Spatial and Temporal Variation of Runoff Trend in Sri Lanka during the Past Decades

Chaminda Samarasooriya Patabendige, So Kazama, Yasanga Suduweli Kondage

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Inconsistency of seasonal monsoon weather patterns during the past several decades have a major influence on surface water management system in the in Sri Lanka. The present study aim is to analyze the changes in the inter-annual and intra-annual spatial and temporal variation of surface water flow in Sri Lanka to understand the surface runoff variation under the past climatic change. The spatially distributed hydrological model was calibrated and validated for four different discharge gauge stations in four basins and employed to simulate the natural surface runoff over the period 1975 - 2005 at daily time interval for 39 river basins. The rank-based, nonparametric Mann-Kendall statistical test was used for trend detection due to its robustness for non-normally distributed and censored data. The results confirm that seasonal runoff changes in basins completely located in dry zone are higher and mainly it is limited to 2nd inter and northeast monsoons. Basins located in the west and east show a significant increasing trend in mean annual runoff volume due to precipitation increase in the southwest monsoon to the west and northeast monsoon to the east. However, river basins located in northwest show general decreasing trend in mean annual runoff volume as inter-monsoon precipitation gets reduced. This study concludes that wet zone basins get wetter while leaving the dry zone drier during the past decades along with climate change.

Original languageEnglish
Title of host publicationMERCon 2019 - Proceedings, 5th International Multidisciplinary Moratuwa Engineering Research Conference
PublisherInstitute of Electrical and Electronics Engineers Inc.
Pages751-756
Number of pages6
ISBN (Electronic)9781728136325
DOIs
Publication statusPublished - 2019 Jul
Event5th International Multidisciplinary Moratuwa Engineering Research Conference, MERCon 2019 - Katubedda, Sri Lanka
Duration: 2019 Jul 32019 Jul 5

Publication series

NameMERCon 2019 - Proceedings, 5th International Multidisciplinary Moratuwa Engineering Research Conference

Conference

Conference5th International Multidisciplinary Moratuwa Engineering Research Conference, MERCon 2019
CountrySri Lanka
CityKatubedda
Period19/7/319/7/5

Keywords

  • distributed hydrological model
  • monsoon rainfall
  • river basin
  • spatial and temporal variability
  • surface runoff

ASJC Scopus subject areas

  • Artificial Intelligence
  • Process Chemistry and Technology
  • Civil and Structural Engineering
  • Electrical and Electronic Engineering
  • Industrial and Manufacturing Engineering
  • Mechanical Engineering
  • Materials Science (miscellaneous)
  • Education

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