DQM method has been used in open channel flows in many topics, i.e. sediment transport and modeling of water surface profile. Below three papers about these topics:
Kaya, B., Ulke, A., & Kazezyılmaz-Alhan, C. M. (2011). Differential quadrature method in open channel flows: Aksu River, Turkey. Journal of Hydrologic Engineering, 17(6), 715-723.
Kaya, B., & Tayfur, G. (2013, July). Differential Quadrature Method for Solving Bed Load Sediment Transport. International Balkans Conference on Challenges of Civil Engineering.
Robati, A., & Barani, G. A. (2009). Modeling of water surface profile in subterranean channel by differential quadrature method (DQM). Applied Mathematical Modelling, 33(3), 1295-1305.