# Burial

Pesticide in the sediment layer may be lost by burial. The amount of pesticide that is removed from the sediment via burial is:

           $$pst\_{bur}=\frac{v\_b}{D\_{sed}}\*pst\_{rchsed}$$                                                             7:4.2.13

where $$pst\_{bur}$$ is the amount of pesticide removed via burial (mg pst), $$v\_b$$ is the burial velocity (m/day), $$D\_{sed}$$ is the depth of the active sediment layer (m), and $$pst\_{rchsed}$$ is the amount of pesticide in the sediment (mg pst).

Table 7:4-2: SWAT+ input variables related to pesticide in the sediment.

| Variable Name | Definition                                                                                    | Input File |
| ------------- | --------------------------------------------------------------------------------------------- | ---------- |
| CHPST\_KOC    | $$K\_d$$: Pesticide partition coefficient (m$$^3$$/g)                                         | .swq       |
| SEDPST\_REA   | $$k\_{p,sed}$$: Rate constant for degradation or removal of pesticide in the sediment (1/day) | .swq       |
| CHPST\_RSP    | $$v\_r$$: Resuspension velocity (m/day)                                                       | .swq       |
| SEDPST\_ACT   | $$D\_{sed}$$: Depth of the active sediment layer (m)                                          | .swq       |
| CHPST\_MIX    | $$v\_d$$: Rate of diffusion or mixing velocity (m/day)                                        | .swq       |
| SEDPST\_BRY   | $$v\_b$$: Pesticide burial velocity (m/day)                                                   | .swq       |