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Computation of Different Parameters in Water Resources Engineering Using Artificial Neural Network
Published in Surendra Kumar Chandniha, Anil Kumar Lohani, Gopal Krishan, Ajay Krishna Prabhakar, Advances in Hydrology and Climate Change, 2023
Ankit Chakravarti, Himanshu Panjiar, Manish Pandey
The flood hydrograph of a river at any downstream section can be modeled and predicted based on the upstream activities in the river. The flood is a natural phenomenon occurring worldwide time to time and the flood hydro-graph prediction can be an effective alarming method for downstream locations. It is well known that flood is an all-round loss incurring phenomena for any locality or regions, so this can be alleviated by some degree by some alarming model based work and soft computing methods are found to be a good option. In this context, several soft computing methods are used for flood hydrograph predictions, such as the Fuzzy logic methods (Tayfur, 2012), the ANN (Tayfur et al., 2007; Tayfur, 2012), and the GA (Tayfur and Moramarco, 2008; Tayfur et al., 2009; Tayfur, 2012). In addition, even some researcher reported the multi-step-ahead flood forecasting method in this field of hydrology (Chang et al., 2014, 2015). The movement of a flood wave along a channel length is an important parameter for flood routing in a river and also for calculating the flood hydrograph at any downstream section. Generally, two most common approaches for flood routing, the first is hydraulic approach based on numerical methods and second is hydrologic approaches, which are based on conservation of mass principle. All the methods require substantial field data; they are costly and time consuming. While the soft computing methods such as ANN is very helpful in modeling this hydrological process (Barbetta et al., 2017, Tayfur et al., 2018).
Streamflow and floods
Published in Stephen A. Thompson, Hydrology for Water Management, 2017
A hydrograph is a graph of stream discharge, or water surface elevation, versus time (Fig. 11.6). Later we discuss relating water surface elevation to discharge using a rating curve. (A graph of water level versus time in a well is also called a hydrograph.) A hydrograph is divided into a rising limb, a crest segment, and a falling limb, or recession curve. The rising limb is controlled by the rate of runoff into the stream, which in turn is related to the physical characteristics of the basin and the intensity-duration characteristics of the storm. The water draining from the basin comes from a varying combination of surface runoff, interflow and baseflow. Surface runoff drains away first since it reaches the channel most rapidly. Interflow drains away next and the lowermost segment of the recession curve is assumed to be comprised entirely of baseflow from groundwater. The point of inflection on the recession limb is assumed to indicate the time when surface runoff to the channel stops (Linsley et al. 1982). The falling limb is a depletion curve -a curve describing the drainage of water from storage. A general baseflow depletion curve can be modeled as an exponentially-decaying process, where discharge at time t+1 is proportional to discharge at time t one period earlier: () Qt+1=kQt
Diffuse pollution-principles, definitions and regulatory aspects
Published in R. Hranova, Diffuse Pollution of Water Resources, 2005
A hydrograph is a plot of flow rate versus time at a point of interest on the drainage system along a man-made conduit or along a natural stream or river. The development of the unit hydrograph theory serves to represent in mathematical form the transformation of rainfall excess into runoff. The unit hydrograph could be defined as the division of the excess rainfall into small pulses of the same duration as the unit rainfall input, and applied uniformly over the whole catchment basin. The unit hydrograph is the multiplier determining individual response hydrographs from the basin with the same duration. All individual hydrographs, based on the unit hydrograph applied for the specific conditions within the catchment area, are summed in order to obtain the final hydrograph, representing the total flow variation during a specified rainfall event for this specific basin.
Towards a high-resolution modelling scheme for local-scale urban flood risk assessment based on digital aerial photogrammetry
Published in Engineering Applications of Computational Fluid Mechanics, 2023
Changbo Jiang, Yuantai Kang, Ke Qu, Yuannan Long, Yuan Ma, Shixiong Yan
Flood management policies and designs are generally based on an estimate of flood frequency, namely the return period (Gilroy & McCuen, 2012). The flood peak discharge is the main concern in flood estimation (Rosbjerg et al., 2013), and it’s the major factor in the magnitude of flood damage. Furthermore, for the prevention of flood disasters and the design of hydraulic structures, it is also important to understand the volume of flooding and the shape of flood hydrograph (Mediero et al., 2010). Different flood hydrograph (e.g. flood volume and duration) will lead to differences in cost of hydraulic structures, and affect flood control policies and flood management strategies (Yue et al., 2002). Similarly, the characteristic quantities (e.g. flood duration and flood hydrograph shapes) of flood process has great influence on urban submergence, which is related to local engineering construction, such as dam and river dikes (Tanaka et al., 2017).
A review of flow estimation by runoff routing in Australia – and the way forward
Published in Australasian Journal of Water Resources, 2020
These are: Groundwater or baseflow. This is the traditional concept of baseflow and is what is generally referred to as the steady-state regional groundwater runoff and is the slowest flow process contributing to the hydrograph. It is known that the lag between rainfall and groundwater runoff to the stream discharge can be substantial, due to the long flow path length in the groundwater system,Interflow. This mechanism occurs within the unsaturated zone and acts with a lag from rainfall to stream flow that is less than that of the baseflow above, due to the quicker response time from rainfall to runoff into the stream, and;Direct runoff, on surface either from a part of the catchment area, or the full catchment area. The response time of this mechanism is short compared with the two above, as no infiltration and flow through soil and rock flow is involved.
Advancing ecohydraulics and ecohydrology by clarifying the role of their component interdisciplines
Published in Journal of Ecohydraulics, 2019
Marie-Pierre Gosselin, Valérie Ouellet, Atle Harby, John Nestler
The disciplinary bases from which ecohydraulics and ecohydrology have emerged differ significantly in focus, scope and scale. From these differences, it is evident that their development and evolution as disciplines were not coordinated by their respective practitioners. Each evolved from separate traditions to address different applied questions of water resources management (and other uses). Typically, hydraulics practitioners make heavy use of calculus to implement conservation principles (of mass, energy, and momentum) at a cell-by-cell level of resolution based on the physical properties of solid boundaries and the dynamics of the fluid boundaries (i.e. inflows and outflows). Governing equations like the Navier–Stokes or St. Venant equations are often discretized (i.e. distributed) into cells or meshes, and characteristics of the flow field are then obtained by aggregating fluid behaviour across the grid or mesh (Escauriaza et al. 2017). In contrast, hydrology makes heavy use of descriptive statistics to implement conservation principles at larger time and space scales (Thompson 2017). For example, the unit hydrograph principle uses observed data to develop rainfall–runoff relationships that can be used to estimate the volume and timing of water entering a river channel from its watershed (Dingman 2015). Then, kinematic wave routing describes the flattening and broadening of a flood wave (based on previously collected flooding data) as it moves downstream after a rainfall event to be used to estimate flood height and arrival time. Another difference lies in the basic units used for analysis. While in hydrology it is the transect and the primary variables of concern are stage and discharge, in hydraulics the basic unit of analysis is a cell or node within a cross section, grid and mesh.