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2020 Vol. 38, No. 4
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2020, 38(4): 1-4.
doi: 10.13205/j.hjgc.202004001
Abstract:
Based on the systematic analysis of natural factors such as hydrogeology and climate conditions of Chinese cities, and the social factors such as new and old urban areas and land use function types, this paper classifies and summarizes the pilot experience of sponge cities in China, and puts forward the construction strategy and paradigm of sponge cities based on regional classification in China and social attributes classification in cities, so as to provide references for sponge city construction promotion in the future.
Based on the systematic analysis of natural factors such as hydrogeology and climate conditions of Chinese cities, and the social factors such as new and old urban areas and land use function types, this paper classifies and summarizes the pilot experience of sponge cities in China, and puts forward the construction strategy and paradigm of sponge cities based on regional classification in China and social attributes classification in cities, so as to provide references for sponge city construction promotion in the future.
2020, 38(4): 5-9,107.
doi: 10.13205/j.hjgc.202004002
Abstract:
After more than four years of innovative practice in 30 sponge city pilot areas across China, the urban ecological environment had been improved significantly, and the pilot results had been remarkable. On the basis of summarizing the pilot experiences, in order to further implement the goals and requirements of the Guiding Opinions on Promoting the Construction of Sponge City issued by the General Office of the State Council, the Ministry of Housing and Urban-Rural Development clearly puts forward the need for "systematic and full-field promotion of sponge city construction" at the 2020 annual National Work Meeting. Based on the research and practice of systematic and full-field promotion of sponge city construction in Shanghai, especially the experience of Lin-gang pilot area, this paper studied from the aspects of system construction, full-field promotion, and promotion of Lin-gang after the pilot, so as to provide reference for the systematic and full-field promotion of sponge city construction in other cities.
After more than four years of innovative practice in 30 sponge city pilot areas across China, the urban ecological environment had been improved significantly, and the pilot results had been remarkable. On the basis of summarizing the pilot experiences, in order to further implement the goals and requirements of the Guiding Opinions on Promoting the Construction of Sponge City issued by the General Office of the State Council, the Ministry of Housing and Urban-Rural Development clearly puts forward the need for "systematic and full-field promotion of sponge city construction" at the 2020 annual National Work Meeting. Based on the research and practice of systematic and full-field promotion of sponge city construction in Shanghai, especially the experience of Lin-gang pilot area, this paper studied from the aspects of system construction, full-field promotion, and promotion of Lin-gang after the pilot, so as to provide reference for the systematic and full-field promotion of sponge city construction in other cities.
2020, 38(4): 10-15,38.
doi: 10.13205/j.hjgc.202004003
Abstract:
The core of sponge city construction is building modern urban stormwater management system with multiple measures of infiltration, detention, storage, purification, harvest, drainage, and achieving integrated objectives, including urban flood control and black and odorous water treatment. It's on the basis of inheriting the ancient wisdom, referencing the experience of the developed countries, summarizing the experience of long term research and practice of stormwater management in China. Low impact development is the critical guiding philosophy of sponge city and the components of sponge city technical system. The correct knowledge of the connotation and relations between low impact development and sponge city is significant for implementing low impact development model and promoting sponge city construction nationwide.
The core of sponge city construction is building modern urban stormwater management system with multiple measures of infiltration, detention, storage, purification, harvest, drainage, and achieving integrated objectives, including urban flood control and black and odorous water treatment. It's on the basis of inheriting the ancient wisdom, referencing the experience of the developed countries, summarizing the experience of long term research and practice of stormwater management in China. Low impact development is the critical guiding philosophy of sponge city and the components of sponge city technical system. The correct knowledge of the connotation and relations between low impact development and sponge city is significant for implementing low impact development model and promoting sponge city construction nationwide.
2020, 38(4): 16-20.
doi: 10.13205/j.hjgc.202004004
Abstract:
In 1968, the USA initiated the national flood insurance program (NFIP), and then continuously improved the research of flood risk analysis. By creating a relatively well-developed system of flood prone area management, flood risk analysis had been widely used in many fields including flood insurance, urban planning, land development, emergency management and so on. After suffering a series of hurricanes, especially the hurricane Sandy in 2012, New York City realized the importance of urban green space for stormwater storage during emergency flood events. Then after continuous research and practice, the requirements of urban green space planning and design based on flood risk analysis were put forward. By summarizing and analyzing the adjustment of flood risk map of New York City under the influence of hurricane Sandy, and its requirements for urban green space planning and design, the enlightenment of flood risk control and urban green space planning and design in China was proposed.
In 1968, the USA initiated the national flood insurance program (NFIP), and then continuously improved the research of flood risk analysis. By creating a relatively well-developed system of flood prone area management, flood risk analysis had been widely used in many fields including flood insurance, urban planning, land development, emergency management and so on. After suffering a series of hurricanes, especially the hurricane Sandy in 2012, New York City realized the importance of urban green space for stormwater storage during emergency flood events. Then after continuous research and practice, the requirements of urban green space planning and design based on flood risk analysis were put forward. By summarizing and analyzing the adjustment of flood risk map of New York City under the influence of hurricane Sandy, and its requirements for urban green space planning and design, the enlightenment of flood risk control and urban green space planning and design in China was proposed.
2020, 38(4): 21-25.
doi: 10.13205/j.hjgc.202004005
Abstract:
This paper studied the connection between the sponge city construction and the river basin comprehensive planning. Through the comparison of the two technical routes, it was considered that the two will further enhance the connection and the coverage of the planning. The Fourth Phase of Comprehensive Environmental Control Project in Suzhou Creek in Shanghai, and the comprehensive management project of Yongding River River Basin in Beijing was studied to further elaborate the viewpoint.
This paper studied the connection between the sponge city construction and the river basin comprehensive planning. Through the comparison of the two technical routes, it was considered that the two will further enhance the connection and the coverage of the planning. The Fourth Phase of Comprehensive Environmental Control Project in Suzhou Creek in Shanghai, and the comprehensive management project of Yongding River River Basin in Beijing was studied to further elaborate the viewpoint.
2020, 38(4): 26-31,58.
doi: 10.13205/j.hjgc.202004006
Abstract:
At present, most researches in China on urban stormwater runoff pollution focus on SS, COD, TN, TP, heavy metals, refractory organics, etc., but there are little systematic researches on the problem of stormwater runoff thermal pollution. Urban stormwater runoff thermal pollution will not only reduce the dissolved oxygen of watershed, but also endanger the survival of aquatic organisms such as cold-water fish, thereby destroy the balance of the entire aquatic ecosystem. By reviewing the research advances of urban stormwater runoff thermal pollution, many aspects were systematically analyzed including sources and main influencing factors of urban stormwater runoff thermal pollution, thermal pollution mechanism and erosion rule of urban stormwater runoff, comparison of the models and methods for urban stormwater runoff thermal pollution load assessment, control measures for urban rainwater runoff thermal pollution. The development direction of research on stormwater runoff thermal pollution in China was proposed, and a scientific basis for the control of urban stormwater runoff thermal pollution and sustainable land development was provided.
At present, most researches in China on urban stormwater runoff pollution focus on SS, COD, TN, TP, heavy metals, refractory organics, etc., but there are little systematic researches on the problem of stormwater runoff thermal pollution. Urban stormwater runoff thermal pollution will not only reduce the dissolved oxygen of watershed, but also endanger the survival of aquatic organisms such as cold-water fish, thereby destroy the balance of the entire aquatic ecosystem. By reviewing the research advances of urban stormwater runoff thermal pollution, many aspects were systematically analyzed including sources and main influencing factors of urban stormwater runoff thermal pollution, thermal pollution mechanism and erosion rule of urban stormwater runoff, comparison of the models and methods for urban stormwater runoff thermal pollution load assessment, control measures for urban rainwater runoff thermal pollution. The development direction of research on stormwater runoff thermal pollution in China was proposed, and a scientific basis for the control of urban stormwater runoff thermal pollution and sustainable land development was provided.
2020, 38(4): 32-38.
doi: 10.13205/j.hjgc.202004007
Abstract:
In urbanized areas, stormwater runoff carries heat enriched in the impervious surface and is discharged into the receiving water body, causing thermal pollution. While we are now in shortage of research on the harm of thermal pollution form stormwater runoff, and the controlling standards and technical measures. The causes of thermal pollution from stormwater runoff, and its impact on aquatic organisms and the water environment were elaborated. The common parameters for evaluating thermal pollution load, policy standards and technical measures for controlling thermal pollution of stormwater runoff were analyzed. A quantitative calculation method for thermal pollution load reduction in stormwater facilities, projects or catchment areas was proposed. The applicability analysis of the control efficiency of thermal pollution by current green stormwater source reduction facilities in China was carried out. The countermeasures and suggestions for the prevention and control of thermal pollution load of stormwater runoff were also proposed based on the actual situation in China.
In urbanized areas, stormwater runoff carries heat enriched in the impervious surface and is discharged into the receiving water body, causing thermal pollution. While we are now in shortage of research on the harm of thermal pollution form stormwater runoff, and the controlling standards and technical measures. The causes of thermal pollution from stormwater runoff, and its impact on aquatic organisms and the water environment were elaborated. The common parameters for evaluating thermal pollution load, policy standards and technical measures for controlling thermal pollution of stormwater runoff were analyzed. A quantitative calculation method for thermal pollution load reduction in stormwater facilities, projects or catchment areas was proposed. The applicability analysis of the control efficiency of thermal pollution by current green stormwater source reduction facilities in China was carried out. The countermeasures and suggestions for the prevention and control of thermal pollution load of stormwater runoff were also proposed based on the actual situation in China.
2020, 38(4): 39-45.
doi: 10.13205/j.hjgc.202004008
Abstract:
In order to study the effect of substrate composition of extensive green roof on the leaching of N, P, COD and SS from rainwater, three green roof models with different substrate compositions were constructed according to rainfall intensity and water quality in central China, and the water quality monitoring of green roof was carried out under 9 simulated rainstorms. The results showed that the green roof facilities in this experiment could reduce TN, NH4+-N, NO3--N and SS, but the leaching of TP and PO43--P was obvious. The outflow of green roof was mainly particulate phosphorus and dissolved nitrogen; removal of SS from the effluent had significant effect on COD purification; the addition of biochar had obvious controlling effect on the outflow pollutants, which could effectively alleviate the problems of high concentration of pollutants in the initial stage of rainfall, and significantly increase the aboveground biomass of plants; the average concentration of N and COD in the effluent from green roof of 5 cm thick was lower than that of 10 cm thick, but the SS effluent was higher, and the plants could not maintain good growth in the later stage of rainfall. The extensive green roof facility had good pollution interception effect after stable operation, and high feasibility and broad application prospects.
In order to study the effect of substrate composition of extensive green roof on the leaching of N, P, COD and SS from rainwater, three green roof models with different substrate compositions were constructed according to rainfall intensity and water quality in central China, and the water quality monitoring of green roof was carried out under 9 simulated rainstorms. The results showed that the green roof facilities in this experiment could reduce TN, NH4+-N, NO3--N and SS, but the leaching of TP and PO43--P was obvious. The outflow of green roof was mainly particulate phosphorus and dissolved nitrogen; removal of SS from the effluent had significant effect on COD purification; the addition of biochar had obvious controlling effect on the outflow pollutants, which could effectively alleviate the problems of high concentration of pollutants in the initial stage of rainfall, and significantly increase the aboveground biomass of plants; the average concentration of N and COD in the effluent from green roof of 5 cm thick was lower than that of 10 cm thick, but the SS effluent was higher, and the plants could not maintain good growth in the later stage of rainfall. The extensive green roof facility had good pollution interception effect after stable operation, and high feasibility and broad application prospects.
2020, 38(4): 46-52,100.
doi: 10.13205/j.hjgc.202004009
Abstract:
The infiltration characteristics in permeable brick pavement system (PBPS) of sponge city construction is its key factors, which influence the runoff producing time and the removal of heavy metals from runoff. Through the seepage test, the soil-water characteristic curves of PBPS soil layers were constructed, and then the infiltration model and the mathematical model for runoff heavy metal pollutant migration of PBPS was established. Finally, the effect of leveling layer soil particle size and base to cushion layer thickness ratio on the runoff producing time and the removal of heavy metals from runoff were illustrated. The results showed that with comprehensive consideration of the PBPS's ability in delaying runoff generation time and removal of heavy metal pollutants, medium sand was the best choice for leveling layer soil; according to the concentration of heavy metal pollutants in the effluent of the structure layer, when the ratio of base to cushion layer thickness ratio was 15∶4, PBPS had the highest adsorption efficiency and good effect on removing heavy metal pollutants in runoff.
The infiltration characteristics in permeable brick pavement system (PBPS) of sponge city construction is its key factors, which influence the runoff producing time and the removal of heavy metals from runoff. Through the seepage test, the soil-water characteristic curves of PBPS soil layers were constructed, and then the infiltration model and the mathematical model for runoff heavy metal pollutant migration of PBPS was established. Finally, the effect of leveling layer soil particle size and base to cushion layer thickness ratio on the runoff producing time and the removal of heavy metals from runoff were illustrated. The results showed that with comprehensive consideration of the PBPS's ability in delaying runoff generation time and removal of heavy metal pollutants, medium sand was the best choice for leveling layer soil; according to the concentration of heavy metal pollutants in the effluent of the structure layer, when the ratio of base to cushion layer thickness ratio was 15∶4, PBPS had the highest adsorption efficiency and good effect on removing heavy metal pollutants in runoff.
2020, 38(4): 53-58.
doi: 10.13205/j.hjgc.202004010
Abstract:
Permeable pavement is one of the key technologies for stormwater runoff emission reduction, of which the frost heaving damage in cold area is an urgent problem. Permeable bricks are widely used pervious pavement materials. The frost resistance of permeable pavement surface in different porosity, water saturation and permeable base thickness was studied through the freeze-thaw cycle experiments. The results showed that the porosity of the surface layer had a negative correlation with its frost resistance, and the higher porosity, the worse frost resistance of the surface layer. There was a negative correlation between the surface water saturation and its frost resistance, also. The frost resistance descended as the water saturation increased. The critical value of the surface water saturation for frost heave damage was 90%. When the water saturation of the surface layer was lower than 90%, the frost resistance was less damaged; when the water saturation of the surface layer was higher than 90%, the frost resistance got obviously worse. The thickness of permeable base had little effect on the frost resistance of permeable pavement. The three main influencing factors on the frost resistance of permeable pavement surface were in the extent sequence of water saturation > porosity > thickness of permeable base.
Permeable pavement is one of the key technologies for stormwater runoff emission reduction, of which the frost heaving damage in cold area is an urgent problem. Permeable bricks are widely used pervious pavement materials. The frost resistance of permeable pavement surface in different porosity, water saturation and permeable base thickness was studied through the freeze-thaw cycle experiments. The results showed that the porosity of the surface layer had a negative correlation with its frost resistance, and the higher porosity, the worse frost resistance of the surface layer. There was a negative correlation between the surface water saturation and its frost resistance, also. The frost resistance descended as the water saturation increased. The critical value of the surface water saturation for frost heave damage was 90%. When the water saturation of the surface layer was lower than 90%, the frost resistance was less damaged; when the water saturation of the surface layer was higher than 90%, the frost resistance got obviously worse. The thickness of permeable base had little effect on the frost resistance of permeable pavement. The three main influencing factors on the frost resistance of permeable pavement surface were in the extent sequence of water saturation > porosity > thickness of permeable base.
2020, 38(4): 59-65.
doi: 10.13205/j.hjgc.202004011
Abstract:
With the rapid development of urbanization and the rapid increase of urban population, urban water demand has increased markedly, resulting in excessive exploitation of groundwater in many cities. At the same time, with the increase of urban construction area, the proportion of impervious area has increased year by year, blocking the paths of rainwater seepage, resulting in the reduction of groundwater recharge volume. Excessive exploitation of groundwater resources has caused a series of problems such as uneven ground settlement, groundwater pollution, and seawater intrusion. In view of the above problems, taking a city in China as an example, the comprehensive benefits of artificial water diversion and sponge city to promote recharge of groundwater were compared in terms of water quantity, water quality and engineering reliability. The results showed that the groundwater recharge of the artificial water diversion was about 7.79×106 m3/a, and the groundwater recharge of the sponge city construction was 3.39×106 m3/a. The pollutants of the two methods were similar, but there existed large great fluctuation of the concentration of rainwater runoff pollutants. Therefore, artificial water diversion had the advantages of easy control of water quantity and relatively stable water quality, but the water volume was limited by the available water sources. While ensuring the effect of groundwater recharge, sponge city construction also had multiple benefits such as rainwater runoff pollution control and flood mitigation. The comprehensive benefits were relatively high, and it's more in line with the concept of sustainable urban development.
With the rapid development of urbanization and the rapid increase of urban population, urban water demand has increased markedly, resulting in excessive exploitation of groundwater in many cities. At the same time, with the increase of urban construction area, the proportion of impervious area has increased year by year, blocking the paths of rainwater seepage, resulting in the reduction of groundwater recharge volume. Excessive exploitation of groundwater resources has caused a series of problems such as uneven ground settlement, groundwater pollution, and seawater intrusion. In view of the above problems, taking a city in China as an example, the comprehensive benefits of artificial water diversion and sponge city to promote recharge of groundwater were compared in terms of water quantity, water quality and engineering reliability. The results showed that the groundwater recharge of the artificial water diversion was about 7.79×106 m3/a, and the groundwater recharge of the sponge city construction was 3.39×106 m3/a. The pollutants of the two methods were similar, but there existed large great fluctuation of the concentration of rainwater runoff pollutants. Therefore, artificial water diversion had the advantages of easy control of water quantity and relatively stable water quality, but the water volume was limited by the available water sources. While ensuring the effect of groundwater recharge, sponge city construction also had multiple benefits such as rainwater runoff pollution control and flood mitigation. The comprehensive benefits were relatively high, and it's more in line with the concept of sustainable urban development.
2020, 38(4): 66-71,76.
doi: 10.13205/j.hjgc.202004012
Abstract:
Urban runoff pollution has caused serious problems to the water environment. As a structure for collecting runoff, municipal inlet can be transformed into pollution interception facilities at the source. The test added a pollution interception net basket to the grate inlet, and sampled the influent and effluent of grate inlet from rainfall events. The results showed that the composition of runoff pollutant was complex. In the beginning of rainy season and when the interval was long, the pollution load of runoff was particularly serious. The removal device was mainly based on physical interception, the removal efficiency of SS was better,the average removal efficiency was 54.5%, and the removal efficiency of COD and other pollutants was relatively lower. As a simple purification measure, the decontamination device could be applied to the municipal water outlet in the newly built, rebuilt and expanded areas, and play a role in management of runoff pollution and black and odor water bodies.
Urban runoff pollution has caused serious problems to the water environment. As a structure for collecting runoff, municipal inlet can be transformed into pollution interception facilities at the source. The test added a pollution interception net basket to the grate inlet, and sampled the influent and effluent of grate inlet from rainfall events. The results showed that the composition of runoff pollutant was complex. In the beginning of rainy season and when the interval was long, the pollution load of runoff was particularly serious. The removal device was mainly based on physical interception, the removal efficiency of SS was better,the average removal efficiency was 54.5%, and the removal efficiency of COD and other pollutants was relatively lower. As a simple purification measure, the decontamination device could be applied to the municipal water outlet in the newly built, rebuilt and expanded areas, and play a role in management of runoff pollution and black and odor water bodies.
2020, 38(4): 72-76.
doi: 10.13205/j.hjgc.202004013
Abstract:
Bio-retention facilities, such as green space and rain garden participate in the natural infiltration and regulation of rainwater and surface runoff, and are important parts of the sponge city. The infiltration of rainwater plays an important role in the reduction of rainwater discharge quantity. At present, the design of soil seepage is mainly based on Darcy's law, but Darcy's law does not apply to the unsaturated soil. In the laboratory, the water head penetration test of different initial soil moisture content of the same soil was carried out. The change of initial soil moisture content was obtained by long-term natural water loss. A function relating water head penetration velocity and time was obtained and compared with the calculation result of Darcy's law. The results may provide reference for calculation in future design of soil infiltration in sponge city.
Bio-retention facilities, such as green space and rain garden participate in the natural infiltration and regulation of rainwater and surface runoff, and are important parts of the sponge city. The infiltration of rainwater plays an important role in the reduction of rainwater discharge quantity. At present, the design of soil seepage is mainly based on Darcy's law, but Darcy's law does not apply to the unsaturated soil. In the laboratory, the water head penetration test of different initial soil moisture content of the same soil was carried out. The change of initial soil moisture content was obtained by long-term natural water loss. A function relating water head penetration velocity and time was obtained and compared with the calculation result of Darcy's law. The results may provide reference for calculation in future design of soil infiltration in sponge city.
2020, 38(4): 77-82,113.
doi: 10.13205/j.hjgc.202004014
Abstract:
Bioretention is one of the typical technical measures for urban stormwater management and sponge city construction. The nitrogen and phosphorus purification mechanism and pollution control effect of bioretention for urban stormwater runoff had been thoroughly investigated. The purification mechanism of different forms of nitrogen and phosphorus was systematically summarized, and the control effect of traditional bioretention on nitrogen and phosphorus in stormwater runoff was analyzed. The improvement of bioretention on the nitrogen and phosphorus purification effect for stormwater runoff was systematically analyzed from four aspects, media types and composition, submerged zone setting, carbon source addition, and media packing arrangement. Based on the current research and the actual engineering demand in the construction of sponge city, the future research directions of nitrogen and phosphorus control were forecasted.
Bioretention is one of the typical technical measures for urban stormwater management and sponge city construction. The nitrogen and phosphorus purification mechanism and pollution control effect of bioretention for urban stormwater runoff had been thoroughly investigated. The purification mechanism of different forms of nitrogen and phosphorus was systematically summarized, and the control effect of traditional bioretention on nitrogen and phosphorus in stormwater runoff was analyzed. The improvement of bioretention on the nitrogen and phosphorus purification effect for stormwater runoff was systematically analyzed from four aspects, media types and composition, submerged zone setting, carbon source addition, and media packing arrangement. Based on the current research and the actual engineering demand in the construction of sponge city, the future research directions of nitrogen and phosphorus control were forecasted.
2020, 38(4): 83-88.
doi: 10.13205/j.hjgc.202004015
Abstract:
Soil permeability was one of the key factors affecting rainwater infiltration, and also an important prerequisite for analyzing the ability of soil to storage rainwater. In view of the current situation that the measured data of urban green space soil permeability was missing, the evaluation method was rare, and the index was insufficient, this paper obtained the data of soil permeable rate, void ratio and moisture content of different urban functional areas by using the actual measurement method. Correlation analysis, factor analysis and multiple linear regression analysis were used to analyze the main factors affecting the soil permeability of urban communities, and exploded to establish a soil permeability evaluation model with higher precision, less data demand and shorter calculation time. This model was used to obtain the infiltration capacity of urban green space rainwater in Beijing, establish the relationship between soil and rainfall-runoff, and get the measured data-oriented, closer to the actual runoff coefficient. The results showed that the soil permeability of the three functional areas in experimental plots were in order of residential area > cultural and educational area > commercial area, and the measured infiltration curves were all consistent with the Horton model. The void ratio, initial moisture content and initial infiltration rate of the internal factors of the soil were closely related to each other. The degree of vegetation coverage in the external factors had a strong negative correlation with human disturbance. Considering the combined effect of internal and external factors, the initial infiltration rate could establish a preliminary linear relationship with initial moisture content and vegetation coverage (R2>0.9). As the proportion of rainfall and impervious area ratio increased, the infiltration amount had smaller impact on runoff coefficient. The ratio of infiltration to rainfall corresponding to the total annual runoff control rate was between 37.6% and 58.2%, and it was negatively correlated with rainfall. The research could provide a theoretical reference for the modeling of sponge city and the design optimization of underlying surface.
Soil permeability was one of the key factors affecting rainwater infiltration, and also an important prerequisite for analyzing the ability of soil to storage rainwater. In view of the current situation that the measured data of urban green space soil permeability was missing, the evaluation method was rare, and the index was insufficient, this paper obtained the data of soil permeable rate, void ratio and moisture content of different urban functional areas by using the actual measurement method. Correlation analysis, factor analysis and multiple linear regression analysis were used to analyze the main factors affecting the soil permeability of urban communities, and exploded to establish a soil permeability evaluation model with higher precision, less data demand and shorter calculation time. This model was used to obtain the infiltration capacity of urban green space rainwater in Beijing, establish the relationship between soil and rainfall-runoff, and get the measured data-oriented, closer to the actual runoff coefficient. The results showed that the soil permeability of the three functional areas in experimental plots were in order of residential area > cultural and educational area > commercial area, and the measured infiltration curves were all consistent with the Horton model. The void ratio, initial moisture content and initial infiltration rate of the internal factors of the soil were closely related to each other. The degree of vegetation coverage in the external factors had a strong negative correlation with human disturbance. Considering the combined effect of internal and external factors, the initial infiltration rate could establish a preliminary linear relationship with initial moisture content and vegetation coverage (R2>0.9). As the proportion of rainfall and impervious area ratio increased, the infiltration amount had smaller impact on runoff coefficient. The ratio of infiltration to rainfall corresponding to the total annual runoff control rate was between 37.6% and 58.2%, and it was negatively correlated with rainfall. The research could provide a theoretical reference for the modeling of sponge city and the design optimization of underlying surface.
2020, 38(4): 89-95.
doi: 10.13205/j.hjgc.202004016
Abstract:
Plants are the basic constituent units of sponge facilities, and their growth and application status greatly affects the function and performance of sponge facilities. This article took the plant landscape of 72 low impact development (LID) facilities in 21 sponge city projects in Beijing as research objects and conducted post-completion evaluation. Through field survey, the species and applying frequency of plants in LID facilities, configuration mode, ornamental characteristics, growth status and existing problems were summarized; analytical hierarchy process (AHP) was used to construct an LID facility plant landscape evaluation system from three aspects, plant ecological habits, rainwater functionality and ornamental properties; the constructed evaluation system was used to rate 10 plant communities for typical LID facilities in Beijing. Based on the results of the evaluation and analysis, the plant configuration with high comprehensive benefits and optimization approaches were proposed, to provide a reference for the plant landscape improvement of LID facilities in Beijing and northern China.
Plants are the basic constituent units of sponge facilities, and their growth and application status greatly affects the function and performance of sponge facilities. This article took the plant landscape of 72 low impact development (LID) facilities in 21 sponge city projects in Beijing as research objects and conducted post-completion evaluation. Through field survey, the species and applying frequency of plants in LID facilities, configuration mode, ornamental characteristics, growth status and existing problems were summarized; analytical hierarchy process (AHP) was used to construct an LID facility plant landscape evaluation system from three aspects, plant ecological habits, rainwater functionality and ornamental properties; the constructed evaluation system was used to rate 10 plant communities for typical LID facilities in Beijing. Based on the results of the evaluation and analysis, the plant configuration with high comprehensive benefits and optimization approaches were proposed, to provide a reference for the plant landscape improvement of LID facilities in Beijing and northern China.
2020, 38(4): 101-107.
doi: 10.13205/j.hjgc.202004018
Abstract:
Transmission thinking is a kind of thinking mode with strong logical response. With sufficient motivation and analysis methods, reasonable conclusions are derived step by step to achieve the goal. Sponge city construction planning needs to be prepared in accordance with local conditions, as well as being rational and pragmatic. Taking the sponge city construction planning of Songjiang District in Shanghai as an example, this paper studied the basic concept and connotation of the transmission thinking, discussed the application of the transmission thinking in the sponge city construction planning in combination with the preparation ideas, contents, technical methods, etc., and initially summarized the preparation methods of the sponge city construction planning based on the transmission thinking, in order to provide reference and technical support to the sponge city construction planning rationally.
Transmission thinking is a kind of thinking mode with strong logical response. With sufficient motivation and analysis methods, reasonable conclusions are derived step by step to achieve the goal. Sponge city construction planning needs to be prepared in accordance with local conditions, as well as being rational and pragmatic. Taking the sponge city construction planning of Songjiang District in Shanghai as an example, this paper studied the basic concept and connotation of the transmission thinking, discussed the application of the transmission thinking in the sponge city construction planning in combination with the preparation ideas, contents, technical methods, etc., and initially summarized the preparation methods of the sponge city construction planning based on the transmission thinking, in order to provide reference and technical support to the sponge city construction planning rationally.
2020, 38(4): 108-113.
doi: 10.13205/j.hjgc.202004019
Abstract:
In this paper, based on the integrated river drainage system model, Infoworks ICM, by coupling sponge cities, urban drainage pipe network, river, drainage pumping station system, the whole process of waterlogging prevention and control system model was established, which conducted coupling evaluation of three processes of waterlogging, including source, process and end. It made up the deficiency of single simulated pipe network or sponge system in traditional waterlogging control measures. The advantages of establishing waterlogging prevention and control system in the whole process were analyzed by simulating the current situation, expanding and perfecting pipeline network system, building low-impact development system and perfecting drainage pumping station system, separately. The simulation results indicated that the coupling effect of the three measures was enhanced to varying degrees on the basis of the present situation. The drainage capacity of pipelines increased gradually, and the area of waterlogging risk decreased by 13.5%, 39.4% and 86.9% through the three measures, respectively. In addition, the waterlogging risk couldn't be throughly solved by one single waterlogging control measure. Therefore, it's effective and ungent to establish a complete waterlogging control system in the whole process.
In this paper, based on the integrated river drainage system model, Infoworks ICM, by coupling sponge cities, urban drainage pipe network, river, drainage pumping station system, the whole process of waterlogging prevention and control system model was established, which conducted coupling evaluation of three processes of waterlogging, including source, process and end. It made up the deficiency of single simulated pipe network or sponge system in traditional waterlogging control measures. The advantages of establishing waterlogging prevention and control system in the whole process were analyzed by simulating the current situation, expanding and perfecting pipeline network system, building low-impact development system and perfecting drainage pumping station system, separately. The simulation results indicated that the coupling effect of the three measures was enhanced to varying degrees on the basis of the present situation. The drainage capacity of pipelines increased gradually, and the area of waterlogging risk decreased by 13.5%, 39.4% and 86.9% through the three measures, respectively. In addition, the waterlogging risk couldn't be throughly solved by one single waterlogging control measure. Therefore, it's effective and ungent to establish a complete waterlogging control system in the whole process.
2020, 38(4): 114-118,163.
doi: 10.13205/j.hjgc.202004020
Abstract:
In this paper, focused on the systematic planning of sponge city construction, the vertical elevation planning system was studied. Based on the traditional analysis of flood control and drainage factors, the analysis of underground space, sponge space and facility layout was added, and the traditional drainage mode of "quick discharge, end management" was changed through vertical planning, to provide vertical support for the establishment of multi-level control mode including source emission reduction, process control and system management. In order to determine the vertical elevation of the city scientifically, on the basis of the traditional vertical planning method, the determining method of the vertical reference elevation was optimized. According to the different functional requirements of the site and the road, the controlling method of the vertical elevation of the site and the road through classification was proposed to construct the vertical spatial model of sponge space and facilities, which could provide practical ideas for the compilation of vertical urban planning in the future, and reference for the vertical coordination of space and facilities in sponge city construction.
In this paper, focused on the systematic planning of sponge city construction, the vertical elevation planning system was studied. Based on the traditional analysis of flood control and drainage factors, the analysis of underground space, sponge space and facility layout was added, and the traditional drainage mode of "quick discharge, end management" was changed through vertical planning, to provide vertical support for the establishment of multi-level control mode including source emission reduction, process control and system management. In order to determine the vertical elevation of the city scientifically, on the basis of the traditional vertical planning method, the determining method of the vertical reference elevation was optimized. According to the different functional requirements of the site and the road, the controlling method of the vertical elevation of the site and the road through classification was proposed to construct the vertical spatial model of sponge space and facilities, which could provide practical ideas for the compilation of vertical urban planning in the future, and reference for the vertical coordination of space and facilities in sponge city construction.
2020, 38(4): 119-123.
doi: 10.13205/j.hjgc.202004021
Abstract:
The background characteristics of a plain river network city were analyzed and defined as "two-high, one-middle and one-low". In view of the old and new urban pilot areas for sponge city, the existing typical problems were discussed from the perspectives of water security, water environment, water ecology and water resources. The key factors, main principles and the recommended scheme of sponge city facilities selection were put forward, and two typical projects were selected to study the construction scheme. The research showed that the sponge city construction in the old urban area should be fully combined with urban renewal, emphasize integration and cohesion, while that in the new urban area should have a higher starting point and standard, and emphasize the demonstration and leading functions.
The background characteristics of a plain river network city were analyzed and defined as "two-high, one-middle and one-low". In view of the old and new urban pilot areas for sponge city, the existing typical problems were discussed from the perspectives of water security, water environment, water ecology and water resources. The key factors, main principles and the recommended scheme of sponge city facilities selection were put forward, and two typical projects were selected to study the construction scheme. The research showed that the sponge city construction in the old urban area should be fully combined with urban renewal, emphasize integration and cohesion, while that in the new urban area should have a higher starting point and standard, and emphasize the demonstration and leading functions.
2020, 38(4): 124-127,140.
doi: 10.13205/j.hjgc.202004022
Abstract:
In order to discuss the application and experiences of the pollution control technology of intercepting shunt system in the treatment of wastewater, we took Xingfu water system in Nanchang as an example, in the areas where the shunting of rain and sewage was planned but not actually achieved in practice, the intercepting shunt system were adopted to achieve the coordinated control of overflow pollution and non-point source pollution. And then, comprehensive control of pollution water system was carried out step by step, in the near and long term. The intercepting shunt system in the treatment of wastewater could be used to comprehensively control the pollution of urban black and odorous water bodies, and achieve better water system control effect finally.
In order to discuss the application and experiences of the pollution control technology of intercepting shunt system in the treatment of wastewater, we took Xingfu water system in Nanchang as an example, in the areas where the shunting of rain and sewage was planned but not actually achieved in practice, the intercepting shunt system were adopted to achieve the coordinated control of overflow pollution and non-point source pollution. And then, comprehensive control of pollution water system was carried out step by step, in the near and long term. The intercepting shunt system in the treatment of wastewater could be used to comprehensively control the pollution of urban black and odorous water bodies, and achieve better water system control effect finally.
2020, 38(4): 128-133.
doi: 10.13205/j.hjgc.202004023
Abstract:
How to reduce the construction cost while increasing the reduction rate of combined sewer overflow (CSO) control system has been widely concerned by the planning & decision makers. In this study, the multi-objective optimization model of CSO system construction cost and CSO reduction rate was established by using Matlab, Python and SWMM. A series of Pareto solution sets were obtained using non-dominant sorting genetic algorithm (NSGA-Ⅱ), so different options were put forward to planning decision makers. For the 3-year storm events, the optimization results showed that the proportion of the construction cost was highest for constructing source low impact development (LID) facilities, followed by constructing the detention tanks and retrofitting the midway pipes. Among the three types of facilities, the contribution of the CSO reduction rate of the detention tanks was the highest, followed by the source LID facilities and the midway pipes.
How to reduce the construction cost while increasing the reduction rate of combined sewer overflow (CSO) control system has been widely concerned by the planning & decision makers. In this study, the multi-objective optimization model of CSO system construction cost and CSO reduction rate was established by using Matlab, Python and SWMM. A series of Pareto solution sets were obtained using non-dominant sorting genetic algorithm (NSGA-Ⅱ), so different options were put forward to planning decision makers. For the 3-year storm events, the optimization results showed that the proportion of the construction cost was highest for constructing source low impact development (LID) facilities, followed by constructing the detention tanks and retrofitting the midway pipes. Among the three types of facilities, the contribution of the CSO reduction rate of the detention tanks was the highest, followed by the source LID facilities and the midway pipes.
2020, 38(4): 134-140.
doi: 10.13205/j.hjgc.202004024
Abstract:
After the first batch of pilot cities construction completed, studies on sponge city planning and simulation increased obliviously. However, studies on continuous monitoring and in-depth analysis of sponge construction were still scarce, which were just the key to optimize the future planning and construction of sponge city. This study selected Hebi in Henan Province as the research area to analyze the characteristics of water quality and runoff reduction rate, before and after the sponge city construction. The purpose was to evaluate the effectiveness of sponge city construction on surface water quality and quantity. Manual monitoring and auto-detecting measures were used to monitor water quality and quantity in study area. From August in 2015 to September in 2018, 10 sample sites were monitored by 16 batches and 109 samples were finally analyzed. Meanwhile, flow data collected by the flowmeters of 20 rainwater discharge pipelines in 2018 were analyzed. The results were as follows: three water quality indexes, NH3-N,TN and DO had higher variation scopes, while pH had a lower variation scope. With the construction of sponge city, water quality had been improved. The runoff reduction rate of 2018 was as high as 85.7%, meeting the expected requirements. However, rainwater was discharged into pipelines when rainfall depth was less than 23 mm. The runoff reduction rate of different parts in study area was significantly different. This study enriched the practical data for sponge city and provided support for its construction and maintenance.
After the first batch of pilot cities construction completed, studies on sponge city planning and simulation increased obliviously. However, studies on continuous monitoring and in-depth analysis of sponge construction were still scarce, which were just the key to optimize the future planning and construction of sponge city. This study selected Hebi in Henan Province as the research area to analyze the characteristics of water quality and runoff reduction rate, before and after the sponge city construction. The purpose was to evaluate the effectiveness of sponge city construction on surface water quality and quantity. Manual monitoring and auto-detecting measures were used to monitor water quality and quantity in study area. From August in 2015 to September in 2018, 10 sample sites were monitored by 16 batches and 109 samples were finally analyzed. Meanwhile, flow data collected by the flowmeters of 20 rainwater discharge pipelines in 2018 were analyzed. The results were as follows: three water quality indexes, NH3-N,TN and DO had higher variation scopes, while pH had a lower variation scope. With the construction of sponge city, water quality had been improved. The runoff reduction rate of 2018 was as high as 85.7%, meeting the expected requirements. However, rainwater was discharged into pipelines when rainfall depth was less than 23 mm. The runoff reduction rate of different parts in study area was significantly different. This study enriched the practical data for sponge city and provided support for its construction and maintenance.
2020, 38(4): 141-144,150.
doi: 10.13205/j.hjgc.202004025
Abstract:
In order to evaluate the construction effect of sponge city, it is necessary to sample and monitor the runoff process of the sponge facilities and areas with different scales. It is difficult for the existing sampling methods and equipments to automatically collect water samples at the initial stage of runoff generation. In this paper, a set of automatic sampling technology for urban rainfall runoff water quality monitoring was developed, which included a non electric driving natural rainfall automatic sampler, an automatic sampling terminal for water quality monitoring that could "zero capture" the underlying surface runoff, an intelligent automatic water quality sampler and other equipments. It solved the problem of collecting initial water samples of natural rainfall and runoff process automatically on any weather condition. It could also record the exact time of sampling process. The practical application showed that the technology had strong applicability, reliable performance and could support the related scientific researches and monitoring activities.
In order to evaluate the construction effect of sponge city, it is necessary to sample and monitor the runoff process of the sponge facilities and areas with different scales. It is difficult for the existing sampling methods and equipments to automatically collect water samples at the initial stage of runoff generation. In this paper, a set of automatic sampling technology for urban rainfall runoff water quality monitoring was developed, which included a non electric driving natural rainfall automatic sampler, an automatic sampling terminal for water quality monitoring that could "zero capture" the underlying surface runoff, an intelligent automatic water quality sampler and other equipments. It solved the problem of collecting initial water samples of natural rainfall and runoff process automatically on any weather condition. It could also record the exact time of sampling process. The practical application showed that the technology had strong applicability, reliable performance and could support the related scientific researches and monitoring activities.
2020, 38(4): 145-150.
doi: 10.13205/j.hjgc.202004026
Abstract:
A new residential district developed via low impact development (LID) was selected as the research project, the multi-target control effect of total runoff volume and peak flow rate was achieved. The method of comparative analysis under the same rainfall event was adopt, six monitoring sites were selected at each outlet (A to F) in the LID residential district, and an outlet (G) from traditional residential district was selected as the comparison monitoring site, which had similar underlying surface types with the LID residential district. The monitoring results via seven typical rainfall events showed that: compared with traditional residential district, the LID residential district's runoff discharge total volume was decreased by 12.1%~100%, while the pollutant reduction rate was 69.6%~100% and the peak flow reduction rate was 12.3%~100%. By continuous modeling of typical annual rainfall data, the results showed that reduction rate of total runoff discharge volume was 77.3%, and that of pollutants was 66.4%. Therefore, both monitoring and modeling results indicated that the LID residential district could effectively control the total discharge of runoff and pollution load. The above research results could provide technical support for the development of sponge-residential district.
A new residential district developed via low impact development (LID) was selected as the research project, the multi-target control effect of total runoff volume and peak flow rate was achieved. The method of comparative analysis under the same rainfall event was adopt, six monitoring sites were selected at each outlet (A to F) in the LID residential district, and an outlet (G) from traditional residential district was selected as the comparison monitoring site, which had similar underlying surface types with the LID residential district. The monitoring results via seven typical rainfall events showed that: compared with traditional residential district, the LID residential district's runoff discharge total volume was decreased by 12.1%~100%, while the pollutant reduction rate was 69.6%~100% and the peak flow reduction rate was 12.3%~100%. By continuous modeling of typical annual rainfall data, the results showed that reduction rate of total runoff discharge volume was 77.3%, and that of pollutants was 66.4%. Therefore, both monitoring and modeling results indicated that the LID residential district could effectively control the total discharge of runoff and pollution load. The above research results could provide technical support for the development of sponge-residential district.
2020, 38(4): 151-157.
doi: 10.13205/j.hjgc.202004027
Abstract:
In this study, we took a typical sponge city project in Qingdao area as the study case, and constructed a SWMM model through collecting, sorting, and generalizing the watershed data. Actual rainfall-runoff monitoring data in rainy season of 2018 was employed for calibration and validation of the model. The results revealed that the construction of sponge city endowed the study area with reduced runoff, and increased infiltration and stagnant capabilities. The results showed that the proportion of rainfall to form runoff decreased from 56% to 29% and the proportion of rainfall to infiltrate increased from 40% to 60%. The depth of detention storage increased from 0.63 mm to 5 mm. The construction target of the study area was to control the total annual runoff at 75%, and the corresponding design rainfall was 27.4 mm. The runoff capture ratio of single event in the research area before and after sponge reconstruction changed significantly. When the short-term (120 min) design rainfall with return period from 1~10 years was used as the model boundary condition for simulation, the runoff capture ratio after sponge reconstruction increased by 26%~34%. It was considered that the study area had basically reached the sponge city construction requirements on rainfall runoff control.
In this study, we took a typical sponge city project in Qingdao area as the study case, and constructed a SWMM model through collecting, sorting, and generalizing the watershed data. Actual rainfall-runoff monitoring data in rainy season of 2018 was employed for calibration and validation of the model. The results revealed that the construction of sponge city endowed the study area with reduced runoff, and increased infiltration and stagnant capabilities. The results showed that the proportion of rainfall to form runoff decreased from 56% to 29% and the proportion of rainfall to infiltrate increased from 40% to 60%. The depth of detention storage increased from 0.63 mm to 5 mm. The construction target of the study area was to control the total annual runoff at 75%, and the corresponding design rainfall was 27.4 mm. The runoff capture ratio of single event in the research area before and after sponge reconstruction changed significantly. When the short-term (120 min) design rainfall with return period from 1~10 years was used as the model boundary condition for simulation, the runoff capture ratio after sponge reconstruction increased by 26%~34%. It was considered that the study area had basically reached the sponge city construction requirements on rainfall runoff control.
2020, 38(4): 158-163.
doi: 10.13205/j.hjgc.202004028
Abstract:
Due to inadequate construction of drainage systems in the past and strict reconstruction limitation at present, historical cultural reservation sites were prone to flooding in a heavy storm. Under the background of sponge city constuction promotion in China, the scientific rain water runoff management for the historical reservation sites turned out to be a key subject for the authority and the specialists. In this paper, historical auditorium surrounding area in Tsinghua University was selected as the case site. Aiming at sponge campus construction, we studied the natural based stormwater management schemes after the detail analysis of site present situation. We selected, designed and built four types of LID-BMPs (i.e., cistern, bioretention basin, porous pavement and swale) schemes in the area. Then, we used SUSTAIN model to evaluate the LID-BMPs' performance in water quantity-quality control and cost-profit balance. Results showed that the LID-BMPs system was able to meet the runoff control target in a designed storm and showed significant reduction in flow volume and pollutant load throughout a typical year.
Due to inadequate construction of drainage systems in the past and strict reconstruction limitation at present, historical cultural reservation sites were prone to flooding in a heavy storm. Under the background of sponge city constuction promotion in China, the scientific rain water runoff management for the historical reservation sites turned out to be a key subject for the authority and the specialists. In this paper, historical auditorium surrounding area in Tsinghua University was selected as the case site. Aiming at sponge campus construction, we studied the natural based stormwater management schemes after the detail analysis of site present situation. We selected, designed and built four types of LID-BMPs (i.e., cistern, bioretention basin, porous pavement and swale) schemes in the area. Then, we used SUSTAIN model to evaluate the LID-BMPs' performance in water quantity-quality control and cost-profit balance. Results showed that the LID-BMPs system was able to meet the runoff control target in a designed storm and showed significant reduction in flow volume and pollutant load throughout a typical year.
2020, 38(4): 164-169,175.
doi: 10.13205/j.hjgc.202004029
Abstract:
In order to quantitatively analyze the computational efficiency of GPU technology for urban rain-flood process numerical simulation, the numerical model based on GPU technology was used to simulate the process of rain and flood in typical cities with different rainfall and grid resolution, and to compare and analyze the efficiency and law of GPU acceleration. The results showed that GPU technology had more advantages than CPU for the simulation of rain-flood process in cities, which could increase the computational efficiency by 23.88~158.72 times, compared with CPU in different situations. In the case of heavy rainstorms and high-resolution grids, the speed-up effect of the GPU model was more obvious, and it kept about 0.29%~8.43% higher than the short return period rainstorms and low-resolution grids conditions. And this technology was proved suitable for simulation of large-scale and high-resolution problems. The model was thus considered as a technical support for rapid simulation forecasting of floods processes.
In order to quantitatively analyze the computational efficiency of GPU technology for urban rain-flood process numerical simulation, the numerical model based on GPU technology was used to simulate the process of rain and flood in typical cities with different rainfall and grid resolution, and to compare and analyze the efficiency and law of GPU acceleration. The results showed that GPU technology had more advantages than CPU for the simulation of rain-flood process in cities, which could increase the computational efficiency by 23.88~158.72 times, compared with CPU in different situations. In the case of heavy rainstorms and high-resolution grids, the speed-up effect of the GPU model was more obvious, and it kept about 0.29%~8.43% higher than the short return period rainstorms and low-resolution grids conditions. And this technology was proved suitable for simulation of large-scale and high-resolution problems. The model was thus considered as a technical support for rapid simulation forecasting of floods processes.
2020, 38(4): 170-175.
doi: 10.13205/j.hjgc.202004030
Abstract:
With the rapid development of urban stormwater management informationization, stormwater management models have been widely used in its planning and design. However, the model accuracy has become the bottleneck of the popularization of the modes. In this paper, taking a LID rain water system as the example, the influence of different proportion of the LID system, and different flow paths in low impact development stormwater system on runoff with differerent represent periods, was systematically analyzed using stormwater management model (SWMM). The simulation results showed that the reduction rate of the total amount of rainwater runoff discharge was 4.32%~26.53%, and the peak reduction rate was 38.46%~61.40%, when the confluence path was considered in the simulation. Therefore, the confluence path was proved to be with great influence on the total discharge and peak discharge of rainwater runoff, and it increased with the increase of LID facilities and decreased with the rise of rainfall return period. In the process of site development, we could improve the control effect of LID facilities on stormwater runoff through reasonable confluence path design. And when using the model to evaluate the effect of rainwater control and utilization, the influence of confluence path on the simulation results should also be fully considered.
With the rapid development of urban stormwater management informationization, stormwater management models have been widely used in its planning and design. However, the model accuracy has become the bottleneck of the popularization of the modes. In this paper, taking a LID rain water system as the example, the influence of different proportion of the LID system, and different flow paths in low impact development stormwater system on runoff with differerent represent periods, was systematically analyzed using stormwater management model (SWMM). The simulation results showed that the reduction rate of the total amount of rainwater runoff discharge was 4.32%~26.53%, and the peak reduction rate was 38.46%~61.40%, when the confluence path was considered in the simulation. Therefore, the confluence path was proved to be with great influence on the total discharge and peak discharge of rainwater runoff, and it increased with the increase of LID facilities and decreased with the rise of rainfall return period. In the process of site development, we could improve the control effect of LID facilities on stormwater runoff through reasonable confluence path design. And when using the model to evaluate the effect of rainwater control and utilization, the influence of confluence path on the simulation results should also be fully considered.
