Simulation and Analysis of the Water Balance of the Nam Co Lake Using SWAT Model

Abstract

Rapid change of alpine lakes in the Tibetan Plateau (TP) is a clear manifestation of regional-scale climate variability that can be investigated by quantifying the regional hydrological cycle. The degree-day model (DDM) coupled with the Soil and Water Assessment Tool (SWAT) model were used to quantify the water budget of the Nam Co Lake over the period of 2007 to 2013. Driven by local observed meteorological data, the coupled model was successfully validated with the observed lake levels (with R2 = 0.65, NSE = 0.61, and PBIAS = −2.26). Analysis of the water balance revealed that rapid enlargement of the Nam Co Lake was primarily associated with precipitation increase while glacier melt played its role as the potential secondary driver in lake expansion. However, temporal analysis of lake expansion displayed that supremacy of precipitation and glacier melt interchanged between the years. It was found that average annual relative contributions of the precipitation, including direct precipitation on the lake, and glacier melt to the lake were 57% (or 667 mm), and 43% (or 502 mm), respectively. Besides, it was observed that annual values of actual evapotranspiration (ET) from the lake, glaciated, and non-glaciated subbasins were 615 mm, 280 mm, and 234 mm respectively. The average annual glacier mass balance (GMB) of the Nam Co basin was −150.9 millimeter water equivalent (mm w.e.). The relatively high amount of glacier melt was a consequence of the substantial increase in annual temperature in the lake basin. This work is of importance for understanding the rapid water cycle in the TP under global warming. Moreover, this work will also be helpful in monitoring and sustaining the local ecosystem and infrastructure, which is under risk due to rapid lake expansion as a result of climate change in the TP.

Future climatic and hydrologic changes estimated by bias-adjusted regional climate model outputs of the Cordex-Africa project: case of the Tafna basin (North-Western Africa)

“…The outputs from hydrological prediction models can have a direct impact on decisions with regard to water resources management (Zettam et al, 2017). Among these models, the soil and water assessment tool (SWAT) model (Arnold et al, 2012) is one of the most widely used model in the world (Senent-Aparicio et al, 2017;Zettam et al, 2017;Grusson et al, 2017;Brouziyne et al, 2017;Adnan et al, 2019;Bouraoui et al, 2005;Srinivasan et al, 2010;Osei et al, 2019;Blanco-Gómez et al, 2019) to simulate watershed hydrology. The SWAT model has already been applied on the Tafna basin with the 1999 version for water resource management (Hagemann et al, 2004) (an old version without GIS interface), and with the 2012 version for modelling of sediment transport (Meddi and Hubert, 2003).…”

Comparison of Cryosat-2 and Icesat-2 on Water Level Monitoring of Nam Co Lake

“…The study area (Figure 1) is Nam Co Lake (30°30´-30°55´N, 90°16´-91°03´E), the highest and second largest lake located in the southeastern TP, the north of Nyainqentanglha Mountains (Adnan et al, 2019). Nam Co lake is also known as heavenly lake in the Tibetan language and it stretches across two counties, Baingoin and Damxung .…”

“…Generally, altimeters with higher accuracy are used to remove interaltimeter biases because only a few lakes in TP have in situ observations. Nam Co lake is the second largest lake and one of the "three holy lakes" on the TP (Adnan et al, 2019). Nam Co lake is basically not affected by human activities, so it is an ideal place for studying the lake change characteristics and climate conditions.…”

Estimation of Water Balance Components of Watersheds in the Manjira River Basin using SWAT Model and GIS

“…Abdelwahab et al (2018) compared simulation of soil erosion in Mediterranean watershed generated by two most widely used models, SWAT Soil and water assessment tool and Annualised agricultural Non-point source (AnnAGNPS) [10]. Muhammad adnan et al(2019) quantified water budget of Nam Co lake by using SWAT (soil and water assessment tool coupled with DDM (Degree day model) over period of 2007 to 2013 [8]. David rivas-tabares(2019) assessed the water balance of cega-eresma-adaja watershed, they assessed land use in detail, water demand for period 2004-2014 of agricultural land using SWAT [4].…”