Search Results (25)

Urbanization is known to increase the volume of stormwater runoff and peak flow rates, which leads to changes in the natural flow regime and increases the likelihood of flooding. Low-impact development (LID) practices seek to reduce runoff volume and peak flow and are generally considered to be a more sustainable solution for urban stormwater management. In this study, we present a systematic approach to address nuisance flooding issues in small cities and communities. As an application, the effectiveness of two LID practices, rain barrels and permeable pavements, were explored in mitigating the urban flooding problem of a highly urbanized small coastal watershed in Alabama, USA. The EPA Stormwater Management Model (SWMM) was first calibrated for water depth using data collected at multiple sites within the watershed during the 2014–2015 period. The calibrated model was then used to first identify the areas prone to flooding using design storms with 1, 2, 5-, 10-, 50-, and 100-year return periods. Floodplain maps were generated for those design storms with HEC-RAS. Next, LID options upstream of those flood-prone areas were assessed to potentially minimize the flooding risks. The results indicate that LID controls can have considerable benefits for stormwater management by reducing runoff volume (1–24%), peak flow rates (18–25%), and water depth (5–15%), potentially returning watersheds to their natural flow regimes, thereby minimizing the flooding risk in urbanized areas. However, the effectiveness of LIDs, especially for the runoff volume, quickly diminishes as the return periods of the storms increase. Rain barrels were identified as the most economical and effective LID within the drainage system. Full article

Low impact development (LID) facilities are designed to maintain water circulation functions on the surface and subsurface. LID facilities can be applied to various areas and are expected to have both short-term and long-term effects, making them widely installed in urban areas. In this study, our objective is to calculate the A-I-R (Area ratio-rainfall Intensity-Runoff reduction rate) curve by applying design standards to tree filter boxes, garden plant pots, infiltration ditches, and rain barrels among various LID facilities. The analysis was conducted by constructing a SWMM-LID model and analyzing 209 items, considering the area ratio (A) and rainfall intensity (I) of the LID facilities. The runoff reduction rate (R) varies by LID facility according to the A-I-R curve. It reaches up to 100.0% for rain barrels, up to 30.0% for infiltration ditches, up to 20.0% for garden plant pot, and up to 12.0% for tree filter boxes. If the A-I-R curve of the LID facility is applied to the design standards, it is expected to facilitate the design of the facility’s size and inlet according to the target reduction rate. Full article

This bibliometric review elucidates the emerging intersection of Internet of Things (IoT) technologies and Green Stormwater Infrastructure (GSI), demonstrating the potential to reshape urban stormwater management. The study analyzes a steadily increasing corpus of literature since 2013, pointing out considerable international collaboration. Prominent contributions originate from the United States, Canada, Italy, China, and Australia, underscoring the global acknowledgement of the potential of IoT-enhanced GSI. Diverse GSI applications such as green roofs, smart rain barrels, bioretention systems, and stormwater detention ponds have demonstrated enhanced efficiency and real-time control with IoT integration. However, existing literature reveals several challenges, notably the requirement of advanced monitoring, the development of predictive optimization strategies, and extensive scalability. Comprehensive cost–benefit analyses are also critical for the widespread acceptance of IoT-integrated GSI. Current research addresses these challenges by exploring innovative strategies such as microbial-fuel-cell-powered soil moisture sensors and large-scale RTC bioretention systems. Emphasis is also on the need for security measures against potential digital threats. Future research needs to focus on real-time data-based monitoring plans, model validation, continuous optimization, and supportive policy frameworks. As the world confronts urban development, climate change, and aging infrastructure, IoT and GSI synergism presents a promising solution for effective stormwater management and enhancement of cultural ecosystem services. Continued exploration in this promising domain is crucial to pave the way for smarter, greener urban environments. Full article

In order to determine the optimal irrigation and drainage mode for the anti-lodging cultivation of Super Rice Japonica 9108, barrel loading tests of different irrigation and drainage modes were carried out in the Water-Saving Park of Hohai University in Nanjing from June to October in 2019 and 2020. Three treatments were set up: Frequent and Shallow Irrigation (FSI), Rain-catching and Controlled Irrigation (RC-CI) and Drought Planting with Straw mulching (DPS). In each mode, the growth index, stem morphology index, material production index and stem mechanical index of rice at yellow maturity period were measured, and their relationship with the lodging index was analyzed. The results showed that compared with FSI, the lodging index of RC-CI was reduced by an average of 24.0%. RC-CI can promote the lateral development of the base internodes, increase the accumulation of stem sheath dry matter and the internode fullness and enhance mechanical strength and anti-lodging ability of the stem. Meanwhile, RC-CI can appropriately reduce the plant height, so as to reduce the bending moment of the base internodes. As a consequence, the lodging risk was effectively reduced. The lodging index of DPS was reduced by an average of 16.0% compared with FSI. Because DPS was subject to severe water deficit, its internodes thickness and stem wall thickness were inferior to that of FSI, leading to the weakening of the mechanical strength of stem, and the morphological characteristics and mechanical characteristics of the stem were not improved. Despite this, DPS still had a strong resistance to lodging. The output rate and conversion rate of the stem sheath were reduced, and while the plant height and center of gravity height were significantly reduced, the bending moment remained low. Thus, DPS can still reduce the lodging risk of rice. Compared with FSI, the average yield of RC-CI increased by 5.8% in two years, and the average yield of DPS was reduced by 4.4% in two years. DPS under severe water deficit reduced the accumulation of dry matter in the panicle and the yield index of rice, which was not conducive to a high yield. Considering the yield and lodging resistance of the super rice “Japonica 9108”, RC-CI is the best irrigation and drainage mode, followed by DPS. This study can provide data support and theoretical support for regulating the lodging resistance of super rice through irrigation measures. Full article

Low-impact development (LID) is increasingly used to reduce stormwater’s quality and quantity impacts associated with climate change and increased urbanization. However, due to the significant variations in their efficiencies and site-specific requirements, an optimal combination of different LIDs is required to benefit from their full potential. In this article, the multi-objective genetic algorithm (MOGA) was coupled with the stormwater management model (SWMM) to identify both hydrological and cost-effective LIDs combinations within a large urban watershed. MOGA iteratively optimizes the types, sizes, and locations of different LIDs using a combined cost- and runoff-related objective function under both past and future stormwater conditions. The infiltration trench (IT), rain barrel (RB), rain gardens (RG), bioretention (BR), and permeable pavement were used as potential LIDs since they are common in our study area—the city of Renton, WA, USA. The city is currently adapting different LIDs to mitigate the recent increase in stormwater system failures and flooding. The results from our study showed that the optimum combination of LIDs in the city could reduce the peak flow and total runoff volume by up to 62.25% and 80% for past storms and by13% and 29% for future storms, respectively. The findings and methodologies presented in this study are expected to contribute to the ongoing efforts to improve the performance of large-scale implementations of LIDs. Full article

Low impact development (LID) has become one of the strategies that effectively mitigate the impacts of climate change. In addition to the ability to reduce nonpoint source (NPS) pollution caused by flash floods from the surface runoff, LID has also been applied to control water quantity under extreme rainfall events. Due to the fact that studies about LID configuration optimization tended to control water quantity and gradually ignored the main functions of water quality treatment, this study aims to consider water quantity and quality to estimate the benefits and optimal configuration of LID by Non-Dominated Genetic Algorithm (NSGA-II). In addition, regarding to the outlet peak flow, hydrologic footprint residence (HFR) was considered to be the water quantity indicator due to the ability to represent the dynamics of flow changes, and the modified quality indicator (Mass Emission First Flush ratio, MEFF₃₀) was corrected to represent the pollutant transport process in a large catchment area. The results show that the flood and MEFF₃₀ reduction rate of LID are inversely proportional to rainfall duration and intensity. The benefit of pollutant reduction, which can still be maintained by 20% and 15% under a big return period and the long duration was about three times than the quantity control. Taking the cost into account, although the rain barrel had the best effect of reduction per unit area, green roofs and permeable pavements had a higher unit cost reduction rate due to the lower costs. The upper and middle reaches of the open channel and the confluence of rainwater sewers should be the optimal LID configuration to achieve the benefits of both flood and pollution reduction. Full article

Urban flooding is a major problem in many coastal cities. The rapidly shifting patterns of land use and demographic increase are making conventional approaches to stormwater management fail. In developing countries such as Ecuador, a lack of monitoring, financial constraints and absence of proper policies exacerbate flooding problems. This work assesses the implementation of two Low Impact Development strategies (LIDs), namely, green streets and rain barrels, as nature-based solutions to mitigate flooding problems. The use of the “Stormwater Management Model” (SWMM) helped to contrast the new approach with the current state of the drainage system, including normal and extreme scenarios. With an implementation of 1.4% (19.5 ha) of the total area with LIDs, the reduction of runoff for short events (200 min) is around 20%, and for extreme events (within 24 h) is around 19% in comparison to the conventional approach. Flooded nodes were reduced to 27% for short events, and to 4% for extreme events. The peak flooding system had a reduction to 22% for short events and 15% for extreme events. These highlights help to increase city resilience, and authorities and stakeholders should engage in climate actions to reduce flood risks complementing drainage operations with nature-based solutions. Moreover, calibrated results in this article serve to increase awareness among municipal authorities regarding the importance of maintaining flooding records to improve modelling results for decision-makings processes. Full article

Source facilities can manage stormwater runoff pollutants while also limiting runoff volume in China’s sponge city construction. However, there is no apparent link between source volume control and runoff pollution reduction. This research uses SWMM to develop a model based on the basic data of a city’s catchment zone in northern China in order to statistically examine the response relationship between the initial runoff volume capture of sponge city construction and the reduction effect of stormwater runoff pollution. Based on the dimensionless constant of the runoff pollution control curve, we suggested a novel approach for evaluating runoff pollution control effectiveness. This method was used to examine the response relationship between runoff volume control and runoff pollution control in three typical initial runoff volume capture facilities in the study area, namely bioretention, permeable pavement, rain barrels, and terminal storage tanks, under various design rainfall conditions. The dimensionless constant (Dc) has good practical application value and can quantitatively quantify the control effect of various facilities on stormwater runoff pollution. The Dc value of the source facilities is higher than that of the terminal control facilities, indicating that the source facilities have a higher ability to reduce rainwater runoff pollution than the terminal facilities, particularly the infiltration facilities. The research ideas and evaluation methods proposed in this paper provide an alternative approach for selecting and optimizing facilities during the planning and designing stages of sponge city construction, which can also be used in the monitoring and evaluation stage after completion to carry out a more effective evaluation of sponge facilities’ effects. Full article

Cities are challenged by climate change impacts, such as extreme rainfall events that affect conventional urban water management systems via increased sewage water overflows resulting in water quality deterioration and urban floods causing infrastructure damage. Investments in blue–green infrastructure (BGI) are increasingly considered to address these issues. However, these should be cost-effective. In this study, the effectiveness of five different BGI strategies and one grey strategy are assessed for a peri-urban catchment area in Oslo (Grefsen) using a cost–benefit analysis. The strategies include (i) wadis; (ii) green roofs; (iii) raingardens, rain barrels and wadis; (iv) infiltration crates; (v) water squares, and (vi) a separate sewage system. Besides economic effectiveness, the study also aims to identify the proper protection level by comparing cost–benefit ratios and net benefits for 60-min rainfall events occurring once every 5, 20, and 100 years (M5, M20, and M100), concerning both the current situation and under future climate change (using the Representative Concentration Pathway 8.5). The analyses revealed the highest BC ratios for wadis (12.0–17.3), separate sewage systems (7.7–15.1), and a combination of raingardens, rain barrels, and wadis (1.6–2.3). Strategies dimensioned for less frequent but more intensive rainfall events yielded higher BC ratios. Results for infiltration crates were difficult to interpret and were found to be very sensitive to input parameters. The other strategies implied a negative BC ratio. The study concludes that investments in BGI in Grefsen, Oslo, can be positively judged from a social–economic perspective and provide suitable information for water-related decision makers to decide upon the strategy selection and the appropriate flood protection level. Full article

The U.S. Environmental Protection Agency stormwater management model was applied to a semi-arid urban micro watershed. The sub-catchment’s current features were modeled as scenario A, while the insertion of a set of LID technologies (rain barrels, bioretention cells, permeable pavement, and infiltration trenches) was represented as scenario B. A third scenario (C), considering only the most feasible LID technologies, was also modeled. All the scenarios were evaluated under two representative storm events (30 and 9 mm in two consecutive days, and 39 mm of rainfall in one day) occurred during the sampling performed in this study. Water quality was also simulated for a 30-mm storm event and compared against field assessment results after a real 30-mm storm event. Through the model, the inefficiency of current evacuation methods after 30- and 39-mm storm events was demonstrated. Simulation of scenario B showed that LID technologies could satisfactorily diminish peak flows generated by the selected storm events as well as runoff-conveyed pollution, while the realistic scenario allowed a lower but satisfactory hydrological performance and almost the same runoff quality than scenario B. This preliminary study could contribute to spread awareness about the benefits of LID technologies in semi-arid urban areas of the developing world. Full article

Smart rainwater harvesting (RWH) systems can automatically release stormwater prior to rainfall events to increase detention capacity on a household level. However, impacts and benefits of a widespread implementation of these systems are often unknown. This works aims to investigate the effect of a large-scale implementation of smart RWH systems on urban resilience by hypothetically retrofitting an Alpine municipality with smart rain barrels. Smart RWH systems represent dynamic systems, and therefore, the interaction between the coupled systems RWH units, an urban drainage network (UDN) and digital infrastructure is critical for evaluating resilience against system failures. In particular, digital parameters (e.g., accuracy of weather forecasts, or reliability of data communication) can differ from an ideal performance. Therefore, different digital parameters are varied to determine the range of uncertainties associated with smart RWH systems. As the results demonstrate, smart RWH systems can further increase integrated system resilience but require a coordinated integration into the overall system. Additionally, sufficient consideration of digital uncertainties is of great importance for smart water systems, as uncertainties can reduce/eliminate gained performance improvements. Moreover, a long-term simulation should be applied to investigate resilience with digital applications to reduce dependence on boundary conditions and rainfall patterns. Full article

In recent years, many urban areas in Ethiopia have experienced frequent flood events as a result of climate change and urban sprawl. Unplanned and unsustainable poor urban storm water management strategies will aggravate the impact and frequency of flood occurrence. In this study, impacts of urbanization and climate change on generated flood magnitude are analyzed using the urban hydrological model of Storm Water Management Model (SWMM) and Low Impact Development (LID) sustainable land use optimization techniques. Three rainfall distribution patterns (TS1, TS2 and TS3) in combination with rainfall duration periods of 10, 30 and 60 min and a pessimistic climate change scenario of RCP 4.5 compared to RCP 8.5 are used for the analysis purpose for selected infiltration and storage LID techniques (Bio-Retention Cell, Infiltration Trench and Rain Barrel). The study results showed that combined LID techniques have a significant impact on urban flood reduction of up to 75%. This significant amount of flood reduction is greater than the amount of excess flood magnitude which occurred as a result of climate change using the most pessimistic climate change scenario. The study results also confirmed that rainfall patterns have a significant impact on peak discharge for shorter rainfall durations. This study highly recommends using cost effective, easy and environmental adaptive and sustainable LID techniques for urban flood management in addition to existing drainage structures. Full article

Uncontrolled urbanization is a frequent cause behind the local flooding of catchment areas. This also results in a degradation of water quality in receivers, as well as causing a disruption of the natural water cycle in the catchment. Classical solutions, such as retention, do not prove to be sufficient under all conditions. An alternative solution is the application of low impact development (LID), which, in the analysed case, takes the form of rain gardens, infiltration trenches and controlled unsealing of catchment components. The work presents the influence of a few variants of solutions on a selected urbanized catchment located in Gorzów Wielkopolski. The assessment was developed using a simulation model, making use of EPA’s Storm Water Management Model (SWMM) software. The nalysed design variants are compared with the described existing state before the implementation of modernization works. Previous results showing that LID may be ineffective as the only solution in systems overloaded with runoff generated by rainfall of relatively low intensities were confirmed. In the case of existing systems, LID should be applied in combination with classical retention systems or in a treatment train and every opportunity to implement LID whether on a property or urban site must be taken. Such solutions in the analysed cases will allow for a reduction of the maximum outflow intensity from the analysed subcatchment by 9 to 17% depending on the analysed rainfall. The results are similar to those obtained in other implementations. However, the interpretation of the results is not as simple and obvious for overloaded systems. In addition to flow rate reduction, reduction of surcharge in the sewer network and reduction of the volume of local flooding must be considered. LID solutions should also, whenever possible, be looked into as early as the stage of planning the land development of the infrastructure. Full article

Sustainability concerns and multiple socio-environmental pressures have necessitated a shift towards Sustainable Urban Water Management (SUWM) systems. Viewing SUWM systems as sociotechnical, this paper departs from eight factors previously identified by transition research: Pressures, Context, Purposes, Actors, Instruments, Processes, Outputs, and Outcomes as a methodological framework for a structured review of 100 articles. The study seeks to analyze empirical cases of planning and implementing SUWM systems worldwide. A wide range of public actors—driven by social and environmental factors rather than by economic pressures—have initiated SUWM projects so as to locally fulfill defined social and environmental purposes. We provide evidence on the emergence of new actors, such as experts, users, and private developers, as well as on the diverse and innovative technical and societal instruments used to promote and implement SUWM systems. We also explore their contexts and institutional capacity to deal with pressures and to mobilize significant financial and human resources, which is in itself vital for the transition to SUWM. Planned or implemented SUWM outputs are divided into green (wet ponds, raingardens, and green roofs) and gray (rain barrels and porous pavements) measures. The outcomes of SUWM projects—in terms of societal and technical learning, and their institutional uptakes—are often implicit or lacking, which seemingly reduces the rate of desirable change. Full article

Low impact development (LID) has been widely applied to mitigate urban rainwater problems since the 1990s. However, the effect of LID practices has seldom been evaluated in detail. In this study, the effect of individual and combined LID practices on the reduction of roof runoff are specifically quantified considering the hydrological relationship between LID at the building scale and the campus scale at Beijing Normal University (BNU). The results show that individual and combined LID practices effectively reduce roof runoff for all types of rainfall and for rainfall with return periods from 0.5 to 50 years at the building scale. Combination scenarios maintain good performance with fewer areas of composed LID. Most values for the effect of combination scenarios are between the effects of composed LID. To achieve the highest cost efficiency, low elevation greenbelts should be the first choice, and green roofs should only be selected when low elevation greenbelts and rain barrels cannot be implemented. At the campus scale, individual and combined LID practices effectively reduce the outflow from and the overflow in the campus and combination scenarios have the best reduction performance. This study provides an important reference for urban water management and LID related decision making. Full article