diff --git a/docs/core/equations.qmd b/docs/core/equations.qmd index 92d5d258f..2546c454e 100644 --- a/docs/core/equations.qmd +++ b/docs/core/equations.qmd @@ -149,12 +149,14 @@ plt.show() The precipitation term is given by $$ - Q_P = P \cdot A(u). + Q_P = P \cdot A. $$ {#eq-precip} -Here $P = P(t)$ is the precipitation rate and $A$ is the wetted area. $A$ is a -function of the storage $u = u(t)$: as the volume of water changes, the area of the free water -surface may change as well, depending on the slopes of the surface waters. +Here $P = P(t)$ is the precipitation rate and $A$ is the maximum area given in the `Basin / profile` table. +Precipitation in the Basin area is assumed to be directly added to the Basin storage. +The modeler needs to ensure all precipitation enters the model, and there is no overlap in the maximum profile areas, else extra water is created. +If a part of the catchment is not in any Basin profile, the modeler has to verify that water source is not forgotten. +It can for instance be converted to a flow rate and added to a Basin as a FlowBoundary. ## Evaporation @@ -192,7 +194,7 @@ MODFLOW 6 boundary conditions in the basin: $$ Q_\text{inf} = \sum_{i=1}^{n} \sum_{j=1}^{m} \max(Q_{\mathrm{mf6}_{i,j}}, 0.0) -$$ {#eq-inf}. +$$ {#eq-inf} Where $i$ is the index of the boundary condition, $j$ the MODFLOW 6 cell index, $n$ the number of boundary conditions, and $m$ the number of MODFLOW 6 cells in