Runoff

Surface runoff and updated surface liquid-water content for roof and impervious-road surfaces, following Oleson et al. (2010, CLM Tech Note Ch. 5) Eqs. 5.47-5.48. With no snow layers (has_snow = 0): runoff is the excess of (w_liq_1/Δt + q_liq_0 - q_seva) above the ponding limit w_pond_max/Δt. With snow layers (has_snow = 1): all liquid water reaching the surface becomes runoff and the surface liquid-water content passes through unchanged. Migrated from UrbanCanopy.jl@9200edd4 src/hydrology.jl:991 (`ImperviousRunoff` @component). Parameterized as observed-only: w_liq_1, q_liq_0, q_seva, has_snow are inputs (parameters); q_over_nosnow, q_over, w_liq_1_new are algebraic outputs.

Solid and liquid runoff from snow capping for snow-covered surfaces, following Oleson et al. (2010, CLM Tech Note Ch. 5) Eqs. 5.153-5.154. When the model has reached its prescribed maximum snow water equivalent, additional precipitation and atmospheric deposition cannot accumulate on the snowpack and is shed to the surface as `snow capping runoff` — the solid stream comes from solid precipitation plus frost (Eq. 5.153) and the liquid stream from liquid precipitation plus dew (Eq. 5.154). Migrated from UrbanCanopy.jl@9200edd4 src/hydrology.jl:823 (`SnowCappingRunoff` @component). Parameterized as observed-only: q_grnd_ice, q_grnd_liq, q_frost, q_dew are inputs (parameters); q_snwcp_ice and q_snwcp_liq are algebraic outputs.