Slide 1
Rainfall Runoff modeling using SWMM INTRODUCTIONRainfall Runoff modelArunoff modelis a mathematical model describing therainfallrunoffrelations of a rainfallcatchment area,drainage basinorwatershed. In other words, the model calculates the conversion of rainfall into runoff.The systems modeled can be classified into two categories: (i) linear and (ii) non-linear. Rainfall-Runoff ModelingRainfall-RunoffWatershedRainfallRunoffRainfall-RunoffModelRainfallRunoffHEC TR-20 HSPF SWMM -- Storm Water Management ModelANSWERS -- Areal Nonpoint Source Watershed Environment Response Simulation
SHE -- Systeme Hydrologique Europeen Hydrodynamic, CS model with physical, distributed parameters PRMS -- Precipitation-Runoff Modeling System. Conceptual, CS model with physical and fitted, HRU parameters NWSRFS -- National Weather Service River Forecast Syst
What Is SWMM?6
The Environmental Protection Agency Storm Water Management Model (EPA SWMM) is a dynamic rainfall-runoff simulation model used for single event or long-term (continuous) simulation of runoff primarily for urban areas.
The runoff component of SWMM operates on a collection of subcatchment areas that receive precipitation and generate runoff.
The routing module of SWMM transports this runoff through a system of pipes, channels, storage/treatment devices, pumps, and regulators.
SWMM tracks the quantity of runoff generated within each subcatchment, and the flow rate and flow depth in each pipe and channel during a simulation period.
THEORY BASED ON STUDY ON SWMM. SWMM conceptualizes a drainage system as a series of water flows between several major compartments. These compartments and the SWMM objects include: The Atmosphere compartment, SWMM uses raingauge objects to represent rainfall inputs to the system. The Land Surface compartment, which is represented through one or more Sub-catchment objects. It receives precipitation. The Groundwater compartment receives infiltration from the Land Surface compartment and transfers a portion of this inflow to the Transport compartment. The Transport compartment contains a network of conveyance elements (channels, pipes, pumps, and regulators) and storage/treatment units that transport water to outfalls.Inflows to this compartment can come from surface runoff, groundwater interflow, sanitary dry weather flow, or from user-defined hydrographs. The components of the Transport compartment are modeled with Node and Link objects.SWMM salient features1. Freely available in public domain2. It incorporates infiltration models Horton, Green-Ampt and SCS CN method.3. Channel flow routing both Kinematics and Dynamic wave routing.4. A Graphical User Interface.Limitations of SWMMNot applicable to large-scale, non-urban watershedsNot applicable to forested areas or irrigated croplandCannot be used with highly aggregated (e.g., daily) rainfall dataIts an analysis tool, not an automated design toolTwo dimensional flows cannot be modeled.It cannot directly read/write the data from/to any GIS format.12Input data for the SWMM 1. Area of sub-catchments and length of drains obtained using GIS.2. Slopes obtained from spot elevations using drainage map.3. Width and depth of drains, by field observations. Width and depth of drains, by field observations.4. Rainfall values from design storm analysis.5. Other input like percentage impervious and roughness coefficients, obtained according to the type of surfaces and land use.SWMM Chronology1971 - SWMM I (M&E, UF, WRE)1975 - SWMM II (UF)1981 - SWMM 3 (UF & CDM)1983 - SWMM 3.3 (PC Version)1988 - SWMM 4 (UF & CDM)2005 SWMM 5 (EPA & CDM)14Methodology.Study area demo
Step 1-Loading study area map into swmmStep 2-set simulation dates start and reporting time .Step3- set nodes/links tab and set flow units.
Step 4-select rain gauge tool and place it on the study area map.Step5 -By clicking on rain gauge give inputs on rainfall data. Step 6- Select sub catchment tool and tracing the sub catchments.Step-7 marking the junctions and outfall.Step8- Now we can unload study area map.
Step9-select subcatcment and editing its parameters like raingauge parameters area ,width, slope ..etc
Step10-select junctions and outfall to give inputs.
Node Flooding Options25
Step11-Give input in conduit parametersJNJN+1Conduit (N)Grelev(NN,1)Grelev(NN,2)Physical Objects used to model a drainage system
STEP 12-RUN SIMULATION THEN IT WILL SHOW THE RESULTS
Runoff Quantity Continuity.Flow Routing Continuity.Sub catchment Runoff Summary. Node Depth Summary.Node Inflow Summary.Node Flooding SummaryOutfall Loading SummaryConduit Surcharge Summary
HYDRAULIC PROFILE
WORK PLAN-SWMM is never used in Agartala area to analyse the various parameters which is responsible for flooding of different node, junctions and conduits .So by study in this area in our future scope of work with the help of SWMM software we like to find out various output like runoff volumes, peak flows and time of concentration etc which will help to give an idea of the scenario of area susceptible to floods and will help in study of storm water drainage management system for the area.
References-Burges, S.J., Wigmosta, M.S., Meena, J.M., 1998. Hydrological effects of land use change in a zero-order catchment. J. Hydrol. Eng. 3 (2), 8697.Braud, I., Breil, P., Thollet, F., Lagouy, M., Branger, F., Jacqueminet, C., Kermadi, S., Michel, K., 2013a. Evidence of the impact of urbanization on the hydrological regime of a medium-sized periurban catchment in France. J. Hydrol. 485, 523.Chormanski, J., Van de Voorde, T., De Roeck, T., Batelaan, O., Canters, F., 2008. Improving distributed runoff prediction in urbanized catchments with remote sensing based estimates of impervious surface cover. Sensors 8, 910932.DUNNE, T., 1978. Field studies of hillslope flow processes. Hillslope hydrology, 227, pp. 293.DISKIN, M.H., 1981. Nonlinear Hydrologic Models, V.P. SINGH, ed. In: Rainfall-Runoff Relationship, May 18-21 1981, Water Resources Publications, pp. 127--146.DINGMAN, S.L., 1994. Physical hydrology. Prentice Hall Upper Saddle River, NJ.DURRANS, S.R., 2003. Stormwater Conveyance Modeling and Design. Waterbury, CT: Haestad Methods, Inc.Dams, J., Batelaan, O., Nossent, J., Chormanski, J., 2009. Improving hydrological model parameterisation in urbanised catchments: Remote sensing derived impervious surface cover maps. In: Feyen, J., Shannon, K., Neville, M. (Eds.), Water and Urban Development Paradigms: Towards and Integration of Engineering Design and Management Approaches. CRC Press, Taylor Francis Group, Boa ration, Florida, USA.
THANK YOU
