sum_of_clm_tech_note/CLM50_Tech_Note_MOSART/2.14.2.-Routing-Processesrouting-processes-Permalink-to-this-headline.sum.md
2024-06-12 10:48:59 +08:00

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Summary of "Routing Processes" in the MOSART model:

Routing Processes in MOSART

  • MOSART divides each spatial unit (e.g., grid cell, watershed) into three categories of hydrologic units: hillslopes, tributaries, and the main channel.
  • MOSART represents three routing processes:
    1. Hillslope routing: Surface runoff is routed as overland flow into the sub-network channel, while subsurface runoff directly enters the sub-network channel.
    2. Sub-network channel routing: The sub-network channel receives water from the hillslopes, routes it through the channel, and discharges it into the main channel.
    3. Main channel routing: The main channel receives water from the sub-network channel and/or inflow from upstream spatial units, and discharges the water to the downstream spatial unit or the ocean.

Routing Equations

  • MOSART uses Manning's equation to estimate the travel velocities across hillslopes, sub-network, and main channels.
  • For hillslopes and sub-network channels, the hydraulic radius is approximated by the water depth.
  • For the main channel, the hydraulic radius is calculated as the ratio of the wetted area to the wetted perimeter.
  • A common continuity equation is used to describe the change in storage (dS/dt) for each routing process, with the inflow (Qin), outflow (Qout), and source/sink terms (R).

Key Assumptions

  • MOSART only routes positive runoff, while negative runoff is mapped directly to the coupler.
  • MOSART does not exchange water with the atmosphere or return water to the land model, but strictly transports water from runoff generation to the basin outlets.