Amount Of Water Research Articles

Control of overflows in interception wells based on water quantity and quality in rainwater pipelines for reducing pollution to rivers

ABSTRACT The separate sewer system has led to severe river pollution because of domestic sewage infiltrations and initial rainfall pollution. Therefore, interception wells (IWs) are installed to divert sewage to the wastewater treatment plant but similarly contribute to overflow-induced river pollution on rainy days. The aim of the present study is to propose a control strategy for the regulation of IWs’ overflow based on the online monitoring data, control measures, and software simulation. The results indicate that during light rain, overflow from the IWs is minimal, requiring no control measures. However during heavy rainfall, the overflow of sewage leads to an increase in the river’s concentration of NH3-N from 0.25 to 3.04 mg/L. Finally, Simulations demonstrate a reduction in river NH3-N levels from 2.27 to 1.33 mg/L after implementation. The results indicated the substantial effectiveness of measures in mitigating the pollution originating from IWs’ overflows during rainfall events.

Upscaling irradiation protocols of Aedes albopictus pupae within an SIT program in Reunion Island.

The implementation of the sterile insect technique against Aedes albopictus relies on many parameters, in particular on the success of the sterilization of males to be released into the target area in overflooding numbers to mate with wild females. Achieving consistent sterility levels requires efficient and standardized irradiation protocols. Here, we assessed the effects of exposure environment, density of pupae, irradiation dose, quantity of water and location in the canister on the induced sterility of male pupae. We found that the irradiation of 2000 pupae in 130ml of water and with a dose of 40Gy was the best combination of factors to reliably sterilize male pupae with the specific irradiator used in our control program, allowing the sterilization of 14000 pupae per exposure cycle. The location in the canister had no effect on induced sterility. The results reported here allowed the standardization and optimization of irradiation protocols for a Sterile Insect Techniqueprogram to control Ae. albopictus on Reunion Island, which required the production of more than 300,000 sterile males per week.

Effect of agriculture on surface water quantity and quality in Gilgel Gibe watershed, southwestern Ethiopia.

Monitoring water quality and quantity is crucial to be sure that water resources are sustainably used. However, there is no monitoring system of water quantity and quality in southwestern Ethiopia, despite expansion of agricultural activities demanding water resources. The objective of this study was to investigate the effect of agriculture on water quantity and quality with special emphasis on irrigation in southwestern Ethiopia. Data of water quantity was collected from four rivers and four irrigation canals during dry season of 2023. Physico-chemical water quality data was collected from 35 sites. Water quantity was calculated by estimating the water discharge of the rivers and irrigation canals. Weighted arithmetic water quality index was calculated to assess the status of the studied rivers. Principal component analysis was used to identify the relation of the sites with water quality parameters. This study revealed that the average amount of abstracted water for irrigation from the four studied rivers was 22,399 m3/day during the studied period, and the average percentage of abstracted water was 17%. Sites downstream of the irrigation site were characterized by poor water quality compared with the upstream sites. Sites surrounded by agricultural land use were correlated with chemical oxygen demand, electric conductivity, nitrate, orthophosphate, water temperature, and pH, whereas all sites surrounded by forest were positively correlated with dissolved oxygen. This study indicates that agricultural activities have a negative impact on surface water quality and quantity if not managed properly. Hence, we recommend sustainable use of water resources for the planned irrigation expansion.

Effectiveness of Hapa as Small Rainwater Harvesting Ponds for Sustainable Agricultural Development in Diversified Arid Regions: Comparative Case Studies From Bankura in India

Water is a unique constituent, which is essential for the survival of humans, animals and plants. Agriculture needs water in large quantities. Supplying irrigation water is a crucial factor in preserving groundwater, determining the water balance and subsequent cropping pattern of any region. The challenge is even greater when it is dryland. The present study is confined to the Bankura district, the arid region of West Bengal in India. Here, for irrigation, small customised ponds, known as hapa, are dug up by individual farmers to store the rainwater. The government encourages farmers by providing funds for hapa creation. In the last 10 years, about 2900 hapas, which can harvest a large quantity of water, have been dug up in croplands. This harvested water indirectly helps in recharging groundwater too. The present study aims to highlight the need for hapas in such arid regions. This study demonstrates a positive link between hapa creation with changing land use land cover patterns, increasing agricultural areas, growing population, and declining rainfall patterns. In support of this, spatial and statistical analyses were performed according to certain key remote sensing indices VCI, NDWI, and Z Scores of the pre-hapa and post-hapa creation periods. The study found that the implementation of the hapa irrigation technique has significantly increased the yield of crops besides generating agricultural labour. Land owners started cultivating multiple crops on their lands which helped to increase annual income. The complete research shows the noteworthiness of hapa irrigation technique as an alternative to a sustainable development programme in arid areas.

Cost prediction for water reuse equipment using interpretable machine learning models

During the initial stages of engineering projects management, the accurate estimation of equipment costs plays a crucial role in determining project approval decisions. However, there is a significant research gap regarding the estimation of investment costs for water reuse equipment. Additionally, cost predictions for such construction projects often suffer from limitations, including low accuracy, limited generalizability, and inefficiency. Advanced machine learning (ML) methods, renowned for their ability to model complex decision-making processes, offer powerful solutions. In this study, four traditional models and four ensemble models were employed to predict the cost of water reuse equipment. The results demonstrated that the ensemble models exhibited significantly superior predictive performance to that of traditional models with the three boosting ensemble models achieving the best performance (traditional models: training R2 = 29.77 %–94.85 %, testing R2 = 30.62 %–71.72 %; boosting ensemble models: training R2 = 97.42 %, testing R2 = 82.16 %–93.79 %). Furthermore, this study simplified the features of predictive models and identified the key variables that influence the cost of water reuse equipment using Shapley additive explanations (SHAP) method. The retrained ensemble models re-constructed based on the selected variables achieved significant predictive performance, with the Gradient Boosting Decision Tree (GBDT) outperforming the other models (training set R2 = 97.37 %, testing set R2 = 93.86 %). The water quantity, inflow conductivity, outflow conductivity, and recovery rate emerged as critical factors affecting the cost of water reuse equipment. Overall, the methods proposed in this study can enhance the versatility of cost prediction processes in environmental engineering scenarios, particularly those concerning the construction costs of water treatment equipment.

Spatiotemporal drivers of Nature's contributions to people: A county-level study

Nature's contributions to people (NCP) encompass both the beneficial and detrimental effects of living nature on human quality of life, including regulatory, material, and non-material contributions. Globally, vital NCPs have been deteriorating, accelerated by changes in both natural and anthropogenic drivers over recent decades. Despite the often inevitable trade-offs between NCPs due to their spatially and temporally uneven distributions, few studies have quantitatively assessed the impacts of different drivers on the spatial and temporal changes in multiple NCPs and their interrelationships. Here we evaluate the effects of precipitation, temperature, population, gross domestic product, vegetation restoration, and urban expansion on four key regulatory NCPs—habitat maintenance, climate regulation, water quantity regulation, and soil protection—in Nei Mongol at the county level. We observe increasing trends in climate regulation and soil protection from 2000 to 2019, contrasted with declining trends in habitat maintenance and water quantity regulation. We have identified the dominant positive and negative drivers influencing each NCP across individual counties, finding that natural drivers predominantly overpowered anthropogenic drivers. Furthermore, we discover significant spatial disparities in the trade-off or synergy relationships between NCPs across the counties. Our findings illustrate how the impacts of various drivers on NCPs and their interrelationships can be quantitatively evaluated, offering significant potential for application in various spatial scales. With an understanding of trade-offs and scale effects, these insights are expected to support and inform policymaking at both county and provincial levels.

Experimental combustion characteristics and NOx emissions for a 600‐MWe utility boiler after the retrofitted: Effects of load variation

AbstractTo enhance the rapid switching ability of the boiler load and reduce NOx emissions, a new combustion system was implemented in a 600‐MWe wall‐fired boiler with swirl burners. This system included two levels of overfire air (OFA) and low NOx combustion technology. Industrial tests were conducted at 300‐, 450‐, and 600‐MWe loads before and after the retrofitted. These tests included measuring flue gas and furnace temperatures with thermocouples and analyzing local gas concentrations using a gas analyzer. The research results indicate that under conditions where the OFA ratio exceeds 30%, the burner exhibits good ignition performance at different loads. At the 600‐MWe load, the nitrogen oxides (NOx) emissions were reduced by 55% compared to before the retrofit. After the retrofit, the flame center inside the furnace of different loads was located at the height of 33.36 m, the first and second‐stage cooling water quantities were slightly higher, the reheat cooling water quantity was greatly reduced after the retrofit, and contributes to the boiler's safe operation. Under different load conditions after the retrofit, the gas temperature near the sidewall was below 850°C, and the O2 concentration near the sidewall was above 5%, effectively suppressing sidewall high‐temperature corrosion and slagging.

Planning the Liveable If Not the Ideal: Frontline Planners’ Discretionary Actions and Inequalities in Everyday Intermittent Water Supply Planning in Tiruppur, India

Millions of urbanites across the Global South receive intermittent water supply (IWS). This paper examines how discretionary action by street-level bureaucrats (SLBs) in everyday water supply planning in IWS systems redistributes water quantities and service quality to alleviate unequal scarcity burdens. Ethnographic findings from the small city of Tiruppur, India, reveal that SLBs’ supply plans aim to distribute water volumes equitably within the network. However, SLBs’ communicative strategies to manage socio-material uncertainties and improve supply predictability, a critical dimension of service quality, reinforce existing socio-spatial inequalities. Rethinking SLBs’ contradictory discretionary actions in everyday water supply plans is crucial for managing water scarcity equitably in the IWS systems of Global South cities.

The Effects of Climate Change on Streamflow, Nitrogen Loads, and Crop Yields in the Gordes Dam Basin, Turkey

The Mediterranean region is highly vulnerable to climate change. Longer and more intense heatwaves and droughts are expected. The Gordes Dam in Turkey provides drinking water for Izmir city and irrigation water for a wide range of crops grown in the basin. Using the Soil and Water Assessment Tool (SWAT), this study examined the effects of projected climate change (RCP 4.5 and RCP 8.5) on the simulated streamflow, nitrogen loads, and crop yields in the basin for the period of 2031–2060. A hierarchical approach to define the hydrological response units (HRUs) of SWAT and the Fast Automatic Calibration Tool (FACT) were used to reduce computational time and improve model performance. The simulations showed that the average annual discharge into the reservoir is projected to increase by between 0.7 m3/s and 4 m3/s under RCP 4.5 and RCP 8.5 climate change scenarios. The steep slopes and changes in precipitation in the study area may lead to higher simulated streamflow. In addition, the rising temperatures predicted in the projections could lead to earlier spring snowmelt. This could also lead to increased streamflow. Projected nitrogen loads increased by between 8.8 and 25.1 t/year. The results for agricultural production were more variable. While the yields of poppy, tobacco, winter barley, and winter wheat will increase to some extent because of climate change, the yields of maize, cucumbers, and potatoes are all predicted to be negatively affected. Non-continuous and limited data on water quality and crop yields lead to uncertainties, so that the accuracy of the model is affected by these limitations and inconsistencies. However, the results of this study provide a basis for developing sustainable water and land management practices at the catchment scale in response to climate change. The changes in water quality and quantity and the ecological balance resulting from changes in land use and management patterns for economic benefit could not be fully demonstrated in this study. To explore the most appropriate management strategies for sustainable crop production, the SWAT model developed in this study should be further used in a multi-criteria land use optimization analysis that considers not only crop yields but also water quantity and quality targets.

Association Between Demographic Characteristics of Users’ and Overall Satisfaction with Water Supply Service

Water constitutes an indispensable resource for various aspects of daily life, encompassing essential needs such as drinking, cooking, sanitation, and irrigation. Beyond household applications, diverse livelihood activities, including livestock management, gardening, crop cultivation, food processing, aquaculture, and fisheries, also rely on water. The assessment of customer satisfaction holds paramount significance in driving performance enhancements for service providers, even within government-owned entities offering critical services like water supply. This research aims to scrutinize the interplay between overall satisfaction with water services and its determinants, including satisfaction with water quality, and various parameters such as water supply hours, tap pressure, supplied water quantity, management responsiveness and communication, and water tariff. Anticipatedly, water supply hours, quantity, and quality are expected to exert a crucial influence on user satisfaction. Although users express a satisfaction level above neutral, it falls short of reaching a fully satisfactory level. Key contributors to user satisfaction involve aspects such as water supply hours, pressure, quantity, and quality, while complaints about water supply yield slightly lower satisfaction. Satisfaction with water service hours, quantity, and quality emerges as a driving force for overall satisfaction. The analysis reveals no significant association between overall satisfaction and demographic variables such as occupation, gender, age, education, and the main income source. However, a noteworthy association exists between satisfaction with water pressure and the water collection method, and a robust link is observed between satisfaction with water quality and respondents' water treatment practices. The provision for complaints is significantly associated with satisfaction regarding management responsiveness and communication. Multiple regression analysis underscores a positive relationship between overall satisfaction with water services and satisfaction with water quality and supply hours, indicating that higher satisfaction with these factors enhances overall satisfaction with water services.

An assessment of the water footprint of the population and agricultural crops in the natura 2000 site ROSCI0434 siretul mijlociu, Romania

The designation of a Natura 2000 site ROSCI0434 Siretul Mijlociu for the protection of habitats and species, whose development is closely tied to the aquatic environment, signifies that the management of water resources, and implicitly, the water footprint, has contributed to maintaining a balanced and favorable status for biodiversity conservation. Given that the Natura 2000 site was declared based on older studies, and the Management Plan for the protected natural area was not yet developed, we are now conducting an assessment of the impact of the water footprint in the current climatic conditions. This includes considering other predominant types of agricultural crops and changes in food habits. This evaluation aims to understand the relationship between the water footprint and the conservation status of species and habitats in light of these new circumstances.The blue and grey water components of the water footprint are the ones that directly affect the natural protected area out of the three components of the water footprint: green, blue, and grey water. The ecological impact of water use in ROSCI0434 Siretul Mijlociu is extensive, affecting both terrestrial and aquatic ecosystems. Pollutants can harm habitats and species, while agricultural water usage alters habitats and disrupts hydrological patterns, impacting breeding and foraging grounds. Additionally, changes in water quantity and quality diminish ecosystem services like water purification and habitat provision, affecting biodiversity and human well-being.

GIS-based groundwater potential zonation and assessment of groundwater quality and suitability for drinking and irrigation purposes in the Shanmughanadhi river basin, south India

To develop a specific watershed scenario, the quantity and quality of groundwater resources must be assessed and monitored locally. In the present study, an attempt has been made to identify possible groundwater potential zones, determine the quality of groundwater resources in this region, and evaluate their suitability for drinking and irrigation purposes. This goal has been achieved with the combined use of the weighted index overlay analysis (WIOA), groundwater quality index (GWQI), Remote Sensing (RS), and Geographic Information System (GIS) techniques. The proposed study area, Shanmuganadhi, is marked with superior rainfall, oscillating temperature, and runoff with litho-units encompassing charnockite (CHK) and hornblende biotite gneiss (HBG). Over-abstraction of groundwater and intensive agricultural practices have resulted in declining and degrading water quantity and quality in this area. The resulting integrated thematic map has been classified into five groundwater potential zones, namely poor, low, moderate, high, and very high, covering 3.2, 45.49, 15.3, 27.9, and 8.1% area, respectively. Sixty groundwater samples were collected during the pre-monsoon (PRM) and analyzed for major Physico-chemical parameters. From the water quality index assessment, over 28.0% of the samples fall within the “excellent,” 8.0% “good” and 4.0% “poor” in CHK, followed by 5.71% “excellent,” 48.57% “good,” 37.14% “poor,” 5.71% “very poor” and 2.87% “unsuitable” for drinking purposes in HBG terrain of this region. Irrigation indices also demonstrated that most of the groundwater samples in the CHK and HBG exposed zones exhibited good classes for irrigation purposes, as evidenced by the SAR and %Na+. The outcome, which shows the research area's groundwater potential zones, is beneficial for improved groundwater resource planning and management. It is concluded that for larger-scale groundwater-quality investigation and assessment, the groundwater quality index-making approach (GWQI) is more practical and dependable. Water planners and decision-makers may find it helpful in effectively controlling and monitoring groundwater quality at the basin or watershed scale. Reducing urban land use and natural runoff from farms can help prevent water contamination in some regions. To ensure the safe use of groundwater, long-term monitoring of these groundwater was suggested.

A qualitative risk assessment model for water reuse: Risks related to agricultural irrigation in Brazil

Urbanization and industrialization are increasing extreme weather events, causing water quantity and quality reduction. Global water scarcity impacts 32.5 % of the urban population and is growing. Brazil has also witnessed water scarcity, notably in the southeast (2014–2015) and south (2019–2020), with reservoirs dropping below 20 % capacity. Water reuse is vital for mitigating scarcity, though it presents risks due to contaminants. Risk analysis studies are crucial for evaluating contamination sources, pathways, and exposure scenarios in water reuse practices. Various methodologies, including quantitative, semi-quantitative, and qualitative analyses, can be employed. Given the uncertainty and diverse factors, qualitative methods are recommended for non-potable water reuse risk analysis. This work presents a qualitative risk analysis methodology that allows to evaluate non-potable water reuse categories. It assesses factors affecting human health and the environment, considering exposure scenarios, characteristics of the receptors, and sources of reused water. The risk analysis of water reuse was carried out focusing on agricultural reuse, considering as alternatives the irrigation of soybean and sugarcane crops. By reviewing literature, the probability of occurrence and the magnitude of impact of the risk factors were identified and rated, using an increasing relative numeric scale. This process resulted in an overall risk value for comparing agricultural irrigation alternatives. The obtained results indicate a promising risk analysis model that can be adjusted and applied to various water reuse modalities and key factors. This adaptable risk analysis model is mainly related to water treatment methods, prompting the proposal of risk control measures.

Remoción y balance de masa en un reactor UASB en el tratamiento de agua residual de una industria chocolatera

Treatment is currently necessary for municipal and industrial wastewaters, given the decli- ning quantity and quality of available water. An anaerobic biological reactor is a suitable option for wastewater treatment because it generates biogas which contains methane, a potential source of energy. The objective of this research was to treat wastewa- ter from a chocolate industry with an applied organic loading rate (OLRappl) of 4.5 kg of chemical oxygen demand (COD)/m3/d and a hydraulic retention time (HRT) of 10.3 h to obtain both, the removal efficiency, and the mass balance in terms of COD. Even though there were variations in the OLRappl and the TRH, the average removal efficiency of COD was 91%. The cal- culated mass balance in terms of COD was close to 100%.

OPTIMIZING WATER USAGE: THE IMPACT OF ALCOHOL HAND RUBS IN LOWER LIMB PRIMARY ARTHROPLASTY

Alcohol hand rubs, endorsed by WHO and NICE guidelines, are integral to modern surgical practices. Our objective was to assess how different scrubbing methods impact overall water usage by the surgical team, shedding light on variations among team members and their environmental implications.Over three consecutive arthroplasty lists spanning a week, water usage during scrubbing was observed for the operating team. Blinding all team members, including the anesthetist, consultant surgeon, orthopaedic registrar, orthopaedic SHO, and scrub nurse, during water usage calculations was implemented. Automated taps, using motion sensors, posed a challenge due to variable water quantity, necessitating water flow calculations per sensor movement. The senior surgeon, with over 20 years of experience, follows a traditional approach, starting with a morning prescrub and using an alcohol tub for each case, except when hands are soiled.We observed a total of 14 cases of lower limb primary arthroplasty. The cumulative water usage for scrubbing by the entire team was 193 liters, yielding a mean of 13.8 liters (±1.85) per case. The anaesthetist demonstrated the most conservative water usage, utilizing a total of 11.85 liters with a mean of 0.84 liters per case. Notably, alcohol rub was employed for half of the observed time, contributing to this efficient use. The senior operating surgeon used a total of 15.6 liters, averaging 1.1 liters per case. In contrast, the SHO and the registrar exhibited the highest water consumption, totaling 121.6 liters and yielding a mean of 5.7 liters per case. The nurses’ collective water usage for scrubbing amounted to 44.8 liters.Adopting alcohol rub, as endorsed by WHO, results in a remarkable 10-fold reduction in water usage, aligning with global health guidelines. This highlights significant potential for resource conservation in surgical procedures, presenting a practical and environmentally conscious approach to surgical scrubbing practices.

Is the World Running Out of Fresh Water?

The quantity of water within Earth and its atmosphere is fixed over time, but water available for human consumption evolves dynamically. We use globally comprehensive geospatial data to establish stylized facts about recent changes in global water resources and potential implications for human welfare. We show that the net change in water volume on arable lands—which account for 90 percent of human water consumption—is almost exactly zero. Rapid water loss is concentrated in regions with large populations, low existing water resources, and low agronomic potential. Incorporating trade data shows that water-scarce regions are net importers of water-intensive goods.

Unlocking the potential of ponds and pondscapes as nature-based solutions for climate resilience and beyond: Hundred evidences

Unlocking the full potential of ponds (small water bodies) and pondscapes (network of ponds) as Nature-based Solutions (NbS) is critical pursuit for enhancing ecosystems and societal resilience to climate change and other societal challenges. Despite scattered initiatives for pond/pondscape creation, restoration and management—each considered here a distinct NbS—there is a significant knowledge gap in utilising ponds/pondscapes as effective NbS. We aimed to assess these NbS in terms of their objectives, outcomes, effectiveness, multifunctionality, delivery of potentially conflicting effects, and the implementation process while considering their Nature's Contributions to People (NCPs, i.e., benefits to society). We compiled data on 183 NbS actions implemented across 93 ponds/pondscapes from 24 countries, predominantly from Europe, via a questionnaire distributed to experienced stakeholders implementing NbS in ponds/pondscapes. One single pond/pondscape may imply more than one NbS action. Two-thirds were in rural areas, and one-third in urban settings. Our analysis revealed that Creation of habitat for biodiversity was a primary delivery objective (targeted NCP) in the implementation of most NbS in ponds/pondscapes, often also combined with other NCPs such as Learning and inspiration, Regulation of water quantity, and Physical and psychological experiences, showcasing their intended multifunctionality. Implemented NbS primarily focused on climate change adaptation (especially Regulation of hazards and extreme events, and water quantity) rather than mitigation, with less emphasis on measures like direct greenhouse gas emissions reduction or enhancing carbon sinks. The costs associated with pond's NbS varied significantly depending on factors such as project scope, objectives, location, socio-economic-cultural system, and specific implementation requirements. The creation of ponds/pondscapes often entailed the highest financial investment, much more than their restoration or their management. In conclusion, our study underscores the multifunctionality of ponds/pondscapes and provides insights about their significant potential as cost-effective NbS for enhancing ecosystem and societal resilience to climate change and biodiversity. It underscores the importance of further research to fully understand and measure the diverse range of NbS they offer, particularly in the context of climate change mitigation. Standardised measurements of the NCP provided by these NbS in ponds/pondscapes are essential for validating managers' claims and exploring their role in addressing climate change.

Analysis of the water temperature and quality characteristics of the Daheiting Reservoir based on coupled hydrology–hydrodynamic–water quality simulations

To analyse the influence of nonpoint source pollution on the water quality in the Daheiting Reservoir, based on measured hydrological and water quality data, a coupled hydrological model for the Panjiakou-Daheiting interval basin and a two-dimensional vertical hydrodynamic and water quality model for the Daheiting Reservoir were constructed. The water quantity and water quality output results of the upstream hydrological model (Soil and Water Assessment Tool, SWAT) were input into the reservoir hydrodynamic-water quality model (CE-QUAL-W2) as boundary conditions. The annual distribution of pollutants in the reservoir was simulated and analysed. The results showed that nutrients such as nitrate nitrogen and phosphate in the reservoir area were stratified, and there were seasonal differences due to the water temperature, dissolved oxygen and upstream inflow. After lowering upstream pollution emissions, the water quality in the reservoir was improved significantly, and compared to that of reducing point source pollution, the effect of reducing nonpoint source pollution is more obvious.

A holistic analysis of Chinese sponge city cases by region: Using PLS-SEM models to understand key factors impacting LID performance

Sponge city is a national sustainable stormwater management program proposed by the Chinese government to deal with urban water issues (e.g., flooding, poor water quality) brought on by climate change and urbanization. Various strategies for sponge city construction are required since environmental constraints differ regionally across the country. To identify regional variations, reveal the inner links between externalities and design elements in sponge city construction, and offer practical suggestions, efforts in two directions are made based on the data of 68 sponge city cases around China: 1) discussing design parameters of four Low Impact Development (LID) facilities, including bioretention cell, permeable pavement, grass swale, and sunken green space, under four regionalization maps of hydrologic, climatic, landform and soil texture factors, and 2) building a holistic Partial Least Squares-Structural Equation Modelling (PLS-SEM) model illustrating the relationship between local characteristics, LID system design, and LID system performance in sponge city construction. The results show that: 1) rainfall and landform factor have great impact on LID facilities design, as their depths tend to be higher in water rich areas and coastal areas. 2) LID types and areas are positively influenced (+0.745) by the total area and permeable portion of a project, while the LID system performance (water quantity and quality control) is negatively impacted (−0.407) by the rainfall amount and clay fraction. 3) comprehensive LIDs choice and design instead of single LID facility shows more significant effect on improving LID system performance. It is recommended to establish different design standards and assessment indexing systems tailored to local environment when constructing sponge city projects.

Localizing and quantifying groundwater‐surface water interactions at different scales: A tracer approach at the River Moselle, Germany

AbstractGroundwater‐surface water interactions (GSI) connect rivers and streams with riparian areas and the adjacent aquifer. Although these interactions exert a substantial control of quantity and quality of both groundwater and surface water, knowledge on GSI along rivers at the regional scale, particularly for inland waterways, is still limited. We investigated GSI along the river Moselle, an important federal inland waterway in Germany, by using radon and tritium to identify gaining (water flux from the aquifer to the surface water) and losing (water flux from the surface water to the aquifer) stream conditions, respectively. Gaining stream conditions were identified by continuously measuring radon along the river during boat surveys with a high spatial resolution (every 2 km) during intermediate (October 2020) and near low flow conditions (August/September 2021). The tritium concentrations in surface water and groundwater and the resulting tritium inventories were used to characterize losing stream conditions Monthly tritium inventories from 2017 to 2022 revealed a mean loss for the whole period of 20.3 % and a mean gain of 21.8%. Both were probably triggered by a combination of losing stream conditions and flood‐induced mass transfer of water from the aquifer back into the river as well as discharge fluctuations. At the investigated site Lehmen there were direct indications of an influence of surface water due to elevated tritium concentrations in the groundwater (up to 13.3 Bq L−1). Using radon mass balance modelling, good agreements of simulated versus measured radon data with respect to two groundwater end‐member scenarios were obtained during intermediate flow (Spearman's ρ: 0.97 and 0.99; MAE: 10.1 and 3.4 Bq L−1) and near low flow (Spearman's ρ: 0.97 and 0.99; MAE: 11 and 6.5 Bq L−1). Considerable groundwater inflow was limited to the meander of Detzem, where cumulated groundwater inflow of about 19 m3 s−1 (9.5% of total discharge) and 4.2 m3 s−1 (3.8% of total discharge) was simulated during intermediate and near low flow, respectively. However, the groundwater inflow was relatively low compared to alpine streams, for example. The study will help to better identify and quantify GSI at the regional scale and provide methodological guidance for future studies focusing on inland waterways.