Hydrology

20 pages, 16638 KiB

Open AccessFeature PaperArticle

Assessment and Mitigation of Fecal Bacteria Exports from a Coastal North Carolina Watershed

by Charles P. Humphrey, Jr., Nicole Lyons, Ryan Bond, Eban Bean, Michael O’Driscoll and Avian White

Hydrology 2023, 10(7), 156; https://doi.org/10.3390/hydrology10070156 - 23 Jul 2023

Viewed by 1517

Abstract

Urban runoff from the Boat House Creek watershed was suspected as a main delivery mechanism for fecal indicator bacteria (FIB) to the lower White Oak River Estuary in coastal North Carolina, but the dominant source of waste (animal or human) was unknown. Water [...] Read more.

Urban runoff from the Boat House Creek watershed was suspected as a main delivery mechanism for fecal indicator bacteria (FIB) to the lower White Oak River Estuary in coastal North Carolina, but the dominant source of waste (animal or human) was unknown. Water samples from eight locations within the watershed were collected approximately monthly for two years for enumeration of Escherichia coli (E. coli), enterococci, physicochemical characterization, and microbial source tracking analyses. Concentrations and loadings of E. coli and enterococci were typically elevated during stormflow relative to baseflow conditions, and most samples (66% of enterococci and 75% of E. coli) exceeded the US EPA statistical threshold values. Concentrations of FIB were significantly higher during warm relative to colder months. Human sources of FIB were not observed in the samples, and FIB concentrations increased in locations with wider buffers, thus wildlife was the suspected main FIB source. Stormwater control measures including a rain garden, water control structures, swale modifications, and check dams were implemented to reduce runoff and FIB loadings to the estuary. Stormflow reductions of >5700 m³ year⁻¹ are estimated from the installation of the practices. More work will be needed to improve/maintain water quality as watershed development continues. Full article

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12 pages, 1791 KiB

Open AccessProject Report

Application of a Novel Amendment for the Remediation of Mercury Mine Sites with Hydrologic Controls

by Stephen McCord, Gregory Reller, Jon Miller and Kim Pingree

Hydrology 2023, 10(7), 155; https://doi.org/10.3390/hydrology10070155 - 22 Jul 2023

Viewed by 1243

Abstract

MercLok^TM P-640 (MercLok) is a proprietary product developed by Albemarle as a mercury (Hg) treatment technology. MercLok captures mercury and sequesters it for a long period under ambient environmental conditions. For this project, MercLok was applied to Hg-contaminated calcines at two abandoned [...] Read more.

MercLok^TM P-640 (MercLok) is a proprietary product developed by Albemarle as a mercury (Hg) treatment technology. MercLok captures mercury and sequesters it for a long period under ambient environmental conditions. For this project, MercLok was applied to Hg-contaminated calcines at two abandoned Hg mine sites in northern California to evaluate its efficacy in rendering such contaminated materials less hazardous and thereby reducing remediation project costs. The first application (Site 1) consisted of two calcines amended with MercLok in isolated reactor buckets under two hydrologic remediation approaches (“repository cap” and “reactive barrier”) while exposed to ambient environmental conditions. Non-amended and amended calcines and their leachates were analyzed for Hg content and related conditions during a five-month study period, demonstrating >95% reduction in leachable Hg. The second application (Site 2) involved full-scale site remediation with the application of both approaches and additional hydrologic controls to minimize run-on, erosion, and runoff. Confirmation sampling and subsequent observations indicate that the amendments and hydrologic controls effectively stabilized the site and minimized Hg releases. These application projects demonstrate the efficacy of MercLok as a component of hydrologic controls for treating Hg-contaminated material to achieve long-term mine site remediation objectives. Full article

(This article belongs to the Special Issue Novel Approaches in Contaminant Hydrology and Groundwater Remediation)

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21 pages, 6972 KiB

Open AccessArticle

The Combined Power of Double Mass Curves and Bias Correction for the Maximisation of the Accuracy of an Ensemble Satellite-Based Precipitation Estimate Product

by Nutchanart Sriwongsitanon, Chanphit Kaprom, Kamonpat Tantisuvanichkul, Nattakorn Prasertthonggorn, Watchara Suiadee, Wim G. M. Bastiaanssen and James Alexander Williams

Hydrology 2023, 10(7), 154; https://doi.org/10.3390/hydrology10070154 - 22 Jul 2023

Viewed by 1807

Abstract

Precise estimation of the spatial and temporal characteristics of rainfall is essential for producing the reliable catchment response needed for proper management of water resources. However, in most parts of the world, gauged rainfall stations are sparsely distributed and fail to properly capture [...] Read more.

Precise estimation of the spatial and temporal characteristics of rainfall is essential for producing the reliable catchment response needed for proper management of water resources. However, in most parts of the world, gauged rainfall stations are sparsely distributed and fail to properly capture the spatial variability of rainfall. Furthermore, the gauged rainfall data can sometimes be of short length or require validation. Following this, we present a procedure that enhances the trustworthiness of gauged rainfall data and the accuracy of the rainfall estimations of five satellite-based precipitation estimate (SPE) products by validating them using the 1779 gauged rainfall stations across Thailand. The five SPE products considered include CMORPH-BLD; TRMM-3B42; CHIRPS; CHIRPS-PL; and TRMM-3B42RT. Prior to validation, the gauged rainfall dataset was verified using double mass curve (DMC) analysis to eliminate questionable and inconsistent readings. This led to the improvement of the Nash–Sutcliffe Efficiency (NSE) between the station of interest and its surroundings by 13.9% (0.758–0.863), together with an average 11.8% increase with SPE products, whilst dropping only 7% of questionable dataset. Three different bias correction (BC) procedures were applied to correct SPE products using gauge-based gridded rainfall (GGR). Once DMC and BC procedures were implemented together, the performance of the SPE products was found to increase significantly. Finally, the application of the ensemble weighted average of the three best-performing bias-corrected SPE products (Bias-CMORPH-BLD, Bias-TRMM-3B42, and Bias-CHIRPS) further enhanced the NSE to 0.907 and 0.880 in calibration and validation time periods, respectively. The proposed DMC-based correction SPE and the weighting procedure of multiple SPE products allows for an easy means of obtaining daily rainfall in remote locations with sufficient accuracy. Full article

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

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16 pages, 1444 KiB

Open AccessReview

Constructed Wetlands as Nature-Based Solutions for Wastewater Treatment in the Hospitality Industry: A Review

by Sara Justino, Cristina S. C. Calheiros, Paula M. L. Castro and David Gonçalves

Hydrology 2023, 10(7), 153; https://doi.org/10.3390/hydrology10070153 - 20 Jul 2023

Cited by 5 | Viewed by 2435

Abstract

The hospitality industry is increasing its awareness of how the integration of nature-based solutions can decrease its environmental impact while maintaining or increasing the service level of the sector. Constructed wetlands (CWs) constitute a promising sustainable solution for proper in situ domestic wastewater [...] Read more.

The hospitality industry is increasing its awareness of how the integration of nature-based solutions can decrease its environmental impact while maintaining or increasing the service level of the sector. Constructed wetlands (CWs) constitute a promising sustainable solution for proper in situ domestic wastewater treatment. This literature review elucidates the status of CWs implementation in the hospitality industry to help foster the exchange of experiences in the field and deliver examples of approaches in different contexts to support future applications of this technology. Most of the studies reported in the literature were conducted in Europe, but studies emanating from Asia and South America are also available. The design of CWs, the horizontal and vertical subsurface flow CWs (HSFCW, VSFCW), and hybrid systems have been reported. The average removal efficiencies of the systems ranged from 83 to 95% for biochemical oxygen demand, 74 to 94% for chemical oxygen demand, 78 to 96% for total suspended solids, 75 to 85% for ammonium, 44 to 85% for ammonia, 50 to 73% for nitrate, 57 to 88% for total Kjeldahl nitrogen, 51 to 58% total nitrogen, and 66 to 99% for total phosphorus. The majority of the systems were implemented as decentralized treatment solutions using HSFCWs, with the second most common design being the hybrid CW systems in order to reduce area requirements, increase treatment efficiency, and prevent clogging. Overall, CWs are a promising sustainable solution which may support access to adequate sanitation worldwide as well as safe wastewater recycling and reuse, leading to more sustainable tourist destinations. Full article

(This article belongs to the Special Issue Recent Advances in Water and Water Resources Engineering)

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14 pages, 4998 KiB

Open AccessArticle

Flood Peaks and Geomorphic Processes in an Ephemeral Mediterranean Stream: Torrent de Sant Jordi (Pollença, Mallorca)

by Miquel Grimalt-Gelabert and Joan Rosselló-Geli

Hydrology 2023, 10(7), 152; https://doi.org/10.3390/hydrology10070152 - 20 Jul 2023

Viewed by 1529

Abstract

The research presented herein studies three episodes of flooding that affected the ephemeral basin of the Sant Jordi stream in northwestern Mallorca. These events are considered common since they do not reach the proportions in terms of the flow rates of other cases [...] Read more.

The research presented herein studies three episodes of flooding that affected the ephemeral basin of the Sant Jordi stream in northwestern Mallorca. These events are considered common since they do not reach the proportions in terms of the flow rates of other cases that have occurred in Mallorca, but they are nevertheless important due to the impact they have on human activity and also due to the morphological changes caused in the basin itself. On the one hand, the development of the field work to characterize and calculate the peak flows is presented, and on the other hand, the geomorphic changes caused by the water and the materials carried away are explained. The results allow us to identify a type of Mediterranean flood, which happens on a regular basis, but which does not stand out for its flows or for its major socio-economic impacts but still has an effect on the natural and anthropic environment. This information can be valuable for local and regional authorities as well as for the public to avoid risk situations and prevent impacts on public and private property caused by future events. Full article

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19 pages, 3306 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

ANN-Based Predictors of ASR Well Recovery Effectiveness in Unconfined Aquifers

by Saeid Masoudiashtiani and Richard C. Peralta

Hydrology 2023, 10(7), 151; https://doi.org/10.3390/hydrology10070151 - 19 Jul 2023

Viewed by 1186

Abstract

In this study, we present artificial neural networks (ANNs) to aid in a reconnaissance evaluation of an aquifer storage and recovery (ASR) well. Recovery effectiveness (REN) is the proportion of ASR-injected water recovered during subsequent extraction from the same well. ANN-based predictors allow [...] Read more.

In this study, we present artificial neural networks (ANNs) to aid in a reconnaissance evaluation of an aquifer storage and recovery (ASR) well. Recovery effectiveness (REN) is the proportion of ASR-injected water recovered during subsequent extraction from the same well. ANN-based predictors allow rapid REN prediction without requiring preparation for and execution of solute transport simulations. REN helps estimate blended water quality resulting from a conservative solute in an aquifer, extraction for environmental protection, and other uses, respectively. Assume that into an isotropic homogenous portion of an unconfined, one-layer aquifer, extra surface water is injected at a steady rate during two wet months (61 days) through a fully penetrating ASR well. And then, water is extracted from the well at the same steady rate during three dry months (91-day period of high demand). The presented dimensionless input parameters were designed to be calibrated within the ANNs to match REN values. The values result from groundwater flow and solute transport simulations for ranges of impact factors of unconfined aquifers. The ANNs calibrated the weighting coefficients associated with the input parameters to predict the achievable REN of an ASR well. The ASR steadily injects extra surface water during periods of water availability and, subsequently, steadily extracts groundwater for use. The total extraction volume equaled the total injection volume at the end of extraction day 61. Subsequently, continuing extraction presumes a pre-existing groundwater right. 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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13 pages, 4488 KiB

Open AccessArticle

Using CMIP6 Models to Assess Future Climate Change Effects on Mine Sites in Kazakhstan

by Saeed Golian, Houcyne El-Idrysy and Desana Stambuk

Hydrology 2023, 10(7), 150; https://doi.org/10.3390/hydrology10070150 - 17 Jul 2023

Cited by 2 | Viewed by 1842

Abstract

Climate change is a threat to mining and other industries, especially those involving water supply and management, by inducing or amplifying some climatic parameters such as changes in precipitation regimes and temperature extremes. Using the latest NASA NEX-GDDP-CMIP6 datasets, this study quantifies the [...] Read more.

Climate change is a threat to mining and other industries, especially those involving water supply and management, by inducing or amplifying some climatic parameters such as changes in precipitation regimes and temperature extremes. Using the latest NASA NEX-GDDP-CMIP6 datasets, this study quantifies the level of climate change that may affect the development of two mine sites (site 1 and site 2) in north–east Kazakhstan. The study analyses the daily precipitation and maximum and minimum temperature a of a number of global circulation models (GCM) over three future time periods, the 2040s, 2060s, and 2080s, under two shared socioeconomic pathway (SSP) scenarios, SSP245 and SSP585, against the baseline period 1981–2014. The analyses reveal that: (1) both maximum and minimum temperature will increase under both SSP in those time periods, with the rate of change for minimum temperature being higher than maximum temperature. Minimum temperature, for example, will increase by 2.2 and 2.7 °C under SSP245 and SSP585, respectively, over the 2040s period at both sites; (2) the mean annual precipitation will increase by an average rate of 7% and 10.5% in the 2040s for SSP245 and 17.5% and 7.5% for SSP585 in the 2080s at site 1 and site 2, respectively. It is also observed that summer months will experience drier condition whilst all other months will increase in precipitation; (3) the values of 24 h precipitation with a 10 year return period will also increase under both SSP scenarios and future time periods for most of the studied GCM and at both mine sites. For instance, over the near future period, a 6.9% and 2.8% increase in 10 year 24 h precipitation is expected to happen over site 1 and site 2, respectively, under SSP245. These predicted changes should be considered as design criteria adjustments for projected water supply and water management structures. Full article

(This article belongs to the Special Issue Climate Change Effects on Hydrology and Water Resources)

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13 pages, 1242 KiB

Open AccessFeature PaperArticle

Analyses of the Effectiveness of Different Media Depths and Plant Treatments on Green Roof Rainfall Retention Capability under Various Rainfall Patterns

by Pearl Ashitey, Rohan Benjankar, Susan Morgan, William Retzlaff and Serdar Celik

Hydrology 2023, 10(7), 149; https://doi.org/10.3390/hydrology10070149 - 14 Jul 2023

Cited by 2 | Viewed by 1203

Abstract

Green roofs have been used to reduce rainfall runoff by altering hydrological processes through plant interception and retention as well as detention within the green roof system. Green roof media depth, substrate type, plant type and density, regional climatic conditions, rainfall patterns, and [...] Read more.

Green roofs have been used to reduce rainfall runoff by altering hydrological processes through plant interception and retention as well as detention within the green roof system. Green roof media depth, substrate type, plant type and density, regional climatic conditions, rainfall patterns, and roof slope all impact runoff retention. To better understand the impacts of media depth (10, 15, and 20 cm), plant (planted and non-planted), and rainfall pattern (low, medium, and high) on rainfall retention, we analyzed data collected between September 2005 and June 2008 from 24 green roof models (61 cm × 61 cm) for growing and non-growing seasons. Our results showed that a planted green roof has greater rainfall retention capability than a non-planted green roof for all media depths. Interestingly, a non-planted green roof system with a 10 cm media depth retained greater rainfall than a planted green roof during both growing and non-growing periods. Retention capability decreased with increasing rainfall amounts for both planted and non-planted green roofs and seasons (growing and non-growing). The 15 cm media depth green roof retained significantly greater rainfall depth than the 20 cm models during medium (0.64 to 2.54 cm) and high (>2.54 cm) rainfall events for the growing season but not during the non-growing season. The study provides insight into the interactive effects of media depth, rainfall amount, plant presence, and seasons on green roof performance. The results will be helpful for designing economical and effective green roof systems. Full article

(This article belongs to the Topic Green Technology, Environmental Management and Corporate Social Responsibility from a Global Perspective)

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14 pages, 2571 KiB

Open AccessArticle

Spatial and Climatic Variabilities of Rainwater Tank Outcomes for an Inland City, Canberra

by Monzur Alam Imteaz, Abdullah Gokhan Yilmaz, Cristina Santos and Amimul Ahsan

Hydrology 2023, 10(7), 148; https://doi.org/10.3390/hydrology10070148 - 13 Jul 2023

Viewed by 930

Abstract

Most of the studies on rainwater harvesting analysis present the outcomes for particular cities, representing a single set of results for a specific city. However, in reality, significant spatial and weather variabilities may exist, due to which presenting only one set of results [...] Read more.

Most of the studies on rainwater harvesting analysis present the outcomes for particular cities, representing a single set of results for a specific city. However, in reality, significant spatial and weather variabilities may exist, due to which presenting only one set of results for a particular city would be misleading. This paper presents the potential weather and spatial variabilities on the expected water savings and supply reliability through the domestic rainwater tank for an inland city. An earlier-developed daily water balance model, eTank, was used for the calculations of annual water savings and reliability. An Australian inland city, Canberra, was selected as a case study and relevant daily rainfall data were collected from the Australian Bureau of Meteorology website. For the analysis of spatial variation, two rain gauge stations within the city of Canberra were selected. For each station, from the historical data, three years were selected as dry, average and wet years. For each weather condition, annual water savings and reliabilities were calculated for different demands with different tank sizes up to 10,000 L connected with different roof sizes. Then, variations in annual water savings and reliabilities among different weather conditions, as well as among different stations, were evaluated. It was found that, with regard to annual water savings, a maximum variation of 68.6% can be expected between dry and wet weather; however, only a 15.4% maximum spatial variation is expected among the selected stations. Regarding reliability, a maximum variation of 123% is expected between dry and wet weather. Whereas, only a 17% spatial variation is expected among the selected stations. Such a study will provide valuable insights for rainwater tank users and stakeholders on potential variabilities due to weather and spatial differences. Full article

(This article belongs to the Topic Hydrological Modeling and Engineering: Managing Risk and Uncertainties)

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12 pages, 3351 KiB

Open AccessArticle

Monitoring Scour at Bridge Piers in Rivers with Supercritical Flows

by Camilo San Martin, Cristian Rifo, Maricarmen Guerra, Bernd Ettmer and Oscar Link

Hydrology 2023, 10(7), 147; https://doi.org/10.3390/hydrology10070147 - 13 Jul 2023

Viewed by 1424

Abstract

Bridges crossing rivers wider than 50 m are typically supported by piers. In a mobile riverbed, scour occurs around bridge piers, and it is the main cause of bridge collapses worldwide, especially during floods. While bridge pier scour has been extensively studied, there [...] Read more.

Bridges crossing rivers wider than 50 m are typically supported by piers. In a mobile riverbed, scour occurs around bridge piers, and it is the main cause of bridge collapses worldwide, especially during floods. While bridge pier scour has been extensively studied, there is still a lack of measuring systems for scour monitoring in the field. In this paper, we present existing devices for scour measurement and analyze their comparative advantages and disadvantages. A study case with a scoured bridge pier in supercritical flow is presented. Results show that supercritical flow patterns previously reported at the laboratory scale also occur in the field. The measured scour supports the hypothesis that supercritical flows, even when having high flow speeds, do not produce higher scour than subcritical flows. A possible explanation linked with the sediment sizes of rivers with supercritical flows is discussed. Further, field measurements of scour around bridge piers are needed to enhance our understanding of this complex and nearly unexplored situation. Full article

(This article belongs to the Special Issue Advances in River Monitoring)

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15 pages, 3907 KiB

Open AccessArticle

Superconducting Gravimeters: A Novel Tool for Validating Remote Sensing Evapotranspiration Products

by Jonatan Pendiuk, María Florencia Degano, Luis Guarracino and Raúl Eduardo Rivas

Hydrology 2023, 10(7), 146; https://doi.org/10.3390/hydrology10070146 - 13 Jul 2023

Viewed by 1343

Abstract

The practical utility of remote sensing techniques depends on their validation with ground-truth data. Validation requires similar spatial-temporal scales for ground measurements and remote sensing resolution. Evapotranspiration (ET) estimates are commonly compared to weighing lysimeter data, which provide accurate but localized measurements. To [...] Read more.

The practical utility of remote sensing techniques depends on their validation with ground-truth data. Validation requires similar spatial-temporal scales for ground measurements and remote sensing resolution. Evapotranspiration (ET) estimates are commonly compared to weighing lysimeter data, which provide accurate but localized measurements. To address this limitation, we propose the use of superconducting gravimeters (SGs) to obtain ground-truth ET data at larger spatial scales. SGs measure gravity acceleration with high resolution (tenths of nm s⁻²) within a few hundred meters. Similar to lysimeters, gravimeters provide direct estimates of water mass changes to determine ET without disturbing the soil. To demonstrate the practical applicability of SG data, we conducted a case study in Buenos Aires Province, Argentina (Lat: −34.87, Lon: −58.14). We estimated cumulative ET values for 8-day and monthly intervals using gravity and precipitation data from the study site. Comparing these values with Moderate Resolution Imaging Spectroradiometer (MODIS)-based ET products (MOD16A2), we found a very good agreement at the monthly scale, with an RMSE of 32.6 mm month⁻¹ (1.1 mm day⁻¹). This study represents a step forward in the use of SGs for hydrogeological applications. The future development of lighter and smaller gravimeters is expected to further expand their use. Full article

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17 pages, 15608 KiB

Open AccessArticle

The Effect of Horizontal Specific Temperature on the Flow Systems of the Transdanubian Mountains (Hungary)

by Márton Veress and Kálmán Péntek

Hydrology 2023, 10(7), 145; https://doi.org/10.3390/hydrology10070145 - 07 Jul 2023

Viewed by 1024

Abstract

This study interprets the development of various flow types of the Transdanubian Mountains. For this, pressure was calculated at different depths and along some profiles the horizontal, specific temperature was calculated based on geoisotherms. This is the value of temperature distribution calculated to [...] Read more.

This study interprets the development of various flow types of the Transdanubian Mountains. For this, pressure was calculated at different depths and along some profiles the horizontal, specific temperature was calculated based on geoisotherms. This is the value of temperature distribution calculated to a given place. It has been established that upwellings develop at sites where the value of horizontal specific temperature is more than 0.8 °C, and partial upwelling can be detected where this value is between 0.6 °C and 0.8 °C. Outflow from the karst is present where this value is below 0.4 °C. Taking into consideration these values, the water temperature of karst springs and the caves of heat effect, the distribution of various flow types are determined. The flow type is also affected by the fault structure of the basin. In the case of horsts subsided to a great degree, since the sediment is thick above such horsts, the water is not able to flow upwards and towards the mountains because the hydrostatic pressure does not prevail any more. Above horsts subsided to a lower degree, the sediment is thin and thus, the water moving upwards is able to flow through. Full article

(This article belongs to the Special Issue Hydro-Geology of Karst Areas)

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14 pages, 2151 KiB

Open AccessArticle

Streamflow Trends in Central Chile

by Claudia Sangüesa, Roberto Pizarro, Ben Ingram, Francisco Balocchi, Pablo García-Chevesich, Juan Pino, Alfredo Ibáñez, Carlos Vallejos, Romina Mendoza, Alejandra Bernal, Rodrigo Valdés-Pineda and Felipe Pérez

Hydrology 2023, 10(7), 144; https://doi.org/10.3390/hydrology10070144 - 07 Jul 2023

Viewed by 1495

Abstract

The availability of water in Chile has shown signs of decline in recent decades. This is problematic because Chile’s economy depends on mining, forestry, and agricultural activities, all limited by the availability of water resources. In this study, daily, monthly and annual flows [...] Read more.

The availability of water in Chile has shown signs of decline in recent decades. This is problematic because Chile’s economy depends on mining, forestry, and agricultural activities, all limited by the availability of water resources. In this study, daily, monthly and annual flows in 31 basins located in the arid–semiarid zones (29°12′ S–33°58′ S) and in the humid–subhumid zones (34°43′ S–38°30′ S) of Chile were evaluated using the Mann–Kendall trend test and the quantile–Kendall procedure during three periods: 1984–2021 (31 stations), 1975–2021 (20 stations), and 1969–2021 (18 stations). Results showed that, at the annual level, trends were predominantly negative in both climatic zones and over the three periods analyzed. In the arid–semiarid zone, a higher frequency of annual significant negative trends was found in maximum flows in 1969–2021 and 1975–2021, compared to the last period under study. The humid–subhumid zone showed significant annual negative trends in all series analyzed. At the monthly level, on the other hand, the arid-semiarid zone showed a decrease in significant negative trends as the number of years analyzed increased, for all flow types. The humid–subhumid zone did not indicate a similar defined pattern. Likewise, the quantile–Kendall procedure showed a reduction in the significant trends as the length of the time series was increased in the arid-semiarid zone, but no such pattern was observed in the humid–subhumid zone. Furthermore, a relationship was observed for the PDO and the summer month flows for both zones. Consequently, it is concluded that the flow trends are generally negative, and their statistical significance depends on the period studied. Full article

(This article belongs to the Section Water Resources and Risk Management)

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20 pages, 8100 KiB

Open AccessArticle

How to Predict the Efficacy of Free-Product DNAPL Pool Extraction Using 3D High-Precision Numerical Simulations: An Interdisciplinary Test Study in South-Western Sicily (Italy)

by Alessandra Feo, Federica Lo Medico, Pietro Rizzo, Maurizio Gasparo Morticelli, Riccardo Pinardi, Edoardo Rotigliano and Fulvio Celico

Hydrology 2023, 10(7), 143; https://doi.org/10.3390/hydrology10070143 - 06 Jul 2023

Viewed by 1416

Abstract

Dense nonaqueous phase liquids (DNAPLs) are known to be denser than water and immiscible with other fluids. Once released into the environment, they migrate downward through the variably saturated zone, causing severe damage. For this reason, it is essential to properly develop a [...] Read more.

Dense nonaqueous phase liquids (DNAPLs) are known to be denser than water and immiscible with other fluids. Once released into the environment, they migrate downward through the variably saturated zone, causing severe damage. For this reason, it is essential to properly develop a rapid response strategy, including predictions of contaminant migration trajectories from numerical simulations modeling. This paper presents a series of simulations of free-product DNAPL extraction by means of a purpose-designed pumping well. The objective is to minimize the environmental impact caused by DNAPL release in the subsurface, estimating the recoverable free-product DNAPL, depending on the hydraulic properties of the aquifer medium, and estimating the leaving residual DNAPL that could act as a long-term pollution source. Coupling the numerical simulations to the bacterial community characterization (through biomolecular analyses), it was verified that (i) the DNAPL recovery (mainly PCE at the study site) through a pumping well would be almost complete and (ii) the application of other remediation techniques (such as bioremediation) would not be necessary to remove the pollution source because (iii) a natural attenuation process is provided by the autochthonous bacterial community, which is characterized by genera (such as Dechloromonas, Rhodoferax, and Desulfurivibrio) that have metabolic pathways capable of favoring the degradation of chlorinated compounds. Full article

(This article belongs to the Topic Groundwater Pollution Control and Groundwater Management)

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16 pages, 1677 KiB

Open AccessArticle

Warm Rain Analysis from Remote Sensing Data in the Metropolitan Area of Barcelona for 2015–2022

by Tomeu Rigo

Hydrology 2023, 10(7), 142; https://doi.org/10.3390/hydrology10070142 - 06 Jul 2023

Viewed by 1018

Abstract

The Metropolitan Area of Barcelona is one of the most densely populated European regions. The hydrological conditions are very extreme, as are those of the Mediterranean Basin, with long drought periods. The management of water systems is one of the priorities, implying the [...] Read more.

The Metropolitan Area of Barcelona is one of the most densely populated European regions. The hydrological conditions are very extreme, as are those of the Mediterranean Basin, with long drought periods. The management of water systems is one of the priorities, implying the understanding of the whole life cycle of water. One of the worst-known steps in this cycle corresponds to the rainfall events occurring between warm and cold periods, with quasi-tropical precipitation but with little or no lightning activity. This manuscript relies on the analysis of this type of precipitation for 2015–2022 for characterization and modelling to provide the signatures that can help diagnose these events in real time. The comparison of cold convective and warm rain events thorough radar, lightning and numerical weather prediction data has allowed us to find the main differences between both types. Warm rain events are predominant in the region, with more than 70% cases exceeding 10 mm of daily precipitation. The maritime influence is crucial in most of the warm rain episodes. Full article

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32 pages, 3724 KiB

Open AccessReview

Comprehensive Overview of Flood Modeling Approaches: A Review of Recent Advances

by Vijendra Kumar, Kul Vaibhav Sharma, Tommaso Caloiero, Darshan J. Mehta and Karan Singh

Hydrology 2023, 10(7), 141; https://doi.org/10.3390/hydrology10070141 - 30 Jun 2023

Cited by 29 | Viewed by 13540

Abstract

As one of nature’s most destructive calamities, floods cause fatalities, property destruction, and infrastructure damage, affecting millions of people worldwide. Due to its ability to accurately anticipate and successfully mitigate the effects of floods, flood modeling is an important approach in flood control. [...] Read more.

As one of nature’s most destructive calamities, floods cause fatalities, property destruction, and infrastructure damage, affecting millions of people worldwide. Due to its ability to accurately anticipate and successfully mitigate the effects of floods, flood modeling is an important approach in flood control. This study provides a thorough summary of flood modeling’s current condition, problems, and probable future directions. The study of flood modeling includes models based on hydrologic, hydraulic, numerical, rainfall–runoff, remote sensing and GIS, artificial intelligence and machine learning, and multiple-criteria decision analysis. Additionally, it covers the heuristic and metaheuristic techniques employed in flood control. The evaluation examines the advantages and disadvantages of various models, and evaluates how well they are able to predict the course and impacts of floods. The constraints of the data, the unpredictable nature of the model, and the complexity of the model are some of the difficulties that flood modeling must overcome. In the study’s conclusion, prospects for development and advancement in the field of flood modeling are discussed, including the use of advanced technologies and integrated models. To improve flood risk management and lessen the effects of floods on society, the report emphasizes the necessity for ongoing research in flood modeling. Full article

(This article belongs to the Special Issue Recent Advances in Water and Water Resources Engineering)

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13 pages, 3674 KiB

Open AccessArticle

Effects of a Gravel Pit Lake on Groundwater Hydrodynamic

by Janja Vrzel, Hans Kupfersberger, Carlos Andres Rivera Villarreyes, Johann Fank and Leander Wieser

Hydrology 2023, 10(7), 140; https://doi.org/10.3390/hydrology10070140 - 30 Jun 2023

Viewed by 1633

Abstract

In Europe, 1132 Mt of sand and gravel were mined in 2019, which causes major changes to the hydrogeological cycle. Such changes may lead to significantly raised or lowered groundwater levels. Therefore, the aggregate sector has to ensure that impacts on existing environmental [...] Read more.

In Europe, 1132 Mt of sand and gravel were mined in 2019, which causes major changes to the hydrogeological cycle. Such changes may lead to significantly raised or lowered groundwater levels. Therefore, the aggregate sector has to ensure that impacts on existing environmental and water infrastructures are kept to a minimum in the post-mining phase. Such risk assessments are often made by empirical methods, which are based on assumptions that do not meet real aquifer conditions. To investigate this effect, predictions by empirical and numerical methods about hydraulic head changes caused by a pit lake were compared. Wrobel’s equation, which is based on Sichardt’s equation, was used as the empirical method, while a numerical groundwater flow model has been solved by means of the finite-element method in FEFLOW. The empirical method provides significantly smaller ranges of increased/decreased groundwater levels caused by the gravel pit lake as the numerical method. The underestimation of the empirical results was related to the finding that field measurements during pumping tests show a larger extent of groundwater drawdown than calculations with the Sichardt’s equation. Simplifications of the 2D model approach have been evaluated against hydraulic head changes derived from a 3D groundwater model. Our results clearly show that the faster and cheaper empirical method—Wrobel’s equation, which is often preferred over the more expensive and time-consuming numerical method, underestimates the drawdown area. This is especially critical when the assignment of mining permits is based on such computations. Therefore, we recommend using numerical models in the pre-mining phase to accurately compute the extent of a gravel/sand excavation’s impacts on hydraulic head and hence more effective protection of groundwater and other related environmental systems. 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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19 pages, 3907 KiB

Open AccessArticle

Predictive MPC-Based Operation of Urban Drainage Systems Using Input Data-Clustered Artificial Neural Networks Rainfall Forecasting Models

by Fatemeh Jafari, S. Jamshid Mousavi and Kumaraswamy Ponnambalam

Hydrology 2023, 10(7), 139; https://doi.org/10.3390/hydrology10070139 - 29 Jun 2023

Viewed by 1499

Abstract

The model predictive control (MPC) approach can be implemented in either a reactive (RE-) or predictive (PR-) manner to control the operation of urban drainage systems (UDSs). Previous research focused mostly on the RE-MPC, as the PR-MPC, despite its potential to improve the [...] Read more.

The model predictive control (MPC) approach can be implemented in either a reactive (RE-) or predictive (PR-) manner to control the operation of urban drainage systems (UDSs). Previous research focused mostly on the RE-MPC, as the PR-MPC, despite its potential to improve the performance of the UDS operations, requires additional computational resources and is more complex. This research evaluates the conditions under which the PR-MPC approach may be preferable. A PR-MPC model is developed, consisting of an adaptive input data-clustered ANN-based rainfall forecasting method coupled to an MPC framework. Observed and forecasted rainfall events are inputs to the internal MPC model, including the rainfall-runoff SWMM simulation model of the system and the MPC optimizer, which is a harmony search-based model determining optimal control policies. The proposed model was used as part of the UDS of Tehran, Iran, under different scenarios of input (rainfall), forecast accuracy (IFAC), and time horizon (IFTH). Results indicate that the PR-MPC performs better for longer-duration rainfall events, while the RE-MPC could be used to control very short storm occurrences. The proposed PR-MPC model can achieve between 85 and 92% of the performance of an ideal model functioning under the premise of perfect, error-free rainfall forecasts for two investigated rainfall events. Additionally, the IFAC can be improved by including rainfall fluctuations over finer temporal resolutions than the forecast horizon as additional predictors. Full article

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12 pages, 2890 KiB

Open AccessArticle

Streamflow Reconstructions Using Tree-Ring-Based Paleo Proxies for the Sava River Basin (Slovenia)

by Glenn Tootle, Abdoul Oubeidillah, Emily Elliott, Giuseppe Formetta and Nejc Bezak

Hydrology 2023, 10(7), 138; https://doi.org/10.3390/hydrology10070138 - 28 Jun 2023

Cited by 2 | Viewed by 1278

Abstract

The Sava River Basin (SRB) extends across six countries (Slovenia, Croatia, Bosnia and Herzegovina, Serbia, Albania, and Montenegro) and is a major tributary of the Danube River (DR). The Sava River (SR) originates in the alpine region of Slovenia, and, in support of [...] Read more.

The Sava River Basin (SRB) extends across six countries (Slovenia, Croatia, Bosnia and Herzegovina, Serbia, Albania, and Montenegro) and is a major tributary of the Danube River (DR). The Sava River (SR) originates in the alpine region of Slovenia, and, in support of a Slovenian government initiative to increase clean, sustainable energy, multiple hydropower facilities have been constructed within the past ~20 years. Given the importance of this river system for varying demands, including energy production, information about past (paleo) drought and pluvial periods would provide important information to water managers and planners. Seasonal (April–May–June–July–August–September—AMJJAS) streamflow data were obtained for two SRB gauges (Jesenice and Catez) in Slovenia. The Jesenice gauge is in the extreme headwaters of the SR, upstream of any major water control structures, and is considered an unimpaired (minimal anthropogenic influence) gauge. The Catez gauge is located on the SR near the Slovenia–Croatia border, thus providing an estimate of streamflow leaving Slovenia (entering Croatia). The Old World Drought Atlas (OWDA) provides an annual June–July–August (JJA) self-calibrating Palmer Drought Severity Index (scPDSI) derived from 106 tree-ring chronologies for 5414 grid points across Europe from 0 to 2012 AD. In lieu of tree-ring chronologies, this dataset was used as a proxy to reconstruct (for ~2000 years) seasonal streamflow. Prescreening methods included the correlation and temporal stability of seasonal streamflow and scPDSI cells. The retained scPDSI cells were then used as predictors (independent variables) to reconstruct streamflow (predictive and/or dependent variables) in regression-based models. This resulted in highly skillful reconstructions of SRB seasonal streamflow from 0 to 2012 AD. The reconstructions were evaluated, and both low flow (i.e., drought) and high flow (i.e., pluvial) periods were identified for various filters (5-year to 30-year). When evaluating the most recent ~20 years (2000 to present), multiple low-flow (drought) periods were identified. For various filters (5-year to 15-year), the 2003 end-year consistently ranked as one of the lowest periods, while the 21-year period ending in 2012 was the lowest flow period in the ~2000-year reconstructed-observed-historic period of record. The ~30-year period ending in 2020 was the lowest flow period since the early 6th century. A decrease in pluvial (wet) periods was identified in the observed-historic record when compared to the paleo record, again confirming an apparent decline in streamflow. Given the increased activities (construction of water control structures) impacting the Sava River, the results provide important information to water managers and planners. Full article

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26 pages, 6617 KiB

Open AccessArticle

Statistical Approach for Computing Base Flow Rates in Gaged Rivers and Hydropower Effect Analysis

by Andrés F. Villalba-Barrios, Oscar E. Coronado-Hernández, Vicente S. Fuertes-Miquel, Jairo R. Coronado-Hernández and Helena M. Ramos

Hydrology 2023, 10(7), 137; https://doi.org/10.3390/hydrology10070137 - 27 Jun 2023

Cited by 1 | Viewed by 1202

Abstract

The calculation of base flow rates in rivers is complex since hydrogeological and hydrological studies should be performed. The estimation of base flow rates in storm hydrograph associated to various return periods is even more challenging compared to other events. This research provides [...] Read more.

The calculation of base flow rates in rivers is complex since hydrogeological and hydrological studies should be performed. The estimation of base flow rates in storm hydrograph associated to various return periods is even more challenging compared to other events. This research provides a novel methodology to compute base flow rates in gaged rivers for extreme events based on statistical correlations of daily flows. The current methodology does not require complex aquifers analysis to compute base flows. Results of computed base flow rates are validated using observed storm hydrographs using a complete record. The proposed methodology was applied considering measurements of a limnigraphic station in the Sinú river located in Montería, Córdoba, Colombia. The analysis confirmed that only using series of multiannual monthly mean flows is possible to estimate base flow of flood hydrograph associated to different return periods. Full article

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22 pages, 71383 KiB

Open AccessArticle

Comparison of the Fuzzy Analytic Hierarchy Process (F-AHP) and Fuzzy Logic for Flood Exposure Risk Assessment in Arid Regions

by Husam Musa Baalousha, Anis Younes, Mohamed A. Yassin and Marwan Fahs

Hydrology 2023, 10(7), 136; https://doi.org/10.3390/hydrology10070136 - 26 Jun 2023

Cited by 5 | Viewed by 1961

Abstract

Flood risk assessment is an important tool for urban planning, land development, and hydrological analysis. The flood risks are very high in arid countries due to the nature of the rainfall resulting from thunderstorms and the land cover, which comprises mostly very dry [...] Read more.

Flood risk assessment is an important tool for urban planning, land development, and hydrological analysis. The flood risks are very high in arid countries due to the nature of the rainfall resulting from thunderstorms and the land cover, which comprises mostly very dry arid soil. Several methods have been used to assess the flood risk, depending on various factors that affect the likelihood of occurrence. However, the selection of these factors and the weight assigned to them remain rather arbitrary. This study assesses the risk of flood occurrence in arid regions based on land cover, soil type, precipitation, elevation, and flow accumulation. Thematic maps of the aforementioned factors for the study area were prepared using GIS. The Fuzzy Analytic Hierarchy Process (F-AHP) was used to calculate the likelihood of the flood occurrence, and land use was used to assess the exposure impact. Using the likelihood map (i.e., probability) from the Fuzzy-AHP and an exposure map, the flood risk was assessed. This method was applied to Qatar as a case study. Results were compared with those produced by fuzzy logic. To explore the pairwise importance of the F-AHP, equal weight analysis was performed. The resulting risk map shows that the majority of urbanized areas in Qatar are within the high-risk zone, with some smaller parts within the very high flood-risk area. The majority of the country is within the low-risk zone. Some areas, especially land depressions, are located within the intermediate-risk category. Comparison of Fuzzy logic and the F-AHP showed that both have similarities in the low-risk and differences in the high-risk zones. This reveals that the F-AHP is probably more accurate than other methods as it accounts for higher variability. Full article

(This article belongs to the Special Issue Water Resources Management under Uncertainty and Climate Change)

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Hydrology, Volume 10, Issue 7 (July 2023) – 21 articles

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