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Flooding is a persistent and challenging issue in many regions, requiring precise methods for estimating peak flood discharge to improve flood management strategies. Accurate discharge estimates are essential for designing effective flood control infrastructure and implementing mitigation measures. This study uses the Nakayasu Synthetic Unit Hydrograph (SUH) method to estimate peak flood discharge for a 2-year return period in the Kening River Flow Area, Parengan sub-district, Tuban district, and East Java Province. This research used various methods for rainfall analysis, including the Gumbel, Pearson III, and log-normal distributions. In contrast, rainfall intensity calculations were carried out using the Mononobe and ABM methods. The research highlights the effectiveness of these methods in predicting rainfall intensity and peak discharge, providing valuable insights for flood management practices. The results show that the Nakayasu SUH method predicts a peak discharge of 206.62 m³/second. By improving the accuracy of flood discharge predictions, this study supports better planning and design of flood control structures, which is crucial for managing flood risks and enhancing infrastructure resilience in flood-prone areas. These findings are expected to improve flood management practices and infrastructure planning.

Ecological disturbances driving state changes in ecosystems are likely to be exacerbated with climate shifts during this century. Temperate montane ecosystems of the Western United States (Mountain West) are especially vulnerable due to their low fertility, heterogeneous landscapes, and tight coupling between terrestrial and aquatic components. We review how catchment level pulse and press disturbances will intensify, and how they are reflected by coupled measurements of stream water chemistry and flow. Detecting effects on watershed processes can be complex and depend on the type and extent of disturbance. Within this context, we discuss the impacts of wildfire (pulse), bark beetle outbreaks (pulse), snowpack shifts (press), and progressive vegetation community shifts (press) on streamflow and chemistry dynamics (hydrochemographs). We used long-term data from three mid- to high-elevation watersheds as examples of how disturbances may influence stream hydrochemographs, including increased variability in winter nitrate export in more recent years with extremes in snowmelt runoff export; variable nitrate export when snow water equivalent was abnormally high or low; and high nitrate flux in the years immediately following sudden forest loss. These examples illustrate the need for long-term continuous monitoring to fill the gap in our understanding of the short- and long-term consequences of climate change-induced disturbances to watersheds. As disturbances increase in severity and frequency and induce ecological state changes, it is critical that we develop our understanding of impacts on downstream communities that depend sociologically and economically on water availability and quality. [ABSTRACT FROM AUTHOR]

Hydrological models serve as effective tools for managing water sources and assessing water components. Although basin hydrological models have been developed, selecting suitable software for modeling specific areas remains challenging. Hence, it's essential to opt for software capable of simulating the hydrological cycle with a simple structure and minimal input parameters. In northwest Iran, AWBM and ARCSWAT software were employed for simulation. AWBM is a simplistic program estimating runoff using precipitation and evaporation indicators, while ARCSWAT is a semi-distributed software for continuous flow simulation. ARCSWAT necessitates various inputs, including geological, land use, and slope maps, along with precipitation, temperature, relative humidity, and radiation statistics. The runoff simulation results during calibration and validation periods were assessed using two statistical indices: Nash Sutcliffe Efficiency (NSE) and the coefficient of determination (R2). A comparison of the statistical indicators revealed NSE values of 0.83 and 0.7 for calibration and validation periods, respectively, and R2 values of 0.83 and 0.8 for calibration and validation periods, respectively, for the semi-distributed SWAT model. In contrast, for the AWBM integrated model in the basin, NSE values were 0.63 and 0.48, and R2 values were 0.48 and 0.48 for calibration and validation periods, respectively, indicating better results in runoff simulation at the monthly time scale. [ABSTRACT FROM AUTHOR]

Various researchers have examined discharge regimes of rivers in Slovenia in the past 75 years: four major studies made by Ilešič, Kolbezen, Hrvatin, and lastly Hrvatin and Frantar have analysed and classified the regimes, and clustered them into regime types. They have varied due to changes in discharge characteristics, mainly as a consequence of climate change. In the present paper, we used average monthly discharges between 1991--2020 to calculate the discharge coefficients and determine the modern typology of the regime types on 36 streams at 45 gauging stations. The final result was five types of contemporary discharge regimes which are a consequence of the landscapes' heterogenous climate- and geodiversity characteristics as well as human interventions. [ABSTRACT FROM AUTHOR]

Radiocarbon and uranium-thorium dating of microbialites and penecontemporaneous cements in a microbialite mound at Death Point at Lakeside, Utah, on the shore of Great Salt Lake, Utah, call for a revision of the Lake Bonneville hydrograph. At about 30,000 cal yr BP, the lake experienced an abrupt rise of about 20 m, then dropped back down to levels near or slightly higher than the modern average elevation of Great Salt Lake. Over the ensuing ~6000 yr the lake experienced a series of fluctuations, up to levels a few tens of meters higher than the modern average Great Salt Lake, then down again. The exact timing and amplitudes of those fluctuations are not known, but importantly, the lake did not rise to levels near the Stansbury shoreline (~80 m higher than Great Salt Lake) until after about 24,000 cal yr BP. After the Stansbury shoreline, the lake rose almost 200 m to its highest level at the Bonneville shoreline by about 17,500 cal yr BP. This interpretation is different from previously published hydrographs, many of which show a relatively steady rise to near the Stansbury shoreline between 30,000 and 25,000 cal yr BP. [ABSTRACT FROM AUTHOR]

Extremely rapid rates of rise in level and discharge in a subset of flash floods ('abrupt wave front floods', AWF) are separate hazards from peak level. Such flood events are investigated for Pennine catchments in northern England using both gauged and historical information. Gauged level and flow digital records at 15‐min intervals provide recent data. Historical information for 122 AWF events is extracted from a chronology of flash floods for Britain. Historical AWF events are mapped and found to occur on every major Pennine catchment; catchment descriptors are derived as a basis for assessing catchment vulnerability. We discuss the disputed origin of AWF. Using gauged data, we contrast the rising limb of AWF and 'normal' floods. We investigate time series of historical AWF, noting a puzzling peak in the late 19th century. Current rainfall and river monitoring does not provide a reliable basis for understanding AWF processes or for operational response and we suggest improvements. Similarly, current models for design flood estimation and forecasting do not generate the observed rapid increase in level in AWF floods. [ABSTRACT FROM AUTHOR]

Method of numerical analysis of the influence of initial depression depth coupled with absolute surface roughness and with Manning's roughness coefficient onto the key hydraulic parameters of the stormwater runoff is proposed. Small highly urbanized catchment with 100% impervious cover was used in stormwater management model numerical simulations for climatic conditions of the Lviv City (Ukraine) at the return period of 1 year. An increase in depression depth from 1 to 5 mm causes reduction in the specific maximum peak runoff from 5.13∙10−3 L/(s∙m2) to 3.29∙10−3 L/(s∙m2), while the critical duration of rainfall increase from 17 min to 56 min. The dimensionless maximum peak flow rate is expressed as a two-parameter exponent function of the initial depression depth, allowing the estimation of the lower limit of this discharge for the practically significant range of the depression depth. [ABSTRACT FROM AUTHOR]

River catchments are dynamic networks that contain multiple levels of spatial and temporal complexity. Benthic macroinvertebrates are key indicator taxa throughout catchments, and beta diversity has been used as a metric to explore determinants of community composition at the catchment scale. Although factors influencing spatial beta diversity have been explored, the determinants of temporal beta diversity have been understudied. In this study, we aimed to understand how shifts in benthic macroinvertebrate community composition over multiple years are related to local and regional variables. We used beta regression with a large, publicly available biomonitoring dataset from river networks in California, USA, to model the effects of local environmental variables, flow variability, and spatial network context on benthic macroinvertebrate temporal beta diversity. The spatial variables channel slope, drainage density, and upstream catchment area had the strongest relationships with macroinvertebrate beta diversity. Channel slope was negatively related to temporal beta diversity, whereas drainage density and upstream catchment area were positively related to temporal beta diversity. Temporal beta diversity was also higher when the rate and magnitude of rises and falls in flow were higher in the hydrograph, as well as when the number of zero-flow days and the duration of flow rises and falls were higher. Overall, our results indicate that temporal beta diversity of freshwater benthic macroinvertebrates is shaped by both long-term hydrological context and spatial context and that these factors may serve as better predictors of long-term community variability than variability in point estimates of environmental measurements. Our study supports the need for biomonitoring efforts at long spatial and temporal timescales and highlights the need to consider metacommunity change in the management of freshwater systems. [ABSTRACT FROM AUTHOR]

Iran's groundwater reservoirs have faced significant and related challenges in the past three decades. The simultaneous decrease in the volume and quality of these waters, which are increasingly contaminated with pollutants, renders them largely unusable for many uses. Therefore, there is an increasing emphasis on evaluating the quality of groundwater and identifying anthropogenic or geogenic factors that affect its quality more than ever before. In this study, the hydrogeochemical pollution caused by major, minor, and trace elements was identified by examining the water table against the electrical conductivity of water resources in Azarshahr plain. Long-term data on water levels and electrical conductivity were obtained from regional water resources in East Azerbaijan province. After initial examination, 33 samples were collected from wells and qanats in the area and transferred to the water laboratory of Tabriz University for analysis. The measured parameters included pH, electrical conductivity, major, minor, and trace elements. The results of chemical analysis showed that the concentrations exceeding the permissible drinking limit for nitrates and elements such as Arsenic, Lead, Nickel, and Chromium. Piper diagrams and Stiff diagrams were used to determine the water type in the area; it was found that the water type is mainly sulfate and bicarbonate-based. The origin of the available water is related to the geological formations in the area as a result of mixing and ion exchange. Furthermore, multivariate statistical analysis using factor analysis revealed four influential factor groups affecting water quality in the area; only the fourth factor was attributed to anthropogenic. In general, most of the trace elements in water sources are influenced by formations and aquifer-rock interactions. The overall trend of groundwater quantity over a 25-year period is relatively stable with a slight downward slope; however, the general trend of electrical conductivity is ascending with a much steeper slope indicating an increase in anthropogenic activities as well as the presence of saline layers, which leads to a decrease in the quality of groundwater. Most of the contaminated samples in terms of major and trace elements are located around Gowgan city at the end of the plain. The pollution at this end is related to dissolution trends along with movement paths of groundwater flow and density of pumping wells in this area. [ABSTRACT FROM AUTHOR]

Abstract Extremely rapid rates of rise in level and discharge in a subset of flash floods (‘abrupt wave front floods’, AWF) are separate hazards from peak level. Such flood events are investigated for Pennine catchments in northern England using both gauged and historical information. Gauged level and flow digital records at 15‐min intervals provide recent data. Historical information for 122 AWF events is extracted from a chronology of flash floods for Britain. Historical AWF events are mapped and found to occur on every major Pennine catchment; catchment descriptors are derived as a basis for assessing catchment vulnerability. We discuss the disputed origin of AWF. Using gauged data, we contrast the rising limb of AWF and ‘normal’ floods. We investigate time series of historical AWF, noting a puzzling peak in the late 19th century. Current rainfall and river monitoring does not provide a reliable basis for understanding AWF processes or for operational response and we suggest improvements. Similarly, current models for design flood estimation and forecasting do not generate the observed rapid increase in level in AWF floods.

ABSTRACT Determining hydrographs for hydraulic works projects such as dams and reservoirs requires the definition of the design rainfall hyetograph. The Chicago method stands out as one of the most used methods, with the advantage of being easy to apply. However, the dependence on traditional and updated IDF equations can be pointed out as a limitation of the method. This study aimed to adapt and apply the Chicago hyetograph method with the intense rainfall equations of the alternative model, which stands out for its ease of obtaining and updating. The equations for estimating rainfall intensities for the duration before and after the peak of the hyetograph were presented. The equations were also adapted to obtain the accumulated depths or volumes of rainfall before and after the peak of the hyetograph. This information allows us to easily obtain the rainfall blocks for each interval of the hyetograph. The method was applied to determine the hyetograph based on the maximum daily rainfall, demonstrating each calculation step. The equations presented here can be implemented in electronic spreadsheets or programming routines, allowing Engineering professionals to apply methods that are more appropriate to local data.

Karst aquifers consist of complex networks of conduits in which groundwater flows and recharge/discharge processes are generally more dynamic than in other types of aquifers. Due to their intrinsic heterogeneity and anisotropy, monitoring, quantifying, and analysing natural responses of karst springs is an efficient tool. Unlike Cenozoic and Mesozoic rocks, in Neoproterozoic karst systems, groundwater circulates and stores generally in dissolution features known as tertiary porosity, as the rock's primary porosity is recrystallized, considered negligible. This article studies the hydrodynamics of a karst portion of the São Miguel River basin, southwest of the state of Minas Gerais, Brazil. The region is predominantly composed of Neoproterozoic carbonate rocks, dating from about 570 to 540 million years ago. During a hydrological year (2019–2020), three karst springs (S1, S2, and S3) were daily monitored through their natural responses (variations of electrical conductivity, EC, temperature, T, and discharge, Q) to rainfall episodes. The data were interpreted based on the analysis of spring hydrographs, time series, recession curves (seasonal and intra‐annual), and statistics of EC, T, and Q variations. The results show the three springs generally exhibit quick flow, typically karstic, in the case of hydrosystems with a well‐structured and functional underground drainage network. The time series indicate the hydrosystem drained by S1 presents slower circulation and a lower degree of linearity, resulting from the higher sinuosity of the system, while the hydrosystems of S2 and S3 have similar behaviours, of quick water circulations immediately after a rainy episode. The degrees of karstification classify S1 and S2 as complex and extensive karst systems consisting of several subsystems, and S3 as a system in which the conduit network is more developed at the upper epiphreatic zone than near the outlet. [ABSTRACT FROM AUTHOR]

The hydrological response of groundwater to rainfall plays a key role in the initiation of deep-seated bedrock landslides; however, the mechanisms require further investigation due to the complexity of groundwater movement in fissured bedrock. In this study, an active translational landslide along nearly horizontal rock strata was investigated. The hydrological response of groundwater to rainfall was analyzed, using the data from a four-year real-time field monitoring program from June 2013 to December 2016. The monitoring system was installed along a longitudinal section of the landslide with severe deformation and consisted of two rainfall gauges, nine piezometers, three water-level gauges, and two GPS data loggers. Much research effort has been directed to exploring the relationship between rainfall and groundwater response. It is found that both the pore-water pressure (PWP) and groundwater level (GWL) responses were significantly influenced by the rainfall pattern and the hydrological properties of the underlying aquifer. The rapid rise and fall of PWP and GWL were observed in the rainy season of 2013 with high-frequency, long-duration, and high-intensity rainfall patterns, especially in the lower section of the landslide dominated by the porous aquifer system. In contrast, a slower and prolonged response of PWP and GWL to rainfall was observed in most monitoring boreholes in 2014 and 2015 with two rainstorms of short duration and high intensity. In the lower section of the landslide, the peak GWL exhibited a stronger correlation with the cumulative rainfall than the daily rainfall in a single rainfall event whereas the peak groundwater level fluctuation (GWLF) exhibited a strong correlation with API with a half-life of 7 days. In the middle section of the landslide, however, relatively lower correlation between rainfall and groundwater response was observed. Three types of groundwater flow were identified based on the recession coefficients of different segments of water-level hydrographs in the landslide area, corresponding to the quick flow through highly permeable gravely soil and well-developed vertical joints in the bedrock, the slow and diffuse flow through the relatively less-permeable bedrock, and the transition between them in the aquifer system. [ABSTRACT FROM AUTHOR]

In the case of absence of reliable information on fluctuations of levels and hydraulic parameters of aquifers within a large catchment, the method of river hydrograph decomposition can be used to assess groundwater component and other constituents of river water recharge. The difficulties and shortcomings of this method, which relies on specific schematizations and assumptions, are analysed and discussed. We propose to take into account the results of calculations of lateral groundwater inflow to the river accomplished using the numerical method based on observations at representative balance sites in order to improve the accuracy of the method of decomposition of the river hydrograph. A proper schematization should also be justified for river catchment (or its part), which describes the interaction of surface water, shallow groundwater, and artesian (deep) interlayer waters, which provides rationale for defining or neglecting groundwater inflow to river during the flood periods. The most disputable issue remains the allocation of the phase of "reverse water inflow to river banks" during flood periods. The groundwater level rise at the beginning of the flood results from the infiltration recharge to the aquifer and from inflow of water from the river. The contribution of inflow to river bank to groundwater level rise is dependent from the distance from the river to the observation well. To establish hydraulic head gradient from the river towards the adjacent groundwater aquifer at flood peak, at least two observation wells are needed, one of which should be located 3-4 m from the river water edge on the elevated part of the bank which is not flooded, and the other should be located 50-70 m from the bank towards the watershed. It is proposed that the phase of maximum groundwater inflow to the river should be adjusted based on the dates of the beginning and ending of the groundwater level decrease during the recession of the river flow during the flood period. The combined application of the described above methods showed that the use of only hydrograph decomposition method underestimates the share of groundwater recharge to the river by 2-5%. Based on the analysis of the Pivdennyi Buh River hydrographs during the 1980-2020 period, general tendencies of changes in the shallow groundwater and deep subsurface recharge of the Pivdennyi Buh River in its upper basin (upstream of the city of Khmilnyk) have been established: deep subsurface recharge prevailed over the shallow groundwater component (33.4 compared to 25.0% of the total). At the same time, the total subsurface runoff constituted on average 58%. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Tikrit University for Humanities is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Arquitectura + is the property of Revista Arquitectura + and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this work, we find the discharge corresponding to linearized full Saint-Venant equations by considering a uniformly distributed lateral inflow along the channel length for a finite-length rectangular channel. The discharge due to the lateral inflow is presented as the convolution of two functions: the lateral inflow distributed along the channel length and the lateral channel response function. We study the behaviour of the lateral channel response function for different cases of the reference discharge, channel width, Manning roughness coefficient, and bottom slope. This response function gets affected by the presence of the upstream and downstream boundary conditions. We observe the maximum peak of the response function near the midpoint location of the channel. For a given channel width, the choice of reference discharge, Manning roughness and slope of the channel plays a crucial role in the accuracy of the hydrographs. The meaning of semi-infinite channels also seems to vary with the slope of the channel. One of the key observations of this study is that the downstream boundary cannot always be ignored and, for those cases, its influence is clearly observed on the hydrographs plotted upstream. [ABSTRACT FROM AUTHOR]

The time of concentration (Tc), which represents the steady-state hydraulic conditions of a watershed, is an essential parameter for understanding precipitation and runoff dynamics in a hydrographic basin. Precise Tc estimates are required in many hydrological models and for the correct scaling of hydraulic structures. In Brazil, common empirical or semi-empirical methods for estimating Tc have not been developed and verified using local data, studies are needed in the area of hydrological modeling, which provide knowledge of the flow dynamics in tropical regions. In this study, we develop a model for estimating Tc for non-urban tropical basins, which are characterized by soils with high to very high runoff potential. The model employs the following input variables: basin area, main thalweg length, and average rainfall intensity, and an unprecedented methodology that applies: the Harmony Search algorithm to optimize parameters, data from 15 basins with areas less than 2,000 km2, 1,002 hydrological events, 46 equations for estimating Tc, and six different statistical techniques. The model is effective for estimating Tc in non-urban basins in a tropical climate region that mostly present soils with a high to very high runoff potential. [ABSTRACT FROM AUTHOR]

The North Railway is one of the longest railway lines in the world, extending for 2750 km from the Riyadh region to Al-Jawf Province through many diverse topographies, including valleys where direct runoff is generated that cross the existing hydraulic protection installations on the railtrack. Direct runoff flows in quantities that exceed the capacity of existing drainage installations and cause several types of damage, owing to the nature of the drainage basins and the impact of changing natural factors and human errors. To ensure the safety of the design of hydraulic drainage installations, this indicates the need for hydrological studies of drainage basins, especially those that include important strategic facilities such as railway lines. In this study, the hydrological modeling of four subdrainage basins (No. 6, 7, 13, and 14) within Wadi Malham was applied and evaluated to determine if the drainage installations can accommodate the direct peak runoff flow. According to the results, the peak flows of 8.9 m3/s for basin No. 7 and 18.2 m3/s for basin No. 13 indicate that they are unable to handle the direct peak runoff flow from the designed storm for a return period of 100 years. The other two basins are able to pass through the peak flow. Based on the findings of this study, we recommend adding an opening for culvert C0400 in basin No. 7 and adding two openings for C0244 in basin No. 13 to accommodate the peak flow. [ABSTRACT FROM AUTHOR]

This study evaluates the effects of climate change (CC) on runoff properties over the case study of the Qaran Talar watershed located in Iran. To consider the two main sources of uncertainty, i.e., Greenhouse Gases emission (GHG) scenarios and outputs of Atmosphere-Ocean General Circulation Models (AOGCMs), a daily rainfall time series was generated for two future periods (2021-2050 and 2070-2099) at three risk levels of 0.1, 0.25 and 0.50. 22 AOGCMs outputs following two emission scenarios (RCP4.5 and RCP8.5) were used. The results showed that the uncertainty of climate change scenarios was primarily owing to the uncertainty of GCMs outputs. Regarding the 2021-2050 period, under both emission scenarios, the increases in peak discharge and flood volume (FV) were estimated to reach 70, 50, and 30% at three risk levels of 0.1, 0.25 and 0.50, respectively, compared to the recent past period. As the current century draws to a close, the difference between the results of the two emission scenarios becomes apparent so that in the far-future period (2070-2099), the RCP8.5 scenario estimates and FV more than the RCP4.5 scenario does. Additionally, it was found that the uncertainty caused by AOGCMs was more than that by GHG emission scenarios. HIGHLIGHTS The impacts of CC on flood hydrographs were discussed.; CC leads to an increasing trend in and FV.; RCP8.5 predicted a greater increase in and FV compared to RCP4.5.; The uncertainty caused by AOGCMs is more compared to GHG scenarios.;

Flash flood events are common in the Mediterranean basin, because of a combination of rugged coastal topography and climatological characteristics. The Balearic Islands are a flood-prone region with the research area, Sóller (Mallorca) being no exception. Between 1900 and 2000, Sóller experienced 48 flash floods with 17 categorised as catastrophic. In Sóller, the local surface water network comprises ephemeral streams. These are natural water networks that only carry water during periods of intense rainfall. Using the available evidence from the 1974 flash flood, this research used Flood Modeller to simulate the event. The research developed a one-dimensional (1D) and a one-dimensional two-dimensional (1D-2D) model that assisted in the understanding of the behaviour of the ephemeral stream during the flood. Analysis of hydraulic parameters such as water flow, depth and velocity provided an appreciation of the interaction between the channel and floodplain. Model development aims to forecast the impending impacts of climate change and urbanisation.

This paper presents a comparison between the black box Nonlinear Auto-Regressive with eXogenous inputs-Neural Network (NARX-NN) and the conceptual Hydrologic Engineering Centre-Hydrologic Modelling System (HEC-HMS) Rainfall-Runoff models. The two models were applied on a small urban watershed to assess its response to fourteen hourly real storm events. The differences between the steps engaged in each model to reach the hydrograph were presented in detail. The estimation of the best parameters is carried out using a weighted average function during the calibration phase. A statistical evaluation was conducted to assess the model's performance thereafter; a critical comparison was made to illustrate the differences and discuss the steps involved. The results indicate that both models successfully reflect the urban basin runoff. However, the NARX-NN outperforms in the testing phase owing to their strength generalization feature. The NARX-NN model has more strength to produce the shape bending of the hydrograph. Consequently, this model is better to highlight the curvatures resulting from the local peaks of rainfall. [ABSTRACT FROM AUTHOR]

Hydrological models for evaluating and predicting the amount of available water in basins, flood frequency analysis, and developing strategies to deal with destructive floods are expanding daily. In this study, HEC-GeoHMS and Arc Hydro extensions in ArcGIS software and the HEC-HMS model were used to simulate design flood hydrographs in the Aydooghmush basin in the northwest of Iran. SCS-CN, SCS-UH, Maskingham, and monthly fixed methods were used to calculate rainfall losses, rainfall-runoff transformation, flood routing, and base flow, respectively. In model calibration with two real flood events, the average of absolute values of the residuals, the sum of the remaining squares, and the weight of the peak mean the error squares for the flood volume were 2.75, 5.91, and 5.32, respectively and for peak discharge were 8.9, 8.0, and 8.0, respectively. Model validation was evaluated as acceptable with a one percent error rate in the peak of discharge and a 19 percent in the flood volume. For maximum 24-hour precipitation, the log-Pearson type 3 was determined as the most suitable distribution in the SMADA model and design precipitation was extracted in different return periods. Thus, for the return period of 2 to 1000 years, the peak discharge and volume of the design flood were simulated equally to 18.8 to 415.6 m3 s-1 and 5.7 to 87.9 MCM, respectively.

Building accurate rainfall–runoff models is an integral part of hydrological science and practice. The variety of modeling goals and applications have led to a large suite of evaluation metrics for these models. Yet, hydrologists still put considerable trust into visual judgment, although it is unclear whether such judgment agrees or disagrees with existing quantitative metrics. In this study, we tasked 622 experts to compare and judge more than 14,000 pairs of hydrographs from 13 different models. Our results show that expert opinion broadly agrees with quantitative metrics and results in a clear preference for a Machine Learning model over traditional hydrological models. The expert opinions are, however, subject to significant amounts of inconsistency. Nevertheless, where experts agree, we can predict their opinion purely from quantitative metrics, which indicates that the metrics sufficiently encode human preferences in a small set of numbers. While there remains room for improvement of quantitative metrics, we suggest that the hydrologic community should reinforce their benchmarking efforts and put more trust in these metrics. Key Points: A group of 622 participants visually judge model simulations similarly to quantitative metrics and considers a Machine Learning model bestNash–Sutcliffe efficiency and Kling–Gupta efficiency are good predictors of overall and high‐flow hydrograph quality but low‐flow metrics are poor predictors of low‐flow qualityWe can discriminate hydrographs that experts consistently consider good or bad purely based on existing quantitative metrics [ABSTRACT FROM AUTHOR]

Nature-based solutions and similar natural water retention measures to manage urban runoff are often implemented by cities in order to reduce runoff peaks, catch pollutants, and improve sustainability. However, the performance of these stormwater management solutions is relatively rarely assessed in detail prior to their construction, or monitored and evaluated following implementation. The objective of this study was to investigate the field-scale performance of road runoff filters with respect to the management of stormwater quantity and quality. This study synthesizes data from two intensive measurement surveys after the construction of sand and biochar-amended road runoff filters. The filters were able to strongly control the runoff volume and shape of the hydrograph. The long-term retention was about half that of the water inflow, and a hydrographic analysis showed the significant but strong event-size-dependent detention of runoff in both the sand and the sand–biochar filters. The biochar amendment in the filter showed no clear hydrological impact. The pollutant attenuation of the implemented road runoff filters was modest in comparison with that observed under controlled conditions. The impact of the biochar layer on the effluent water quality was observed as the levels of phosphorous, organic carbon, K, Ca and Mg in the sand–biochar filter effluent increased in comparison with the sand filter. [ABSTRACT FROM AUTHOR]

Groundwater pumping can reduce streamflow in nearby waterways ('streamflow depletion'), a process which must be accounted for in integrated management of surface and groundwater resources. However, causal identification of streamflow depletion from hydrographs alone is challenging because pumping impacts are masked by other drivers of hydrologic variability. To identify potential indicators of streamflow depletion, we used synthetic hydrographs and an analytical streamflow depletion model to assess potential pumping impacts on specific hydrograph characteristics ('hydrologic signatures') for 215 streamgages spanning the conterminous United States (CONUS). We found that streamflow depletion commonly impacts signatures associated with seasonal and annual low flows and low flow recessions. The largest impacts occurred during dry years, suggesting streamflow depletion may be evident in dry years even where impacts are unmeasurable in wet years. Random forest models indicated that streamflow depletion could significantly impact Annual, Summer, and Fall signatures in most streams. Our finding that multiple hydrologic signatures are consistently responsive to streamflow depletion across CONUS suggests that the underlying hydrological processes linking pumping to streamflow reductions are consistent across diverse settings, information that will aid in identifying indicators of streamflow depletion from streamflow hydrographs. [ABSTRACT FROM AUTHOR]

The aim of this study is to model a rapid maximum runoff, response to a calculated rain with a probability of occurrence of 1% for several case studies within the Northwest Region of Romania, studied through NWPEAT project. The purpose of the study is focused also to identify the effect of raising ecological dams made of local materials in modifying the maximum torrential runoff at the outlet area from the peatlands sites. The methodology was applied to representative case studies, which revealed different/diversified conditions, both from the climatic, morphological, pedological, land cover or hydrological points of view. The first stage of the methodology focused on evaluating the inventory of the studied sites, the peatlands catchment features, their spatial analysis using morphological units and within the water balance, the analysis of runoff and aridity coefficients, etc. The modeling of the rain-runoff process was applied for two scenarios for each site, involving the presence or absence of the ecological dam. The results are quite dispersed from one case to another. Thus, we noticed a reduction in the maximum runoff of 70% in the case of the Mlaștina de la Iaz peatland, 40% in the case of the Lacul Manta peatland and only 8% in the case of the Ic Ponor peatland site. The difference between the three cases is made by the different patterns of some natural factors, among which are the peatland area, catchment area, shape of the basin and the slope, the degree of coverage with trees or less developed vegetation, the different layout of the sites compared to the flow directions of water vectors on the slope, etc.

Abstract In many developing countries, due to economic constraints, a single station on a river reach is often equipped to record flow variables. On the other hand, hydrographs at the upstream sections may also be needed for especially assessing flooded areas. The upstream flow hydrograph prediction is called the reverse flood routing. There are some reverse flood routing pocedures requiring sophisticated methods together with substantial data requirements. This study proposes a new reverse flood routing procedure, based upon the simple kinematic wave (KW) equation, requiring only easily measurable downstream stage data. The KW equation is first averaged along a channel length at a fixed time, t, assuming that channel width is spatially constant, and then the spatially averaged equation is averaged in time, Δt. The temporally averaged terms are approximated as the arithmetical mean of the corresponding terms evaluated at time t and t + Δt. The Chezy roughness equation is employed for flow velocity, and the upstream flow stage hydrograph is assumed be described by a two parameter gamma distribution (Pearson Type III). The spatially averaged mean flow depth and lateral flow are related to the downstream flow stage. The resulting routing equation is thus obtained as a function of only downstream flow stage, meaning that the method mainly requires measurements of downstream flow stage data besides the mean values of channel length, channel width, roughness coefficient and bed slope. The optimal values of the parameters of reverse flood routing are obtained using the genetic algorithm. The calibration of the model is accomplished by using the measured downstream hydrographs. The validation is performed by comparing the model-generated upstream hydrographs against the measured upstream hydrographs. The proposed model is applied to generate upstream hydrographs at four different river reaches of Tiber River, located in central Italy. The length of river reaches varied from 20 to 65 km. Several upstream hydrographs at different stations on this river are generated using the developed method and compared with the observed hydrographs. The method predicts the time to peak with less than 5% error and peak rates with less than 10% error in the short river reaches of 20 km and 31 km. It also predicts the time to peak and peak rate in other two brances of 45 km and 65 km with less than 15% error. The method satisfactorily generates upstream hydrographs, with an overall mean absolute error (MAE) of 42 m3/s.

SCS (Soil Conservation Service) synthetic unit hydrograph technique was used to estimate the storm runoff overflows entering the Housha tunnel. The flood hydrographs were derived under different storm event durations for the ungauged Husha Catchment area. Geomorphological and hydrological parameters of the watershed were extracted using GIS measurement tools. The data identified various parameters (time to peak, time of base, and peak flow) of the synthetic unit hydrograph. The peak discharge (Qp in m3 s−1 cm−1) of rainfall excess for different time durations (5, 10, 20, 30, 60, 120, 180, 360, and 720 minutes) was estimated. The results revealed that the peak discharge (Qp) decreased with the increase in time of rainfall excess. The maximum peak discharge (27.5 in m3 s−1 cm−1) was reached 84 minutes after the beginning of the rainfall storm for 5 minutes of rainfall excess whereas the minimum peak discharge (5.2 in m3 s−1 cm−1) was reached after 7 hours and 22 minutes for 12 hours of rainfall excess. Geographic information system (GIS) data-based SCS synthetic unit hydrograph model was verified by comparing the simulated runoff with the estimated runoff from measured rainfall data of the watershed. HIGHLIGHTS The study is focusing on areas with undeveloped basins in Jordan.; SCS synthetic unit hydrograph technique was used for an arid region.; The flood hydrographs were derived for ungauged catchment.; Geomorphological and hydrological parameters of the watershed were extracted using GIS measurement tools.; A digital elevation model (DEM) data set was used in this study.;

Study region: The Aswan region is a vast plateau in the South of Egypt located 150 m above mean sea level (AMSL). Within this region, the tourist city of Aswan is Egypt’s southernmost city, located on the east bank of the Nile River. Study focus: The occurrence of flash floods can severely impact low-lying and densely populated areas. Therefore, highly vulnerable areas require effective mitigation measures to guarantee public safety and preserve archeological sites of great importance. This study investigates the interaction between the soil, surface water, and groundwater in the Aswan region of Egypt. Based on the rainfall analysis and the watershed hydrology, six different scenarios were run using the MODFLOW and Watershed Modeling System (WMS) software, which simulated rainfall recurrence intervals of 2, 5, 10, 25, 50 and 100 years. New hydrological insights for the region: The model's results indicated that an increase in the recurrence interval produced a rise in the groundwater level (GWL) up to 8.82 m (AMSL). Therefore, constructing three dams was proposed as a solution at the three basins of Al- Haytah, Al-Kimab, and Umm-Buwayrat. The proposed solution allows the storage of large volumes of water upstream. It mitigates GWL's rise within and near Aswan City. The presented study can be applied to vulnerable watersheds in arid and semi-arid regions. It can help policymakers to integrate additional sustainable solutions into construction dams and their implementation in development plans.

Flood routing through rivers is very important for the design of protection measures. Sensitivity analysis was performed using HEC-RAS 1D to show the effect of Manning’s coefficient, reach length, peak inflow hydrograph, base time of the inflow hydrograph, channel bed slope, channel side slope, and channel bed width on the peak discharge and the shape of the downstream hydrograph. About 1,600 synthetic realizations were generated using HEC-RAS 1D to train, validate, and test the artificial neural networks (ANNs). The network was trained to estimate the peak discharge from river reach and inflow hydrograph parameters. Testing this network shows a very good agreement between the predicted and actual peak discharges. Another network is trained to predict the whole outflow hydrograph from inflow hydrograph for a certain reach. Hence, flood routing through rivers can be performed using ANNs easily, accurately and quickly.

Design MotivationThe Cordoba Cultural Complex aims to promote social interaction, cultural diffusion and skill cultivation. This structural system will consist of two buildings standing 65 feet above ground connected by a bridge The guitar-shaped design of the Cordoba Complex was inspired by its intended use, which is centered around performing arts. The design was also influenced by MAJISA's aim to reduce the negative impact of development and promote urban sustainability. In order to achieve these goals, the Cordoba Cultural Complex will feature a green roof and solar panels.Design ApproachSchematic renderings created to portray Architectural concept Concept transferred into AutoCAD for Construction Documents Floor occupancies & live loads were assigned based on ASCE 7-101 Dead Loads were assigned based on various structural resources Steel/Composite members were designed based on AISC Steel Manual Foundation and Seismic design to meet constraints required by the site locationMAJISA Consulting EngineersKPFF Consulting Engineers Client ConsultantBill Thorpe, S.E. PrincipalRachel Goossens, Project EngineerStewart Hooks, Project EngineerPeter Duong, Project EngineerFaculty Advisor:   Dr. Joel Lanning, P.E.;  Department of Civil & Environmental Engineering

Urban development areas, having greater impervious surfaces such as roads, parking spaces and building roofs, have an adverse impact on the urban environment, as they generate more runoff. This situation could even worsen during extreme rainfall events as it accumulates stormwater runoff more rapidly and causes the occurrence of flash floods. In this study, eight historical extreme rainfall events with rainfall depths between 40 and 70 mm were chosen to investigate the performance of permeable pavement as an urban runoff mitigation measure approach in stormwater management. A commercial center was selected as a case study, with a total catchment area of 3,425 m2 and consisting of double-row roadside car parking spaces with tarred surfaces covering 61% of the total catchment area. The front road of the shophouses was assumed to be replaced with a modular-based precast stormwater detention system, and a drainage model was developed to mimic the system. Simulations of the stormwater flowing through the detention system were performed with Storm Water Management Model version 5.0, and it was found that the detention system could endure seven out of the eight storms. The only storm that overwhelmed the system demonstrated an intense rainfall pattern that peaked in the first hour. [ABSTRACT FROM AUTHOR]

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It is important to investigate the hydrological consequences of current climate change. Hydrological responses to climate warming and wetter conditions include changes in discharge (frequency, amplitude, and volume). This paper describes current climate change and its impact on hydrological flow within the Horyn River basin. Daily air temperature and precipitation data obtained from the 17 meteorological stations located in and nearby the Horyn River basin, in combination with hydrological data (such as daily water discharges obtained from 9 water gauges), were used for the analysis of climate variability and its hydrological consequences. Analyses of meteorological variables and water discharges are crucial for the assessment of long-term changes in the river regime. Thiessen polygons were used to determine the area of influence of assigned specific meteorological stations, which affect the river's catchments within the Horyn River basin. As a result of the trend analysis, it was observed that discharge within the Horyn River basin decreased over time. These results were congruent with the trends of precipitation data and air temperature data of the stations determined by the Thiessen polygons and basin boundaries. To understand current changes in the daily flow in the basin, changes in air temperature and precipitation for the period 1991-2020 were compared with the period of the climatic norm (1961-1990). A similar analysis was done for daily water discharges. Increasing air temperature and decreasing precipitation in the current period led to a significant decrease in discharges in the Horyn River basin, especially during the spring flood period. [ABSTRACT FROM AUTHOR]

Attenuation, time lag, outflow peak and storage are very essential factors required in flood risk prediction and flood pattern. However, the accurate prediction strongly depends on appropriate calibration of routine parameters of the model, such as weighting factor (x) and storage time constant (K). The weighting factor being used to determine storage time constant has not been given consideration in the previous studies and this could have led to inaccurate prediction in the past. In this work, a set of data obtained from an ungauged Awara river in Ondo State, Nigeria were used to test the effects of a weighting factor, x at levels ranging from 0.1-0.5 at interval of 0.1. The Muskingum model was used to obtain the storage and weighted discharge storage. It was observed that the correlation coefficient (R2) decreases with an increase in the weighting factor (x). This implies that there is a strong relationship between storage and weighted discharge storage at 0.1-0.3 levels of x while, the relationship is fair at 0.4-0.5 levels. It is therefore appropriate to choose a value of x ranging between 0.1 and 0.3 for attenuation prediction, while values of x ranging between 0.4 and 0.5 would be appropriate for accurate prediction of both outflow peak and storage. [ABSTRACT FROM AUTHOR]

The MODKARST mathematical code is used to simulate both brackish and non-brackish karst springs and provides useful information on the hydrological and hydrogeological characteristics of their aquifers. Next to this, MODKARST can also explain the often peculiar behavior of these springs, inherited from the complexity of the structures that most of the times form fractures, cavities, and conduits in carbonate formations in tectonically complex areas. The simulation focuses on explaining the complex behavior of the Azmak spring. Azmak is a large brackish karst spring in SW Turkey, which displays peculiarities both in terms of its hydrograph and seawater intrusion mechanism. In particular, during the recession period, contrary to the chloride concentrations of its water which appears more or less stable, its hydrograph shows fluctuations. The MODKARST simulation showed that the discharge fluctuation during the recession period is due to the operation of a siphon, while the abnormal variation of its chloride content is due to its predominant seawater intrusion mechanism which is the Venturi effect. [ABSTRACT FROM AUTHOR]

The estimation of surface runoff and discharge peak using the Snyder's model and SCS Dimensionless UH (SCS-DUH) method are one of the best alternatives solutions appropriate for analyzing the hydrologic systems in the ungauged watersheds. These two methods were applied to estimate the discharge peak and design their hydrographs in the drainage basins of Royal Nature Reserve (Imam Turki Bin Abdullah) in Saudi Arabia. To estimate the discharge peak by applying Snyder's model and SCS-DUH method using the morphometric parameters deriving from the SRTM DEM30m and three rainstorms of 40, 50 and 60mm. The estimation of discharge peak (Qp) using Snyder's model was depended on the SRTM DEM30m outputs and the hydrology parameters of the duration (Td) of Unit Hydrograph (UH), time to peak (Tp), time base of the UH (Tb), UH width at 50% and 75% of the peak discharge. However, the estimation of the discharge peak by The SCS-DUH method was computed using the drainage area (A), the direct runoff (Qd) and the time to peak (Tp). The direct runoff was determined by the runoff ratio 0.20 of the unimproved areas, proposed by the Soil Conservation Service (SCS). But, the time to peak was computed using the average of the concentration time obtained from Johnstone-Cross and Dooge models. The hydrographs design was done by the time ratio method recommended by the SCS. The estimated discharge peak computed by Snyder's model varies with a maximum of 93.4 to 2092.9 m³/s, an average of 61.1 to 1368.4 m³/s and a minimum of 28.7 to 644.0 m³/s in Al Shuwaiki and Khtal watersheds, respectively. The estimated discharge peak computed by SCS-DUH method was ranged from 21.5 to 482.3 m³/s for the rainstorm of 40mm in Al Suwayki and Khtal, respectively, from 28.5 to 602.9 m³/s for the rainstorm of 50mm and from 34.1 to 723.5 m³/s for the rainstorm of 60mm, in Um Nqy and Khtal, respectively. The hydrology study of ungauged basins in Royal Nature Reserve (ITBA) shows the great potential of the integrated employment of GIS technics and the hydrology models to estimate the discharge peak and design their hydrographs. [ABSTRACT FROM AUTHOR]

The water issue has become a frontier of public debate globally due to public awareness of sustainable development. Nigeria's water resources are under serious threat from inadequate catchment management that includes widespread pollution from indiscriminate waste disposal. Stormwater is now recognized as a valuable resource rather than a nuisance, especially in large urban centers. Growing demand for water has exerted pressure on groundwater via dug well and boreholes scattered virtually in every dwelling in Nigeria. This challenge motivated this investigation of the feasibility of harvesting stormwater for due purposes of supplementing water supply and flash flood management. This study aims at quantification of harvestable stormwater and identification of potential capturing sites using Spatial Hydrological Analysis of GIS model and Synthetic Hydrograph. The result indicated total harvestable stormwater for 24-hr rainfall of 161.3 Mm3 and three available capturing sites of eight depressions identified. This volume is a good incentive to incorporate storm harvesting in overall water resources sustainable management. [ABSTRACT FROM AUTHOR]

Dam-break is a serious disaster resulting in severe damage to downstream communities. Therefore, analyzing the affected range and the evolution process of dam-break floods in advance is valuable. However, the difficulties and challenges lie in the complexity of the breaking process of earth-rock dams, the uncertainty in the evolution of dam-break floods, and the geographical variability. Given this, the objective of this study is to analyze the characteristics of the dam-break flood evolution. The study chooses Chengbi River Reservoir as the research object, HEC-RAS as the simulation software, unsteady flow differential equations and one-dimensional Saint-Venant equations as the control equations, and it uses four-point implicit finite difference method for discrete solution. In this paper, the dam-break flood evolution is simulated under three boundary conditions (full breach, 1/2 breach, 1/3 breach), and the main results are as follows. From the dam site section to the Tianzhou hy-drological station section, the peak discharge decay rates of the three schemes are 78%, 77%, and 67%, respectively. The water level decay rates of the three schemes are 47%, 36%, and 30%, respectively. A 1 m increase in the bursting water level elevation increases the peak flow by ap-proximately 7%, and the highest water level in front of the dam by 1 m, and delays the peak time by 1.5 h on average. In addition, the preliminary inundation extent for the Baise City is obtained. The analysis results can provide a fundamental basis for flood control as well as a reference for flood disaster management.

Hydrological models for evaluating and predicting the amount of available water in basins, flood frequency analysis, and developing strategies to deal with destructive floods are expanding daily. In this study, HEC-GeoHMS and Arc Hydro extensions in ArcGIS software and the HEC-HMS model were used to simulate design flood hydrographs in the Aydooghmush basin in the northwest of Iran. SCS-CN, SCS-UH, Maskingham, and monthly fixed methods were used to calculate rainfall losses, rainfall-runoff transformation, flood routing, and base flow, respectively. In model calibration with two real flood events, the average of absolute values of the residuals, the sum of the remaining squares, and the weight of the peak mean the error squares for the flood volume were 2.75, 5.91, and 5.32, respectively and for peak discharge were 8.9, 8.0, and 8.0, respectively. Model validation was evaluated as acceptable with a one percent error rate in the peak of discharge and a 19 percent in the flood volume. For maximum 24-hour precipitation, the logPearson type 3 was determined as the most suitable distribution in the SMADA model and design precipitation was extracted in different return periods. Thus, for the return period of 2 to 1000 years, the peak discharge and volume of the design flood were simulated equally to 18.8 to 415.6 m³ s-1 and 5.7 to 87.9 MCM, respectively [ABSTRACT FROM AUTHOR]