The relationship between field soil water content variability and soil moisture deficit prediction from meteorological data

摘要

The Hybrid Soil Moisture Deficit (SMD) model (Schulte et al., 2005) was designed to predict soil moisture conditions as a function of water balance for agro-climatic regions in Ireland. It is assumed to work between the field scale (1,000 m~2) and theregional scale (100 km~2) and is being developed to predict runoff at the field scale. However soil physical properties that affect the water balance vary significantly at field scale. This study provides preliminary evidence of how a point estimation of SMD can be used as a predictor of a field water balance. Point SMD predictions calculated from meteorological data measured on farm were compared with continuous time series point volumetric water content (theta_p) and periodic observations of variation in field volumetric water content (theta_f) both measured by time domain reflectometery. The theta_p and theta_f trends were relatively similar.