Climate and Soil Databases and Sub-Models
WEPS: Weather Sub-model and Databases
WEPS requires wind speed and direction to simulate the process of soil erosion by wind. These and other weather variables such as precipitation, air temperature, and solar radiation are also needed to drive temporal changes in hydrology, soil erodibility, crop growth, and residue decomposition in WEPS.
For more detail on the science behind this sub-model: WEPS technical Documentation.
WEPS: Soil Sub-model and Databases
The soil properties that control soil wind erodibility vary with time during a crop rotation or annually. The objective of the SOIL sub-model is to simulate these temporal soil properties on a daily basis in response to various driving processes. On days when wind erosion or management activities occur, the EROSION and MANAGEMENT sub-models may also update some of the same temporal variables. The driving processes that change soil temporal properties are mostly weather related and the sequence of occurrence of individual driving processes is highly variable. The SOIL sub-model must be able to update the soil variables, given an arbitrary driving process and the soil conditions for the prior day.
The soil data that is accessed and used by WEPS is from current NRCS SSURGO soil survey data.
For more detail on the science behind this sub-model: WEPS technical Documentation.