Glacier hydrological process modeling based on improved SWAT+: A case
study in the Upper Yarkant River Basin
Abstract
Glaciers have proven to be a particularly sensitive indicator of climate
change, and the impact of glacier melting on downstream water supplies
is becoming increasingly important as the world’s population expands and
global warming continues. Data scarcity in mountainous catchments, on
the other hand, has been a substantial impediment to hydrological
process simulation. Therefore, an integrated glacier hydrological
process module was introduced for the Soil and Water Assessment Tool
Plus model (SWAT+), in which an enhanced temperature-index glacier melt
algorithm considering solar radiation was employed to maintain model
clarity and favorable performance in this study. Furthermore, SWATplusR
was introduced for sensitivity analysis using the Sobol approach, and
Integrated Parameter Estimation and Uncertainty Analysis Tool Plus
(IPEAT+) was coupled with this enhanced model (SWAT+Glacier) to perform
calibration and validation in the Upper Yarkant River (UYR) basin. The
result indicated that (i) including glacial-hydrological processes
considerably improved simulation precision, with an NSE promotion of 2.6
times and R 2 of 1.7 times greater than the original
model; (ii) it is an efficient and feasible way to simulate
glacial-hydrological processes with SWAT+Glacier and calibrate it using
observed discharge data in data-scarce and glacier melt dominated
catchments; and (iii) we discovered that glacier runoff is intensively
distributed throughout the summer season, accounts for about 78.5% of
the annual glacier runoff, and glacier meltwater provides approximately
52.5% (4.4×10 9m 3) of total runoff
in the study area.