100-year Return Research Articles

The Impact of River Mouth Sediment Deposition on Flood Risk: The Case Study of The Sakarya River

Flooding is a natural disaster that causes loss of life and property worldwide. Floods can be predicted and their damages can be reduced. Various natural and man-made factors can cause floods. Sediment movement can be counted as one of the causes of floods, albeit rarely. The Sakarya River bed and river mouth is one of the risky areas for flooding due to sediment deposition. Due to the activities of quarries on the Sakarya River, the amount of sediment carried by the river increases, and the damage to the river bed morphology. In rare cases, the mouth of the river is completely closed due to sedimentation, which has caused many disasters such as coastal flooding and capsizing of marine vessels, leading to loss of life and property. Therefore, the occurrence of floods due to sediment deposition at the mouth of Sakarya River was investigated. The 5, 10, 25, 50, 100, and 500-year return period flows in the downstream part of the Sakarya River and Karasu district were analyzed with the 2D flood model in case of insufficient discharge from the river mouth. Water depth, velocity, and flood hazard maps for these return periods were prepared. The impact of flooding on Karasu district was analyzed in terms of affected buildings and affected area (ha). Thus, the effects of the floods occurring in the downstream region as a result of the interventions to the river bed in the upstream region were analyzed.

Analysis and Flood Mapping of Pekalen Watershed of Probolinggo Regency Using HEC-RAS Application

Flooding is one of the natural disasters that needs attention, especially in the Pekalen watershed, Probolinggo Regency. The purpose of this research is to analyze the design flood discharge and mapping of the area potentially affected by inundation. The research stages began with arithmetic area average rainfall analysis, log pearson type III design rainfall analysis, chi squared and smirnov-kolmogorov distribution fit test, mononobe rainfall intensity, HSS Nakayasu design flood discharge analysis, and flood mapping with HEC-RAS 2D flood modeling. The design flood discharge of Pekalen watershed at 10-year return period is 421.4 m³/s, 25-year return period is 455.12 m³/s, and 50-year return period is 479 m³/s. The areas potentially affected by inundation at 25 years return periods are Sukomulyo, Sukokerto, Pajarakankulon, Kradenan, Tanjung, Karangbong, Temenggungan, Karanggeger, Ketompen, Petemon, Selogudigwetan, Selogudigkulon, Puspan, Braniwetan, Branilor, Sumbersecang, Satreyan, Maronkidul, Gerongan, Brabe, Condong, Racek, Pesawaran, Ranugedang, Jangkang, Segaran, Ranuagung, Tiris, Andungsari, Andungbiru, and Sumberaren.

Analysis of Infiltration Wells Needs in Flood Management in Sunyaragi Urban Village Cirebon City

The development of a city results in increased urbanization. This development leads to changes in land use in urban areas, creating large areas covered by buildings and roads, which reduces infiltration and increases surface runoff. With high rainfall of 147.238 mm per month, Sunyaragi Village often experiences flooding during the rainy season, especially on St. Taman Pemuda. This study aims to determine the number of infiltration wells needed to reduce the risk of flooding in Sunyaragi Urban Village, Cirebon City. The research employs descriptive methods using Arc-GIS remote sensing and quantitative methods, including hydrological analysis to measure rainfall intensity, hydraulics analysis to assess drainage channel capacity, and infiltration well analysis to determine the required number of infiltration wells. Based on the analysis results, the maximum runoff discharge value in the 5-year return period on St. Taman Pemuda is 0.00562 m³/sec, indicating that eight infiltration wells are needed. These wells are planned to be cylindrical, with a diameter of 1 m and a depth of 3 m, achieving an efficiency value of 85.04% in reducing runoff discharge.

Applying Results of Extended Genotyping to Management of Positive Cervicovaginal Human Papillomavirus Test Results: Enduring Guidelines.

The Enduring Consensus Cervical Cancer Screening and Management Guidelines Committee developed recommendations for the use of extended genotyping results in cervical cancer prevention programs. Risks of cervical intraepithelial neoplasia grade 3 or worse were calculated using data obtained with the Onclarity HPV Assay from large cohorts. Management recommendations were based on clinical action thresholds developed for the 2019 American Society for Colposcopy and Cervical Pathology Risk-Based Management Consensus Guidelines. Risk estimates were reviewed in relation to clinical action thresholds and used as the basis for draft recommendations. After an open comment period, recommendations were finalized and ratified through a vote by the Consensus Stakeholder Group. Colposcopy is recommended after positive tests for human papillomavirus (HPV) types 16 and 18. For those positive for HPV 45, 33/58, 31, 52, 35/39/68, or 51 but negative for 16 or 18, triage with cytology or dual stain testing is recommended. When screening with primary HPV testing, for patients who test positive for HPV types 56/59/66 and no other carcinogenic types, repeat HPV testing in 1 year is recommended. When screening with cotesting, for those who test positive for HPV types 56/59/66 and no other carcinogenic types, 1-year return is recommended for negative for intraepithelial lesion or malignancy, atypical squamous cells of undetermined significance, and low-grade squamous intraepithelial lesion, and colposcopy is recommended for atypical squamous cells cannot exclude high-grade squamous intraepithelial lesion (ASC-H), atypical glandular cells, high-grade squamous intraepithelial lesion, or carcinoma. When patients without prior high-grade cytology (atypical squamous cells cannot exclude high-grade squamous intraepithelial lesion, atypical glandular cells, high-grade squamous intraepithelial lesion, or carcinoma) or histology (cervical intraepithelial neoplasia [CIN]2, CIN3, or adenocarcinoma in situ) are being followed, use of extended genotyping results is acceptable. When high-grade cytology or histology results are present, or when patients are being followed after treatment of CIN2+, management using the 2019 guidelines is recommended. Human papillomavirus extended genotyping can guide clinical management in the setting of a positive HPV test result.

A new approach on design and verification of integrated sustainable urban drainage systems for stormwater management in urban areas.

Stormwater runoff control is often a concern due to urbanization and extreme rainfall events. Sustainable urban drainage systems can support traditional hydraulic networks in rainwater management by providing local runoff disposal and reuse of collected stormwater. The objective of the study is based on an innovative analytical-probabilistic approach for evaluating the functioning of rainwater tanks in stormwater management with the potential for using collected water for non-potable purposes. A pilot case of a rainwater tank integrated with an infiltration system was considered within the framework of the Polisocial Award 2023at the Off-Campus Cascina Nosedo of Politecnico di Milano (Italy). The performances of the rainwater tank in satisfying irrigation were evaluated through a new version of an analytical probabilistic approach, whose validation confirmed it is promising and offers excellent perspectives in the field of stormwater management. The probabilistic equation developed in this study relates the probability of rainwater reuse to the main parameters involved in the process (i.e., storage volume, irrigation area, rainfall depth, etc.), enabling to define the management rules of the storage for the optimization of the stormwater management. In the application, to consider an irrigation area lower than 30m2, ensures the fully meeting of the requirements by the system in the rainiest year, and to avoid falling below the 50% (2-year return period) during the driest year.

ANALISIS PENGARUH PERUBAHAN TATA GUNA LAHAN MENGGUNAKAN EPA-SWMM DI DAS KRUKUT

Flooding in Jakarta, a lowland area traversed by several rivers, has become a recurring challenge due to increased development, business activities, and land-use changes. This study aims to calculate the design flood discharge for various return periods and analyze the impact of land-use changes on flooding in the Krukut River Basin. The analysis utilized ArcGIS for land-use changes and EPA-SWMM for hydrological and hydraulic simulations. Results indicate that changes in land cover have led to an increase in flood discharge, for instance, in the 2-year return period from 106.01 m³/s (2006) to 108.25 m³/s (2017), and in the 100-year return period from 204.61 m³/s (2006) to 208.93 m³/s (2017). Mitigation efforts, such as the implementation of infiltration wells, were effective in reducing flood discharge, with EPA-SWMM simulations showing a reduction in the 100-year return period from 208.93 m³/s to 186.22 m³/s. This study recommends the implementation of infiltration wells and the enforcement of spatial planning regulations (RTRW) as conservation strategies to mitigate flood risks in the Krukut River Basin.

Multidimensional Urban Waterlogging Risk Assessment Based on a Refined Inundation Model

To enhance the scientific and accurate assessment methods for urban waterlogging risk in City B and to promote sustainable urban development, this paper conducts a detailed evaluation of waterlogging risk from three dimensions: pedestrian safety, road traffic, and waterlogging-prone areas. After considering existing monitoring technologies and the constructed waterlogging model, the paper identifies standing water depth, standing water duration, and standing water velocity as the key indicators for waterlogging risk assessment and utilizes scenario simulation methods to evaluate waterlogging risk across these dimensions. Additionally, the paper employs boundary conditions of 2-h short-duration rainfall with a 5-year return period and 24-h long-duration rainfall with a 50-year return period for the assessment. The evaluation results indicate that, for pedestrian safety, under both short and long-duration rainfall conditions, low-risk areas represent the largest proportion of risk areas, reaching 6.36% and 10.83% of the total area, respectively. In the road traffic assessment, the proportions of severely congested roads under short- and long-duration rainfall conditions are 27.06% and 57.15%, respectively. In the evaluation of waterlogging-prone areas, high-risk areas account for the largest proportion of risk areas under both short- and long-duration rainfall conditions, reaching 0.64% and 1.42% of the total area, respectively.

Multi-hazard stress testing under extreme rainstorms in the Shenzhen metropolitan area

ABSTRACT A severe rainstorm can trigger numerous natural hazards of multiple types in cities with hilly terrain, such as landslides, debris flows, and flooding. Such compound hazards may pose much greater risks than a single hazard to the safety of residents and infrastructures. This study focuses on a metropolitan area of Shenzhen, China and develops a multi-hazard stress testing method for hazard risk management against extreme rainstorms. The probable maximum precipitation in Shenzhen is first estimated using the storm transposition method considering orographic intensification and moisture maximisation, with the centre peak amount being 1441 mm in 24 hours at Tanglang Mountain. An integrated physically-based multi-hazard simulation model, EDDA, is then utilised to simulate the processes of initiation, propagation and transformation of landslides, debris flows and flooding in a unified manner. Under the designated extreme rainstorms of a 1000-year return period and 85% of probable maximum precipitation, deposit depths of landslides and debris flows can be large in some urban areas near the foot of Tanglang Mountain; flooding can be very extensive in the flat built-up regions, with 21.8% and 31.7% of the study area flooded, respectively. The produced multi-hazard maps can facilitate the design of risk mitigation measures against extreme rainstorms.

Research on optimal scheduling of minor and moderate floods for cascade reservoirs in the lower reaches of the jinsha river considering power generation

The comprehensive cascade reservoir system is extensively used for flood control and power generation. Traditional reservoir scheduling often treats these tasks as competing objectives, prioritizing flood control during the flood season and neglecting power generation benefits. This approach, primarily applied to large floods, leads to hydraulic resource wastage and power generation loss during minor and moderate floods. The lower Jinsha River cascade reservoirs have significant flood control storage capacity, allowing part of the capacity to be used for maintaining higher water levels without compromising safety under minor and moderate floods within a 20-year return period. This paper proposes an optimal scheduling model that considers both flood control and power generation tasks for the lower Jinsha River cascade reservoirs. The Multi-objective Particle Swarm Optimization (MOPSO) algorithm was used to find non-inferior solution sets. An evaluation index system was developed to select optimal solutions under different flood frequencies, using the Minimum Discriminant Information Principle and VIKOR model. The results indicate that the optimal scheduling scheme under 20-year, 10-year, and 5-year return period floods can enhance power generation by 1.64, 1.71, and 1.35 billion kWh, respectively, compared to conventional scheduling. This approach supports coordinated flood control and power generation scheduling, contributing to the high-quality development of the Yangtze River Economic Belt.

PENGENDALIAN BANJIR SUNGAI BENGKANG UNTUK MENDUKUNG KAWASAN EKONOMI KHUSUS MANDALIKA

Changes in land use that have occurred over a period of several years in the Kuta area have resulted in a lack of water catchment areas. The impacts caused by the lack of catchment areas are flooding and reduced water quality in rivers. The flood disaster in the Bengkang River caused damage to bridge infrastructure and people’s homes. The Bengkang river basin is divided into 3 sub – basins with a total area of 10,45 km2. Based on the results of the design flood analysis using the Nakayasu synthetic unit hydrograph method, the largest flood discharge value was obtained, namely 32,859 m3/second for a return period of 25 years. Hydraulic modeling was carried out to determine the water level and the ability of the river section to receive flow using HEC-RAS 6.1 software. Based on the simulation results with a return period of 5 years, it is known that flooding occurs in the middle and lower reaches of the Bengkang River, so structural mitigation is needed, namely normalization and repair of embankments. A 25-year return period flow simulation was carried out using a cross – section of the channel plan and no runoff was obtained in the Bengkang River.

Normalization of Suak Ujong Kalak estuary as a flood reduction effort for Meulaboh city

Abstract Meulaboh City frequently experiences flooding, with runoff flowing into the Suak Ujong Kalak Estuary, a natural outlet for the city’s drainage system. Currently, the estuary is unable to effectively accommodate the runoff, exacerbating the flood risk. This study aims to evaluate the existing condition of the Suak Ujong Kalak Estuary and propose a normalization plan to improve flood control. The research employs a descriptive-quantitative methodology, involving field surveys, data collection, and hydrological and hydraulic analyses. The hydrological analysis includes rainfall frequency analysis, chi-square testing, and rainfall intensity calculation using the Mononobe method. Flood discharge estimation is based on the Rational method for a 25-year return period. Hydraulic analysis is conducted using HEC-RAS 6.3.1 software. The results show that the estuary receives an inflow of 79.33 m3/second, which exceeds its current capacity. Hydraulic analysis reveals that the estuary cannot accommodate the discharge, causing overflow with an average height of 0.6 meters and a storage capacity of 40,798.43 m3. To address this, the study recommends a normalization effort, involving excavation with an average depth of 1 meter, to improve the estuary’s capacity and reduce flooding in Meulaboh City.

Variations in Present and Future Hourly Extreme Rainfall: Insights from High-Resolution Data and Novel Temporal Disaggregation Model

Extreme rainfall-induced events adversely affect agriculture, infrastructure, and socioeconomic development in a region. Therefore, a comprehensive understanding of their occurrences and past and future variability in the context of global warming is imperative, especially at the fine temporal (sub-daily) and spatial (local to regional) scales for better contextualizing inferences from a policymaking perspective. This study provides a detailed analysis of global warming’s impacts on extreme rainfall in Jiangsu Province, utilizing the latest high-resolution ERA5-Land reanalysis data and the latest climate models. A novel temporal disaggregation model was developed to predict future hourly extreme rainfall. The results show that the bias-corrected model reduced the overestimation of extremes by as much as ~7.4% for the location parameter and accurately reproduced the spatial variability of rainfall. Projections from eight climate models indicate a future increase in rainfall intensity by an average of over 7%. Moreover, the projections indicate two contrasting trends for different event durations: short-duration events (e.g., 1 h) show a 7.1% increase at the 5-year return period and a more pronounced 8.9% increase at the 50-year return period. Conversely, long-duration events (e.g., 24 h) experience an 8.4% increase at the 5-year return period and a smaller 6.0% increase at the 50-year return period. This suggests that rarer, short-duration events are expected to increase more than less rare ones, while rarer, long-duration events show a smaller increase than their less rare counterparts. Addressing spatial heterogeneity in extreme rainfall patterns provides actionable insights for climate adaptation and mitigation, supporting initiatives like the ‘Jiangsu Province Climate Change Adaptation Action Plan’. This study underscores the need for policy-driven, community-led climate actions to mitigate flood risks and enhance resilience in a region vulnerable to flooding amidst global warming and increasing human interventions.

Joint Probability Distribution of Extreme Wind Speed and Air Density Based on the Copula Function to Evaluate Basic Wind Pressure

To investigate an appropriate wind load design for buildings considering dynamic air density changes, classical extreme value and copula theories were utilized. Using wind speed, air temperature, and air pressure data from 123 meteorological stations in Shandong Province from 2004 to 2017, a joint probability distribution model was established for extreme wind speed and air density. The basic wind pressure was calculated for various conditional return periods. The results indicated that the Gumbel and Gaussian mixture model distributions performed well in extreme wind speed and air density fitting, respectively. The joint extreme wind speed and air density distribution exhibited a distinct bimodal pattern. The higher the wind speed was, the greater the air density for the same return conditional period. For the 10-year return period, the air density surpassed the standard air density, exceeding 1.30 kg/m3. The basic wind pressures under the different conditional return periods were more than 10% greater than those calculated from standard codes. Applying the air density based on the conditional return period in engineering design could enhance structural safety regionally.

Pesisir Barat Lampung Wave Characteristic Comparative Study

The need for ocean data is important to increase the utilization of ocean areas. A facility, development, system, or structure in the ocean cannot be planned properly without data in that ocean. One of the important data in water areas is ocean waves. In the offshore area of Pesisir Barat, wave characteristic data is still very hard to find. Knowledge of the ocean characteristics of the Pesisir Barat waters is needed, one of which is in the form of wave characteristics. To obtain more comprehensive information, two satellite reanalysis data sources were analyzed. The average height of significant wave height in the Perisir Barat is 1.75 to 2.25 m from BMKG and only 0.25 to 1.00 m from ECMWF. Based on the wave direction, the ocean waves in the Pesisir Barat move North to Northwest (NW), perpendicular to the coastline. The distribution of the annual maximum significant wave height matches the theoretical Log-normal distribution. Extreme significant wave height is obtained with a value of 4.10 to 4.29 m for a 100-year return period and 3.09 to 3.39 m for a 1-year return period. In terms of design or study of maritime potential in the western waters of Lampung, these values can be a benchmark as a basic study of wave characteristic data.

Urban Waterlogging Simulation and Disaster Risk Analysis Using InfoWorks Integrated Catchment Management: A Case Study from the Yushan Lake Area of Ma’anshan City in China

Under the dual pressures of climate change and urbanization, cities in China are experiencing increasingly severe flooding. Using the Yushan Lake area in Ma’anshan City, Anhui Province, as a case study, we employed the InfoWorks Integrated Catchment Management (ICM) hydraulic model to analyze the drainage and flood prevention system of the region and assess the current infrastructure for drainage and flood control. There are 117 pipelines with a return period lower than one year for stormwater and combined sewer systems, accounting for 12.3% of the total number of pipelines. The number of pipelines meeting the one-year but not the three-year return period standard is 700, representing 70.2%. Only 17.5% of the pipelines are capable of handling events exceeding the one-year standard. In simulating a 24 h, 30-year return period rainfall event, the results indicate that floodwater accumulation in the study area is predominantly between 0.15 m and 0.3 m. Most risk areas are classified as low risk, covering an area of 36.398 hectares, followed by medium and high-risk areas, which cover 8.226 hectares and 3.087 hectares, respectively. The Ma’anshan Yushan Lake area has, overall, certain flood control capabilities but faces flood risks during storms with return periods exceeding three years. This research offers valuable insights for improving urban flood management in Ma’anshan City through the development of a stormwater management model for the Yushan Lake area.

Identifying homogeneous hydrological zones for flood prediction using multivariable statistical methods and machine learning

One method for estimating floods in areas lacking statistical data is the use of regional frequency analysis based on machine learning. In this study, statistical and clustering-based approaches were evaluated for flood estimation in the Karkheh watershed. The hydrological homogeneity of the obtained zones was then assessed using linear moments and heterogeneity adjustment methods proposed by Hosking and Wallis. Then, the ZDIST statistic was used to calculate the three-parameter distributions for stations within each hydrologically homogeneous cluster. These parameters were computed using linear moments, and floods with different return periods at each station were estimated using regional relationships. The results indicated the creation of two clusters in this area, with five stations in cluster one and 11 stations in cluster two. The statistical homogeneity values for clusters one and two were calculated as 0.33 and 0.17, respectively, indicating the homogeneity of each region. Generalized Pearson type III and generalized extreme value distributions were selected as the best regional distributions for clusters 1 and 2, respectively. The results also showed that floods could be estimated for return periods of 2, 5, 25 years, and more. The highest estimated flood is predicted at the Jelugir-e Majin station, where the flood with a 2-year return period reaches 1034 m3 s−1. This increases to 5360 m3 s−1 for a 100-year return period. The approach presented in this study is recommended for similar regions lacking complete information.

Perioperative Femur Fractures in muscle sparing anterolateral - Modified Watson-Jones approach to primary total hip arthroplasty: A retrospective cohort study

BackgroundPeriprosthetic femur fractures (PFF) are a rare early complication in primary total hip arthroplasty (THA) that may result in revision and burden the healthcare system. A previous study identified a PFF rate of 8.3 % at 90 days with the modified anterolateral Watson-Jones (AL) approach to THA. This study assesses the PFF rate and risk factors with this approach at 90 days and 1-year post-operative follow-up. Methods580 primary THAs performed using the AL approach were retrospectively reviewed for risk factors associated with perioperative PFF including demographics, intra-operative and postoperative factors, and disposition. Results507 included patients had a 90-day PFF rate of 1.6 % (n = 8): 6 intraoperative (1.2 %), and 2 postoperative (0.4 %), significantly lower than previously reported (p < 0.001). 1 additional postoperative PFF fracture was operatively managed with open reduction internal fixation (ORIF) on day 302; 1-year PFF rate was 2.5 %. All fractures healed uneventfully after treatment. The 1-year return to operating room rate for PFF was 0.3 %. Patients with PFF were significantly older (p = 0.036) compared to non-PFF patients. Implant type significantly predicted PFF. ConclusionThe rarity of PFF among our cohort highlights the efficacy of the AL approach to avoid this complication.

ANALISIS DEBIT RENCANA UNTUK PERENCANAAN BANGUNAN PENGENDALI BANJIR DI DAS WAI RUATA KABUPATEN MALUKU TENGAH

The high rainfall, rapid urbanization, and the presence of impermeable surfaces have drastically increased surface runoff, overwhelming river systems with high water volumes. Changes in land use and rapid population growth further escalate flood risks. Analyzing planned discharge rates and flood control building planning becomes urgent to mitigate losses and risks caused by floods in the Wai Ruata watershed. Calculations indicate that for the Q100 Log Normal (2475.17 m3/s, the channel height is 2.50302 m, closely approximating public information (2.5 m), with a difference of 0.00302 m or 0.302 cm. This suggests that the calculated maximum flood water level based on planned discharge analysis using the rational method for Log Normal probability of 2.503 m is reasonably accurate. It can serve as a reference for flood control building design heights, potentially lasting around 100 years in the Wai Ruata watershed. Planned flood discharges in the Wai Ruata watershed are as follows: for a 2-year return period, 505.80 m3/s (Gumbel), 449.27 m3/s (Log Normal), 462.56 m3/s (Log-Pearson Type III); for a 50-year return period, 1868.80 m3/s (Gumbel), 2016.26 m3/s (Log-Normal), and 1837.18 m3/s (Log-Pearson); and for a 100-year return period, 2137.98 m3/s (Gumbel), 2475.17 m3/s (Log-Normal), 2166.93 m3/s (Log-Pearson). Gumbel planned flood discharge data can be used for a 25-year lifespan of water structures, whereas for a 100-year lifespan, Log-Normal planned flood discharge is more suitable.

Probabilistic risk analysis of local verification of Load Model 1 in Eurocode for Soil-Steel Composite bridges in Sweden

Bridges must be designed to ensure safety for all users. At the same time, the design should be performed with an appropriate risk level. In Sweden, Soil-Steel Composite bridges (SSCB) are the most common bridge type. For SSCB, local verification of Load Model 1 in Eurocode is most often governing the design. The objective of this study was to investigate whether local verification of LM1 load case could be modified without decreasing the agreed risk level in Eurocode. Weight in motion measurements from real traffic were extrapolated with Rice formula. Monte Carlo simulations were used to simulate the 1000-year return period event to obtain the acceptable risk level as prescribed in Eurocode. The results show that the local verification of LM1 is conservative, considering the acceptable risk level in Eurocode. With a modified implementation of local verification, this paper shows that a potential saving of up to 14% in terms of economic cost and CO2-equivalents is possible. A modified implementation of local verification of LM1 in Eurocode for SSCB is proposed, which could reduce the climate impact by up to 14% associated to the construction of new SSCB in Sweden.

Impact of Refined Boundary Conditions of Land Objects on Urban Hydrological Process Simulation

Urbanization has led to an increase in impervious areas and, consequently, an increase in the surface runoff volume and runoff rate. This has exacerbated urban flooding and highlighted the importance of modeling urban hydrological processes. The Waterview Community of Hangzhou City (WCHC) was taken as the study area, and three scenarios were developed: the original scenario, the rough description scenario, and the fine description scenario. The urban hydrological processes were simulated through a coupled model incorporating actual measurements and four design precipitation events (1-year, 5-year, 10-year, and 20-year return periods). The results show the following: (1) The refined depiction scenario has the highest accuracy in terms of measured precipitation, with an average error of 0.54 cm. (2) During different precipitation return periods, the refined depiction scenario shows the smallest range of accumulated water, with a more realistic distribution. On average, it differed from the original scenario by 21.45% and from the rough depiction scenario by 32.18%. (3) The simulation results after the refinement of the feature boundaries are more reasonable in terms of the flow rate and flow direction, indicating that the simulation results have better dynamics. The results showed that refined boundary conditions improved the accuracy and dynamics of urban hydrological simulations, especially in terms of their reflection of actual water accumulation under varying precipitation conditions.