) deficit, irrigated about half of the hydrated treatment; and (iii) winter irrigated, filling the top 2 m soil profile and deficit-irrigating trees in summer. We found that the winter irrigation mitigated the effect of water shortage from April through June. Moreover, winter-irrigated trees managed to tap into the deep profile for water uptake until August. Later, trees depleted the soil water and experienced drought stress.
With improved hydration in spring and possible deep soil water use in summer, winter-irrigated trees increased yields by 30% after two years. Thus, winter watering orchards has the potential to sustain farming during climate shifts, and there is need to continue to investigate and improve this application.
How to cite: Kamai, T. and Sperling, O.: Irrigation targeting deep soil water storage for mitigating water supply uncertainity in orchards, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9834, https://doi.org/10.5194/egusphere-egu25-9834, 2025.
The changing environmental constraints require even more adaptations of management techniques in agriculture and the qualitative improvement of wine production represents a sector of international strategic importance. Many wine-producing areas are located in environments currently suffering, or are expected to experience in the future, water deficits that can affect grape and wine quality. In the framework of the CISAV project (financed by the University of Naples Research Funding - FRA), three years of irrigation experiments (from 2021 to 2023) have been carried out on the autochthonous Piedirosso’ cultivar (Vitis vinifera sp) planted in a vineyard of volcanic environment, at the footslope of the Somma Vesuvius Complex (Campania Region, southern Italy), in temperate Mediterranean climate. The preliminary application of geophysical and radiometric proximal soil sensors (i.e., EMI and γ-ray) allowed to state the high homogeneity of the vineyard soils and the selection of adjacent zones where to conduct and monitor irrigated and non-irrigated control treatments. A non irrigated zone characterized by lava outcropping (lava zone - LZ) was monitored separately from the remaining control zone (not irrigated - NIZ) and the treated one (irrigated zone - IZ). Three soil profiles (one for each zone) were dug up to 120 cm of depth. Young, poorly developed, very deep, loamy sand, from slightly acid to neutral the pH, and deeply rooted are the soils. Soil properties suggest behavior as excessively drained and scarcely retaining water and nutrients for the plant supply. In the IZ, 50% of the calculated crop evapotranspiration (ETc) has been returned to the plants by drip irrigation system in post-veraison until harvest. By a meteorological point of view, 2022 was the year with the highest Huglin bioclimatic index (2768), the rainiest veraison-harvest period (206 mm) but also that with the highest calculated water deficit (-225 mm). Measures of midday stem water potential (MSWP) and stomatal conductance (gs) performed in pre- and post-veraison until harvest were consistent with an improved health status of the plants during the irrigation treatment over the 3 years, since the MSWP and the gs of the IZ were always higher than those measured for the NIZ vines. The response of the grapevines in terms of grape quality parameters was compared between treatments and over the years. The irrigation treatment produced significantly different grape characteristics (i.e. berry weight and volume, total soluble solids content, pH, titratable acidity) and phenolic compounds content at harvest (i.e., anthocyanins, tannins and total phenols in skin and seeds), and significantly improved fruit yield, allowing the grapes to achieve the quality parameters required by the “Lacryma Christi del Vesuvio DOP” production protocol.
How to cite: Ruocco, P., Amalfitano, C., Basile, B., De Mascellis, R., Mataffo, A., Matrone, A., Palladino, M., Perreca, C., Scognamiglio, P., and Vingiani, S.: Drip-irrigation treatment of an autochthonous grapevine cultivar (Vitis vinifera L, cv Piedirosso) at the footslope of Mount Vesuvius (southern Italy). Effects on grape enological characteristics and phenolic content. , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11570, https://doi.org/10.5194/egusphere-egu25-11570, 2025.
The agricultural sector plays a vital role in food security and water resource management. Climate change impacts, combined with growing population and increasing food demand, have led to higher plant water consumption, making effective water management crucial in agriculture. This study examines how climate change affects agricultural water footprint (WF) in Türkiye from 1990 to 2019, along with local climate parameters, production quantities, and yield data.
Our research shows distinct climate change patterns in Türkiye: slight decreases in average wind speed and solar radiation, a significant decline in relative humidity, and a clear upward trend in maximum and minimum temperatures. While reduced wind speed and solar radiation may slightly decrease plant water consumption, the higher temperatures and lower humidity likely have more substantial negative effects on evapotranspiration. Importantly, we found that crop yield is the main factor influencing agricultural WF variations in Türkiye. Despite climate challenges, technological advances and better farming practices led to around 60% increase in crop yield. This improvement reduced virtual water content (VWC) of crops by 35% and decreased the country's total agricultural WF by around 10%. However, the relatively small reduction in WF compared to the significant improvements in yield and VWC indicates the strong influence of climate change and changing crop patterns.
Although the national agricultural WF exhibits a modest declining trend over the 30-year period, indicating improvements in water resources, climate change continues to pose significant challenges. Since such substantial yield increases are unlikely to continue, climate change impacts on WF are expected to worsen. These findings highlight the critical need for comprehensive water management strategies to address climate change effects and maintain sustainable water resources in Türkiye.
How to cite: Muratoglu, A., Demir, M. S., and Kartal, V.: Water Footprint Dynamics in Turkish Agriculture: Linking Climate Change and Crop Yields, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2695, https://doi.org/10.5194/egusphere-egu25-2695, 2025.
Accurate estimation of effective precipitation (Peff) - the portion of rainfall stored in soil and utilized by plants - is fundamental for sustainable irrigation planning and soil water management. Despite its critical role in agricultural water use efficiency, existing Peff calculation methods often lack regional specificity and validation against physical soil-water processes. This study evaluates the performance of two widely-used precipitation estimation methods (CROPWAT and Dependable Rain FAO/AGLW) against detailed soil water balance calculations from the Soil and Water Assessment Tool (SWAT) in the Ceyhan Basin, Türkiye.
Our SWAT model incorporated local soil characteristics, topography, and climate data to simulate soil-water dynamics and establish a benchmark for Peff estimation. The comparative analysis revealed distinct seasonal patterns in method accuracy. The CROPWAT method showed strong agreement with SWAT results during the May-November, with deviations of only 4-14% in the autumn months. However, it significantly overestimated Peff during winter months (December-April) by 30-35%. Conversely, the Dependable Rain method performed optimally during winter, with deviations of 6-12% in December-January, but showed substantial inaccuracies (>70%) during January-September, improving only during periods of higher effective precipitation.
These findings demonstrate that current Peff estimation methods have complementary strengths in different seasons, suggesting the need for a more nuanced, season-specific approach to irrigation planning. The substantial variations in method accuracy highlight the importance of considering local soil conditions and seasonal climate patterns in irrigation system design. Our results indicate that effective irrigation planning requires carefully selecting Peff estimation methods based on growing season characteristics and local soil-water dynamics.
This study contributes to improving irrigation water management by providing quantitative evidence for the limitations of current Peff estimation methods and emphasizing the need for regionally calibrated approaches. These insights are particularly relevant for semi-arid regions where efficient use of rainfall in agriculture is crucial for sustainable water resource management.
How to cite: Demir, M. S. and Muratoglu, A.: Effective Precipitation Models in Irrigation Planning: Validation and Comparison Using the SWAT Method, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2696, https://doi.org/10.5194/egusphere-egu25-2696, 2025.
How to cite: Fan, X. and Schütze, N.: Impact of changes in waterlogging due to climate change on crop rotation systems under different irrigation scheduling strategies and soil textures, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10064, https://doi.org/10.5194/egusphere-egu25-10064, 2025.
The intensifying effects of climate change on soil hydrology and agricultural water use require comprehensive understanding for sustainable maize production, a key crop in Türkiye's agricultural system. This study combines empirical trend analysis with AquaCrop model simulations under the RCP 4.5 climate change scenario to investigate the complex interactions between climate change, soil-water dynamics, and agricultural water footprint (WF) of maize cultivation from 2004 to 2022 in a major agricultural region (Akşehir) of Türkiye, providing critical insights for irrigation management and food security.
Through Mann-Kendall tests and Sen's slope estimators, coupled with AquaCrop model simulations, we identified considerable climate change-induced shifts in hydroclimatic parameters affecting soil-water relationships. Reference evapotranspiration (ET₀) showed a significant decreasing trend (τ = -0.43) with a decline of 2.7 mm/year, while crop evapotranspiration (ETc) exhibited an even stronger declining pattern (τ = -0.58) with a decrease of 2.8 mm/year. These trends occurred against a backdrop of significantly increasing atmospheric CO₂ concentration (τ = 1.000) with an annual increase of 2.1 ppm/year.
The analysis of WF components revealed promising trends for sustainable water management under changing climate conditions. The unit blue WF showed a significant decreasing trend (τ = -0.35) with an annual reduction of 4.27 m³/ton, indicating improved irrigation efficiency, while the unit total WF demonstrated a strong declining trend (τ = -0.58) with a decrease of 2.7 m³/ton/year. Although the unit green WF showed a slight increasing trend (τ = 0.17) with an annual increase of 1.17 m³/ton, this shift from blue to green water use suggests a positive transition toward more sustainable water management practices in a changing climate. This favorable redistribution of water sources, combined with improved irrigation efficiency, has supported agricultural productivity, as evidenced by the marginally significant increasing trend in maize production (τ = 0.39).
While these findings demonstrate successful adaptation of maize cultivation systems to changing climatic conditions in our study region under the RCP 4.5 scenario, broader country-level and global analyses are essential to understand geographic variations in water productivity and potential shifts in agricultural suitability under climate change. These spatially explicit insights would be valuable for developing targeted adaptation strategies and ensuring sustainable food production across different agro-ecological zones. Our results highlight the importance of regional-scale studies in understanding climate-water-crop interactions and emphasize the need for integrated approaches to enhance agricultural water productivity while maintaining environmental sustainability in the face of accelerating climate change.
*Key Words:* Climate change, water footprint, AquaCrop model, soil hydrology, maize production
How to cite: Nas, H., Kartal, V., Demir, M. S., and Muratoglu, A.: Hydroclimatic Parameter Shifts and Their Impact on Maize Production: A Multi-Decade Assessment in Akşehir/Türkiye, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15227, https://doi.org/10.5194/egusphere-egu25-15227, 2025.
