TITLE:
Calibration and Validation of the SWAT Model on the Watershed of Bafing River, Main Upstream Tributary of Senegal River: Checking for the Influence of the Period of Study
AUTHORS:
Moussé Landing Sane, Soussou Sambou, Issa Leye, Didier Maria Ndione, Samo Diatta, Ibrahima Ndiaye, Mamadou Lamine Badji, Seïdou Kane
KEYWORDS:
SWAT, Hydrological Modelling, Senegal River, Bafing Makana
JOURNAL NAME:
Open Journal of Modern Hydrology,
Vol.10 No.4,
October
28,
2020
ABSTRACT: Management of reservoir water resources requires the
knowledge of flow inputs in this reservoir. Hydrological rainfall-runoff model
is used for this purpose. There are several types of hydrological model
according the description of the hydrological processes: black-box models,
conceptual models, deterministic physical based model. SWAT is a semi-distributed
hydrological model designed for water quality and quantity. This versatile tool
has been used all around the world to assess and manage water resources. The
main objective of the paper is to calibrate and validate the SWAT model on the
watershed of Bafing located between 10°30' and 12°30'
north latitude and between 12°30' and 9°30' west longitude to assess climate change
on this river flows. A DEM with a resolution of 12.5 m × 12.5 m, the
daily average flows and the daily observed precipitations on the period
1979-1986 (long period) are used as inputs for the calibration, while
precipitations for the period 1988-1994 are used for the validation. The
sensitivity analysis was done to detect the most determining coefficients
during the calibration step. It shows that 19 parameters are required. Then,
the effect of the period on the parameters calibration is checked by considering first the whole period of study and then each year of the period of
study. The Nash criterion was used to compare the calculated and the observed
hygrographs in each case. The results showed that the longer is the period of
calibration, the more accurate is the Nash criterion. The calibration per year
gave a best Nash criterion except for a single year. During the validation, the
parameters calculated on the long period lead to the best Nash criterion. The
values of the Nash criterion calibration and
validation are very suitable. These results of calibration can be used to
study the long-term evolution of flow at Senegal River on Bafing Makana.