Modeling Typhoon‐Induced Alterations on River Sediment Transport and Turbidity Based on Dynamic Landslide Inventories: Gaoping River Basin, Taiwan

Abstract

This study examines the impacts of storm-triggered landslides on downstream sediment and turbidity responses in the Gaoping River Basin, Taiwan using the Soil and Water Assessment Tool (SWAT). Attention is given to analyzing the increased and altered baseline of suspended sediment load and turbidity after the disturbances caused by the rainfall and landslides associated with Typhoon Morakot in 2009. SWAT parameters were calibrated by the observed hydrometric data from 1999 to 2003 using the log-scale root-mean-square error (log-RMSE) and Nash-Sutcliffe Model Efficiency. Both parameter sets were applied for the simulation of suspended sediment yield and turbidity with annual updated landslide inventories for the period 2004-2012. The landslide updating mirrors the physical land-cover changes and has slightly improved the model performance, yet landslides alone cannot explain the difference between Morakot-induced and SWAT-simulated sediment discharge. The set of parameters calibrated by log-RMSE can better approximate the increased baseline and typhoon induced alterations. The results show alterations in sediment erosion and transport: (1) drastically increased the turbidity baseline and occurrence of high-turbidity; (2) altered coefficient and exponent values of the sediment rating curve; and (3) altered relationship between rainfall and induced turbidity during major rainfall events. The research in this study provides an improved modeling approach to typhoon-induced alterations on river sediment loads and turbidity.

Soil Erosion Modelling and Risk Assessment in Data Scarce Rift Valley Lake Regions, Ethiopia

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Assessment of Sediment Transport Functions with the Modified SWAT-Twn Model for a Taiwanese Small Mountainous Watershed

“…Many studies have conducted the survey of landslide characteristic changed after the 921 earthquake [26,27,[54][55][56][57]. Due to the lack of landslide calculation in the SWAT model, we integrated the landslide estimation equation developed by [28] into the SWAT model. The landslide volume was calculated by using the correlation between the landslide area and volume (R 2 = 0.79) (Equation (19)).…”

Chamoli Disaster: Pronounced Changes in Water Quality and Flood Plains Using Sentinel Data

“…The water quality parameters: Chl-a and total suspended matter (TSM), coloured dissolved organic matter (CDOM), turbidity, and water clarity are important parameters to study climatic variables for lakes, coastal water, ponds, and river waters (Prasad and Singh 2010;Chang, Harrison, and Huang 2015;Garg, Aggarwal, and Chauhan 2020;Menon et al 2011;Song et al 2012). These parameters are also important to monitor the quality of water bodies and sources of water pollutants.…”