Hasil untuk "River protective works. Regulation. Flood control"

Kashafad Bin Hafiz, Aftab Alam Khan, S.M. Mustafizur Rahman et al.

Saint Martin Island (SMI), the first coral reef ecosystem at the Bay of Bengal is ecologically significant for its unique biological richness. The purpose of this study is to monitor environmental health by measuring hazardous metals in coral reef and evaluating the ecological status. The study assesses environmental health state and identifies the probable source using various indices such as contamination factor and degree, pollution load index, geo accumulation index, enrichment factor, ecological risk index, potential ecological risk index, mean effects range median quotient, modified hazard quotient, toxicity risk indicator, and positive matrix factorization, hieracia cluster analysis. The measured constituents are found in range, for As (0.07–2.30), Pb (18.18–28.53), Hg (0.03–0.08), Fe (30160–65445.21), Cd (0.02–5.73), Mn (511–806), Cu (6.2–22.85), Zn (27.7–87), Cr (14.13–58.73), and Ni (32.25–132.13) mg/kg. All the stations were found with higher concentration of Ni in seabed sediments than the threshold limits. The source of toxins from upstream is an issue to consider when analyzing coral health from an ecotoxicological standpoint. The study area also coincided with the newly established SMI marine protected area (MPA) by Ministry of Forest, Environment and Climate Change, Bangladesh, and the sample sites are distinct within the framework of the methodological study. Thus, this research is expected to help for monitoring and establishing baseline for evaluating the ecological status for management plans.

Kyle McElroy, Austin Becker

ABSTRACT An expert mental model (EMM) explores how U.S. municipalities integrate flood risk management (FRM) into urban planning, offering insights beyond existing literature. Motivated by the challenges urban planners face in balancing flood risk with competing priorities like development, housing, and economic growth, this study combines a literature review, expert interviews, and model analysis to map the influences shaping FRM integration. The EMM highlights an interplay between external (physical risks, societal support, funding), institutional (political will, resources), and process influences (data, collaboration). The model brings forward perception and value influences, individual biases, and shared municipal values, showing how these shape FRM integration alongside technical and institutional factors commonly emphasized in FRM planning literature. External pressures, existing practices, political realities, and internal capabilities all influence urban planners. The model reveals power asymmetry between plan developers and decision‐makers, the limits of technical tools once planning moves beyond analysis, and the strong influence of federal and state guidance, funding, regulations, capacity, partnerships, and physical drivers. By considering institutional, cognitive, and political influences, municipalities can develop more resilient FRM strategies. This approach offers a framework for understanding barriers to FRM integration and can be adapted for use in different municipal contexts.

C. Hauer, L. Schmalfuss, U. Pulg

Abstract The damage potential in river systems due to flood flows has increased as a result of the increased infrastructure and population growth along river corridors, frequently accompanied by an incomplete understanding of flood safety and the impact of climate change. In particular, so‐called catastrophic flood events in alpine areas are generally accompanied by massive channel beds and floodplain erosion with a higher damage potential than inundation only. It has been recently shown that critical flow conditions might be an important driver of uncontrolled erosion and channel avulsion in terms of extraordinary flood events. A systematic analysis, however, of the parameters driving critical flow conditions is lacking. Thus, the aim of this study was to conduct a systematic numerical evaluation of the hydraulic parameters responsible for critical flows in steep mountain channels as a baseline study for future improved flood impact assessment and mitigation measure design. The systematic analysis of standardized river bathymetries revealed that channel slope, roughness and river widening impose decreasing influences on alpine rivers to produce critical flow conditions. However, there is a risk that due to human interventions, altering the natural slope–roughness relationship to increase the discharge capacity for flood safety might promote critical conditions. These findings should be considered in future hydraulic engineering practice.

Wenhong Cao, Xu Geng, Chunjing Liu et al.

Bedforms are formed by sediment particles under the action of flow, which in turn affect flow and sediment movement. However, the fundamental mechanisms behind the formation and development of bedforms under varying flow conditions, the interconnection between sediment particle movement and bed morphology development, as well as the influence of bedforms on flow and sediment transport, are still not well understood. In the current study, the moveable bed load transport flume experiments under different flow conditions were done, and the development processes of two-dimensional and three-dimensional dunes formed under different flow intensities were simulated. The detailed structure of the bedforms was measured by laser scanning technology, the characteristics of the bedforms were analyzed in detail, and the relations between the formation of the bedforms and the movement of sediment particles are discussed. The results found that the correlation coefficients of the longitudinal profile curve can serve as a quick reference for distinguishing two-dimensional and three-dimensional dunes. When the crestline ratio is used as the criterion for two-dimensional and three-dimensional dunes, the relative amplitude of the dune crestline and the included angle with the flow direction should also be comprehensively considered. The lee side angles of dunes calculated using the triangle generalization method and local section tangent method are compared and show that the values obtained by the former method are only about half of that of the latter. It is also found that the lee side angles of dunes are related to the dune height. The superimposed dunes generally exist in the downstream area of the stoss side of the dunes. The local bed slopes on the stoss side of the dunes show reverse slopes. The superimposed dunes improve the local bed height and further increase the reverse slope degree of the stoss side. A streamwise ridge is an important form located in the upstream area of the dunes stoss side, and they are symmetrically distributed on both sides. Multiple streamwise ridges divide the stoss side of the dunes into relatively independent movement areas, restricting the movement of sediment particles to specific regions. According to the distribution characteristics of bed morphologies, the effects of dunes on sediment particle movement and flow energy consumption are analyzed.

Paul Samuels

Alexander Metelkin, Bernhard Vowinckel

The settling behavior of sediment aggregates is a critical factor influencing the transport of fine-grained sediment in riverine and marine environments. Due to the small size and fragile structure of cohesive sediment aggregates, direct measurement of their porosity and permeability is challenging. While porosity often is estimated using settling velocity relations, permeability is frequently overlooked. The current study examines the impact of considering non-negligible permeability on the properties of flocs. Aggregate properties are compared by calibrating experimental data to two settling models in a dilute regime: one assumes a fractal structure of aggregates and neglects permeability, while the other assumes constant porosity and permeability. The current results demonstrate that both models describe the experimental data of highly porous aggregates with similar accuracy. Aggregate dynamics are further investigated in more complex flow conditions using numerical simulations applying a volume penalization method to geometrically resolve flocs. The behavior of permeable and impermeable flocs is compared in dense suspension regimes and during dilute settling in density-stratified environments. The current findings reveal that permeability significantly influences settling dynamics in complex scenarios and should be considered when determining aggregate properties.

Thomas Wallace, Kaley Crawford‐Flett, Matthew Wilson et al.

ABSTRACT Levees play a crucial role in flood protection, but globally, there is a need for more knowledge about levee networks and their flood routing effects. Without complete knowledge, the question arises: ‘What is the flood risk associated with an unknown or partially known levee portfolio?’ Unknown or undocumented levees can be maladaptive and undermine system resilience. However, current literature often does not acknowledge undocumented levees, assuming all assets are known. A greater understanding would provide insight into present vulnerabilities and enable more complete management of our flood protection systems, reducing communities' risk. Our research assessed the physical condition of two undocumented levees in a case study. Computational flood modelling then simulated (1) their present condition, (2) their removal and (3) their reconstruction to a good physical condition. This determined their effect on inundation area and building damages, allowing their classification. The undocumented levees in the case study were significantly degraded, leading to an insignificant impact on flood routing and flood damages in their present state. However, if reconstructed, the levees could be valuable if the surrounding land were developed. More broadly, this study illustrates the importance of identifying and integrating undocumented levees into network modelling and maintenance.

Dragan Čakmak, Veljko Perović, Dragana Pavlović et al.

ABSTRACT The aim of this study is to determine the level and source of pollution by potentially toxic elements (PTEs) due to torrential floods in the catchment area of the Drina River under complex geological conditions. The degree of soil and sediment pollution by PTEs was estimated by calculating the Pollution Index (PI) and the Geo‐accumulation index (Igeo). Sources of PTEs were determined using Principal component analysis (PCA) for soil and sediment and the Positive Matrix Factorisation (PMF) model for sediment. To fully include the spatial component when determining the source of PTEs, Bivariate Local Moran's I analysis was also applied. By comparing the applied methods, it was determined that PCA is suitable for determining the sources of PTEs in soil and for investigating the sedimentation process in sediment, while the PMF model is more suitable for determining the sources of PTEs in sediment. It was also determined that when the geological substrate is rich and after high‐intensity flooding, there is an increase in As, Cd, Co, Cu and Fe content in sediment compared with soil. Arsenic was partially impacted by anthropogenic factors, with Igeo values for soil (16.21%) and sediment (21.76%) at the polluted level.

Saeideh Pourentezari, Hossein Salehi, Alireza Razeghi Haghighi et al.

ABSTRACT In hydrologic modeling, forecasting peak floods is a complex and high‐priority task, particularly in regions with limited in situ observations. This research investigates the potential of utilizing satellite‐based precipitation products with near real‐time updates (NRT‐SbPP), together with deep learning, to improve peak flow estimation and flood forecasting. Using Integrated Multi‐satellitE Retrievals for Global Precipitation Measurement (IMERG), the Final version as a reference, four NRT‐SbPPs were evaluated: Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks (PERSIANN)‐Cloud Classification System (CCS), PERSIANN‐Dynamic‐Infrared–RainRate (PDIR), the IMERG‐Early, and IMERG‐Late. This study evaluated the performance of these datasets for streamflow simulation using the Hydrologic Modeling System (HEC‐HMS) in a sub‐basin of the Russian River watershed. Bias correction was performed using Long Short‐Term Memory (LSTM) networks, with IMERG‐Final serving as the reference precipitation dataset. This correction improved the quality of the input rainfall data and led to more accurate streamflow simulations. For example, the Root Mean Square Error of IMERG‐Late decreased from 1.98 to 1.48 mm with LSTM, resulting in performance metrics similar to those of observed discharge (Nash‐Sutcliffe Efficiency: 0.82). Most importantly, PDIR exhibited significant enhancement, with a 36% correlation coefficient increase (from 0.52 to 0.81), as well as high rates for extreme event detection. The further findings establish the potential of employing LSTM methods and using IMERG‐Final as a reference to incorporate NRT‐SbPPs within real‐time flood forecasting and early warning frameworks. This method leverages the new technologies of satellite‐based meteorological data and offers an efficient, cost‐effective option to enhance flood prediction and disaster risk management, especially in data‐scarce regions.

نسرین اعظمی, عبدالواحد خالدی درویشان, لیلا غلامی

مقدمه فرسایش خاک، به‌طور خاص و تخریب خاک، به‌طور عام در نتیجه فعالیت انسان، امروزه به‌عنوان یک معضل اجتماعی مطرح بوده و نقش عامل انسانی در پیدایش و تسریع روند تخریب خاک در بسیاری از مناطق روشن شده است. دستیابی به آمار و اطلاعات دقیق در مورد میزان فرسایش خاک و رسوب در حوزه‌های آبخیز به‌منظور اجرای برنامه‌های حفاظت خاک و تعیین روش‌های مبارزه با فرسایش خاک و کاهش تولید رسوب ضروری است. به‌دلیل کمبود آمار در زمینه فرسایش خاک و تولید رسوب در بسیاری از حوزه‌های آبخیز کشور، به‌کارگیری روش‌های تجربی مناسب برای برآورد فرسایش، رسوب‌دهی و به‌ویژه نسبت تحویل رسوب اجتناب‌ناپذیر است.   مواد و روش بدین منظور در پژوهش حاضر از مدل‌های برآورد نسبت تحویل رسوب شامل مدل‌های تجربی مبتنی بر متغیرهای زودیافت و سه مدل SATEEC، InVEST و WaTEM/SEDEM در حوزه آبخیز معرف-زوجی خامسان در غرب ایران استفاده شد. مدل WaTEM/SEDEM در بخش WaTEM برای برآورد فرسایش خاک مبتنی بر مدل RUSLE و در بخش SEDEM مبتنی بر عملکرد عوامل فیزیکی مؤثر در رابطه انتقال رسوب است. در بسیاری از منابع از روش سزیم-137 به‌عنوان تنها روش موجود و قابل‌اعتماد برای اندازه‌گیری اجزای بودجه رسوب شامل فرسایش کل، رسوب‌گذاری کل، فرسایش خالص (رسوب‌دهی) و نسبت تحویل رسوب به‌ویژه در مقیاس دامنه و زیرحوزه آبخیز یاد شده است. برای ارزیابی مدل‌های مورداستفاده، از نتایج محاسبه نسبت تحویل رسوب در روش سزیم-137 حاصل پژوهش‌های قبلی استفاده شد که برای کل حوزه آبخیز و متوسط 15 زیرحوزه آبخیز به‌ترتیب برابر 25.61 و 58.94 درصد است و صحت آن با استفاده از داده‌های رسوب مشاهداتی در خروجی حوزه آبخیز مورد تأیید قرار گرفته است.   نتایج و بحث از بین مدل‌های بررسی شده برای برآورد نسبت تحویل رسوب، مدل‌های Renfro and Waldo (1983)، Williams and Brendt (1962)، Roehl (1962)، با بارش مازاد یک ساعت، Walling (1983)، Ferro (1995)، Vanoni (1975) و USDA (1972)، در مقیاس کل حوزه آبخیز و مدل‌های Renfro (1975)، USDA (1972)، USDA-SCS (1979)، SATEEC and Roehl (1962)، با بارش مازاد یک ساعت در مقیاس زیرحوزه آبخیز نزدیک‌ترین برآوردها را به روش سزیم-137 با در نظر گرفتن خطای 10± درصد داشتند و به‌عنوان مدل‌های مناسب برای برآورد نسبت تحویل رسوب در حوزه آبخیز معرف-زوجی خامسان انتخاب شدند. همچنین، این مدل‌ها می‌توانند برای برآورد نسبت تحویل رسوب در حوزه‌های آبخیز مشابه با حوزه آبخیز معرف-زوجی خامسان نیز مورداستفاده قرار داده شوند.   نتیجه‌‌گیری در مقیاس زیرحوزه آبخیزها برآوردهای معادلات مبتنی بر متغیرهای زودیافت جز روش Roehl (1962)-بارش مازاد 0.1 ساعت به‌طور معنی‌داری کمتر از مدل SATEEC بوده، از طرفی برآوردهای تمام روش‌های مذکور به‌جز روش  Roehl (1962) بارش مازاد 0.1 ساعت به‌طور معنی‌داری بیشتر از مدل WaTEM/SEDEM و InVEST بود. این موضوع بر اهمیت در نظر گرفتن شرایط بارش مازاد برای برآورد نسبت تحویل رسوب در معادلات ارائه شده توسط Roehl تأکید دارد. همچنین، در مقیاس کل آبخیز نیز برآوردهای معادلات مبتنی بر متغیرهای زودیافت به‌جز روش Mutchler and Bowie (1975)، کمتر از نتایج مدل SATEEC بود. اختلاف زیاد عملکرد روش‌های مورد بررسی در دو مقیاس زیرحوزه آبخیز و کل حوزه آبخیز ناشی از اثر انکارناپذیر دشت میانی حوزه آبخیز خامسان در کاهش شدید انتقال رسوب زیرحوزه آبخیزها تا خروجی کل حوزه آبخیز بوده است.

Luke Fallowfield, Davide Motta

Abstract Hydraulic modelling of culverts relating to the flood risk posed by debris in watercourses has previously only assessed the impact of fixed culvert blockage levels, without analysing the change in flooding as blockage levels increase. With increasing flow rates in rivers during flood events, there is concern that existing culverts may be undersized and therefore already posing a substantial flood risk regardless of them becoming blocked by debris. In this article, two‐dimensional (2D) flood modelling is used to produce flood maps detailing the change in flood area and property flooding as culverts become increasingly blocked at several sites in the Northwest of England. The results show a clear distinction between sites where the accumulation of blockage is the key contributing factor towards local flood risk, and sites where the presence of the culvert itself is the predominant flood risk factor. The blockage induced flood risk metric is introduced to characterise the contribution of culvert blockage to the overall flood risk.

Gonghuan Fang, Zhi Li, Jing Yang et al.

Abstract Floods are one of the most affective climate‐related disasters, and climate change has altered their intensity and frequency worldwide. This study examined long‐term changes in flood characteristics (including magnitude, frequency, and timing) in 30 alpine headwaters of the large endorheic Tarim River Basin, Central Asia. The contributions of climatic factors to flood (magnitude and timing) changes were investigated using numerical experiments in combination with the random forest approach. The following results were obtained: (1) Annual maximum flood peaks increased at most stations (89% stations) during 1961–2015 with increased flood frequency. Earlier flood peaks were observed in spring with a rate of 1.38 day per decade; for other seasons, changes in the occurrence time of flood peaks showed strong spatial variability. (2) Precipitation was the dominant factor for the increased flood magnitude in most catchments of the southern slope of the Tianshan Mountains, and temperature played a greater role in the northern Kunlun Mountains. (3) For flood timing changes, melt level height and precipitation were the most influential factors in the alpine catchments in the Tarim River Basin. The results provide information on the spatiotemporal variations of floods and their driving factors in this alpine basin under climate change.

مهران زند, مرتضی میری, محمدرضا کوثری

شناسایی رخدادهای فرین از نظر زمانی و مکانی در یک منطقه طی دوره مشخص می‌تواند نقش مهمی در مدیریت و کنترل پیامدهای ناشی از این رخدادها داشته باشد. هدف این پژوهش، بررسی رخدادهای فرین دما و بارش استان لرستان است. داده‌های مورد استفاده شامل داده‌های بارش، بیشینه و کمینه دمای روزانه نه ایستگاه سینوپتیک استان لرستان طی دوره آماری مشترک 28 ساله (2017-1990) است. محاسبه شاخص‌های حدی (26 شاخص حدی بارش و دما بر اساس توصیه گروه کارشناسی CCL/CLIVAR) با استفاده از قابلیت‌های نرم‌افزار R انجام و روند تغییرات هر یک از شاخص‌ها با استفاده از آزمون من‌کندال بررسی شد. نتایج بررسی روند رخداد شاخص‌های حدی سرد و گرم نشان داد که برای تمامی ایستگاه‌ها در حالت کلی، روند شاخص‌های گرم با افزایش و روند بیشتر شاخص‌های سرد با کاهش همراه شده است. بین شاخص‌های حدی گرم، بیشترین روند افزایشی به‌­ترتیب برای شاخص شب‌های گرم و روزهای گرم رخ داده است. روند افزایشی برای شب‌های گرم تمامی ایستگاه‌ها در سطح 99 درصد و برای شاخص روزهای گرم در 23 درصد ایستگاه‌ها در سطح 95 درصد و برای 77 درصد در سطح 99 درصد معنی‌­دار است. بین شاخص‌های حدی سرد، بیشترین کاهش برای روزهای یخبندان و روزهای سرد رخ داده است. روند کاهشی روزهای یخبندان برای 45 درصد از ایستگاه‌ها در سطح 99 درصد و روند کاهشی روزهای سرد برای 77 درصد از ایستگاه‌ها در سطوح مختلف 90، 95 و 99 درصد معنی‌­دار هستند. نتایج حاصل از بررسی فراوانی رخداد و روند شاخص‌های حدی بارش نشان داد که مجموع بارش این استان همانند بسیاری از مناطق کشور با کاهش مواجه شده است. در مقابل، وقوع بارش‌های حداکثری علاوه‌­بر این‌که در سطح استان قابل‌ توجه است، طی دوره 2017-1990 روند افزایشی داشته­‌اند. این شرایط می‌تواند بیانگر افزایش بارش‌های شدید و کوتاه ‌مدت و در مقابل کوتاه‌تر شدن فصل بارش منطقه باشد.

Bowen Xue, Yan Xie, Yanhui Liu et al.

With the rapid development of China’s social economy, it is the most important task for the water conservancy industry to make use of the existing water conservancy engineering measures to carry out the research on river basin flood control dispatching. Large-scale joint operation of river basins usually needs to consider meteorological and hydrological conditions, historical flood data, multireservoir engineering conditions, and multiple flood control targets, which is a complex decision-making problem. Therefore, electing the optimal operation model of reservoir flood control optimization is very important. In this paper, Luanhe River Basin is taken as the research area, and three kinds of constraints, namely, water balance constraint, reservoir flood control capacity constraint, and water release decision constraint, are set to construct the flood control optimization model. Taking the minimum square of the sum of reservoir discharge and interval flood discharge as the objective function, genetic algorithm (GA), particle swarm optimization (PSO), Spider swarm optimization (SSO), and grey wolf optimization (GWO) are introduced into flood control optimal operation to seek the minimum value of objective function, and the results are compared and analyzed. Through the analysis of optimization results, the optimization ability and convergence effect of grey wolf optimization algorithm are better than those of genetic algorithm and particle algorithm, and the results are more stable than those of spider swarm algorithm. It has a good model structure and can make full use of the results of three wolf groups for optimization. Through the analysis of scheduling results, the results of genetic algorithm and particle swarm optimization algorithm are similar, while those of spider swarm optimization algorithm and grey wolf optimization algorithm are similar and slightly better than those of the first two. Moreover, the search range of grey wolf optimization algorithm for solving long sequence problems is wider and the calculation time is shorter. Therefore, the grey wolf optimization algorithm can be applied to solve the flood control operation optimization model of Panjiakou Reservoir Group.

Markus Eder, Lukas Löschner, Mathew Herrnegger et al.

Abstract Flood risk managers face increasing challenges in anticipating future developments and coordinating flood risk management on a regional level. The regional floodplain evaluation matrix (RegioFEM), a method to support a future‐oriented flood risk management at a regional scale, was applied in a section of the Raab River in Austria. The developed method uses several parameters assessing the consequences of changes in the study area, which lead to changes in flood risk. Settlement development, planned flood protection measures and the likely increase of flood runoff due to climatic changes are considered. Parameters include hydrological (e.g., peak reduction), hydraulic (inundation area), spatial (affected buildings) and monetary (damage potential) ones. The results of the application of the RegioFEM were presented at a regional expert workshop, conducted to gain feedback about the possibilities and limitations of implementing the method into practice. Considering future changes and evaluating their impacts on flood risk can provide stakeholders and decision makers valuable information for sustainable flood risk management.

Lisa Dillenardt, Paul Hudson, Annegret H. Thieken

Abstract In recent years, German cities were heavily impacted by pluvial flooding and related damage is projected to increase due to climate change and urbanisation. It is important to ask how to improve urban pluvial flood risk management. To understand the current state of property level adaptation, a survey was conducted in four municipalities that had recently been impacted by pluvial flooding. A hybrid framework based on the Protection Motivation Theory (PMT) and the Protection Action Decision Model (PADM) was used to investigate drivers of adaptive behaviour through both descriptive and regression analyses. Descriptive statistics revealed that participants tended to instal more low‐ and medium‐cost measures than high‐cost measures. Regression analyses showed that coping appraisal increased protection motivation, but that the adaptive behaviour also depends on framing factors, particularly homeownership. We further found that, while threat appraisal solely affects protection motivation and responsibility appraisal affects solely maladaptive thinking, coping appraisal affects both. Our results indicate that PMT is a solid starting point to study adaptive behaviours in the context of pluvial flooding, but we need to go beyond that by, for instance, considering factors of the PADM, such as responsibility, ownership, or respondent age, to fully understand this complex decision‐making process.

David R. Johnson, Jingya Wang, Nathan B. Geldner et al.

Abstract Standards‐based levee design aims to protect against events with specific probabilities, for example eliminating overtopping from a storm surge with a 1% annual exceedance probability (i.e., a “100‐year” event). This allows levee segments to be analyzed independently but ignores interior dynamics and overall risk. We present and implement a framework for calculating optimal risk‐informed design heights. Using this design paradigm and multi‐objective evolutionary algorithms, we identify levee and floodwall design heights that minimize the total system cost and expected flood losses over 50 years. With our model, decision makers may feasibly evaluate hundreds or thousands of alternative designs over a large ensemble of future states of the world. Comparing to the existing design elevations of the Larose to Golden Meadow Hurricane Protection Project in coastal Louisiana, over multiple climate change scenarios, we identify system configurations of similar cost that reduce the expected value of discounted residual risk of 26%–73% ($8–85 million). We also achieve the same residual risk at 90%–97% of the cost of the existing system (saving $19–73 million).

C. J. Pearson, S. M. Reaney, M. T. Perks et al.

Abstract Practical approaches for managing flooding from fluvial sources are moving away from mitigation solely at the point of impact and towards integrated catchment management. This considers the source areas, flow pathways of floodwaters and the locations and exposure to the risk of communities. For a field site in southern Nepal, we analyse catchment response to a range of simulated rainfall events, which when evaluated collectively can help guide potential flood management solutions. This is achieved through the adoption of SCIMAP‐Flood, a decision support framework that works at the catchment‐scale to identify critical source areas for floodwaters. The SCIMAP‐Flood Fitted inverse modelling approach has been applied to the East Rapti catchment, Nepal. For multiple flood impact locations throughout the catchment, SCIMAP‐Flood effectively identifies locations where flood management measures would have the most positive effects on risk reduction. The results show that the spatial targeting of mitigation measures in areas of irrigated and rainfed agriculture and the prevention of deforestation or removal of shrubland would be the most effective approaches. If these actions were in the upper catchment above Hetauda or upstream of Manahari they would have the most effective reduction in the flood peak.

B. Surya, Haeruddin Saleh, Seri Suriani et al.

The complexity of spatial use has an impact on poverty and the development of slum settlements towards a decrease in environmental quality. In this study, we aim to analyze (1) urbanization and spatial expansion as determinants of spatial dynamics in suburban areas, (2) the effect of spatial expansion, land use change, population increase, and spatial activity patterns on the development of slum settlements, and (3) the relationship between control of spatial planning, handling land reclamation, and improving the quality of infrastructure with improving the quality of the environment and the sustainability of handling slum settlements in the suburbs. We use a sequential explanatory design, which is a combination of quantitative and qualitative research, and data are obtained through observation, in-depth interviews, surveys, and documentation. The results showed that slum settlements in watersheds and coastal areas as well as inadequate support for infrastructure services resulted in excessive groundwater use, soil pollution, and surface water quality pollution resulting in less smooth river flow regulation, lowering of water levels, urban flooding, and disease transmission. Weak control over spatial use, utilization of water catchment areas, and the inadequate fulfillment of slum settlement infrastructure services cause a decrease in environmental quality. These results indicate that it is very important to deal with slum settlements in a sustainable manner, including spatial use and environmental, economic, and social aspects. This study recommends that the handling of slum settlements requires policy support from the government in an effort, to meet the city target without slums by 2030 in Makassar City, Indonesia.

Choudhurimayum Pankaj Sharma, Pradeep Srivastava

Figure S1: (A) Infrared Stimulated Luminescence (IRSL) of LD-1818 exhibiting feldspar contamination. (B) IRSL counts of all samples after complete etching including LD-1818 after re-etching. (C) Optical Stimulated Luminescence (OSL) decay curves of all samples; Figure S2: (A) Pre heat test (dotted line represents 220 °C plateau) and (B) Dose recovery test of LD-3170; Figure S3: OSL characteristics of LD-2011. (A) Probably distribution of ED all discs and (B) Sensitivity corrected luminescence growth curve; Figure S4: Radial plot of all OSL samples with ages; Table S1: Elemental, isotopic and age details of detrital zircon U-Pb geochronology of paleoflood deposits.