Laboratory and numerical experiments were conducted to investigate the evolution of soil water evaporation during a continuous drying event. Simulated soil water contents and temperatures by the calibrated model well reproduced measured values at different depths. Results show that the evaporative drying process could be divided into three stages, beginning with a relatively high evaporation ra...

Increasing crop yield and water use efficiency (WUE) in dryland farming requires a quantitative understanding of relationships between crop yield and the water balance over many years. Here, we report on a long-term dryland monitoring site at the Loess Plateau, Shanxi, China, where winter wheat was grown for 30 consecutive years and soil water content (0-200 cm) was measured every 10 days. The ...

A simple soil–vegetation–atmosphere transfer (SVAT) model designed for scaling applications and remote sensing utilization will be presented. The study is part of the Semi-Arid Land Surface Atmosphere (SALSA) program. The model is built with a single-bucket and single-source representation with a bulk surface of mixed vegetation and soil cover and a single soil reservoir. Classical atmospheric ...

687 Edgar Buckingham became involved with soil physics for 5 yr at the turn of the twentieth century. His general goal was to advance understanding of moisture movement and evaporation from soils to improve irrigation and crop management. Specifi cally, he was interested in elucidating why evaporation from near the soil surface in arid areas during summer months was self-limiting (Buckingham, 1...

By employing chemical and isotopic tracers ((15)N and (18)O in NO(3)(-)), we investigated the main processes controlling nitrate distribution in the unsaturated zone and aquifer. Soil water was extracted from two soil cores drilled in a typical agricultural cropping area of the North China Plain (NCP), where groundwater was also sampled. The results indicate that evaporation and denitrification...

The weather patterns of the west side of the Sierra Nevada Mountains (cold, wet winters and hot, dry summers) strongly influence how water is partitioned between transpiration and evaporation and result in a specific strategy of water use by ponderosa pine trees (Pinus ponderosa) in this region. To investigate how year-round water fluxes were partitioned in a young ponderosa pine ecosystem in t...

Efficient irrigation management requires a good quantification of evapotranspiration. In the case of olive orchards, which are the dominant crop in vast areas of southern Europe, very little information exists on evaporation. Measurements of aerodynamic conductance and evaporation above and below an olive orchard allowed the calibration of a transpiration model of olive trees based on the Penma...

Monthly composites of the Normalized Difference Vegetation Indices (NDVI), derived from the National Oceanic and Atmospheric Administration's (NOAA) Advanced Very High Resolution Radiometer (AVILRR), were transformed linearly into monthly evaporation rates and compared with detailed hydrologic-model simulation results for five watersheds across the United States. Model-simulated monthly evapora...

[1] The soil water content plays a fundamental role in a number of important environmental processes, including those involved in the water cycle, vegetation dynamics, soil biogeochemical cycles, and land-atmosphere interactions. Despite the recent efforts spent in the analytical modeling of the stochastic soil moisture dynamics in dryland ecosystems, the probabilistic characterization of the s...