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Two batches of 15NH4+ and 15NO3− labeling experiments were conducted to understand the complex nitrogen (N) fates and transformations in bioretention systems, respectively. The fates of 15NH4+ were first traced in six bioretention systems with different wet-dry regimes and submerged zone settings during four months, indicating: (1) 15N was mainly leached during the second storm events following the 15NH4+ addition during the first storm events, suggesting nitrification during the dry period; (2) the main 15NH4+ fates after four-month exposure were: soil media 59.6%–80.0%, outflow 5.3%–16.4%, plants 2.3%–8.9%, denitrification losses 0–28.4%; (3) longer antecedent dry weather period and submerged zone could help alleviate outflow NO3− leaching. The occurrence time, positions and rates of major N transformation processes were later examined by the 15NO3− labeling experiment in a bioretention system over an 8 d wet-dry cycle, indicating: (1) during the brief wet period, hydraulic mixing of “old” water and “new” inflow mainly occurred; (2) during the subsequent dry period, gross rates of nitrification, denitrification and mineralization showed “pulse effects”, i.e. peaking at 24–48 h and decreasing significantly within 72 h; (3) denitrification became more dynamic with soil media depth, especially in submerged zone. This study evidenced the feasibility of 15N labelling method in studying N dynamics in bioretention systems and would inform future engineering and stormwater management practices.
Fan Wang; Chuansheng Wang; Yanyan Zheng; Xiaoyue Li; Huapeng Qin; Wei Ding. Estimating nitrogen fates and gross transformations in bioretention systems with applications of 15N labeling methods. Chemosphere 2020, 270, 129462 .
AMA StyleFan Wang, Chuansheng Wang, Yanyan Zheng, Xiaoyue Li, Huapeng Qin, Wei Ding. Estimating nitrogen fates and gross transformations in bioretention systems with applications of 15N labeling methods. Chemosphere. 2020; 270 ():129462.
Chicago/Turabian StyleFan Wang; Chuansheng Wang; Yanyan Zheng; Xiaoyue Li; Huapeng Qin; Wei Ding. 2020. "Estimating nitrogen fates and gross transformations in bioretention systems with applications of 15N labeling methods." Chemosphere 270, no. : 129462.
Green roof can reduce runoff by its rainwater retention ability and has been widely used in storm water management. The rainwater retention performance of green roof fluctuates with the variation of rainfall frequency and monthly rainfall conditions. In this study, we conduct a continuous monitoring of 58 rainfall events over 18 months on four different vegetation green roofs in Shenzhen, China. We analyze the variation of the rainwater retention effect of green roofs and the influencing factors. The results show that, the rainwater retention depth of green roof for single rainfall event is between 0.4 mm and 37 mm, the rainwater retention rate is in the range of 2% to 100%; the monthly rainwater retention depth is 13-148 mm and its retention rate is 29%-70%; the annual total rainwater retention depth of green roof is 610-660 mm and the total retention rate is 44%-49%. The rainwater retention rate and the retention amount are negatively and positively correlated with rainfall depth respectively, and both are significantly positively correlated with the antecedent dry period in daytime. In addition, monthly average solar radiation, vegetation types and change of plant coverage also have a great influence on the retention effect of rain water between months. Different plants show very different rainwater retention performance in different months due to their differences in evapotranspiration ability and physiological activity of vegetation. Our research can provide scientific guidance for the performance evaluation and application of green roofs.
Yinchao Hu; Huapeng Qin; Zixuan Lin. Variation and influencing factors of rainwater retention of green roofs in Shenzhen. Journal of Shenzhen University Science and Engineering 2020, 37, 347 -354.
AMA StyleYinchao Hu, Huapeng Qin, Zixuan Lin. Variation and influencing factors of rainwater retention of green roofs in Shenzhen. Journal of Shenzhen University Science and Engineering. 2020; 37 (4):347-354.
Chicago/Turabian StyleYinchao Hu; Huapeng Qin; Zixuan Lin. 2020. "Variation and influencing factors of rainwater retention of green roofs in Shenzhen." Journal of Shenzhen University Science and Engineering 37, no. 4: 347-354.
Low impact development (LID) facilities have ability to increase evapotranspiration (ET), and thus moderate the hydrological cycle and mitigate urban heat island (UHI) effects. However, it is difficult to measure ET of LID facilities by traditional methods (e.g. weighing lysimeter, Bowen ratio system and eddy covariance system) in urban environment. A recently developed method, called three-temperature model (3T model), has been used to measure actual ET of natural underlying surfaces in situ. However, its applicability in ET measurement for LID facilities has not been investigated. In order to investigate the accuracy of this method to estimate ET of LID facilities and its influencing factors, the experimental devices for vegetated LID (green roof with Zoysia tenuifoli (GRZ) and green roof with Callisia repens (GRC)) and non-vegetated LID (permeable concrete pavement (PCP) and permeable brick pavement (PBP)) were installed. The method was validated by comparing the ET measured by 3T model with that measured by weighing platform (hourly data, n = 223–302 for each facility). After validation, the method was used to measure ET variations of typical LID facilities under moist sub-tropical weather condition in Shenzhen, China. The results indicate the coefficient of determination (R2) between ET measured by 3T model and weighing platform is 0.63, 0.60, 0.70 and 0.65 for GRZ, GRC, PCP and PBP, respectively, and the slopes of regression equations are close to 1 and their intercepts are close to 0. Furthermore, the 3T model has higher absolute relative error (ARE) of ET estimation in the early morning and the late afternoon than that in the rest of daytime. This is mainly due to the effect of energy related factors, such as solar radiation, air temperature and the difference between reference surface temperature and air temperature. In addition, ET rates of LID facilities can maintain at a relatively high level in the first few days after rainfall. However, ET of PCP decreases faster than that of other LID facilities during the drying period. These results demonstrate the ability and accuracy of 3T model to measure variations of ET of LID facilities in situ.
Yuanyan Zhang; Huapeng Qin; Jingyi Zhang; Yinchao Hu. An in-situ measurement method of evapotranspiration from typical LID facilities based on the three-temperature model. Journal of Hydrology 2020, 588, 125105 .
AMA StyleYuanyan Zhang, Huapeng Qin, Jingyi Zhang, Yinchao Hu. An in-situ measurement method of evapotranspiration from typical LID facilities based on the three-temperature model. Journal of Hydrology. 2020; 588 ():125105.
Chicago/Turabian StyleYuanyan Zhang; Huapeng Qin; Jingyi Zhang; Yinchao Hu. 2020. "An in-situ measurement method of evapotranspiration from typical LID facilities based on the three-temperature model." Journal of Hydrology 588, no. : 125105.
Urban waterlogging is a dilemma faced by many highly urbanizing areas. To solve the contradiction between the space requirement for waterlogging control and the scarcity of urban space, time-sharing utilization of the multi-function sponge space (MFSS) is promoted in some urbanizing areas. The MFSS is designed to have certain social or economic functions during dry or light rain events and detains stormwater on heavy rain events. However, there is lack of understanding on how to achieve the maximum benefit of multi-function. In this study, three time-sharing utilization modes are proposed to use MFSS to detain runoff: when the rain event begins (Mode A), when cumulative rainfall is greater than a specific threshold (Mode B), or when rainfall intensity is higher than a specific threshold (Mode C). A methodological framework based on the Storm Water Management Model (SWMM) is proposed to evaluate the waterlogging reduction performance of the three modes under different rainfall conditions and thresholds for enabling MFSS in an urbanizing catchment in Shenzhen, China. The performance is measured by comparing the total volume of overflow from manholes of the drainage system with and without MFSS during a storm event. The results indicate that: (1) Under Mode A, the performance is more effective under a light storm event with an early peak; (2) Under Mode B, as the cumulative rainfall threshold for enabling MFSS increases, the overflow first decreases and then increases. Different threshold values have to be set for different types of rainfall events to achieve the best performance; (3) Under Mode C, as the rainfall intensity threshold for enabling MFSS increases, the overflow also first decreases and then rapidly increases at a high threshold value. The mode has an identical range of optimal thresholds under different types of rainfall events. Furthermore, Mode C has higher efficiency in overflow reduction than the other two modes, no matter whether under design storms or historical storms. Therefore, Mode C is recommended as an efficient and stable utilization mode for MFSS.
Ming Cheng; Huapeng Qin; Guangtao Fu; Kangmao He. Performance evaluation of time-sharing utilization of multi-function sponge space to reduce waterlogging in a highly urbanizing area. Journal of Environmental Management 2020, 269, 110760 .
AMA StyleMing Cheng, Huapeng Qin, Guangtao Fu, Kangmao He. Performance evaluation of time-sharing utilization of multi-function sponge space to reduce waterlogging in a highly urbanizing area. Journal of Environmental Management. 2020; 269 ():110760.
Chicago/Turabian StyleMing Cheng; Huapeng Qin; Guangtao Fu; Kangmao He. 2020. "Performance evaluation of time-sharing utilization of multi-function sponge space to reduce waterlogging in a highly urbanizing area." Journal of Environmental Management 269, no. : 110760.
Adding a submerged zone (SZ) is deemed to promote denitrification during dry periods and thus improve NO3− removal efficiency of a bioretention system. However, few studies had investigated the variation of nitrogen concentration in the SZ during dry periods and evaluated the effect of the variation on nitrogen removal of the bioretention system. Based on the experiment in a mesocosm bioretetion system with SZ, this study investigated the variation of nitrogen concentration of the system under 17 consecutive cycles of wet and dry alternation with varied rainfall amount, influent nitrogen concentration and antecedent dry periods (ADP). The results indicated that (1) during the dry periods, NH4+ concentrations in SZ showed an exponential decline trend, decreasing by 50% in 12.9 ± 7.3 h; while NO3− concentrations showed an inverse S-shape declining trend, decreasing by 50% in 18.8 ± 6.4 h; (2) during the wet periods, NO3− concentration in the effluent showed an S-shape upward trend; and at the early stage of the wet periods, the concentration was relatively low and significantly correlated with ADP, while the corresponding volume of the effluent was significantly correlated with the SZ depth; (3) in the whole experiment, the contribution of nitrogen decrease in SZ during dry periods to NH4+ and NO3− removal accounted for 12% and 92%, respectively; and the decrease of NO3− in SZ during the dry period was correlated with the influent concentration in the wet period and the length of the dry period.
Kangmao He; Huapeng Qin; Fan Wang; Wei Ding; Yixiang Yin. Importance of the Submerged Zone during Dry Periods to Nitrogen Removal in a Bioretention System. Water 2020, 12, 876 .
AMA StyleKangmao He, Huapeng Qin, Fan Wang, Wei Ding, Yixiang Yin. Importance of the Submerged Zone during Dry Periods to Nitrogen Removal in a Bioretention System. Water. 2020; 12 (3):876.
Chicago/Turabian StyleKangmao He; Huapeng Qin; Fan Wang; Wei Ding; Yixiang Yin. 2020. "Importance of the Submerged Zone during Dry Periods to Nitrogen Removal in a Bioretention System." Water 12, no. 3: 876.
Adding a submerged zone (SZ) is deemed to promote denitrification during dry periods and thus improve NO3--N removal efficiency of a bioretention system. However, few studies had investigated the variation of nitrogen concentration in the SZ during dry periods and evaluated the effect of the variation on nitrogen removal of the bioretention system. Based on the experiment in a mesocosm bioretetion system with SZ, this study investigated the variation of nitrogen concentration of the system under 17 consecutive cycles of wet and dry alternation with varied rainfall amount, influent nitrogen concentration and antecedent dry periods (ADP). The results indicated that (1) during the dry periods, NH4+-N concentrations in SZ showed an exponential decline trend, decreasing by 50% in 12.9 ± 7.3 hours; while NO3--N concentrations showed an inverse S-shape decline trend, decreasing by 50% in 18.8 ± 6.4 hours; (2) during the wet periods, NO3--N concentration in the effluent showed an S-shape upward trend; and at the early stage of the wet periods, the concentration was relatively low and significantly correlated with ADP, while the corresponding volume of the effluent was significantly correlated with the SZ depth; (3) in the whole experiment, the contribution of nitrogen decrease in SZ during dry periods to NH4+-N and NO3--N removal accounted for 12% and 92%, respectively; and the decrease of NO3--N in SZ during the dry period was correlated with the influent concentration in the wet period and the length of the dry period.
Kangmao He; Huapeng Qin; Fan Wang; Wei Ding; Yixiang Yin. Importance of the Submerged Zone during Dry Periods to Nitrogen Removal in a Bioretention System. 2020, 1 .
AMA StyleKangmao He, Huapeng Qin, Fan Wang, Wei Ding, Yixiang Yin. Importance of the Submerged Zone during Dry Periods to Nitrogen Removal in a Bioretention System. . 2020; ():1.
Chicago/Turabian StyleKangmao He; Huapeng Qin; Fan Wang; Wei Ding; Yixiang Yin. 2020. "Importance of the Submerged Zone during Dry Periods to Nitrogen Removal in a Bioretention System." , no. : 1.
Reduction in runoff and increase in actual evapotranspiration (AET) are two well-known benefits of green roofs. However, few studies have been carried out to investigate how green roofs affect runoff and AET when there is interaction between them. Such interaction is most prominent when green roofs have an additional storage layer. In this study, a modified hydrological model for green roofs is proposed to explicitly describe water retention and release in different layers and during wet/dry periods, which can reflect the interaction between runoff and AET under alternating dry and wet conditions. After calibration and validation with experimental data, the model was used to evaluate the combined effects of runoff reduction and increase in AET for green roofs under moist sub-tropical weather condition (such as Shenzhen, China). The results indicate that the daily AET and event runoff of green roofs decrease with increasing antecedent dry period (ADP); an additional storage layer can increase the ability of green roofs in reducing runoff and increasing AET. Generally, the effect is more pronounce under weather conditions with higher temperature, more rainfall amount and longer ADP. Such results provide hydrologists and engineers with a new and effective tool to simulate and understand the performance of green roofs by considering water retention and release in the layers.
Shu-Xiao Li; Hua-Peng Qin; Yue-Nuan Peng; Soon Thiam Khu. Modelling the combined effects of runoff reduction and increase in evapotranspiration for green roofs with a storage layer. Ecological Engineering 2018, 127, 302 -311.
AMA StyleShu-Xiao Li, Hua-Peng Qin, Yue-Nuan Peng, Soon Thiam Khu. Modelling the combined effects of runoff reduction and increase in evapotranspiration for green roofs with a storage layer. Ecological Engineering. 2018; 127 ():302-311.
Chicago/Turabian StyleShu-Xiao Li; Hua-Peng Qin; Yue-Nuan Peng; Soon Thiam Khu. 2018. "Modelling the combined effects of runoff reduction and increase in evapotranspiration for green roofs with a storage layer." Ecological Engineering 127, no. : 302-311.
Sewer interception systems have been built along rivers in rapidly urbanizing areas to collect unregulated sewage discharges due to misconnections between storm sewers and sanitary sewers. During storm events, combined sewage might overflow from these systems into rivers through orifices and deteriorate water quality in rivers. Interception system overflows (ISOs) from different orifices in a sewer interception system might interact with each other, therefore pollutants from ISOs show a spatial variation. This paper aims to understand the spatial variation of pollutants from ISOs for informed decision making. In this study, an urbanized catchment in China is chosen as the study area, and the Storm Water Management Model (SWMM) is used to examine the spatial variation of pollutants from ISOs and to analyze the effect of sewer separation on ISOs. The results obtained from the case study indicate that: (1) Critical rainfall amounts which trigger overflows decrease downstream in an interception system while annual ISO volumes and pollutant loads from ISOs increase downstream; additionally, these variations are influenced by sizes and slopes of interceptors; (2) Runoff is the main source of COD from ISOs while sewage is the main source of NH3-N, and ratios of pollutants from sewage to ISOs increase downstream; (3) Sewer separation can significantly reduce pollutant loads from sewage to ISOs, but it cannot significantly reduce pollutant loads from runoff. In order to mitigate ISO pollution, it is suggested to increase conveyance capacities of interceptors in the downstream, separate sewage from runoff, and promote source control for urban runoff in highly urbanized areas.
Sidian Chen; Hua-Peng Qin; Yu Zheng; Guangtao Fu. Spatial variations of pollutants from sewer interception system overflow. Journal of Environmental Management 2018, 233, 748 -756.
AMA StyleSidian Chen, Hua-Peng Qin, Yu Zheng, Guangtao Fu. Spatial variations of pollutants from sewer interception system overflow. Journal of Environmental Management. 2018; 233 ():748-756.
Chicago/Turabian StyleSidian Chen; Hua-Peng Qin; Yu Zheng; Guangtao Fu. 2018. "Spatial variations of pollutants from sewer interception system overflow." Journal of Environmental Management 233, no. : 748-756.
Increasing impervious land cover has great impacts on groundwater regimes in urbanized areas. Low impact development (LID) is generally regarded as a sustainable solution for groundwater conservation. However, the effects of LID on the spatial-temporal distribution of groundwater are not yet fully understood. In this case study, a coupled Storm Water Management Model (SWMM) and Finite Element Subsurface FLOW system (FEFLOW) model was used to simulate surface and groundwater flow in an urbanized area in Shenzhen, China. After verification, the model was used to analyze the spatial-seasonal variations of groundwater head and hydrological processes under different LID scenarios. The results indicate that if the runoff from 7.5% and 15% of impervious area is treated by LID facilities, the annual surface runoff decreases by 5% and 9%, respectively, and the spatial average groundwater head relative to sea level pressure increases by 0.9 m and 1.7 m in the study area, respectively. The rise in groundwater head generally decreases from the recharge zones to the discharge zones surrounded by the streams and coastal waters. However, the groundwater head change is determined not only by the location in the catchment, but also by the hydraulic conductivity of underlying aquifer and LID infiltration intensity. Moreover, LID significantly enhances groundwater recharge and aquifer storage in the wet seasons; in turn it increases aquifer release and groundwater discharge in the dry seasons. However, LID has the potential to increase the risk of groundwater flooding during wet seasons in areas with poor aquifer drainage capacity and shallow groundwater depth. The findings from this study provide the basis for further assessing the benefit and risk of LID infiltration for groundwater supplementation in the urbanized areas.
Yu Zheng; Sidian Chen; Huapeng Qin; Jiu Jimmy Jiao. Modeling the Spatial and Seasonal Variations of Groundwater Head in an Urbanized Area under Low Impact Development. Water 2018, 10, 803 .
AMA StyleYu Zheng, Sidian Chen, Huapeng Qin, Jiu Jimmy Jiao. Modeling the Spatial and Seasonal Variations of Groundwater Head in an Urbanized Area under Low Impact Development. Water. 2018; 10 (6):803.
Chicago/Turabian StyleYu Zheng; Sidian Chen; Huapeng Qin; Jiu Jimmy Jiao. 2018. "Modeling the Spatial and Seasonal Variations of Groundwater Head in an Urbanized Area under Low Impact Development." Water 10, no. 6: 803.
The introduction of a saturated zone (SZ) has been recommended to address the issue of nitrogen removal fluctuation in the bioretention system, which is one of the most versatile low-impact development facilities for urban stormwater management. Nine experimental columns were used to characterize the nitrogen concentration variations over the outflow during wetting periods and in SZ during the antecedent drying periods (ADPs), as well as compare removal efficiencies of various nitrogen species in systems with different SZ depths under alternate drying and wetting conditions. Results indicated that NO3−-N concentrations in the outflow showed quasi-logistic curve-shaped variations over time: being low (<0.5 mg/L) in the early process, sharply increasing thereafter, and finally flattening around 3.0 mg/L with NO3− leaching; NH4+-N and organic nitrogen (ON) concentrations were consistently low around 0.5 mg/L and 1.8 mg/L, respectively during the wetting periods. NH4+ removal efficiency in bioretention systems was consistently high around 80%, not varying with the increasing SZ depth; ON removal efficiency had a slight rise from 57% to 84% and NO3− removal efficiency was significantly enhanced from −23% to 62% with the SZ depth increasing from 0 to 600 mm. Deeper SZ could store more runoff and promote more denitrification of NO3− and mineralization of ON during the ADPs, providing more “old” water with low NO3− and ON concentrations for water exchange with “new” inflow of higher NO3− and ON concentrations during the wetting periods. The total nitrogen (TN) removal, a combined result of the instantaneous removal through adsorption and retention in the upper soil layer during the wetting periods and the gradual removal via denitrification and mineralization in SZ during the ADPs, was also improved by increasing the SZ depth; TN removal efficiency was elevated from 35% to 73% when the SZ depth increased from zero to 600 mm.
Chuansheng Wang; Fan Wang; Huapeng Qin; Xiangfei Zeng; Xueran Li; Shaw-Lei Yu. Effect of Saturated Zone on Nitrogen Removal Processes in Stormwater Bioretention Systems. Water 2018, 10, 162 .
AMA StyleChuansheng Wang, Fan Wang, Huapeng Qin, Xiangfei Zeng, Xueran Li, Shaw-Lei Yu. Effect of Saturated Zone on Nitrogen Removal Processes in Stormwater Bioretention Systems. Water. 2018; 10 (2):162.
Chicago/Turabian StyleChuansheng Wang; Fan Wang; Huapeng Qin; Xiangfei Zeng; Xueran Li; Shaw-Lei Yu. 2018. "Effect of Saturated Zone on Nitrogen Removal Processes in Stormwater Bioretention Systems." Water 10, no. 2: 162.
In this study, storm water management model (SWMM) was coupled with environment fluid dynamic code (EFDC) to investigate the effects of low impact development (LID) controls at urban catchment scale on mitigating the nutrient pollution in Deep Bay, southeastern China. Six scenarios with different area percentage of LID practices were proposed and simulations were carried out using an annual historical rainfall in 2014 and the 0.25-year return period (T=0.25) design rainfall event. The output rainfall runoff nutrient loads (RRNLs) from the Deep Bay Basin and water quality variations were observed using ocean-land coupled model. RRNLs mainly occurred during May and September, with 2866.6t dissolved inorganic nitrogen (DIN) and 169.7t phosphate (PO43-P), accounting for 77% of the annual load. The RRNL reduction rates had a positive correlation with the area LID practices with annual historical rainfall and design rainfall event. The annual reduction rates for DIN and PO43-P were approximately 58.1% and 62.3%, respectively, when the LID practice area accounted for 90% of impervious land. The monthly mean concentration of seawater nutrient decreased with the increase of the LID practices’ area percentage to impervious land area. Configuring 90% impervious land to LID practices, the maximum monthly mean concentration of nutrient could be reduced by about 15.2%~18.3%. And the peak concentration of seawater nutrient could be decreased by about 15% after episodic event and be delayed about a half day. The impact of rainfall runoff load from basin could be alleviated by LID practices, thereby mitigating the nutrient pollution in coastal zone. The method and simulation results in this study will provide a scientific basis for integrated coastal zone water environment management and LID practice planning.
Sidian Chen; Mingfeng Zheng; Huapeng Qin; Xueran Li. Effects of Low Impact Development Practices on the Mitigation of Nutrient Pollution in Deep Bay, China. International Low Impact Development Conference China 2016 2017, 1 .
AMA StyleSidian Chen, Mingfeng Zheng, Huapeng Qin, Xueran Li. Effects of Low Impact Development Practices on the Mitigation of Nutrient Pollution in Deep Bay, China. International Low Impact Development Conference China 2016. 2017; ():1.
Chicago/Turabian StyleSidian Chen; Mingfeng Zheng; Huapeng Qin; Xueran Li. 2017. "Effects of Low Impact Development Practices on the Mitigation of Nutrient Pollution in Deep Bay, China." International Low Impact Development Conference China 2016 , no. : 1.
Vegetated dry swales were designed to promote infiltration, retain storm water, and reduce the surface runoff peak flow. As an important part of swales, the underdrain system, filled with gravels, was usually equipped with a perforated pipe to drain water from upper layers during rainfall events. In most existing models (e.g., SWMM) that were widely used to simulate the hydrological process for vegetated dry swales, outflow from the underdrain system was usually simplified as orifice flow related to water head, and the hydraulic process in the gravel layer and in the perforated pipe on the bottom of the swales could not be described. A hydraulic model of vegetated dry swales was developed in this study by combining an overland flow model, an infiltration model, and an underdrain streamflow model. The flow in the underdrain system was divided into two sections, i.e., the flow through the gravel channel and the flow through the perforated pipe. The former was simulated through a permeability model for porous media, and the latter was described by applying an equation. For the development of the function, data were collected for the calibration of parameters in field tests in Shenzhen, southern China, and water infiltration rate from the gravel channel to the perforated pipe was assumed to be proportional to the water head in the gravel channel and the orifice area on the perforated pipe. Combining an overland flow model, an infiltration model, and an underdrain streamflow model, the vegetated dry swale model was performed to analyze surface runoff retention and underdrain streamflow performance in a dry swale with a perforated pipe after calibration and validation with measured data. The study demonstrated that the proposed model could accurately describe the hydraulic process in the underdrain system of a vegetated dry swale and advance better understandings of dry swale hydraulic performance.
Sidian Chen; Huapeng Qin; Shuxiao Li. Modeling of Streamflow in an Underdrain System of Vegetated Dry Swales. International Low Impact Development Conference China 2016 2017, 1 .
AMA StyleSidian Chen, Huapeng Qin, Shuxiao Li. Modeling of Streamflow in an Underdrain System of Vegetated Dry Swales. International Low Impact Development Conference China 2016. 2017; ():1.
Chicago/Turabian StyleSidian Chen; Huapeng Qin; Shuxiao Li. 2017. "Modeling of Streamflow in an Underdrain System of Vegetated Dry Swales." International Low Impact Development Conference China 2016 , no. : 1.
Impervious surfaces have become common due to traditional urban development and construction. However, it may affect the urban ecosystem and have negative impacts on the quantity of base flow due to the infiltration decrease. Currently, low impact development (LID) has received increasing attention because it is able to increase base flow by increasing the infiltration rate. However, the effects of LID on the base flow in urbanized areas have not been fully discussed. In this paper, the Hydrological Simulation Program-FORTRAN (HSPF) is proposed to evaluate the impact of LID planning on base flow of an urban area in Shenzhen, China. Meteorological data, a topographical map, land use data, and remote sensing data of this study area are used as inputs in the model. Besides, three months of observed hydrologic data of the watershed in 2015 is used for calibration and validation. The model, coupled with a digital filter method, is used to analyze the change of base flow due to urbanization with and without LID impacts. The results indicate that, under extreme ideal circumstance, the maximum area (48%) of impervious surface is retrofitted to LID. The maximum potential base flow increase in the study area is 15%, which is far more than that in realistic world.
Qi Zhang; Zhijie Zhao; Huapeng Qin. Evaluation of the Effects of Low Impact Development on Base Flow in an Urbanized Watershed Using HSPF. International Low Impact Development Conference China 2016 2017, 1 .
AMA StyleQi Zhang, Zhijie Zhao, Huapeng Qin. Evaluation of the Effects of Low Impact Development on Base Flow in an Urbanized Watershed Using HSPF. International Low Impact Development Conference China 2016. 2017; ():1.
Chicago/Turabian StyleQi Zhang; Zhijie Zhao; Huapeng Qin. 2017. "Evaluation of the Effects of Low Impact Development on Base Flow in an Urbanized Watershed Using HSPF." International Low Impact Development Conference China 2016 , no. : 1.
As an environmental friendly measure for surface runoff reduction, low impact development (LID) has been applied successfully in urban areas. However, due to high price of land and additional expense for LID construction in highly urbanized areas, the developers of real estate would not like to proceed LID exploitation. Floor area ratio (FAR) refers to “the ratio of a building’s total floor area to the size of the piece of land upon which it is built.” Increasing FAR indicates that the developers can construct higher buildings and earn more money. By means of awarding FAR, the developers may be willing to practice LID construction. In this study, a new residential district is selected as a case study to analyze the tradeoff between the runoff reduction goal achieving by LID practices and the incentive of awarding FAR to promote LID construction. The System for Urban Stormwater Treatment and Analysis IntegratioN (SUSTAIN) model is applied to simulate the runoff reduction under various LID designs and then derive the Pareto-optimal solutions to achieve urban runoff reduction goals based on cost efficiency. The results indicates that the maximum surface runoff reduction is 20.5%. Under the extremity scenarios, the government has options to award FAR of 0.028, 0.038 and 0.047 and the net benefits developers gain are 0 CNY, one million CNYand two million CNY, respectively. The results provide a LID construction guideline related to awarding FAR, which supports incentive policy making for promoting LID practices in the highly urbanized areas.
Ming Cheng; Huapeng Qin; Kangmao He; Hongliang Xu. Can floor-area-ratio incentive promote low impact development in a highly urbanized area?—A case study in Changzhou City, China. Frontiers of Environmental Science & Engineering 2017, 12, 8 .
AMA StyleMing Cheng, Huapeng Qin, Kangmao He, Hongliang Xu. Can floor-area-ratio incentive promote low impact development in a highly urbanized area?—A case study in Changzhou City, China. Frontiers of Environmental Science & Engineering. 2017; 12 (2):8.
Chicago/Turabian StyleMing Cheng; Huapeng Qin; Kangmao He; Hongliang Xu. 2017. "Can floor-area-ratio incentive promote low impact development in a highly urbanized area?—A case study in Changzhou City, China." Frontiers of Environmental Science & Engineering 12, no. 2: 8.
Haifeng Jia; Shaw L. Yu; Huapeng Qin. Low impact development and sponge city construction for urban stormwater management. Frontiers of Environmental Science & Engineering 2017, 11, 20 .
AMA StyleHaifeng Jia, Shaw L. Yu, Huapeng Qin. Low impact development and sponge city construction for urban stormwater management. Frontiers of Environmental Science & Engineering. 2017; 11 (4):20.
Chicago/Turabian StyleHaifeng Jia; Shaw L. Yu; Huapeng Qin. 2017. "Low impact development and sponge city construction for urban stormwater management." Frontiers of Environmental Science & Engineering 11, no. 4: 20.
Green roofs suffer from water stress during prolonged dry periods. Periodically irrigation is usually needed to maintain the health of green roofs. This paper presents a green roof model for simulating the long term variation of soil moisture of green roofs with a storage layer. The model mainly incorporates a HYDRUS-1D model for the soil layer and an evaporation model for the storage layer. It explicitly accounts for the effects of evaporation from the storage layer on the soil moisture. After calibration and validation with the observed data of a pilot green roof, the model was implemented to evaluate the efficiency of various irrigation schemes for the green roofs built with different structural designs under typical weather conditions in Shenzhen, China. The results indicate that without irrigation the green roofs experience water stress (defined as soil moisture © 2016 Elsevier B.V.
Hua-Peng Qin; Yue-Nuan Peng; Qiao-Ling Tang; Shaw-Lei Yu. A HYDRUS model for irrigation management of green roofs with a water storage layer. Ecological Engineering 2016, 95, 399 -408.
AMA StyleHua-Peng Qin, Yue-Nuan Peng, Qiao-Ling Tang, Shaw-Lei Yu. A HYDRUS model for irrigation management of green roofs with a water storage layer. Ecological Engineering. 2016; 95 ():399-408.
Chicago/Turabian StyleHua-Peng Qin; Yue-Nuan Peng; Qiao-Ling Tang; Shaw-Lei Yu. 2016. "A HYDRUS model for irrigation management of green roofs with a water storage layer." Ecological Engineering 95, no. : 399-408.
In current literature, the first flush effect of urban runoff pollution has been studied and reported extensively. However, the effects of middle and final flushes on pollutant flushing were not given much attention. In addition, few previous studies have discussed the suitability of the widely used exponential wash-off model for describing the middle or final flush processes. In this paper, the Shiyan River catchment, a typical rapidly urbanizing catchment in China, is chosen as a study area to analyze the effects of first, middle and final flushes based on monitoring hydrographs and pollutographs. In order to simulate the middle and final flush processes observed in storm events, a new, realistically simple, parsimonious model (named as logistic wash-off model) is developed with the assumption that surface pollutant loads available for wash-off increase with cumulative runoff volume following a logistic curve. The popular exponential wash-off model and the newly developed model are used and compared in simulating the flush processes in storm events. The results indicate that all the three types of pollutant flushing are observed in the experiment; however, the first flush effect is weak, while the middle and final flush effects are substantial. The exponential model has performed well in simulating the first flush process but failed to simulate well the middle and final flush processes. However, the logistic wash-off model has effectively simulated all the three types of pollutant flush, and particularly, it has performed better in simulating the middle and final flush processes than the exponential model. © 2016 Elsevier B.V.
Hua-Peng Qin; Kang-Mao He; Guangtao Fu. Modeling middle and final flush effects of urban runoff pollution in an urbanizing catchment. Journal of Hydrology 2016, 534, 638 -647.
AMA StyleHua-Peng Qin, Kang-Mao He, Guangtao Fu. Modeling middle and final flush effects of urban runoff pollution in an urbanizing catchment. Journal of Hydrology. 2016; 534 ():638-647.
Chicago/Turabian StyleHua-Peng Qin; Kang-Mao He; Guangtao Fu. 2016. "Modeling middle and final flush effects of urban runoff pollution in an urbanizing catchment." Journal of Hydrology 534, no. : 638-647.
Understanding the sources of chemical components in roof runoff can help to prevent water quality problems in rooftop rainwater harvesting. To identify the contribution of wet deposition to the mass of components in roof runoff, the samples from air, rainwater, dust buildup and roof runoff were collected from an urban site in Shenzhen of China in 2011–2012. The results indicate that: (1) wet deposition has a dominant contribution to the mass of total organic carbon (TOC), NH4+, NO3–, Cl– and organic acids in the roof runoff, while the mass of NH4+, acetic acid and formic acid in the roof runoff may be greatly reduced by the neutralization between the components with alkaline dust buildup on the rooftop; and (2) wet deposition partially contributes to the mass of Na+, K+, Mg2+, Ca2+, F– and SO42– in the roof runoff, while other factors like dust buildup on the rooftop and chemical reactions also have a non-negligible impact. Furthermore, TOC, NH4+, NO3– and organic acids in the wet deposition are mainly influenced by the atmospheric pollution due to fast increase in fossil fuel consumption (e.g. vehicle emissions). Therefore, the effects of wet deposition should be carefully considered for rooftop rainwater harvesting in urbanized areas.
Hua-Peng Qin; Qiao-Ling Tang; Li-Yu Wang; Guangtao Fu. The impact of atmospheric wet deposition on roof runoff quality in an urbanized area. Water Policy 2015, 46, 880 -892.
AMA StyleHua-Peng Qin, Qiao-Ling Tang, Li-Yu Wang, Guangtao Fu. The impact of atmospheric wet deposition on roof runoff quality in an urbanized area. Water Policy. 2015; 46 (6):880-892.
Chicago/Turabian StyleHua-Peng Qin; Qiao-Ling Tang; Li-Yu Wang; Guangtao Fu. 2015. "The impact of atmospheric wet deposition on roof runoff quality in an urbanized area." Water Policy 46, no. 6: 880-892.
Surface water quality deterioration is a serious problem in many rapidly urbanizing catchments in developing countries. There is currently a lack of studies that quantify water quality variation (deterioration or otherwise) due to both socio-economic and infrastructure development in a catchment. This paper investigates the causes of water quality changes over the rapid urbanization period of 1985–2009 in the Shenzhen River catchment, China and examines the changes in relation to infrastructure development and socio-economic policies. The results indicate that the water quality deteriorated rapidly during the earlier urbanization stages before gradually improving over recent years, and that rapid increases in domestic discharge were the major causes of water quality deterioration. Although construction of additional wastewater infrastructure can significantly improve water quality, it was unable to dispose all of the wastewater in the catchment. However, it was found that socio-economic measures can significantly improve water quality by decreasing pollutant load per gross regional production (GRP) or increasing labor productivity. Our findings suggest that sustainable development during urbanization is possible, provided that: (1) the wastewater infrastructure should be constructed timely and revitalized regularly in line with urbanization, and wastewater treatment facilities should be upgraded to improve their nitrogen and phosphorus removal efficiencies; (2) administrative regulation policies, economic incentives and financial policies should be implemented to encourage industries to prevent or reduce the pollution at the source; (3) the environmental awareness and education level of local population should be increased; (4) planners from various sectors should consult each other and adapt an integrated planning approach for socio-economic and wastewater infrastructure development.
Hua-Peng Qin; Qiong Su; Soon-Thiam Khu; Nv Tang. Water Quality Changes during Rapid Urbanization in the Shenzhen River Catchment: An Integrated View of Socio-Economic and Infrastructure Development. Sustainability 2014, 6, 7433 -7451.
AMA StyleHua-Peng Qin, Qiong Su, Soon-Thiam Khu, Nv Tang. Water Quality Changes during Rapid Urbanization in the Shenzhen River Catchment: An Integrated View of Socio-Economic and Infrastructure Development. Sustainability. 2014; 6 (10):7433-7451.
Chicago/Turabian StyleHua-Peng Qin; Qiong Su; Soon-Thiam Khu; Nv Tang. 2014. "Water Quality Changes during Rapid Urbanization in the Shenzhen River Catchment: An Integrated View of Socio-Economic and Infrastructure Development." Sustainability 6, no. 10: 7433-7451.
Growing concern on climate-related flood hazards has led to increasing interest in understanding the interactions between climate, flood, and human responses. This paper jointly investigates climate change trends, impacts on flood events, flood vulnerability and risk, and response strategies in the Pearl River Delta (PRD), a rapidly urbanizing coastal area in southeast China. Our analysis based on a reanalysis dataset and model projections are integrated with literature results, which indicates a climate scenario of increasing mean temperature, precipitation, sea level, typhoon intensity, and the frequency of extreme weather events in the PRD. These trends, together with the continuing urbanization in flood-prone areas, are expected to increase flood frequency and aggravate both the scale and degree of flooding in the PRD area. We further estimate the flood vulnerability of the 11 PRD cities using the indicator system method. The results suggest that the exposure and sensitivity of central cities (Hong Kong, Macao, Shenzhen, and Guangzhou) are very high because of highly exposed populations and assets located in lowland areas. However, the potential vulnerability and risk can be low due to high adaptive capacities (both by hard and soft flood-control measures). A novel framework on flood responses is proposed to identify vulnerable links and response strategies in different phases of a flood event. It further suggests that the flood risks can be mitigated by developing an integrated climate response strategy, releasing accurate early warning and action guidance, sharing flood-related information, and applying the advantages of online social network analysis.
Liang Yang; Jürgen Scheffran; Huapeng Qin; Qinglong You. Climate-related flood risks and urban responses in the Pearl River Delta, China. Regional Environmental Change 2014, 15, 379 -391.
AMA StyleLiang Yang, Jürgen Scheffran, Huapeng Qin, Qinglong You. Climate-related flood risks and urban responses in the Pearl River Delta, China. Regional Environmental Change. 2014; 15 (2):379-391.
Chicago/Turabian StyleLiang Yang; Jürgen Scheffran; Huapeng Qin; Qinglong You. 2014. "Climate-related flood risks and urban responses in the Pearl River Delta, China." Regional Environmental Change 15, no. 2: 379-391.