The user can choose whether all the branches within a demand site will have the same monthly variation in demand, or whether each branch can have a different monthly variation.
Separately, the user can choose whether all land use branches within a catchment will have the same climate data (Soil Moisture Method Climate, FAO Climate or MABIA Climate), or whether each branch can have different climate data. This second option might be necessary if there is a large variation in the elevation among different land uses within a catchment. Alternatively, the catchment could be divided into several different catchment nodes according to elevation, so that the climate within each catchment did not vary by land use.
Before December 2010, WEAP incorrectly used the Latent Heat of Vaporization (2260 kJ/kg, at 100 C) instead of the Latent Heat of Fusion (334 kJ/kg) for calculating snow melt in the soil moisture method. Although we recommend that you use Latent Heat of Fusion, if you have a previously calibrated model that used Latent Heat of Vaporization, you might want to use that setting instead.
If you have linked your WEAP model to a MODFLOW model, you can choose whether all land use branches within a catchment will pump from the same MODFLOW layer or set of layers (see the Pump Layer variable under Soil Moisture Method Irrigation or FAO Irrigation), or whether each land use branch can pump from a different layer or set of layers.
Menu Option: General: Basic Parameters