Variations in Hydrological Variables using Distributed Hydrological Model in Permafrost Environment
Penulis/Author
Naveed Ahmed (1); Genxu Wang (2); Martijn J. Booij (3); Dr. Ir. Hero Marhaento, S.Hut., M.Si., IPM (4); Foyez Ahmed Prodhan (5); Shahid Ali (6); Sarfraz Munir (7); Muhammad Zia-ur-Rehman Hashmi (8)
Tanggal/Date
2022
Kata Kunci/Keyword
Abstrak/Abstract
The Yangtze River Source Region (YaRSR) is located in the third polar region, the most threatened zone by global
warming after the Arctic. Permafrost covers eighty percent of the total area of YaRSR, while the rest is seasonally
frozen ground. Due to a significant rise in air temperature, degradation of the permafrost could occur. Permafrost
coverage in a river basin greatly controls its hydrology. This study focuses on hydrological modeling in this
permafrost environment using the Soil and Water Assessment Tool (SWAT). The SWAT model was calibrated
(1985–2000) and validated (2001–2015) on a daily time step. The results were also compared on a monthly time
scale. An impermeable layer was introduced within the SWAT model to represent the permafrost conditions. The
streamflow is strongly dependent on the seasonal variation of precipitation and temperature, and the rising limb
of the hydrograph shows the melting of snow, the contribution of soil water, and thawing of permafrost during
the spring-summer season. The permafrost layer well restricted the deep percolation of water. During the spring
season, streamflow mainly consists of surface runoff because of the frozen soils. Permafrost and frozen ground
thawing lead to an increase in the contribution of groundwater flow to streamflow. Ultimately, the frozen ground
depletes as the temperature gets close to the freezing point. This study also describes the SWAT model application to better analyze and understand the hydrology of the permafrost/frozen ground with limited data
availability
