6th International Virtual Congress (IYSC-2020) And Workshop. 10th International Science Congress (ISC-2020).  International E-publication: Publish Projects, Dissertation, Theses, Books, Souvenir, Conference Proceeding with ISBN.  International E-Bulletin: Information/News regarding: Academics and Research

Flood Hazard Assessment in Dhobi-Khola Watershed (Kathmandu, Nepal) using Hydrological Model

Author Affiliations

  • 1Golden Gate International College, Battisputali, Kathmandu, Nepal
  • 2Central Department of Hydrology and Meteorology, Tribhuvan University, Kirtipur, Nepal
  • 3Golden Gate International College, Battisputali, Kathmandu, Nepal
  • 4Genesis Consultants Pvt. Ltd, Lalitpur, Nepal

Int. Res. J. Environment Sci., Volume 5, Issue (11), Pages 21-33, November,22 (2016)

Abstract

Flood, one of the main hazards in Nepal, requires an effective modelling to mitigate their impacts. Flood inundation models provide anestimation of flood extents and depths that are used in the preparation of hazard maps. Streams, like Dhobi-Khola in Kathmandu, with potential flood risks to infrastructures and settlements, are not studied to a level to predict and mitigate the flood hazards. This study assesses the flood vulnerable sites of Dhobi-Khola watershed and delineate theflood prone areas using hydrological HEC-HMS model and GIS application.The model was calibrated and validated in Bagmati River with discharge data of Gaurighat and rainfall data of Sundarijal stations. The model was then transposed to Dhobi-Khola watershed using hydrological data of Budhanilkantha station. The Slope-Area method of discharge measurementwas used to validate the model outputs in Dhobi-Khola using the field survey data. Final model outputswere used to predict the floods for different return periods using HEC-RAS model together with HEC-GeoRAS to generate flood inundation maps. Results indicate that the maximum flood depth can reach up to 5.24 m in 100 year return period (YRP) in Dhobi-Khola watershed. One site is inundated during the flood of 5 YRP and three sites in 10 to 20 YRPs. A total of five and seven sites is inundated during flood of 50 and 100 YRP, respectively. Vulnerabilityassessment showed two sites are very highly vulnerable and a site in low flood vulnerable due to low levee height, putting several households in the riverbanks and surrounding at the highest risk.

References

  1. Smith Keith (2000)., Environmental hazards assessing risk and reducing disaster., 3rd Edition, Routledge 11 New Fetter Lane, London, 1-420, ISBN-10: 0415224640.
  2. Mishra O.P., Ghatak M. and Ahmed K. (2012)., Background paper flood risk management in south Asia., Mishra O. P., Ghatak M., Kamal A. and Kumar R. (Eds.), SAARC workshop on flood risk management in South Asia. Islamabad, Pakistan, SAARC Disaster Management Centre, New Delhi.
  3. Adhikari B.R. (2013)., Flooding and Inundation in Nepal Terai: Issues and Concerns., Hydro Nepal, 12(7), 59-65.
  4. Shakya B., Ranjit R., Shakya A., Bajracharya S. and Khadka N. (2007)., Estimation of 2002 Extreme Flood over Balkhu River Using NOAA Based Satellite Rainfall and HEC-HMS Hydrological Model, and Assessment of Flood Education of People Living Near the Flood Risk Zone of Balkhu River., International Symposium on Geo-Disasters, Infrastructure Management and Protection of World Heritage Sites, Kathmandu, 215-223.
  5. Ranjit R. (2006)., Floods in Kathmandu valley with special reference to 2002 extreme weather in Balkhu watershed., Kathmandu, Nepal: CDES, TU.
  6. Hazarika M. K., Bormudol A., Phosalath S., Sengtianthr V., and Samarakoon L. (2006)., Flood hazard in savannakhet province, Lao PDR maping using HEC-RAS, Remotesensing, and GIS., The 6th Annual Mekong Flood Forum, Lahor.
  7. Piman T. and Babel M.S. (2013)., Prediction of Rainfall-Runoff in an Ungauged Basin: Case Study in the Mountainous Region of Northern Thailand., J. Hydrol. Eng., 18(2), 285-296, doi: 10.1061/(ASCE)HE.1943-5584.0000573.
  8. Rees H.G., Holmes M.G.R., Young A.R. and Kansakar S. R. (2004)., Recession-based hydrological models for estimating low flows in ungauged catchments in the Himalayas., Hydrol.Earth Syst. Sc., 8, 891-902.
  9. Shrestha S. and Alfredsen K. (2011)., Application of HBV Model in Hydrological Studies of Nepali River Basins: A Case Study., HydroNepal, 8, 38-43.
  10. Shrestha M.S., Artan G.A., Bajracharya S.R. and Sharma R. R. (2008)., Using satellite-based rainfall estimates for streamflow modelling: Bagmati Basin., J. Flood Risk Manag., 1, 89-99, doi: 10.1111/j.1753-318X.2008.00011.x
  11. Bharati L., Gurung P. and Jayakody P. (2012)., Hydrologic Characterization of the Koshi Basin and the Impact of Climate Change., Hydro Nepal, 18-22.
  12. Neupane R.P., Yao J. and White J.D. (2013)., Estimating the effects of climate change on the intensification of monsoonal-driven stream discharge in a Himalayan watershed., Hydrol. Process., doi: 10.1002/hyp.10115.
  13. Immerzeel W.W., Pellicciotti F. and Bierkens M.F.P. (2013)., Rising river flows throughout the twenty-first century in two Himalayan glacierized watersheds., Nat. Geosci., 6, 1-4, doi: 10.1038/ngeo1896.
  14. Nepal S., Krause P., Flügel W.A., Fink M. and Fischer C. (2014)., Understanding the hydrological system dynamics of a glaciated alpine catchment in the Himalayan region using the J2000 hydrological model., Hydrol. Process., 28, 1329-1344.
  15. Lutz A.F., Immerzeel W.W., Shrestha A.B. and Bierkens M.F.P. (2014)., Consistent increase in High Asia’s runoff due to increasing glacier melt and precipitation., Nat. Clim. Change, doi: 10.1038/NCLIMATE2237.
  16. Thakuri S. (2015)., Coupling Glacio-Hydrological Response to Climate Varibility in Mt. Everest Region (Central Himalaya)., Ph.D. Thesis Submitted to the University of Milan, Italy, 181.
  17. Dixit A.M., Upreti B.N., Paudel D., Aryal P., Koirala P. K., Jnavaly S.S. and Shrestha S.N. (2011)., Nepal Disaster Report: Policies, Practices, and Lessons., Ministry of Home Affairs (MoHA), Government of Nepal and Disaster Preparedness Network-Nepal (DPNet-Nepal) with support from United Nations Development Programme Nepal (UNDP), ActionAid Nepal and National Society for Earthquake Technology-Nepal (NSET), Kathmandu, Nepal, 186.
  18. Faulkner H., Parker D., Green C. and Beven K. (2007)., Developing a translational discourse to communicate uncertainty in flood risk between science and the practitioner., Ambio, 36(7), 692-703.
  19. Shrestha P. (2010)., Climate change impact on River dynamics of the Bagmati Basin, Kathmandu Nepal., Ministry of Environment, Kathmandu.
  20. Aryal K.R. (2007)., Mapping Disaster Vulnerability from Historical Data in Nepal., Northumbria University, UK, 52.
  21. Irwin D., Joshi A., Basnet S., Pande K.R., Duwal S., Dawadi G.S., Pokhrel R.M., Poudyal P., Adhikari T.R., Rakhal B. and Tamang D. (2013)., Land Use, Multi-Hazard and Recommendations for Risk Sensitive Land Use Planning in Kathmandu Valley., Genesis Consultancy (P) Ltd. & Welink Consultants (P) Ltd., Kathmandu, Nepal.
  22. Zhang H.L., Wang Y.J., Wang Y.Q., Li D. X. and Wang X.K. (2013)., The effect of watershed scale on HEC-HMS calibrated parameters: A case study in the Clear Creek watershed in Iowa, US., Hydrol.Earth Syst. Sc., 17, 2735-2745, doi: 10.5194/hess-17-2735-2013.
  23. Arekhi S. (2012)., Runoff modeling by HEC-HMS Model (Case Study: Kan watershed, Iran)., Intl J.Agri. CropSci., 4 (23), 1-5, www.ijagcs.com IJACS/2012/4-23/1807-1811.
  24. Li M., Shao Q., Zhang L. and Chiew F.H.S. (2010)., A new regionalization approach and its application to predict flow duration curve in ungauged basins., J. Hydrol., 389, 137-145, http://dx.doi.org/10.1016/j.jhydrol.2010.05.039.
  25. Ouarda T.B.M.J., Girard C., Cavadias G.S. and Bobee B. (2001)., Regional flood frequency estimation with canonical correlation analysis., J. Hydrol., 254, 157-173, http://dx.doi.org/10.1016/S0022-1694(01)00488-7.
  26. Hosking J.R.M. and Wallis J.R. (1997)., Regional Frequency Analysis an Approach Based on L-Moment., Cambridge University.
  27. Roe J., Dietz C., Restrepo P., Halquist J., Hartman R., Horwood R., Olsen B., Opitz H., Shedd R. and Welles E. (2010)., NOAA’s Community Hydrologic Prediction System., Hydrology and sedimentation for a changing future: Existing and emerging issues; Proceedings of the 2nd Joint Federal Interagency Conference [9th Federal interagency sedimentation conference and 4th Federal interagency hydrologic modeling conference]; 27 June - 1 July; Las Vegas, NV.
  28. Pappenberger F., Beven K., Horritt M. and Blazkova S. (2005)., Uncertainty in the calibration of effective roughness parameters in HEC-RAS using inundation and downstream level observations., J. Hydrol., 302, 46-69, http://dx.doi.org/10.1016/j.jhydrol.2004.06.036.
  29. Pender G. and Faulkner H. (2010)., Flood Risk Science and Management., John Wiley & Sons Ltd, UK.
  30. Bhat G.K., Karanth A., Dashora L. and Rajasekar U. (2013)., Addressing flooding in the city of Surat beyond its boundaries., Environ. Urban., 25, 429-441, doi: 10.1177/0956247813495002.
  31. Reshma T., Reddy V. K. and Pratap D. (2013)., Simulation of Event Based Runoff Using HEC-HMS Model for an Experimental Watershed., Intl J. Hydraul. Eng., 2, 28-33.
  32. Reed S., Moreda F. and Gutierrez A. (2010)., Lessons learned from transitioning NWS operational hydraulic models to HEC-RAS., ASCE-EWRI World Water Congress.
  33. Roy D., Begam S., Ghosh S. and Jana S. (2013)., Caliberation and Validation of HEC-HMS Model for a River Basin in Eastern India., J. Asian Res. Publ. Network, 8, 1-17.
  34. Singh S., Shrestha B.R., Shrestha S.D. and Shrestha K.B. (2008)., Bagmati Action Plan (2009-2014)., National Trust for Nature Conservation, Kathmandu.