Spatial patterns of evaporation in a small catchment

Abstract

In this study a network of three eddy covariance stations rotated between five measurement sites is used to measure evaporation (E) within the Hydrological Open Air Laboratory (HOAL) in Petzenkirchen, Austria for 8 years. Discharge measurements at the tributaries and outlet of the main catchment allow for E to be estimated for 6 subcatchments using the water balance method. Year to year variability in monthly E measured by the eddy covariance stations is found to be driven primarily by net radiation and temperature and annual E by net radiation. Year to year variability in the water balance-based E estimate was driven by precipitation. The two methods are found to be consistent, when storage and leakage are accounted for. Daily and seasonal patterns can be seen resulting from the agricultural land use cycle, due to the variations in land cover during the growing season.

Keywords

• evapotranspiration
• water balance
• agricultural catchment
• experimental catchment