Hydrology

22 pages, 44511 KiB

Open AccessArticle

Deep Learning Prediction of Streamflow in Portugal

by Rafael Francisco and José Pedro Matos

Hydrology 2024, 11(12), 217; https://doi.org/10.3390/hydrology11120217 - 19 Dec 2024

The transformative potential of deep learning models is felt in many research fields, including hydrology and water resources. This study investigates the effectiveness of the Temporal Fusion Transformer (TFT), a deep neural network architecture for predicting daily streamflow in Portugal, and benchmarks it [...] Read more.

The transformative potential of deep learning models is felt in many research fields, including hydrology and water resources. This study investigates the effectiveness of the Temporal Fusion Transformer (TFT), a deep neural network architecture for predicting daily streamflow in Portugal, and benchmarks it against the popular Hydrologiska Byråns Vattenbalansavdelning (HBV) hydrological model. Additionally, it evaluates the performance of TFTs through selected forecasting examples. Information is provided about key input variables, including precipitation, temperature, and geomorphological characteristics. The study involved extensive hyperparameter tuning, with over 600 simulations conducted to fine–tune performances and ensure reliable predictions across diverse hydrological conditions. The results showed that TFTs outperformed the HBV model, successfully predicting streamflow in several catchments of distinct characteristics throughout the country. TFTs not only provide trustworthy predictions with associated probabilities of occurrence but also offer considerable advantages over classical forecasting frameworks, i.e., the ability to model complex temporal dependencies and interactions across different inputs or weight features based on their relevance to the target variable. Multiple practical applications can rely on streamflow predictions made with TFT models, such as flood risk management, water resources allocation, and support climate change adaptation measures. Full article

(This article belongs to the Special Issue Editorial Board Members’ Collection Series: The Flood Estimation and Forecasting Chain: Meteorological–Hydrological–Hydraulic Forecasts and Predictive Uncertainty towards Operational Decisions)

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14 pages, 2692 KiB

Open AccessArticle

Technical Considerations in the Preliminary Design of the Pumped Storage Hydropower (PSH)

by Haoyong Tian, Zaimin Ren, Chenchen Yao, Chao Wang, Meirong Li and Chunchen Xia

Hydrology 2024, 11(12), 216; https://doi.org/10.3390/hydrology11120216 - 13 Dec 2024

Abstract

The development of renewable energy is an effective avenue for achieving net zero goals. It requires many energy storage systems (ESSs) for adjusting the unstable power generated by renewable energy. To date, PSH is the most technically mature, economically reasonable, and reliable ESS. [...] Read more.

The development of renewable energy is an effective avenue for achieving net zero goals. It requires many energy storage systems (ESSs) for adjusting the unstable power generated by renewable energy. To date, PSH is the most technically mature, economically reasonable, and reliable ESS. Currently, various countries have developed PSH. As of 2022, the global installed capacity of PSH has reached 175,060 MW, with an annual increase of 10,300 MW. This paper addresses several technical considerations in the preliminary design of PSH systems, drawing on extensive design experience. Key factors such as the selection of dam sites, installed capacity, and characteristic water levels are thoroughly discussed. These design choices are influenced by a range of factors, including geological and topographical conditions, hydrological parameters, environmental impacts, sedimentation, submersion areas, and resettlement issues. PSH is highly effective in meeting power demands, regulating frequency and phase, serving as an emergency power reserve, and improving the power factor of electrical networks. It enhances the quality of renewable energy sources such as wind, photovoltaic, and tidal power, which are characterized by intermittent supply. Beyond its technical advantages, PSH also contributes to local employment and tourism and supports pollutant reduction efforts. Compared to other energy storage systems, PSH has a more significant environmental impact and requires a longer construction period. Thus, exploring new forms of PSH is crucial. Innovative approaches such as utilizing constructed reservoirs, lakes, seas, and abandoned pits can reduce both investment and construction time while minimizing the environmental impact. This paper aims to provide some technical references and feasible plans to governments, owners, and engineers during the planning and preliminary design stages of a PSH project. Full article

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25 pages, 9673 KiB

Open AccessArticle

A Systematic Modular Approach for the Coupling of Deep-Learning-Based Models to Forecast Urban Flooding Maps in Early Warning Systems

by Juliana Koltermann da Silva, Benjamin Burrichter, Andre Niemann and Markus Quirmbach

Hydrology 2024, 11(12), 215; https://doi.org/10.3390/hydrology11120215 - 12 Dec 2024

Abstract

Deep learning (DL) approaches to forecast precipitation and inundation areas in the short-term forecast horizon have up until now been treated as independent research problems from the model development perspective. However, for the urban hydrology area, the coupling of these models is necessary [...] Read more.

Deep learning (DL) approaches to forecast precipitation and inundation areas in the short-term forecast horizon have up until now been treated as independent research problems from the model development perspective. However, for the urban hydrology area, the coupling of these models is necessary in order to forecast the upcoming inundation area maps and is, therefore, of the utmost importance for successful flood risk management. In this paper, three deep-learning-based models are coupled in a systematic modular approach with the aim to analyze the performance of this model chain in an operative setup for urban pluvial flooding nowcast: precipitation nowcasting with an adapted version of the NowcastNet model, the forecast of manhole overflow hydrographs with a Seq2Seq model, and the generation of a spatiotemporal sequence of inundation areas in an urban catchment for the upcoming hour with an encoder–decoder model. It can be concluded that the forecast quality still largely depends on the accuracy of the precipitation nowcasting model. With the increasing development of DL models for both precipitation and flood nowcasting, the presented modular approach for model coupling enables the substitution of individual blocks for better and newer models in the model chain without jeopardizing the operation of the flooding forecast system. Full article

(This article belongs to the Special Issue New Perspectives in the Flood Forecasting Chain (Weather Prediction, Rainfall-Runoff Modeling, and Communication with Stakeholders))

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12 pages, 4113 KiB

Open AccessArticle

Brazil’s Daily Precipitation Concentration Index (CI) Using Alternative Fitting Equation and Ensemble Data

by Gerardo Núñez-González

Hydrology 2024, 11(12), 214; https://doi.org/10.3390/hydrology11120214 - 10 Dec 2024

Abstract

In recent years, precipitation concentration indices have become popular, and the daily precipitation concentration index has been widely used worldwide. This index is based on the Lorenz curve fitting. Recently, some biases in the fitting process have been observed in some research. Therefore, [...] Read more.

In recent years, precipitation concentration indices have become popular, and the daily precipitation concentration index has been widely used worldwide. This index is based on the Lorenz curve fitting. Recently, some biases in the fitting process have been observed in some research. Therefore, this research’s objective consisted of testing the performance of one alternative equation for fitting the Lorenz curve through the analysis of the daily precipitation concentration in Brazil. Daily precipitation data from 735 time series were used to fit the Lorenz curve and calculate the concentration index. Therefore, the goodness of fit was evaluated to determine which equation better describes the empirical data. Results show that the mean value for the concentration index based on Equation (1) was 0.650 ± 0.079, while the mean value based on Equation (2) was 0.624 ± 0.070. The results of the fitting performance show a better fitting with Equation (2) compared to Equation (1) as indicated by R², RSS, and RMSE values, R² = 0.9959 for Equation (1) versus 0.9996 for Equation (2), RSS = 252.78 versus 22.66, and RMSE = 1.5092 versus 0.0501. Thus, Equation (2) can be considered an alternative to improve the calculation of the concentration index. Full article

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19 pages, 3323 KiB

Open AccessArticle

Nature-Based Solutions (NbSs) to Improve Flood Preparedness in Barcelona Metropolitan Area (Northeastern Spain)

by Carlos Sánchez-García, Óscar Corvacho-Ganahín, Albert Santasusagna Riu and Marcos Francos

Hydrology 2024, 11(12), 213; https://doi.org/10.3390/hydrology11120213 - 9 Dec 2024

Abstract

This paper presents a novel study of the Nature-based Solutions (NbSs) approach to analyze and propose mitigation measures for extreme floods. The study area is the Llobregat River in Catalonia, which crosses urban areas. We have selected one section in the final stretch [...] Read more.

This paper presents a novel study of the Nature-based Solutions (NbSs) approach to analyze and propose mitigation measures for extreme floods. The study area is the Llobregat River in Catalonia, which crosses urban areas. We have selected one section in the final stretch of 4.5 km in the Barcelona Metropolitan Area. The section has suffered several damages in the last floods (e.g., 2016, 2018 and 2019), and we propose measures to reduce flood risk. Therefore, we proposed the following three specific objectives: (a) the identification of critical areas in the river stretches; (b) the identification of NbS opportunities and utilities; and (c) the mitigation measures in concrete areas from NbSs. The effectiveness of a NbS is based on the 2D simulation of the Gloria flood event (20–21 January 2020) with HEC-RAS software (version 6.0) for the better management of stormwater, and it is influenced by design and placement aspects; however, the better use of NbSs can improve flood mitigation and enhance urban resilience. Full article

(This article belongs to the Special Issue Advances in Urban Hydrology and Stormwater Management)

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20 pages, 3426 KiB

Open AccessArticle

Using Two Water Quality Indices for Evaluating the Health and Management of a Tropical Lake

by Meareg D. Nerae, Fasikaw A. Zimale, Tammo S. Steenhuis and Mebrahtom G. Kebedew

Hydrology 2024, 11(12), 212; https://doi.org/10.3390/hydrology11120212 - 8 Dec 2024

Abstract

With increasing pressure on freshwater resources in developing countries due to population growth, further research and potential interventions are crucial. Lake Tana, located in the headwaters of the Blue Nile, serves as a critical example of these precious freshwater resources. This study evaluated [...] Read more.

With increasing pressure on freshwater resources in developing countries due to population growth, further research and potential interventions are crucial. Lake Tana, located in the headwaters of the Blue Nile, serves as a critical example of these precious freshwater resources. This study evaluated the water quality of Lake Tana for both ecological health and drinking purposes using the Arithmetic Weighted Water Quality Index (AW WQI) and the Canadian Council of Ministers of the Environment Water Quality Index (CCME WQI). Samples were collected from 20 lake sampling stations four times between July 2018 and June 2019 to calculate the two water quality indices using ten measured parameters. The average annual AW WQI ranged from good to very poor for ecological health and very poor to unsuitable for drinking water. The CCME WQI categorized Lake Tana’s water quality as poor to fair for both uses. According to the water quality indices, the water quality was most impacted by turbidity, dissolved oxygen, ammonium, and phosphorus. However, except for ammonium, these factors were immaterial for lake management because the lake was nitrogen-limited, and the turbidity resulted from sediment stirred up by waves from the lake bottom, which cannot be managed easily. Dissolved oxygen is related to turbidity. Moreover, the WQIs did not identify two pesticides in the lake that negatively affected the fish. Thus, WQI indices may document water quality changes over time. Therefore, in addition to a favorable economic and political climate, improving lake water management requires insights from experts, the scientific literature, and possibly additional monitoring in addition to what is provided by the WQIS. Full article

(This article belongs to the Topic Climate Change and Human Impact on Freshwater Water Resources: Rivers and Lakes)

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22 pages, 16670 KiB

Open AccessArticle

Characterizing Soil and Bedrock Water Use of Native California Vegetation

by Alan L. Flint, Lorraine E. Flint, Michelle A. Stern, David D. Ackerly, Ryan Boynton and James H. Thorne

Hydrology 2024, 11(12), 211; https://doi.org/10.3390/hydrology11120211 - 8 Dec 2024

Abstract

The effective characterization of landscape water balance components—evapotranspiration, runoff, recharge, and soil storage—is critical for understanding the integrated effects of the water balance on vegetation dynamics, water availability, and associated environmental responses to climate change. An improved parameterization of these components can improve [...] Read more.

The effective characterization of landscape water balance components—evapotranspiration, runoff, recharge, and soil storage—is critical for understanding the integrated effects of the water balance on vegetation dynamics, water availability, and associated environmental responses to climate change. An improved parameterization of these components can improve assessments of landscape stress and provide useful insights for predicting and managing vegetation responses to climate change. Hydrology models typically are not able to address water availability below the mapped soil profile, but we refined a landscape hydrology model, the Basin Characterization Model, by balancing measures of actual evapotranspiration (AET) with modeled subsurface soil water holding capacity, including bedrock storage. The purpose of this study was to characterize the effective rooting depth (the depth of soil and bedrock storage required to support AET) for 35 native vegetation types in California in order to quantify soil and bedrock water use, which ranged from 0 to 3.1 m for most vegetation types, exceeding mapped soil depths. This resulted in the quantification of bedrock water use, increasing available water 67% over that calculated by mapped soils alone. We found that mid-elevation vegetation types with lower water and energy limitations have the highest evapotranspiration rates and deepest effective rooting depth. We also evaluated the resilience to drought with this more spatially realistic characterization of water and vegetation interactions. Full article

(This article belongs to the Section Hydrological and Hydrodynamic Processes and Modelling)

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29 pages, 15662 KiB

Open AccessArticle

Water Discharge Change in the Rivers of the South of the Boreal Forest Zone of Eastern European Russia at the End of the Late Holocene and in the Anthropocene: The Vyatka River

by Artyom V. Gusarov and Achim A. Beylich

Hydrology 2024, 11(12), 210; https://doi.org/10.3390/hydrology11120210 - 4 Dec 2024

Abstract

Based on long-term observations of the water discharge (WD) from 1878 to 2018, the main trends and patterns of its change in the basin of one of the largest rivers in the east of the East European Plain, the Vyatka River, were revealed [...] Read more.

Based on long-term observations of the water discharge (WD) from 1878 to 2018, the main trends and patterns of its change in the basin of one of the largest rivers in the east of the East European Plain, the Vyatka River, were revealed using a set of standard statistical procedures and a graphical analysis of the WD probability curves. Three main phases of the annual river WD were identified, corresponding to the periods 1878–1929, 1930–1977, and 1978–2018. The first and third periods were characterized by increased WD (by 22–23%) relative to the medium period, and the differences in the average annual WD characteristics between these periods were statistically significant. It is also noteworthy that the difference in the average annual WD between the first and last periods of increased WD was very small and statistically insignificant. A gradual increase in the share of the so-called normal annual WD and a decrease in the abnormal (including extreme) annual WD were noted from 1878–1929 to 1978–2018 in the predominantly northern half of the river basin. At the same time, in the predominantly southern half of the basin, according to the analysis of only the periods 1930–1977 and 1978–2018, the so-called normal and abnormal WD remained almost unchanged; only a slight increase in positive anomalies of the WD was noted. Increased intra-annual variability in the WD was characteristic of the period of its reduced average annual value. Between the three identified periods, a gradual reduction in the water runoff coefficient was observed during the warm (mainly summer) season in the Vyatka River basin. The specified long-term variability in the water discharge of the Vyatka River was chiefly due to long-term changes in climatic factors, primarily the ratio of the air temperature and precipitation, expressed as the De Martonne aridity index. The duration of the principal cycle of these changes was 82 years. An additional contribution could also have been made by the widespread reduction in cropland in the study region in recent decades. The obtained results can be preliminarily considered representative of the entire southern sector of the boreal forest zone (taiga zone) of the east of the East European Plain. Full article

(This article belongs to the Section Hydrology–Climate Interactions)

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15 pages, 7252 KiB

Open AccessArticle

Linking Land Use Change and Hydrological Responses: The Role of Agriculture in the Decline of Urmia Lake

by Amirhossein Mirdarsoltany, Alireza B. Dariane, Mahboobeh Ghasemi, Sepehr Farhoodi, Roza Asadi and Akbar Moghaddam

Hydrology 2024, 11(12), 209; https://doi.org/10.3390/hydrology11120209 - 3 Dec 2024

Abstract

The water level and surface area of Urmia Lake, located in the northwest of Iran, has decreased dramatically, presenting significant challenges for hydrological modeling due to complex interactions between surface and groundwater. In this study, the impact of agricultural activities on streamflow within [...] Read more.

The water level and surface area of Urmia Lake, located in the northwest of Iran, has decreased dramatically, presenting significant challenges for hydrological modeling due to complex interactions between surface and groundwater. In this study, the impact of agricultural activities on streamflow within one of the largest sub-basins of Urmia Lake is assessed using the Soil and Water Assessment Tool (SWAT) for hydrological assessments. To have accurate assessments, land use change detections were considered by a novel method, which merges the Normalized Difference Vegetation Index (NDVI) with the Digital Elevation Model (DEM) to create a two-band NDVI-DEM image, effectively differentiating between agricultural and rangeland fields. Our findings reveal that agricultural development and irrigation, escalating between 1977 and 2015, resulted in increased annual evapotranspiration (ET) (ranging from 295 mm to 308 mm) and a decrease in yearly streamflow, from 317 million cubic meters to 300 million cubic meters. Overall, our study highlights the significant role that agricultural development and irrigation may play in contributing to the shrinking of Lake Urmia, underscoring the need for improved regional water management strategies to address these challenges, though further analysis across additional basins would be necessary for broader conclusions. Full article

(This article belongs to the Section Surface Waters and Groundwaters)

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23 pages, 9027 KiB

Open AccessArticle

Investigating Induced Infiltration by Municipal Production Wells Using Stable Isotopes of Water (δ¹⁸O and δ²H), Four Mile Creek, Ohio

by Idah Ngoma, Jonathan Levy, Jason A. Rech and Tedros M. Berhane

Hydrology 2024, 11(12), 208; https://doi.org/10.3390/hydrology11120208 - 3 Dec 2024

Abstract

Many municipalities around the world place their production wells in shallow alluvial aquifers that are adjacent to streams. Pumping these wells then induces the infiltration of surface water into the aquifer, allowing the greater extraction of water without significantly depleting the aquifer. However, [...] Read more.

Many municipalities around the world place their production wells in shallow alluvial aquifers that are adjacent to streams. Pumping these wells then induces the infiltration of surface water into the aquifer, allowing the greater extraction of water without significantly depleting the aquifer. However, induced infiltration poses a risk of introducing contamination from surface water into groundwater systems. The goal of this study was to quantify the amount of induced infiltration due to municipal pumping at the Four Mile Creek well field in Oxford, Ohio, using stable isotopes of water oxygen (δ¹⁸O) and deuterium (δ²H). In areas of municipal pumping, we sampled water from the production wells, Four Mile Creek, and from monitoring wells that we hypothesized to be both influenced and not influenced by induced infiltration. Samples were collected over 10 months in 2012 and over 12 months in 2021. In 2012, surface water δ¹⁸O values ranged from −3.89 to −8.04‰, and δ²H ranged from −26.55 to −55.65‰ at sampling sites. PW1 δ¹⁸O values ranged from −4.71 to −7.39‰ with a mean of −6.61 and −32.01 to −47.86‰ with a mean of −42.74‰ for δ²H. PW2 δ¹⁸O values ranged from −5.74 to −7.34‰, with a mean of −6.45‰, and δ²H ranged from −36.29 to −47.82‰ with a mean of −42.43‰. PW3 had lower values of both δ¹⁸O and δ²H, ranging from −6.36 to −8.02‰ and −47.7 to −40.35‰, and with means of −7.08 and −45.11, respectively. In 2021/2022, surface water δ¹⁸O values ranged from −5.32 to −7.93‰, and the δ²H ranged from −36.14 to −50.56‰. PW1 δ¹⁸O values ranged from −6.15 to −7.54‰ with a mean of −7.13‰, and δ²H ranged from −43.52 to −49.01‰ with a mean of −45.99‰. PW2 δ¹⁸O values ranged from −5.72 to −7.34‰, with a mean of −6.70‰, and δ²H ranged from −36.69 to −46.14‰, with a mean of −43.61‰. Using the time averaged values of δ¹⁸O of groundwater, production wells and surface water, the percentages of surface water resulting from induced infiltration in 2012 were 57%, 59% and 15% at the three wells, respectively, while in 2021, PW1 had 35% and PW2 91%. The amount of induced infiltration was apparently related to the pumping rates of the production wells, the length of time of pumping and the distance between Four Mile Creek and production wells. Our results indicate that stable isotopes of water provide a reliable method of quantifying groundwater/surface water interaction in alluvial aquifers. Full article

(This article belongs to the Special Issue Isotope Hydrology in the U.S.)

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26 pages, 56682 KiB

Open AccessArticle

Multi-Model Assessment of Climate Change Impacts on the Streamflow Conditions in the Kasai River Basin, Central Africa

by Samane Lesani, Salomon Salumu Zahera, Elmira Hassanzadeh, Musandji Fuamba and Ali Sharifinejad

Hydrology 2024, 11(12), 207; https://doi.org/10.3390/hydrology11120207 - 30 Nov 2024

Abstract

The Congo River Basin is the second-largest watershed globally, flowing through nine countries before reaching the Atlantic Ocean. The Kasai River Basin (KARB), containing about one-fourth of Congo’s freshwater resources, plays a strategic role in sustaining navigation, food production, and hydroelectricity generation in [...] Read more.

The Congo River Basin is the second-largest watershed globally, flowing through nine countries before reaching the Atlantic Ocean. The Kasai River Basin (KARB), containing about one-fourth of Congo’s freshwater resources, plays a strategic role in sustaining navigation, food production, and hydroelectricity generation in Central Africa. This study applies a multi-model framework suited for data-scarce regions to assess climate change impacts on water availability in the KARB. Using two conceptual hydrological models calibrated with four reanalysis datasets and fed with bias-corrected outputs from 19 climate models under two representative climate pathways (RCPs), we project changes in the mean annual discharge ranging from −18% to +3%, highlighting the sensitivity of impact assessments to model and input data choices. Additionally, streamflow signatures (Q10, Q50, Q90) are projected to decline by approximately 9%, 18%, and 13%, respectively, under RCP 8.5. Annual hydropower potential is estimated to decrease by 14% and 5% under RCPs 4.5 and 8.5, respectively. These findings provide actionable insights for water management practices in the KARB, including guiding the development of adaptive strategies to optimize water allocation, mitigate risks of scarcity, and support sustainable agricultural and industrial activities in the region. Full article

(This article belongs to the Topic Hydrology and Water Resources Management)

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22 pages, 5895 KiB

Open AccessArticle

Optimizing the Master Recession Curve for Watershed Characterization and Drought Preparedness in Eastern Cape, South Africa

by Solomon Temidayo Owolabi and Johanes A. Belle

Hydrology 2024, 11(12), 206; https://doi.org/10.3390/hydrology11120206 - 28 Nov 2024

Abstract

Regions grappling with water scarcity are compelled to fortify their hydrological analytical protocols for efficacious drought disaster preparedness, considering the escalating influence of climate change on river periodicity and the sustainable management of water resources. Hence, this study presents a novel optimization and [...] Read more.

Regions grappling with water scarcity are compelled to fortify their hydrological analytical protocols for efficacious drought disaster preparedness, considering the escalating influence of climate change on river periodicity and the sustainable management of water resources. Hence, this study presents a novel optimization and standardization approach for master recession curve (MRC) parameterization to improve the existing MRC computation for environmental flow (EF) parameterization. The study framework is based on constructing MRC using the RECESS computational tool. The concept involved normalizing quadratic improvement in the digitally filtered, smoothed, and automatically extracted MRC parameters from 24 long-term winter streamflows (2001–2020) in South Africa. The optimum recession length suitable for MRC computation obtained was ten days based on the significant proportion of the variance in streamflow as a function of flow timing (R² > 0.935), EF consistency in most watersheds (p-value < 0.00), optimum standard error, and the appreciable years of significant discharge. The study obtained the MRC index, EF threshold, and the probable diminution period of 3.81–73.2, 0.001–20.19 m³/s, and 3.78 to 334 days based on the periods of significant discharge ranging between 4 and 20 years, respectively. The concurrent agreement of rainfall trend and baseflow (p-value < 0.05) with MRC parameters validate their performance as tools for EF conservation. The intra-variation in MRC across the 24 stations alluded to the overriding influence of river aquifer connectivity on watershed viability. The study provides profound insight into perennial and ephemeral rivers’ viability/vulnerability, indispensable for watershed prioritization, policy formulation, early warning systems, and drought preparedness. Full article

(This article belongs to the Special Issue Editorial Board Members’ Collection Series: Integrated Surface Water and Groundwater Resources Management)

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22 pages, 13992 KiB

Open AccessArticle

Simulation of Seawater Intrusion and Upconing Processes in Mediterranean Aquifer in Response to Climate Change (Plana de Castellón, Spain)

by Barbara del R. Almazan-Benitéz, Maria V. Esteller-Alberich, Arianna Renau-Pruñonosa and José L. Expósito-Castillo

Hydrology 2024, 11(12), 205; https://doi.org/10.3390/hydrology11120205 - 28 Nov 2024

Abstract

In coastal regions, groundwater is often the only freshwater resource available for human consumption, agriculture, and other productive activities. From a management point of view, it is essential to understand the processes that occur in a coastal aquifer affected by seawater intrusion and [...] Read more.

In coastal regions, groundwater is often the only freshwater resource available for human consumption, agriculture, and other productive activities. From a management point of view, it is essential to understand the processes that occur in a coastal aquifer affected by seawater intrusion and upconing processes and evaluate their potential response to climate change as these scenarios usually indicate a decrease in aquifer recharge. Therefore, the dynamics of seawater intrusion and the upconing process in the Plana de Castellón aquifer on the Mediterranean coast were analysed by building and calibrating a new numerical model of flow and transport using the MODFLOW and SEAWAT codes. The model was used to examine two Shared Socioeconomic Pathway (SSP) climate change scenarios (SSP1–2.6 and SSP5–8.5) when considering field data with constant extraction conditions. The results suggest that by 2050, groundwater levels could rise by 0.18 m (on average) in the SSP1–2.6 scenario and by 0.12 m for the SSP5–8.5 scenario. In these cases, aquifer recharge and groundwater discharge to the sea could increase compared to the historical period, as precipitation is not expected to decrease significantly during this timeframe, even in the most unfavourable scenario (SSP5–8.5). The result would be the attenuation of seawater intrusion and a decrease in the volume of the aquifer that is affected by the upconing process, resulting in total dissolved solids values below 2000 mg/L. The innovation of this research lies in the fact that the numerical model allowed the dynamics of seawater intrusion and the upconing process to be adequately represented, especially in the latter process, as it was not possible to model it with real data in another study. These results can improve and facilitate decision-making for the management of the aquifer and contribute to plans for future exploitation strategies. Full article

(This article belongs to the Section Hydrology–Climate Interactions)

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23 pages, 4480 KiB

Open AccessArticle

Geographical Information System-Based Site Selection in North Kordofan, Sudan, Using In Situ Rainwater Harvesting Techniques

by Ibrahim Ahmed, Elena Bresci, Khaled D. Alotaibi, Abdelmalik M. Abdelmalik, Eljaily M. Ahmed and Majed-Burki R. Almutairi

Hydrology 2024, 11(12), 204; https://doi.org/10.3390/hydrology11120204 - 28 Nov 2024

Abstract

The systematic identification of appropriate sites for different rainwater harvesting (RWH) structures may contribute to better success of crop production in such areas. One approach to improving crop yields in North Kordofan, Sudan, that is mostly adaptable to the changing climate is in-field [...] Read more.

The systematic identification of appropriate sites for different rainwater harvesting (RWH) structures may contribute to better success of crop production in such areas. One approach to improving crop yields in North Kordofan, Sudan, that is mostly adaptable to the changing climate is in-field water harvesting. The main objective of this study is to employ a geographical information system (GIS) in order to identify the most suitable sites for setting in situ water harvesting structures, aiming to address climate change in this area. A GIS-based model was developed to generate suitability maps for in situ RWH using multi-criteria evaluation. Five suitability criteria (soil texture, runoff depth, rainfall surplus, land cover, and slope) were identified; then, five suitability levels were set for each criterion (excellent, good, moderate, poor, and unsuitable). Weights were assigned to the criteria based on their relative importance for RWH using the analytical hierarchy process (AHP). Using QGIS 2.6.1 and ArcGIS 10.2.2 software, all criterion maps and suitability maps were prepared. The obtained suitability map for the entire region showed that 40% of the region area fell within the “good” class, representing 7419.18 km², whereas 26% of the area was “excellent”, occupying 4863.75 km². However, only 8.9% and 15.6% of the entire region’s area were “poor” and “unsuitable” for RWH, respectively. The suitability map of the delineated pilot areas selected according to the attained FAO data revealed that one location, Wad_Albaga, was found to be in an excellent position, covering an area of 787.811 km², which represents 42.94% of the total area. In contrast, the Algabal location had 6.4% of its area classified as poor and the remaining portion classified as excellent. According to the findings from the validated trial, Wad_Albaga is located in a good site covering 844 km², representing 46.04%, while Algabal is classified as a moderate site, covering 341 km² or 18.6% of the area. This study concluded that the validation of the existing trial closely matched the suitability map derived using FAO data. However, ground data from field experiments provided more accurate results compared to the FAO suitability map. This study also concluded that using GIS is a time-saving and effective tool for identifying suitable sites and discovering the most appropriate locations for rainwater harvesting (RWH). Full article

(This article belongs to the Topic Application of Smart Technologies in Water Resources Management)

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27 pages, 3446 KiB

Open AccessArticle

A Novel Time-Varying P-III Distribution Curve Fitting Model to Estimate Design Floods in Three Gorges Reservoir Operation Period

by Yuzuo Xie, Shenglian Guo, Sirui Zhong, Xiaoya Wang, Jing Tian and Zhiming Liang

Hydrology 2024, 11(12), 203; https://doi.org/10.3390/hydrology11120203 - 26 Nov 2024

Abstract

Design floods are traditionally estimated based on the at-site annual maximum flood series, including historical information of hydraulic structures. Nevertheless, the construction and operation of upstream reservoirs undermine the assumption of stationarity in the downstream flood data series. This paper investigates non-stationary design [...] Read more.

Design floods are traditionally estimated based on the at-site annual maximum flood series, including historical information of hydraulic structures. Nevertheless, the construction and operation of upstream reservoirs undermine the assumption of stationarity in the downstream flood data series. This paper investigates non-stationary design flood estimation considering historical information from the Three Gorges Reservoir (TGR) in the Yangtze River. Based on the property that the distribution function of a continuous random variable increases monotonically, we proposed a novel time-varying P-III distribution coupled with the curve fitting method (referred to as the Tv-P3/CF model) to estimate design floods in the TGR operation period, and we comparatively studied the reservoir indices and parameter estimation methods. The results indicate that: (1) The modified reservoir index used as a covariate can effectively capture the non-stationary characteristics of the flood series; (2) The Tv-P3/CF model emphasizes the fitness of historical information, yielding superior results compared to time-varying P-III distribution estimated by the maximum likelihood method; (3) Compared to the original design values, the 1000-year design peak discharge Q_m and 3-day and 7-day flood volumes in the TGR operation period are reduced by approximately 20%, while the 15-day and 30-day flood volumes are reduced by about 16%; (4) The flood-limited water level of the TGR can be raised from 145 m to 154 m, which can annually generate 0.32 billion kW h more hydropower (or increase by 6.8%) during flood season without increasing flood prevention risks. Full article

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16 pages, 7739 KiB

Open AccessArticle

Analyzing Hydrodynamic Changes in Dubai Creek, UAE: A Pre- and Post-Extension Study

by Khaled Elkersh, Serter Atabay, Tarig Ali, Abdullah G. Yilmaz, Maruf Md. Mortula and Geórgenes H. Cavalcante

Hydrology 2024, 11(12), 202; https://doi.org/10.3390/hydrology11120202 - 25 Nov 2024

Abstract

This paper presents a comparative study that examines the effects of the Dubai Creek extension on its hydrodynamics and water flushing dynamics. Dubai Creek (Khor Dubai) is a 24 km long artificial seawater stream located in the emirate of Dubai. The creek has [...] Read more.

This paper presents a comparative study that examines the effects of the Dubai Creek extension on its hydrodynamics and water flushing dynamics. Dubai Creek (Khor Dubai) is a 24 km long artificial seawater stream located in the emirate of Dubai. The creek has experienced the impact of the rapid urbanization of Dubai and a major 13 km extension project, which connected the creek to the Arabian Gulf from the other side. In this paper, two-dimensional hydrodynamic and flushing models were created using Delft3D Flexible Mesh (2021.03) to investigate the water circulation and water quality of the creek before and after the extension. The hydrodynamic models were calibrated and validated to accurately simulate water levels and currents with correlation values close to 1 and very small RMSE and bias. Flushing models were created to simulate water renewal along the creek. The results of the flushing models showed a significant improvement in the flushing characteristics of pollutants in terms of the residence times of the extended creek (Existing Creek) model compared to the old one (Old Creek). This improvement emphasized the positive impact of the creek extension project on the local aquatic ecosystem and its overall water quality. Full article

(This article belongs to the Special Issue Hydrodynamics and Water Quality of Rivers and Lakes)

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17 pages, 11609 KiB

Open AccessArticle

Groundwater Response to Snowmelt Infiltration in Seasonal Frozen Soil Areas: Site Monitoring and Numerical Simulation

by Yongjun Fang, Xinqiang Du, Xueyan Ye and Enbo Wang

Hydrology 2024, 11(12), 201; https://doi.org/10.3390/hydrology11120201 - 25 Nov 2024

Abstract

Spring snowmelt has a significant impact on the hydrological cycle in seasonally frozen soil areas. However, scholars hold differing, and even opposing, views on the role of snowmelt during the thawing period in groundwater recharge. To explore the potential recharge effects of spring [...] Read more.

Spring snowmelt has a significant impact on the hydrological cycle in seasonally frozen soil areas. However, scholars hold differing, and even opposing, views on the role of snowmelt during the thawing period in groundwater recharge. To explore the potential recharge effects of spring snowmelt on groundwater in seasonal frozen soil areas, this study investigated the vadose zone dynamics controlled by soil freeze–thaw processes and snowmelt infiltration in the Northeast of China for 194 days from 31 October 2020 to 12 May 2021. Responses of groundwater level and soil moisture to snowmelt infiltration show that most snowmelt was infiltrated under the site despite the ground being frozen. During the unstable thawing period, surface snow had already melted, and preferential flow in frozen soil enabled the recharge groundwater by snowmelt (rainfall), resulting in a significant rise in groundwater levels within a short time. The calculated and simulated snowmelt (rainfall) infiltration coefficient revealed that during the spring snowmelt period, the recharge capacity of snowmelt or rainfall to groundwater at the site is 3.2 times during the stable thawing period and 4.5 times during the non-freezing period. Full article

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26 pages, 7774 KiB

Open AccessArticle

Hydrological Sustainability of Dam-Based Water Resources in a Mediterranean Basin Undergoing Climate Change

by Nicola Montaldo, Serena Sirigu, Riccardo Zucca, Adriano Ruiu and Roberto Corona

Hydrology 2024, 11(12), 200; https://doi.org/10.3390/hydrology11120200 - 25 Nov 2024

Abstract

The Flumendosa dams are a key part of the water resources system of the island of Sardinia. The analysis of a long-term (1922–2022) hydrological database showed that the Flumendosa basin has been affected by climate change since the middle of the last century, [...] Read more.

The Flumendosa dams are a key part of the water resources system of the island of Sardinia. The analysis of a long-term (1922–2022) hydrological database showed that the Flumendosa basin has been affected by climate change since the middle of the last century, associated with a decrease in winter precipitation and annual runoff (Mann–Kendall τ = −0.271), reduced by half in the last century, and an increase in the mean annual air temperature (Mann–Kendall τ = +0.373). We used a spatially distributed ecohydrological model and a water resources management model (WARGI) to define the economic efficiency and the optimal water allocation in the water system configurations throughout the evaluation of multiple planning and management rules for future climate scenarios. Using future climate scenarios, testing land cover strategies (i.e., forestation/deforestation), and optimizing the use of water resources, we predicted drier future scenarios (up to the end of the century) with an alarming decrease in water resources for agricultural activities, which could halt the economic development of Sardinia. In the future hydrological conditions (2024–2100), irrigation demands will not be totally satisfied, with up to 74% of future years being in deficit for irrigation, with a mean deficit of up to 52% for irrigation. Full article

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18 pages, 3346 KiB

Open AccessReview

The Catastrophic Water Loss of Ancient Lake Prespa: A Chronicle of a Death Foretold

by Dejan Trajkovski and Nadezda Apostolova

Hydrology 2024, 11(12), 199; https://doi.org/10.3390/hydrology11120199 - 25 Nov 2024

Abstract

The Prespa–Ohrid lake system in the southwest Balkan region is the oldest permanent lake system in Europe and a global hotspot of biodiversity and endemism. Its smaller component, Lake Macro Prespa (or simply called Prespa), shared by North Macedonia, Albania and Greece has [...] Read more.

The Prespa–Ohrid lake system in the southwest Balkan region is the oldest permanent lake system in Europe and a global hotspot of biodiversity and endemism. Its smaller component, Lake Macro Prespa (or simply called Prespa), shared by North Macedonia, Albania and Greece has suffered a dramatic water-level fall (nearly 10 m since the 1950s). It was greater in the periods 1987–1993 and 1998–2004 and has further accelerated in the last 5 years. Analysis of satellite images (remote sensing) revealed that over the period 1984–2020 Prespa Lake lost 18.87 km² of its surface (6.9% of its size, dropping from 273.38 km² to 254.51 km²), with a decline in the volume of water estimated as about 54%, even reaching 56.8% in 2022. The environmental status of the lake has also been compromised and the process of its eutrophication is enhanced. The aim of this study is to summarize the current understanding of the diminishing trend in the water level and the factors that have contributed to it. The lake is highly sensitive to external impacts, including climate change, mainly restricted precipitation and increased water abstraction for irrigation. Importantly, nearly half of its outflow is through karst aquifers that feed Ohrid Lake. Of note, the hydrology and especially hydrogeology of the catchment has not been studied in sufficient detail and accurate data for the present state are missing, largely due to a lack of coordinated investigations by the three neighboring countries. However, recent estimation of the water balance of Prespa Lake, elaborated with the consideration of only the natural sources of inflow (precipitation and river runoff) and outflow (evaporation and loss of water through the karst channels) suggested a negative balance of 53 × 10⁶ m³ annually. Our study also offers an estimated projection for the water level in the future in different climate scenarios based on linear regression models that predict its complete loss before the end of the present century. Full article

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