Floodplain Mapping for Indus River: Chashma –Taunsa Reach

Usman Khalil, Noor Muhammad Khan, Habib -ur- Rehman


Floods are the most critical among all the natural calamities. Flood water inundate the floodplain areas and cause vast damages to life and property. It is thus essential to address this natural calamity to decrease the effect it causes to property and people. In this study, Indus River reach Chashma-Taunsa (252 km) was selected, that experienced exceptionally high flood in 2010, due to which huge damages occurred to life and property. In this study, flood hydraulic modelling and floodplain mapping has been performed to have initial assessment of flood vulnerability and to provide vision for emergency preparedness plan. Flood mapping can further precede flood hazard and risk maps. To perform hydraulic modelling and floodplain mapping HEC-RAS, ArcGIS and its extension Hec-GeoRas were used as tools. HEC-RAS model input cross-sections data were collected from physical survey and extracted from DEM SRTM 90 m by using Hec-GeoRas. Comparison was made between surveyed and SRTM DEM extracted cross-sections; to perform necessary verification and merging the channel data in DEM extracted cross-section. Frequency analysis has been conducted by using Gumbel’s and Log Pearson Type III distributions to determine the flood peaks for extreme events. Frequency analysis result shows that the flood of 2010 in study area has return period of 180 years. Cross-sections data and results of frequency analysis were used in HEC-RAS to perform unsteady flow analysis for low to extreme events. HEC-RAS model was calibrated and validated for year 2010 and 2006, respectively. Coefficient of determination (R2) 0.95 & 0.90 and Nash and Sutcliffe coefficient that 0.93 & 0.86 were calculated, that show good calibration and validation respectively. Results of HEC-RAS model were exported in ArcGIS to perform inundation mapping. Depth and area of flooded extent for 2010 flood were calculated as 8.1 m and 1900 km2, respectively. Flood inundation maps of the whole study area were prepared for 25, 500 year and 2010 year return period flood. Floodplain maps show flooded area depth from 7.1 to 9.1 m for 25 year to 500 return period floods, respectively. Flood inundation maps will be an important tool for Engineers, Planners for emergency actions plans and for flood management.

Full Text:



Raghunath M.H., (1991), Hydrology, New Age International (P) Limited New Delhi.

Seyedeh, S. S., Thamer, A. M., Mahmud, A. R. B., Majid, K. K., and Amir S.(2008), Integrated Modelling for Flood Hazard Mapping Using Watershed Modelling System, American Journal of Engineering and Applied Sciences 1 (2): 149-156.

Milly, P.C.D., Wetherald, R.T., Dunne, K.A., Delworth, T.L., (2002), Increasing risk of great floods in a changing climate, Nature 415, 514-517.

UN, (2010), World Urbanization Prospects, the 2009 Revision. United Nations, Department of Economic and Social Affairs, Population Division.

Milly, P.C.D., Betancourt, J., Falkenmark, M., Hirsch, R.M., Kundzewicz, Z.W., Lettenmaier, D.P., Stouffer, R.J., (2008), Stationarity is dead—whither water management? Science 319 (5863), 573–574.

FFC (2011), Annual Flood Report-2010, Federal Flood Commission of Pakistan.

EXCIMAP (2007), Hand book on good practices for flood mapping in Europe

Knebl, M.R., Yang, Z. L., Hutchison, K., Maidment, D.R., (2005) Regional Scale Flood Modeling using NEXRAD Rainfall, GIS, and HEC-HMS/RAS: A case study for the San Antonio River Basin Summer 2002 storm event. Journal of Environmental Management 75, 325–336.

Ahmad, F. (2007), Probabilistic flood risk analysis in Chenab Riverine area in Muzaffargarh district. M.Sc.Thesis, Center of Excellence in Water Resources Engineering, University of Engineering and Technology Lahore.

Ackerman C T.(2004), Hydraulic Modeling of the Salt River, Arizona Using Hec-GeoRas, Hydrologic Engineering Center, Davis, CA.

Ackerman C T. (2000),Hec-GeoRas: Linking GIS to Hydraulic Analysis Using ARC/INFO and HEC-RAS, Hydrologic Engineering Center, Davis, CA.

Fosu C.,Forkuo K E., Asare YM., (2012),River Inundation and Hazard Mapping – a Case Study of Susan River – Kumasi, Department of Geomatics Engineering, Kwame Nkrumah University of Science &Technology, Private Mail Bag, Kumasi, Ghana, proceedings of global geospatial conference 2012 Quebec city, Canada, 14-17 May 2012

Hussain R., (2003), Food zone mapping using GIS and hydraulic model, M.Sc. Thesis, Center of Excellence in Water Resources Engineering, University of Engineering and Technology Lahore.

Hamid A., (1999), Estimation of flood damages caused by River Jhelum in Muzaffarabad- Kohala reach using HEC-2, M.Sc. Thesis, Center of Excellence in Water Resources Engineering, University of Engineering and Technology Lahore.

Hailea A. T. and T.H.M. Rientjes (2005), Effects of Lidar DEM Resolution in Flood Modelling: A Model Sensitivity Study for the City of Tegucigalpa, Honduras.

Horritt M.S., & Batesb P.D., (2002), Evaluation of 1D and 2D numerical models for predicting river flood inundation, Journal of Hydrology, Vol. 268, PP. 87-99.

Tabyaoui H., HammichiElF., Er-Rguiouag A M., LahrachA., (2010), hydraulic modelling using Hec-Ras and GIS, application to Oued Inaouen (Taza, Northern Morocco), Faculty of Sciences and Technique, Fez, B.P. 2202 – Route d’Imouzzer, Fez, Morocco

Latif, Q. (2007), Effect of channel improvement on water levels for Kabul River under flood conditions. M.Sc. Thesis, Center of Excellence in Water Resources Engineering, University of Engineering and Technology Lahore.

Salajegheh A., Bakhshaei M., Chavoshi S., Keshtkar R.A., Najafi Hajivar N.M., (2009), Floodplain mapping using HEC-RAS and GIS in semi-arid regions of Iran, DESERT 83-93

Tariq, M.A., (2005), Determination and Implementation of Flood Risk Zoning, employing Physiographic and Hydraulic Parameters for Flood Prone Areas of Chiniot Distt., M.Sc. Thesis, Center of Excellence in Water Resources Engineering, UET, Lahore.

Shafiq M.C. (2013), Hill Torrents Management initiatives in Southern part of Punjab an overview, Impact analysis & way forward, Pakistan Engineering Congress, PP.291-313

Hashmi H.N., Siddiqui T.M., Ghumman A.R., Kamal M.A., & Mughal H.R., (2012), A critical analysis of 2010 floods in Pakistan, African Journal of Agricultural Research, Vol. 7(7), PP. 1054-1067.

FFC(2007), Second Flood Protection Sector Project – Package C, Strengthening Flood Forecasting, Management and Warning System, Flood forecasting model – Indus river

HEC (2005),HEC-GeoRAS – An extension for support of HEC-RAS using ArcGIS, CPD-83, September 2005. Hydrologic Engineering Center, Institute for Water Resources, U.S. Corps of Engineers, Davis, CA.

Patra K.C. (2008), Hydrology and Water Resources Engineering. Second Edition. Narosa Publishing House Pvt, Ltd.

Zhang Jingyia and Hall, M.J. (2004), Regional flood frequency analysis for the Gan-Ming River basin in China. Journal of hydrology. Volume 296, Page 98-117.

C. T. Haan,(1997),“Statistical Methods in Hydrology.”Iowa StateUniversity Press, Ames, Iowa. I'. Haefner, Journal of Water.

S. B. Shaw and S. J.Riha, (1983),“Assessing Possible Changes inFlood Frequency Due to Climate Change in Mid-sizedWatersheds.” School of Civil and EnvironmentalEngineering, Hollister Hall, Cornell University, Ithaca, NY14853-3501, USA.

Copyright (c) 2017 Pakistan Journal of Engineering and Applied Sciences

Powered By KICS