7.14 - What is the Difference Between an Elevation and Orographic Adjustment?
An elevation adjustment can be applied with the Modified or Original Blaney-Criddle method to estimate potential consumptive use for any crop type (see Section 126.96.36.199). The elevation adjustment corrects for lower mean temperatures that occur at higher elevations. An elevation adjustment is automatically applied with the Pochop method for bluegrass (see Section 188.8.131.52). With StateCU, the elevation adjustment is applied to the potential consumptive use of a particular crop type. The elevation adjustment can be selected through the GUI under the View/Edit Crop Coefficients window (see Section 184.108.40.206).
An orographic adjustment can be applied with monthly or daily method to estimate potential consumptive use for any crop type (see Section 3.1.7). This adjustment is only available under a Structure Scenario. The orographic adjustment corrects for climate station data (temperature and precipitation) that is at a different location than the irrigated lands. With StateCU, the orographic adjustment is applied to a particular CU location (e.g. structure). The orographic adjustment can be specified through the GUI under the Climate Station Assignments window (see Section 220.127.116.11).