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hazard map based on the nonstationary flood frequency using a generalized extreme value distribution model for the Becho floodplain in the upper Awash River basin. The distributional location parameter was modeled as a function of rainfall amount of different durations, annual total precipitation from wet days, yearly mean maximum temperature and time as covariates. The one-dimensional Hydrological Engineering Center River Analysis System (HEC-RAS) hydraulic model with steady flow analysis was used to generate flood hazard map input, depth and velocity, and inundation extent for different return periods. The result indicated that the model as a function of rainfall, such as monthly rainfall (August) and annual wet day precipitation, provided the best fit to the observed hydrological data. Rainfall as a covariate can explain the variation in the peak flood series. The developed hazard map based on depth alone and the combination of depth and velocity thresholds resulted in more than 70% of the floodplain area being classified as a high hazard zone under 2, 25, 50, and 100-years return periods. The current study assists water resource managers in considering changing environmental factors and an alternative flood frequency model for developing flood hazard management and mitigation strategies.
przez dekady oddziaływanie treści niejawnych o DOL, w zderzeniu z marginalnym ich wykorzystywaniem podczas różnego rodzaju ćwiczeń wojskowych – wygenerowało sytuację, w której zagadnienia ogniskujące się wokół DOL i ich literacka prezentacja może być postrzegana na poziomie niemalże marginalnym. Z kolei doświadczenia wojenne z terytorium Ukrainy (zwłaszcza po 24. lutego 2022 r.) wskazują, że obiekty te są ważnymi elementami szeroko postrzeganego systemu obronnego państwa. Przywoływana ważność stała się tym samym impulsem do przeprowadzenia adekwatnych badań naukowych, których pisemne opracowanie przedkładane jest w niniejszym opracowaniu.
classified content on RAS, in a collision with its marginal use during various types of military exercises, has generated a situation in which issues focusing on RAS and their literary presentation can be perceived at an almost marginal level. In turn, war experiences in Ukraine (especially after February 24, 2022) indicate that these facilities are important elements of the widely perceived defence system of the state. The invoked importance became the same impulse to conduct scientific research, the written study of which is presented in this study.
Tamanrasset Valley watershed in Algeria, where the HEC-RAS model was used to calculate water flow profiles for various flood events that occurred downstream. The objective of the study was to generate flood maps for extreme river flood events in the area, which could help assessing the risk of flood vulnerability in the area study. The process involved using the HEC-RAS 1D model to simulate the water flow in the river, taking into account the various flow and boundary conditions. The results of the simulation were then exported and analyzed in GIS-based software, HEC-GeoRAS, to prepare the flood inundation maps. The flood maps were based on the water level at each cross-section, which was calculated using the water surface profiles generated by HEC-RAS. The study aimed to identify flood zones using a combination of HEC-GeoRAS and GIS. The HEC-GeoRAS extension was utilized in a GIS environment to determine flood zones associated with 10-year, 20-year, 50-year, and 100-year return periods. The results of the study confirmed the effectiveness of the integration of GIS and HEC-RAS and demonstrated the performance of the model. Based on these findings, the study recommends the application of this model in planning and management programs for both residential and agricultural areas, to ensure appropriate measures are taken for future flood defense.
jest hodowlą biodynamicznym, z jednoczesnym znikomym wpływem na otaczające go ekosystemy, wpisującym się idealnie w gospodarka o obiegu zamkniętym (GOZ). W mniejszej pracy zaprezentowano wyniki wpływ sposobu regulacji natężenia przepływu wody w Recyrkulacyjnych Systemach Akwakulturowych (RAS) na straty energii wykazując, że pod kątem strat energii optymalną metodą regulacji natężenia przepływu wśród przebadanych jest wykorzystanie zaworu gilotynowego. Metoda ta charakteryzuje się najmniejszymi stratami energii w całym zakresie regulacji, umożliwia płynne sterowanie natężeniem przepływu, a dzięki sposobowi ustawiania stopnia zamknięcia zaworu za pomocą wysuwania dźwigni daje prosty sposób uzyskania żądanego stopnia introwersji.
is biodynamic farming with a minimal impact on the surrounding ecosystems, which fits perfectly into the circular economy (circular economy). A smaller paper presents the results of the influence of the method of regulating the water flow rate in Recirculating Aquaculture Systems (RAS) on energy losses, showing that in terms of energy losses, the optimal method of regulating the flow rate among those tested is the use of a guillotine valve. This method is characterized by the lowest energy losses over the entire adjustment range, enables smooth control of the flow rate, and thanks to the method of setting the valve closing degree by extending the lever, it provides a simple way to obtain the desired degree of introversion.
przez Główny Urzędu Geodezji i Kartografii. Obszar badań obejmuje Kazimierz Dolny położony nad Wisłą. Badania przeprowadzono w trzech etapach. Po pozyskaniu danych z numerycznego modelu terenu i elementów doliny rzecznej (np. przekrojów poprzecznych doliny) oraz opracowaniu warstwy szorstkości na podstawie wskaźników Manninga, wymodelowano wody wezbraniowe dla powodzi dziesięcio-, stu- i pięćset letniej. Analiza ryzyka wykazała, że powódź 100-letnia powoduje już dość znaczne szkody w dobrach ludzkich i kulturowych, a powódź 500-letnia znacznie je powiększa, niszcząc 2016 budynków i zalewając obszar o powierzchni niemalże 207 ha.
Geodesy and Cartography. The research area covers the small historic city Kazimierz Dolny located on the Vistula River. The research was carried out in three stages. After digital elevation model and river valley elements (e.g. valley cross sections) data acquisition, as well as elaborating a roughness layer based on Manning's indicators, the ten-, one-hundred- and five-hundred-year floods water were modelled. The risk analysis showed that the 100-year flood is already causing quite significant damage to human and cultural assets, and the 500-year flood significantly increases it, destroying 2,016 buildings and flooding an area of almost 207 hectares.
mixture. Results obtained for laboratory-produced mixture containing 4% RAS and plant-produced mixture containing 1% RAS were compared with the results of the reference mixture. Statistical analysis of void content in asphalt mixtures did not indicate significant differences; therefore, performance properties of mixtures may be compared without concern about the influence of physical properties. The research confirmed a significant increase in mixture stiffness with an increase in RAS content, especially at medium (15°C) and high (30°C) service temperatures. Compared to the reference mixture, mixtures incorporating RAS displayed an increase in indirect tensile strength as well. Lower temperature sensitivity of mixtures with RAS was also observed, both in terms of stiffness modulus and indirect tensile strength. Fatigue tests confirmed the positive effect of RAS on the obtained value of strain corresponding to fatigue life of 1 million load cycles.
laboratoryjnej z dodatkiem 4% RAS oraz mieszanki z dodatkiem 1% RAS (wyprodukowanej w wytwórni). Analiza statystyczna w zakresie zawartości wolnych przestrzeni w mieszankach mineralno-asfaltowych nie wykazała istotnych różnic, co pozwala porównać cechy eksploatacyjne mieszanek bez obciążenia wpływem cech fizycznych. Badania potwierdziły istotny wzrost sztywności mieszanek wraz ze zwiększeniem dodatku RAS, zwłaszcza w średnich (15°C) wyższych (30°C) temperaturach użytkowych. Mieszanki z dodatkiem RAS wykazały wzrost w stosunku do mieszanki referencyjnej także w zakresie wytrzymałości na rozciąganie pośrednie. Jednocześnie stwierdzono mniejszą wrażliwość termiczną mieszanek z RAS, zarówno w aspekcie modułu sztywności jak i wytrzymałości na rozciąganie pośrednie. Badania zmęczeniowe potwierdziły pozytywny efekt dodatku gontów papowych do mieszanki na uzyskaną wartość odkształcenia odpowiadającego trwałości 1 miliona cykli obciążeń.
seems certain that in the future, there will also be 4D and 5D models. However, the results obtained from very sophisticated models are frequently questionable, and designers in the field of hydraulic structures must have considerable experience distinguishing important information from irrelevant information. Thus, this paper aims to investigate the effect of the selected boulder block ramp hydraulic structure at Poniczanka stream on the bed-load transport. We evaluated sediment transport using the CCHE2D numerical model. We analysed several scenarios depending on the river bed type (erodible, non-erodible, rocky) and examined the rock blocks used for hydraulic structure construction. The obtained results were compared with the Hjulström and the Shields graph, which are a classic approach for identifying fluvial processes in river channels. In addition to these two methods, numerical modelling using the 1D HEC-RAS (Hydrologic Engineering Center’s River Analysis System) modelling were conducted, which included the determination of horizontal and vertical changes to the river bed morphology of the examined section of river reach as well as providing the basic hydrodynamics parameters which, from the practical point of view, designers involved in the process of designing ramps could use.
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rzece Odrze.
the discharge of floods in the Odra River, Poland.
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increasingly necessary for all the actors concerned (decision-makers, technicians, and the population) to identify protection issues. In 2018, in the extreme south of Algeria, In-Guezzam City suffered a devastating flood that caused significant damage and loss of human and material resources. More than 100 homes collapsed, and approximately 345 families were displaced. Currently, there is no research work to assess the hydrological situation and the risk of flooding in this region. Therefore, the main purpose of this study is to shed light on the risk of flash floods in the extreme south of Algeria with more specific attention to the August 2018 floods as well as the climate trends over the past 30 years using Mann–Kendall test and Sen’s Slope Estimator. The chosen approach involves a hydrological study and hydrodynamic modeling using HEC-RAS software. This latter allows for simulating floods using statistical methods and creating several regional flood hazard maps.
wastewaters in order to go through treatment. Thus, the WWTP, situated 17 km from the mouth of the estuary, has become the only discharge point for treated domestic wastewater into the Sebou estuary. This study aims to model the Sebou estuary water quality and assessment of the impact of WWTP. Our study started with hydraulic modelling of the river using a 1D model (HECRAS 5.0.6), since water quality is strongly depending on hydraulic regime. HEC RAS has been calibrated and validated using hydraulic and morphological database of the years 2019 and 2021. The spatiotemporal evolution of hydraulic variables (water velocity, water level, etc.) was calculated by the hydraulic model and used in the water quality module to simulate the biochemical oxygen demand (BOD5). Two scenarios were put under examination, one is a simulation of discharges of untreated wastewaters by six collectors (mean BOD5 of 300 mg/L) and the second is a simulation of discharge after treatment at the WWTP (mean BOD5 of 24 mg/L). The simulation showed an Impact of the tidal cycle and fresh water flows (coming from the upstream) on the urban wastewater discharges fate. Calculations of the BOD5 provided by the model are in good agreement with field measurements. The first simulation results show that water quality of the Sebou River does not meet WHO standards (average quality about 7 mg/l of BOD5). The second simulation shows that the treatment plant reduces the concentration of BOD5 in the river to about 3 mg/l compared to the case before their installation, the quality of the water in the estuary is changing to become good after having been just average. In addition, the BOD5 concentration downstream of the WWTP changes according to the tidal cycle. Finally, the results show the very positive impact of Kenitra’s WWTP on the water quality of the Sebou River estuary.
settlements. The river hydraulics is studied by using 30-metre remotely sensed shuttle radar topographic mission - digital elevation model (SRTM DEM) and Arc Map. 32 cross-sections are imported from Geographic Information System (GIS) to HEC-RAS. On historical peak flow results, the extreme value frequency distribution is applied, and a flood is determined for a 100-year return period, with a discharge estimated as 2223 cubic metres. Three steady flow profiles are adopted for HEC-RAS, the first is for the maximum historical peak data, the second is for the 100-year return period, and the third profile is for the latter 100-year period with a safety factor of 1.28. With remote sensing-based assessments, the proposed location for a bridge is determined and then verified with a field survey which was physically conducted. The maximum water height estimated in the river is about 4.26 m. This bridge will facilitate about 50 thousand population of Masahan and its surroundings. It will create a shortest link between Khyber Pakhtunkhwa and Azad Kashmir and thus will enhance tourism and trade activities.
process, such as riverbank retreat, which cannot be easily measured and predicted by any model. The meandering flow along the Bhagirathi-Hooghly river has created riverbank erosion and riverbank retreat conditions in several areas, through which measuring bank stability and erosion is quite complex. As a result, the BSTEM model, integrating with HEC-RAS, has been used in this article to measure riverbank erosion and retreat accurately. Riverbank erosion and retreat data for 2019–2020 have been simulated based on data observed from 2016 to 2018 for accurate measurement. In addition, the total sediment yielded from the river bank has been calibrated and simulated with the help of sediment transport formulation in HEC-RAS, which indicates a gradual increase in river erosion at present (2019–2020). This model is expected to help formulate government policy on protecting riverbank erosion and river restoration in the future.
for the development of hydraulic models and mapping of simulation results has become standard practice for floodplain assessment. The objective of the current investigation is to use one-dimensional floodplain modeling of the Bhima River between Lonikand and Rahu using the RAS-mapper tool (HEC-RAS). The modeled river reach is about 67 km long, near the Pune administrative division of Maharashtra, India. The hydrodynamic flow computations were carried out for the years 2005 and 2017. A total of 595 cross sections along the main river was employed for hydrodynamic flow simulations. In this study, cross-sections and past observed flood data have been used to develop a 1-D integrated hydraulic model of the Bhima River. The simulated water levels are also validated with observed water levels and found to be reasonably correlated.
system. The choice of the Ras El Ma source is justified by the fact that it constitutes the main outlet of the Liassic aquifer at the Southwest of Taza town. The structural approach highlighted that the impact of South Rifan and North Middle Atlas faults, oriented mainly NE-SW to ENE-WSW and NW-SE, tectonically linked to the Hercynian and late-Hercynian phases; these faults compartmentalized the karst into panels. The functioning of this karst system is based on the coupling of inputs and outputs, the analysis of interannual hydrograph, flood hydrographs, the recession curves and the analysis of hydrogeochemical results. Respectively, the obtained results are presented as follows: A close relationship between flow rates and precipitation, interannual hydrographs marked by a contrasting variation in flow rates and a periodicity that occurs between low water and high-water years. Concerning flood hydrographs, there are two types, a unit modal hydrographs type which generally occurs following time concentrated rainfall and a second multi modal hydrographs type which follows the repetitive rainfall in the basin. The study of recession curves reveals a clear complexity of the systems supplying the source. However, due to the low drying-off coefficients (7.66∙10-4), the aquifer seems to have a poorly developed drainage network in a flooded area. According to the Mangin method [1975], this karstic system is classified in the category of poor or complex karst systems taking into accounts two parameters (i) and (K), which characterize the functioning of the infiltration zone and the volume of flooded karst, respectively. The physicochemical parameters study highlighted the nature of drained rock by the sources. The correlation between conductivity and different chemical elements shows that bicarbonates and calcium are responsible for the mineralization of the waters of this source. It can be concluded that the low values of mineralization occur during the winter and spring floods. The spring regains its normal mineralization during the summer period.
HEC-RAS. The area in the vicinity of Narai Drain was inundated due to the catastrophic food occurred in the year 2010, which caused huge damage to public property, livestock, communication, and infrastructure. In this study, the Narai Drain watershed was classifed into three watersheds, namely Narai Drain Upper, Lower, and Regi Drain. GIS technology was used to delineate the watersheds while the discharges were computed using the WinTR-20 mode. Expected rainfall depths were obtained by using Log-Pearson type III Distribution for diferent return periods (i.e., 2, 5, 10, 25, 50, 100, 200). The area inundated by the food was estimated by using HEC-RAS. These results were then incorporated in GIS to prepare food inundation maps. Maximum inundation occurred in the sensitive area of Narai Drain Lower for a 10-year return period. The integrated modeling approach used in this study was found very useful to delineate the area vulnerable to food with a good estimation of inundation depths at various discharge values. The results show that in the upper reach of the Narai Drain, most of the area lying near the food zone was safe for a 100-year return period, while the lower reach was vulnerable even for a return period of 10 years.
performed by the hydraulic HEC-RAS model. This model is dedicated to the description of floods at the dam following a breach in the dike. The main factors considered in this simulation include the level of flood water, the flood hydrograph, and the typical scenario for this breach. The flood risk analysis revealed that the maximum of flood wave flow registered at the breach is (Qmax = 9253.02 m3∙s–1), and is beginning to mitigate downstream of the dam along the El Arab River where it reached at the last village with a low flow (Q = 1110.64 m3∙s–1). This simulation allowed drawing the risk map which showed the areas threatened by flood wave resulting from a total failure of the work, and consequently required a plan of security measures to moderate as much as possible the consequences of floods. A sensitivity analysis was conducted to approach the parameters of impact of the breach on the dam failure scenario. It was confirmed that these parameters as formulation time, breach width and side slope have a great influence on the dam failure scenario with the four adjustments (±20 and ±50).
of open drainage channels, under the influence of sedimentary transport processes. The application of the Hydrologic Engineering Center’s River Analysis System (HEC-RAS) software is to examine two-phase mathematical models. In our case it is the flow and the sedimentary charge along a trapezoidal earth channel of a wetland north east of Algeria. The results of these models were validated by actual data obtained during the observation period from 2017 to 2018, for various rainy events. The solid transport and sedimentation velocity equations of Engelund and Hansen and Van Rijn respectively used by this model, give Nash performance criteria equal to 0.95 and determination coefficient R2 equal to 0.91. On the other hand, the laying of a coarse gravel layer of median diameter of the grains d50% = 60 mm on the bottom of the channels reduces the rate of sedimentation by about 32% over an 11-year period. This satisfying objective study of the modelling allows to obtain an approach to the renovation and a plan for new design of drainage systems, that participates to the sustainable development in the agricultural field.
drenarskich pod wpływem procesów transportu zawiesiny. W dwufazowym modelu matematycznym wykorzystano program HEC-RAS (Hydrologic Engineering Center’s River Analysis System). Zmiennymi w modelu były przepływ i ładunek zawiesiny wzdłuż ziemnego kanału o trapezoidalnym przekroju w środowisku podmokłym północnowschodniej Algierii. Wyniki modelu porównano z rzeczywistymi danymi opadowymi pozyskanymi w różnych okresach w latach 2017 i 2018. Równania Engelunda i Hansena (transport zawiesiny) i Van Rijna (tempo sedymentacji) użyte w modelu dały w wyniku kryterium Nasha równe 0,95 i współczynnik determinacji R2 równy 0,91. Warstwa grubego żwiru o medianie średnic ziaren d50% = 60 mm na dnie kanału spowalniała tempo sedymentacji o ok. 32% w ciągu 11 lat. Przedstawione badania umożliwiają nowe podejście do renowacji istniejących i projektowania nowych systemów drenarskich, które przyczyniają się do zrównoważonego rozwoju rolnictwa.
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performed in the designated section of the Kłodnica river from km 49 + 799 to km 49 + 739, i.e. geodetic measurements of the Kłodnica riverbed and technical inventory of the analysed bridge object, a digital terrain model (NMT) was developed, followed by hydraulic calculations of the water flow Q1% and the flow accumulation (damming) in the clear span of the Wrocławski bridge. The accumulation height was calculated using the formula given in the study by Bajkowski et al. [2000]. Calculations of the accumulation height of designed flow in the clear span of the bridge were also made using the HEC-RAS program. The calculations were made in two variants – in the first variant, calculations were performed for the selected section of Kłodnica without a bridge, and in the second variant, with the bridge. The so-called clear span reserve (bridge clearance) was also calculated, computed as the difference in ordinates of the keystone arch of the bridge span and the stacked water table of the design flow in the bridge clear span. The obtained calculation results indicate no risk of Q1% flow accumulation in the cross-section of the Wrocławski bridge. The calculated accumulation of the design flow will not cause flooding from the Kłodnica riverbed. Preliminary conclusions indicate a possible necessity to verify flood hazard zones for the flow with a probability of exceedance p = 1%, developed for the Kłodnica river in the centre of Gliwice town, developed as part of the ISOK project.
przyjętym odcinku rzeki Kłodnicy od km 49 + 799 do km 49 + 739, tj. pomiarów geodezyjnych koryta Kłodnicy i inwentaryzacji technicznej analizowanego obiektu mostowego, opracowano numeryczny model terenu (NMT), a następnie wykonano obliczenia hydrauliczne przepływu wody Q1% i wysokości spiętrzenia tego przepływu w świetle mostu Wrocławskiego. Wysokość spiętrzenia obliczono za pomocą wzoru podanego w opracowaniu Bajkowskiego i in [2000]. Wykonano także obliczenia spiętrzenia przepływu obliczeniowego w świetle tego mostu za pomocą programu HEC–RAS. Obliczenia wykonano w dwóch wariantach – w wariancie pierwszym wykonano obliczenia dla wytypowanego odcinka Kłodnicy bez mostu, a w wariancie drugim z mostem. Obliczono również tzw. zapas w świetle mostu, jako różnicę rzędnych zwornika łuku przęsła mostu i spiętrzonego zwierciadła wody przepływu obliczeniowego w świetle mostu. Uzyskane wyniki obliczeń wskazują na brak zagrożenia spiętrzenia przepływu Q1%, w przekroju mostu Wrocławskiego. Obliczone spiętrzenie przepływu obliczeniowego nie spowoduje wystąpienia wód tego przepływu z koryta Kłodnicy. Stwierdzono wstępnie ewentualną konieczność weryfikacji stref zagrożenia powodziowego dla przepływu o prawdopodobieństwie przewyższenia p = 1%, opracowanych dla rzeki Kłodnicy w centrum Gliwic, opracowanych w ramach projektu ISOK.
podstawie pomiarów terenowych, modelowania numerycznego oraz z użyciem wykresu Hjulströma określono miejsca, w których występuje erozja koryta, transport lub sedymentacja rumowiska. Modelowanie numeryczne przeprowadzono dla przepływu wezbraniowego Qwez = 16,9 m3·s–1, zaobserwowanego w rzece 5 sierpnia 2013 roku, oraz dla przepływów prawdopodobnych: Q50% = 59 m3·s–1, Q25% = 99 m3·s–1, Q10% = 165 m3·s–1 i Q1% = 321 m3·s–1. Podjęto także próbę wyznaczenia dla badanego odcinka rzeki wartości przepływu korytotwórczego.
consisted of 100-m long segment upstream of the existing block ramp and 65 m downstream of it. The analysis was done based on field measurements, numerical modeling with HEC-RAS and Hjulström’s graph. Numerical modeling was conducted for observed flood Qfl ood = 16.9 m3·s–1 on 5 August 2013, and for the t-years floods: Q50% = 59 m3·s–1, Q25% = 99 m3·s–1, Q10% = 165 m3·s–1 and Q1% = 321 m3·s–1. For the analyzed reach an attempt was done to determinate dominant discharge.
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odcinku od km 0+000 do 6+576. Obliczone za pomocą modelu konceptualnego OTTHYMO potencjalne przepływy (spływy powierzchniowe) przyjęto jako dane wejściowe do modelu hydraulicznego HEC-RAS, który umożliwił transformację przepływów w cieku i wyznaczenie przepływów w poszczególnych przekrojach obliczeniowych (przepływów zredukowanych). Niezależne obliczenia przepływów potencjalnych i zredukowanych przeprowadzono za pomocą modelu SWMM, który jest modelem dynamicznym o parametrach rozłożonych. Obliczone za pomocą modeli HEC-RAS i SWMM przepływy zredukowane o prawdopodobieństwach przekroczenia 1, 2 i 10% są do siebie podobne w przekrojach obliczeniowych II, III i IV – w 7. na 9 przypadków różnice w przepływach nie przekraczają 25%. Największe wartości przepływów zredukowanych o określonym prawdopodobieństwie przekroczenia obliczono w przekroju II, przy zastosowaniu obydwu modeli. Przepływy zredukowane są mniejsze od przepływów potencjalnych obliczonych za pomocą modeli OTTHYMO i SWMM. Wyniki obliczeń wskazują na możliwość stosowania w zlewniach miejskich zarówno modelu HEC-RAS, jak i modelu SWMM.
0+000 to 6+576. Potential flows (surface runoff) calculated using the conceptual OTTHYMO model were taken as an input data to the hydraulic HEC-RAS model, which enabled transformation of the flows in the watercourse and determining flows in the individual cross-sections (reduced flows). Independent calculations of potential and reduced flows was performed using the SWMM model, which is a dynamic model with distributed parameters. Calculated using HEC-RAS and SWMM models reduced flows with probability of exceedance of 1, 2 and 10% are similar in the computational cross-sections II, III and IV – in 7 out of 9 cases the differences in the flows do not exceed 25%. The highest values of reduced flows with a certain probability of exceedance were calculated in the cross-section II, using both models. The results of calculations indicate the possibility of use in an urban catchments of both the HEC-RAS model and the SWMM model.
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