## 2.14.5. Difference between CLM5.0 and CLM4.5[¶](#difference-between-clm5-0-and-clm4-5 "Permalink to this headline")
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1.  Routing methods: RTM, a linear reservoir method, is used in CLM4.5 for river routing, whilst in CLM5.0, MOSART is an added option for river routing based on the more physically-based kinematic wave method.
    
2.  Runoff treatment: In RTM runoff is routed regardless of its sign so negative streamflow can be simulated at times. MOSART routes only non-negative runoff and always produces positive streamflow, which is important for future extensions to model riverine heat and biogeochemical fluxes.
    
3.  Input parameters: RTM in CLM4.5 only requires one layer of a spatially varying variable of channel velocity, whilst MOSART in CLM5.0 requires 13 parameters that are all available globally at 0.5 ° resolution.
    
4.  Outputs: RTM only produces streamflow simulation, whilst MOSART additionally simulates the time-varying channel velocities, channel water depth, and channel surface water variations.