Qinhuai River Research Articles

Safety Analysis of Deep Foundation Excavation in Water-Rich Soft Soils Based on BIM

Recent years have seen a great concern on the construction safety of the deep foundation pit with complicated geological conditions due to an increasing number of accidents. However, there are not, currently, sufficient research studies on the safety analysis of the deep foundation pit in water-rich soft soils. As a result, dynamic predictions of the safety risk during the whole construction process are inadequate due to the lack of research studies. Therefore, this paper presents an approach for the construction safety of the deep foundation pit in water-rich soft soils, which combines the building information modeling (BIM), the finite element analysis (FEA), and the finite difference method (FDM). By using BIM technology, the author attempts to establish a 3D information model and a bracing structure model. Based on the application programming interface and the C# language, the data conversion from BIM-ANSYS-FLAC3D is realized. The author then attempts to analyze the ground surface settlement and horizontal displacement during the excavation of the deep foundation pit through FLAC3D, and the purpose of which is to identify potential safety hazards so that reasonable control measures can be taken. The approach presented in this article has been validated in the Project of Qinhuai River Ship Lock. Since the excavation and the after-construction stages of this project have been completed smoothly, this approach has been proved valid and applicable.

Spatiotemporal Analysis of Water Quality Using Multivariate Statistical Techniques and the Water Quality Identification Index for the Qinhuai River Basin, East China

Monitoring water quality is indispensable for the identification of threats to water environment and later management of water resources. Accurate monitoring and assessment of water quality have been long-term challenges. In this study, multivariate statistical techniques (MST) and water quality identification index (WQII) were applied to analyze spatiotemporal variation in water quality and determine the major pollution sources in the Qinhuai River, East China. A rotated principal component analysis (PCA) identified three potential pollution sources during the wet season (mixed pollution, physicochemical, and nonpoint sources of nutrients) and the dry season (nutrient, primary environmental, and organic sources) and they explained 81.14% of the total variances in the wet season and 78.42% of total variances in the dry season. The result of redundancy analysis (RDA) showed that population density, urbanization, and wastewater discharge are the main sources of organic pollution, while agricultural fertilizer consumption and industrial wastewater discharge are the main sources of nutrients such as nitrogen and phosphorus. The water quality of the Qinhuai River basin was determined to be mainly Class III (slightly polluted) and Class IV (moderately polluted) based on WQII. Temporally, the change trend of WQII showed that water quality gradually deteriorated between 1990 and 2005, improved between 2006 and 2010, and then deteriorated again. Spatially, the WQII distribution map showed that areas with more developed urbanization were relatively more polluted. Our results show that MST and WQII are useful tools to help the public and decision makers to evaluate the water quality of aquatic environment.

The fouling layer development on MD membrane for water treatments: An especial focus on the biofouling progress

This study evaluated the fouling development of membrane distillation (MD) when treating different feed waters were taken from three local water bodies: Xuanwu Lake, Nan Lake and Qinhuai River. Trends of flux decline could be divided into three phases including a similar rapid decline in first phase, a slow decline in phase II, while significant difference was observed in the last phase. It could be seen that inorganic matters in feed waters had some influences on the attachment of salt crystals to membrane, mainly in the form of CaCO3. Furthermore, the biovolume exhibited little difference but the amount of extracellular polymeric substances (EPS) was distinct in the three systems. 16S rRNA revealed that although the microbial communities in feed waters had different structures, they on-membrane microbes shared the same dominant communities in the early stage due to the same growth environment including Tepidimonas, Meiothermus, OLB14_norank, Env.OPS 17_norank and Schlegelella with a relatively stable proportion of 63.5%–68.0%. However, at the later operational phase, the bacteria composition was changed with community succession, and Armatimonadetes_norank, Hydrogenophilaceae_uncultured and Methyloversatilis respectively thrived on the three scaling membrane surfaces which was correlated with the concentration of feed water, resulting the influence of inorganic substances on microbial growth was enhanced. A result obviously suggested that bacteria had great influence on the degree of flux decline due to their structure and property, especially at the later operational phase. It would be helpful to explore the structure and potential function of dominant communities on membranes and provide basic theory for the treatment of microbial pollution.

Correction to: An Integrated Modelling Approach for Flood Simulation in the Urbanized Qinhuai River Basin, China

The original version of this article contains incorrect symbol in eq. 7 and incorrect font style in eq. 8 which have been corrected.

Distinct microbial metabolic activities of biofilms colonizing microplastics in three freshwater ecosystems

Concerns are growing about the increasing amounts of microplastics (MPs) and their ecological impacts, especially the influences of “plastisphere” in the freshwater ecosystems. Although the microbial structure and composition of biofilms are investigated, knowledge of their microbial functions remains limited. Herein, we investigated the functional diversity of carbon metabolism in biofilms colonizing one inert (glass) and two MPs as polyvinyl chloride (PVC) and polyethylene terephthalate (PET) substrates incubated for 44 days in situ in the Niushoushan River, the Qinhuai River, and Donghu Lake. 2D confocal laser scanning microscopy images visualized distinct micro-structures and biofilm compositions on three substrates. BIOLOG ECO microplates indicated variation on carbon utilization capacities of biofilms of inert and MPs in three freshwater ecosystems. Biofilms on PET showed lower capacities and carbon metabolism rates than those on glass and PVC, indicating the presence of substrate-specific functional diversity. The Shannon-Wiener diversity, Simpson diversity and Shannon evenness indices for the Niushoushan River and Donghu Lake were ordered as glass > PVC > PET. Besides to MPs-specific factors, environmental factors including nutrient (i.e., TN and TP) and turbidity largely shaped biofilm carbon metabolism. Overall findings demonstrated that as specific niches, MPs influenced microbial-mediated carbon cycling in the freshwater ecosystems and MPs-promoted microbial communities posed ecological significance.

Microbial carbon metabolic functions of biofilms on plastic debris influenced by the substrate types and environmental factors

As an artificial type of microbial carrier, plastic debris has been widely detected in freshwater habitats, and the potential impacts of the plastisphere (biofilms colonized on plastics) in aquatic ecosystems have drawn increasing attention. Distinct community compositions and structures of biofilms in plastic and natural substrates have been recorded in freshwater environments. However, the microbial metabolic functioning of the plastisphere was underestimated, especially in freshwater environments. In this study, the effects of substrate types on the carbon metabolic functions of biofilms were studied by in situ cultivation of biofilms on plastics (polyvinyl chloride, PVC and polyethylene, PE) and natural substrate (cobblestone) for 44 days in two rivers (the Niushoushan River and the Qinhuai River) and two lakes (Donghu Lake and Xuanwu Lake). Biofilms on plastics showed higher biomasses than those on natural substrates in all ecosystems. Variations in the micro-structure and compactness of biofilms developed under different substrates were observed from scanning electron microscope and confocal laser scanning microscope image analyses. The carbon metabolic activities of the biofilms evaluated by BIOLOG EcoPlate were different between plastics (PVC and PE) and natural substrate (cobblestone) in the four freshwater ecosystems. In the Niushoushan River, PE-associated biofilms had different capacity in using carbon sources from cobblestone-associated biofilms as illustrated by the Shannon-Wiener diversity index and Shannon evenness index. Additionally, the metabolic functional diversity profiles of biofilms on PVC were significantly different from those on cobblestone in the other three aquatic ecosystems. Moreover, results from variation partitioning analysis suggested that the impact of environmental factors (contribution: 21%) on microbial carbon metabolic functions was much greater than that of substrate types (contribution: 6%). These findings illustrated distinct microbial functions of biofilms inhabited on plastics, and environmental factors play a decisive role in the differentiation and specificity of carbon metabolism of the plastisphere. This study offers new insights that plastics serving as artificial microbial niches have the ability to affect the microbial-mediated carbon cycling process in aquatic ecosystems.

An Integrated Modelling Approach for Flood Simulation in the Urbanized Qinhuai River Basin, China

The accurate simulation and prediction of flood response in urbanized basins remains a great challenge due to the spatial and temporal heterogeneities in land surface properties. We hereby propose an integrated modelling approach that consists of a semi-distributed conceptual hydrological model and a novel parameterization strategy. The modelling approach integrates the Xinanjiang (XAJ) model, Taihu Basin (TB) model, and Nash instantaneous unit hydrograph (IUH) into a framework. Model parameters are calibrated by optimizing their relationships with corresponding physical factors. The proposed modelling approach is applied in the Qinhuai River basin (QRB), China. The modelling approach shows satisfactory performance in flood simulation both for calibration and validation of flood events in the QRB. The approach has temporal and spatial prediction capability by using the established relationships between parameter values and physical factors. Robustness analysis reveals that the different sets of flood events used for parameter relationship calibration led to similar model performance. Numerical experiments show that impervious coverage poses strong influences on the model performance and needs to be considered in flood routing simulations for small- or medium-intensity flood events.

Assessing the Effects of Urban Landscape Area and Pattern Change on Flood Events in Qinhuai River Basin, China

AbstractUrbanization significantly affects hydrological processes, but the influence level of urban landscape area change (ULAC) on flood magnitude has not been quantified, the response laws of flo...

Inferring the invasion mechanisms of the red swamp crayfish in China using mitochondrial DNA sequences

The red swamp crayfish, Procambarus clarkii, is a native species in north-eastern Mexico and south-central USA. P. clarkii was introduced to China in 1929 and has been used as an aquaculture species in China since 1983. It currently exists in most of the provinces of China, but threatens local fish, crustaceans, aquatic plants and local freshwater ecosystems. We examined the genetic variation in partial mitochondrial ND2 gene of 831 individuals collected from 25 P. clarkii populations in 13 provinces of China to infer the expansion pathways and mechanisms. Six haplotypes were detected. All six haplotypes appeared in four populations in Nanjing and a population located near Nanjing whereas only 1–5 of the six haplotypes were present in other populations. These data suggest that the populations in Nanjing are probably the source of all other populations in China. There were no significant relationships between geographic distances and genetic distances in 25 populations, whereas significant relationship was found in four populations in Qinhuai River covering 50 km in Nanjing. These data suggest that the expansion mainly be human-mediated in large scale, and active disposal or non-anthropogenic passive dispersal might have played an important role in expansion at a smaller scale. In some places far away from Nanjing, several haplotypes existed, suggested multiple introduction events may have happened. Although aquaculture of this species could bring huge economic benefit, its potential to negatively affect native biota and entire ecosystems should not be ignored.

Cross-basin analysis of freshwater ecosystem health based on a zooplankton-based Index of Biotic Integrity: Models and application

Abstract Quantitative evaluation of the aquatic ecosystem health is crucial to formulate policies about environmental water management and ecological restoration. However, it is often difficult to quantitatively compare or estimate the health of aquatic ecosystems for different watersheds. In this study, we developed a Freshwater Ecosystem Health Index (FEHI) based on a modified Zooplankton-based Index of Biotic Integrity (ZIBI) to address this difficulty. The ZIBI was developed based on the top six principal components (cumulative % = 88.6%) of 32 zooplankton community indicators. Then the ZIBI was transformed into the FEHI by using the arc-tangent function (to make FEHI fall into (0,1)). FEHI rating scales that were defined as (0,0.2), [0.2,0.4), [0.4,0.6), [0.6,0.8), [0.8,1) fall within bad, poor, fair, good, and excellent freshwater ecosystem health condition, respectively. Moreover, we established six estimation models of FEHI, respectively, directing at six situations that the available indicators are limited. The FEHI calculation and estimation models were then applied to evaluate three lakes and four river basins in eastern China. The results showed that the aquatic ecosystem health was good in areas that included rivers in Tongxiang plain, Meiliang Bay of Taihu Lake, rural area of Qinhuai River basin, Shahu Lake during Summer/Autumn. However, the aquatic ecosystem health was bad or fair in Xuanwu Lake (an urban shallow lake), the urban area of Qinhuai River basin, Huaihe basin, Yinghe basin, and Shahu Lake in winter. The FEHI will be a new and effective approach for quantitative evaluation/estimation of freshwater aquatic ecosystem health in eastern China.

Detection and attribution of flood responses to precipitation change and urbanization: a case study in Qinhuai River Basin, Southeast China

Abstract Both flood magnitude and frequency might change under the changing environment. In this study, a procedure combining statistical methods, flood frequency analysis and attribution analysis was proposed to investigate the response of floods to urbanization and precipitation change in the Qinhuai River Basin, an urbanized basin located in Southeast China, over the period from 1986 to 2013. The Mann–Kendall test was employed to detect the gradual trend of the annual maximum streamflow and the peaks over threshold series. The frequency analysis was applied to estimate the changes in the magnitude and frequency of floods between the baseline period (1986–2001) and urbanization period (2002–2013). An attribution analysis was proposed to separate the effects of precipitation change and urbanization on flood sizes between the two periods. Results showed that: (1) there are significant increasing trends in medium and small flood series according to the Mann–Kendall test; (2) the mean and threshold values of flood series in the urbanization period were larger than those in the baseline period, while the standard deviation, coefficient of variation and coefficient of skewness of flood series were both higher during the baseline period than those during the urbanization period; (3) the flood magnitude was higher during the urbanization period than that during the baseline period at the same return period. The relative changes in magnitude were larger for small floods than for big floods from the baseline period to the urbanization period; (4) the contributions of urbanization on floods appeared to amplify with the decreasing return period, while the effects of precipitation diminish. The procedure presented in this study could be useful to detect the changes of floods in the changing environment and conduct the attribution analysis of flood series. The findings of this study are beneficial to further understanding interactions between flood behavior and the drivers, thereby improving flood management in urbanized basins.

Combined effects of urbanization and climate change on watershed evapotranspiration at multiple spatial scales

How urbanization-associated land use/land cover change (LULCC) affects the ecohydrological cycle through altering evapotranspiration (ET) processes is not clear for rice paddy dominated watersheds. The purpose of this study was to understand long-term (2000–2013) spatial and temporal variations of ET over the Qinhuai River Basin in a humid region, southern China. We revised the Soil and Water Assessment Tool (SWAT) by incorporating new algorithms describing hydrological processes of rice paddies. Using the improved SWAT model driven by remote sensing-derived LULCC and local climatic data, we separated the effects of LULCC on ET from climate at the watershed scale. We showed that the modified SWAT model significantly improved monthly streamflow estimates. The Nash-Sutcliffe model efficiency (NSE) was 0.86 and coefficient of determination (R2) was 0.88 for the calibration period (1990–1994) while the NSE was 0.65 and R2 was 0.71 for the validation period (1995–1999). We also found good agreements between modelled daily ET and lysimeter-based measurements for an experimental rice paddy field (R2 = 0.75, p less than 0.01). For areas with little land cover change, ET rates increased over time due to the increase in potential ET (PET) during 2000–2013. However, the contribution from rice paddy to the watershed-level ET decreased over time coincident with a period of rapid urbanization and loss of rice paddy field. Dynamic attribution analysis indicated that the negative contribution of LULCC to change in ET increased from 53% in 2000 to 61% in 2013 while the positive contribution of climate variability decreased from 47% in 2000 to 39% in 2013. We concluded that factors affecting ET varied with spatial scale. Conversion of rice paddy field to urban use directly resulted in significant ET reduction at the watershed scale despite the rise in the air temperature and potential ET in the study region. The improved SWAT model provides a better integrated method for understanding ET processes and assessing the impacts of environmental change on ecosystem services in a rapidly urbanizing region.

Research on key technologies for construction of super-deep railways stations near existing lines in the flood land area of the Yangtze River

In this paper, taking Nanjing Mochou Lake Metro Station as an example, the key technologies for the construction of super-deep stations near existing lines in the flood land area of the Yangtze River are studied. Mochou Lake Station is located in Mochou Lake Park on the Qinhuai River. It is a four-level underground island-type platform station, which is interchanged with the existing Line 2 Mochou Lake Station. The station used the “two-light and two-dark” construction method. The first and the second underground floor of the station used an open excavation order method, and the third and the fourth underground floor used to cover and cut-bottom up method. According to the monitoring results and settlement analysis results of the main structure, the construction method of “two-, light and two-dark, ” can help control the deformation of the construction area and ensure the safety of the surrounding structures and existing stations.

Effects of Urbanization on Watershed Evapotranspiration and Its Components in Southern China

Understanding the effects of land use change on evapotranspiration (ET) and its partitioning to transpiration and evaporation is important for accurately evaluating the likely environmental impacts on watershed water supply, climate moderation, and other ecosystem services (e.g., carbon sequestration and biodiversity). This study used a distributed hydrologic model, MIKE SHE, to partition evapotranspiration into soil evaporation, transpiration, ponded water evaporation, and interception, and examined how the ET partitions affected the water balance in the Qinhuai River Basin from 2000 to 2013. Simulated daily ET was compared to measurements at an eddy flux research site during 2016–2017 (R2 = 0.72). Degradation in rice-wheat rotation fields and expansion of impervious surfaces impacted not only total watershed evapotranspiration, which showed a significant downward trend (p < 0.05), but also its partitioning. A significant (p < 0.01) decrease in transpiration was detected. Ponded water evaporation was the only ET partition that exhibited a significant positive trend (p < 0.05). We concluded that the reduced transpiration as a result of land use and land cover change was the primary factor driving the variation of watershed scale evapotranspiration. In addition, there was an increase in annual water yield (23%) as a response to significant reduction in ET (7%) due to a 175% expansion of urban area in the study watershed. Our study provided insights to the mechanisms of land surface–water cycle interaction and better understanding of the effects of land use change on urban micro-climate such as “urban dry island” and “urban heat island” effects.

Residues, bioaccumulation, and trophic transfer of pharmaceuticals and personal care products in highly urbanized rivers affected by water diversion

Little information is available on the bioaccumulation and trophic transfer of pharmaceuticals and personal care products (PPCPs) in urban rivers system, particularly for those affected by water transfer. Herein, a comprehensive study was conducted to investigate the biological residues, bioaccumulation and trophic transfer of 45 PPCPs in the Nanjing Qinhuai River system under the background of water diversion projects. A total of 30 compounds were detected with a descending order of overall concentration as plankton > benthic mollusc > fish (except grass carp). Higher biological residues were observed in the downstream than those in the upstream, with the largest increase for fish (136.4 %) and the lowest increase for phytoplankton (5.4 %). However, the bioaccumulation classifications of most PPCPs were unchanged among the three different water-diversion regions. Trophic magnification factors (TMFs) of organic UV filters (homosalate, oxybenzone, ethylhexyl methoxycinnamate and octocrylene) ranged from 1.23 to 2.04, suggesting trophic magnification potential, while trophic dilution for pharmaceuticals (sertraline, citalopram, caffeine and roxithromycin) with TMFs of 0.42 to 0.50 were observed. A notable positive correlation was observed between the pH-dependent distribution coefficient (logDow) and the TMFs of the PPCPs (P < 0.05). Although the human health hazard assessment indicated no immediate health risk via the consumption of freshwater food, attention should be paid to the joint effects of PPCPs.

Mechanism of biofilm formation on a hydrophobic polytetrafluoroethylene membrane during the purification of surface water using direct contact membrane distillation (DCMD), with especial interest in the feed properties

The impact of feed water quality on biofilm formation during membrane distillation (MD) was investigated in this study, particularly emphasizing the interrelationship between organics, salts, and microbes. Two types of typical natural surface waters in Nanjing, China, were chosen as feed solutions for long-term MD operation, including the Qinhuai River and Xuanwu Lake. The biofilms that developed under different feed water qualities exhibited distinct Foulant compositions and structures, causing different flux decline trends for the MD system. Accordingly, two typical patterns of biofilm formation were suggested for the MD operation of the two different kinds of surface waters in this study. Organics from a primal feed solution and dead bacteria were the key to the establishment of a biofilm on the membrane, and this needs to be effectively removed from the MD system through pre-treatment and process control strategies. Finally, a feasible strategy for MD biofouling control was suggested.

Prediction of hydrological responses to land use change

The change of land use and land coverage (LULC) has a direct impact on the underlying surface of the drainage basin, hence alters the rainfall-runoff processes. This study described the procedure to use the CA-Markov model to predict the future distributed land use in the Qinhuai River basin in 2028 based on the historical evolution. The hydrological model HEC-HMS was then utilized to examine the impact of land use change on the hydrological responses of the drainage basin. The major findings were as follows: (1) from 2001 to 2010, major changes detected in land use were substantial conversion of paddy fields, forest land and dryland into urban land (increased by 56.81%), following the trend recognized by CA-Markov model, urban land and dry land were predicted to increase by 17.47% and 14.05% by 2028. (2) the projected land use in 2028 resulted in various degrees of increase in flood peak and volume according to the severity of the floods characterized by flood volumes, the smaller floods were predicted to result in more significant increase with 3.5% increase in flood peak and 2.9% increase in flood volume while these values decreased to 0.4% and 1.1% for a big scale flood; (3) greater increase in urbanization leads to greater change of the flood peak and volume change. For small scale floods, when the proportion of urban land use increases by 30% to 60% hypothetically, the relative increment in flood peaks increase from 4.7% to 8.1% with 4% to 6.6% increase in the flood volume; (4) on the sub-basin scale, the trend of change in urban land use and the flood peak and volume were consistent. The methods and conclusions may shed light on urban land development and management and design of flood control measures in a large river basin.

Water Environment Quality Assessment Based on Normal Cloud-fuzzy Variable Set Evaluation Model

Gao, Y.; Lai, L.; Yao, M., and Ma, Z., 2019. Water environment quality assessment based on normal cloud-fuzzy variable set evaluation model. In: Guido-Aldana, P.A. and Mulahasan, S. (eds.), Advances in Water Resources and Exploration. Journal of Coastal Research, Special Issue No. 93, pp. 39–46. Coconut Creek (Florida), ISSN 0749-0208.Water environmental quality assessment is an important groundwork for river planning, governance, and management. A normal cloud-fuzzy variable evaluation model which incorporated the minimum relative entropy weights was proposed to evaluate the water quality of 13 monitoring points in the Qinhuai River in 2016. The evaluation results proved to be more reasonable and effective in comparison with the results of the single-factor index evaluation method, fuzzy comprehensive evaluation method and cloud model. The analysis of model-level eigenvalue (H) showed that most of the water quality of the Upper Qinhuai River and Qinhuai New River is better in flood season than in non-flood season, which also showed the pollution characteristics of urban industry and domestic sewage. However, the water quality of the Outer Qinhuai River and inner Qinhuai River is worse in the flood season than in non-flood season, which showed the typical pollution characteristics of urban sewage and catering. The study results can be helpful for future evaluation and research of water environment in regions and river basins.

Risk Assessment Method and Application of Embankment Engineering Based on Cloud Model

Huang, X.; Yang, Z.; Chen, Y.; Fang, G., and Yang, H., 2019. Risk assessment method and application of embankment engineering based on cloud model. In: Guido-Aldana, P.A. and Mulahasan, S. (eds.), Advances in Water Resources and Exploration. Journal of Coastal Research, Special Issue No. 93, pp. 310–319. Coconut Creek (Florida), ISSN 0749-0208.Based on the risk factors of the embankment engineering, the risk factors of the embankment engineering are classified, and the risk evaluation index system of the embankment project is set up, which includes 5 aspects, including load, protection, dike body characteristics, embankment base characteristics and dangerous situation statistics, which are 20 indexes, the grade and standard of each index are determined, and cloud model method was applied to evaluate the risk of embankment project in the Qinhuai River between Qiqiaoweng and Dongshan Bridge in Nanjing. The results show that the evaluation value of embankment engineering between Qiqiaowen and Dongshan Bridge in 2007 is 87.99, which is a general safe grade, which is consistent with the assessment at that time. However, the evaluation value is 95.67 in 2017, which belongs to the Safe grade, which is consistent with the Qinhuai River regulation target in Nanjing, and is consistent with the actual situation, which validates the validity and applicability of the cloud model evaluation method.

Sensitivity Analysis of Parameters of a HEC-HMS Model with Polders

Gao, Y.; Zhang, Z., and Liu, Y., 2019. Sensitivity analysis of parameters of a HEC-HMS model with polders. In: Guido-Aldana, P.A. and Mulahasan, S. (eds.), Advances in Water Resources and Exploration. Journal of Coastal Research, Special Issue No. 93, pp. 163–169. Coconut Creek (Florida), ISSN 0749-0208.The imperviousness percentage, polder allowable water depth, and drainage modulus are the main features that determine the effectiveness and efficiency of flood control with polders. This study is aimed to examine the impact of impervious percentage, polder allowable water depth, and drainage modulus on peak flow and flood volume for simulating flood processes. A Hydrologic Engineering Center-Hydrologic Modelling System (HEC-HMS) model is developed to simulate flood control with polders in order to explore the impact of these impervious percentage, polder allowable water depth, and drainage modulus. The Qinhuai River Basin is employed as the research area as it is a typical watershed that uses polders for flood control. The results demonstrate that the flood volume and peak flow increase with the impervious percentage increases from 20% to 70%. When the polder allowable water depth increases, the flood volume decreases but the peak flow increases. With the decrease of drainage modulus, the peak flow and flood volume decrease. This study provides a reference and guidance to simulate flood control with polders and the impact of the three features in the Qinhuai River Basin. In addition, it could be easily adopted for other basins with polder.