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Based on the projected increase in hurricane landfall frequency on the middle to lower US east coast, we examined the crucial role of the estuarine wind field in exacerbating coastal flooding. A regionally refined atmospheric and two high-resolution hydrology and ocean models are integrated to provide plausible and physically consistent ensembles of hurricane events and the associated flooding inside the Delaware Bay and River, a US mid-Atlantic estuary. Model results show that the hurricane propagation direction, estuarine geometry, remote surge from the open ocean, and direct nearshore upwind stress could magnify the flood magnitude. More specifically, inland-bound tracks that make landfall before reaching the mid-Atlantic coast produce a more significant surge within Delaware Bay than the shore-parallel tracks, where the estuarine wind direction plays the primary role in surge amplification. Ultimately, this study emphasized the need for integrated models to capture the nonlinear dynamics and interactions in flood hazard modeling. [ABSTRACT FROM AUTHOR]

Historical records in the Delaware River Basin reveal complex and spatially diverse flood generating mechanisms influenced by the region's mountains‐to‐plains gradients. This study focuses on predicting future flood hazards and understanding the underlying drivers of changes across the region. Using a process‐based hydrological model, we analyzed the hydrometeorological condition of each historical and future flood event. For each event, at the subbasin scale, we identified the dominant flood generating mechanism, including snowmelt, rain‐on‐snow, short‐duration rain, and long‐duration rain. The rain‐induced floods are further categorized based on the soil's Antecedent Moisture Condition (AMC) before the event, whether dry, normal, or wet. Our historical analysis suggests that rain‐on‐snow is the primary flood mechanism of the Upper Basin. Although most frequent, the magnitude of rain‐on‐snow floods is often less severe than short rain floods. In contrast, historical floods in the Lower Basin are primarily caused by short rain under normal AMC. Given the uncertainties in climate projections, we used an ensemble of future climate scenarios for flood projections. Despite variations in regional climate projections, coherent perspectives emerge: the region will shift toward a warmer, wetter climate, with a projected intensification of extreme floods. The Upper Basin is projected to experience a marked decrease in rain‐on‐snow floods, but a substantial increase in short rain floods with wet AMC. The largest increase in flood magnitude will be driven by short rains with wet AMC in the Upper Basin and by short rains with normal AMC in the Lower Basin. Plain Language Summary: The Delaware River Basin spans a diverse landscape, from mountains to coastal plains. This geographic diversity makes the region susceptible to various flood events with distinct causes and timing. For example, in spring 2005, a rain‐on‐snow event accelerated the melting of an existing snowpack, leading to significant flooding. Then, in the summer of 2011, heavy rainfall from Hurricane Irene caused widespread inundation in the basin. This study focuses on predicting future flood hazards and understanding the underlying drivers of changes across the region. We found that, historically, the Upper Basin has mostly experienced floods caused by rain‐on‐snow, while the Lower Basin floods have been primarily driven by short, intense rainfalls. Intriguingly, even though rain‐on‐snow floods are most frequent in the Upper Basin, they are often less intense than floods caused by short rain, resulting in high‐frequency, low‐magnitude flood events. As climate models predict a shift toward a warmer and wetter regional climate, simulations suggest that the Upper Basin is likely to experience fewer rain‐on‐snow floods and more short rain‐driven floods intensified by wetter pre‐flood soil conditions. Despite variability in regional climate projections, a prevailing consensus suggests that the region's future floods will be more severe, predominantly driven by short, intense rainfalls. Key Points: Historical floods in the Delaware River Basin are primarily from rain‐on‐snow at the Upper Basin and short, intense rain at the Lower BasinFuture climate shifts the Upper Basin's primary flood mechanism from rain‐on‐snow to short, intense rain amplified by wetter pre‐flood soilsDespite climate projection uncertainties, consensus is future extreme floods, particularly from short rains, will intensify regionally [ABSTRACT FROM AUTHOR]

Based on the projected increase in hurricane landfall frequency on the middle to lower U.S. East Coast, we examined the crucial role of the estuarine wind field in exacerbating coastal flooding. A regionally refined atmospheric and two high-resolution hydrology and ocean models are integrated to provide plausible and physically-consistent ensembles of hurricane events and the associated flooding inside the Delaware Bay and River, a U.S. mid-Atlantic estuary. Model results show that the hurricane propagation direction, estuarine geometry, remote surge from the open ocean, and direct nearshore upwind stress could magnify the flood magnitude. More specifically, inland-bound tracks that make landfall before reaching the mid-Atlantic coast produce a more significant surge within Delaware Bay than the shore-parallel tracks, where the estuarine wind direction plays the primary role in surge amplification. Ultimately, this study emphasized the need for integrated models to capture the nonlinear dynamics and interactions in flood hazard modeling. [ABSTRACT FROM AUTHOR]

Rivers or watercourses in Sylhet plain of Bangladesh are very dynamic over time. The aim of the present study is to investigate the channel planform dynamics, the prediction of future lateral migration of the bankline and assessment of the hazards associated with Manu River, Bangladesh. The name Manu River represents the river study reach from Tripura, India to Moulvibazar, Bangladesh of 41.6 km. Channel contraction and expansion are very frequent in this river. Studies had shown that the sinuosity of the river varies from 1.36 to 2.48. Also the meandering ratio of the river ranges from 0.32 to 1.67. Satellite data were collected and analyzed to determine the planform characteristics, meandering parameters and bankline migration rates between 1975 and 2013. The study is based on the Landsat satellite imagery of 1975, 1988, 1999, 2003 and 2005 and aerial photograph of 2009 and 2013 which were accumulated from United States Geological Survey. Specific critical bends have been elected where bank erosion and accretion rates were severe. The purpose of this paper is to show the erosion rate, behavior and pattern of upstream side of Manu River, Bangladesh through the study period of 38 years from 1975 to 2013 by comparing its different geomorphological parameters. This study has contributed to develop a model for bankline migration prediction of the forthcoming years and address the physical hazard to provide a risk surface. Present assessment has revealed that, there are some critical regions where erosion would be up to 29.18 hectares in 2025. [ABSTRACT FROM AUTHOR]

Streams are continually changing position as a consequence of hydraulic forces acting on their beds and banks. This stress is mainly a result of climatic changes from year to year in the amount of water flow variation that occurs in the stream (Matsuda, 2004). The present study has been conducted to scrutinize the meandering parameters at critical bends of Kushiyara River using Remote sensing technology and Geographic information system. The name Kushiyara River used here to represent the river reach from India border, Zokigonj to the confluence with Kalni River. The width of the Kushiyara River changes over time. Eight critical bends have been selected over different places which are changing with the time. The Sinuosity of the river also varies from 1.11 to 2.24. The minimum width as found was 96.12m near Fertilizer industry; Fenchugonj (chainage 90.1 km) in 1997, the maximum width was 272.9m at Ranigonj union, Sunamgonj (chainage 156.5 km) in 2006. The study shows that the meandering ratio varies from 0.32 to 1.23.Wavelength of the Kushiyara River vary from 1062.85m to 2240.57m. The river shows its characteristics relation between the radius of curvature and width. [ABSTRACT FROM AUTHOR]