1 / 23

Hydrological Analysis of Paprika's Small Slope Basins: A PhD Project Overview

This project investigates the hydrology of two small slope basins in Nepal, focusing on climatic data comparisons and hydrological balance in the Koshi river catchment. Detailed analyses include examining precipitation datasets from CRU and Aphrodite, assessing discharge reliability, and the interplay of temperature, discharge, and precipitation. The study addresses discrepancies in runoff coefficients and discharge contributions among sub-catchments. The goal is to enhance understanding of catchment hydrology and inform future water management strategies in the region.

nyla
Télécharger la présentation

Hydrological Analysis of Paprika's Small Slope Basins: A PhD Project Overview

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Paprika’s hydrological stations

  2. More Paprika’s hydrology

  3. Two smallslope basins could be studied in a detailedhydrologicalfield approach. PhD project submitted for funding (feb. 2011) at UM2 CoP Pangboche4000-6500m Kharikola1600-4000m

  4. Spatialized climate data sets

  5. Available climate datasets précipitation (*) bilinear interpolation

  6. Comparison of seasonal (monthly) precipitation CRU versus Aphrodite on 1952-2006 period over Koshi basin

  7. Spatial comparison of monthly precipitation CRU versus Aphrodite on 1952-2006 period over Koshi basin (resol = 0.25°) monthly bias (CRU-Aphro) monthly correlation between CRU and Aphro (636 values for each cell) Bias: higher CRU values over Tibet plateau (~1000 mm/year) better agreement in the southern basin Correlation: good correlation CRU-Aphrodite on southern part of the basin

  8. Spatial comparison of monthly precipitation TRMM versus Aphrodite on 2000-2007 period over Koshi basin (resol = 0.25°) monthly bias (Aphro-TRMM) monthly correlation between TRMM and Aphro (120 values for each cell) Bias: higher TRMM values over Tibet plateau and in south of Nepal (up to 350 mm/year)  probably reflect a bad aphrodite precipitation interpolation (lack of gages) over Tibet plateau higher Aphrodite values along the montains (up to 1000 mm/year)  TRMM :only rain , Aprhodite : rain+ snow better agreement over a small area in the southern basin Correlation: low correlation TRMM-Aphrodite on north-west part of the basin

  9. DHM’s hydrological balance

  10. Comparison of annual/monthly discharge and precipitation - 5 sub catchments of Koshi river at Chatara (93% of Koshi catchment area at Chatara) - 600.1 : Awa Gaon 29 700 km² 606 : Simle 33 500 km² 690 : Mulghat 5 880 km² 652 : Khurkot 10 200 km² 670 : Rabuwabazar 3 720 km² 695 : Chatara 57 300 km² Awa Gaon Rabuwabazar Khurkot Simle Mulghat Chatara • Aims : • Analysing the reliability of discharge measurements • Basic anlayses of the catchment hydrology • Data : • Discharge : DHM data base • Precipitation : spatial mean precipitation calculated for each catchment with aphrodite data

  11. The main problems : 1. For all the catchment the runoff coefficients C (annual and seasonal time steps) happen to be higher than one All catchments All seasons C >>1 in 2005 Exemple of the Dud Koshi catchment at the annual scale :

  12. 2. This pattern can not be explain by snow or ice melting as it is • observed in all season an mainly in Winter and October-November • it does not exhibit a seasonal cycle Exemple of Dud Koshi winter (=DJF) runoff coefficient • May be it can be explain • by the uncertainty of low flows measurement ? • by the catchment precipitation estimations (Aphrodite)

  13. Inconsistency for Arun river : • Decreasing discharges at Awa Gaon and Simle • No decreasing trend observed for the precipitation Arun – Awa Gaon – 29700 km² Decreasing trend in annual discharge No significant trend for annual precipitation (green curves) Arun – Simle – 33500 km² Break in the annual discharge time serie (near 1996-1997)

  14. 4. Inconsistency in the sub catchments contributions to the total Koshi catchment discharge • We have computed the ratio Qsubcatchment/Qkoshi (annual and seasonal scale) •  The sum of the 5 ratio is greater than one ! Annual contribution of the 5 subcatchments to the Koshi annual discharge (black curve) • This pattern also appears at the seasonal scale • not systematicaly the same year than for annual discharges • the years with runoff coefficient and contribution inconsistencies are not simultaneous !

  15. Comparison of monthly temperature, discharge and precipitation (standardized values)  Show consistent pattern : maximum discharge, temperature and precipitation simultanously happen during summer (Monsoon)

  16. Data bases

  17. HYDRACCESS • DHM hydro & climato • EvK2 climato • Paprika hydro &climato Contact : Pierre Chevallier

  18. Spatial infos • Aphrodite • CRU • TRMM • NCEP • Etc. Contacts: François Delclaux Luc Neppel

  19. ArcGis Projection WGS 84UTM 45N (Nepal) UTM 43N (Pakistan) DEM Snow Cover Hydrology Etc. Contacts: Pierre Chevallier

More Related