The effects of urbanization on soil structure can be extensive. Infiltration of rain water through soils can be greatly reduced, plus the benefits of infiltration and biofiltration devices can be severely jeopardized. Our research group (along with others), have been studying disturbed urban soils for several decades, both in the laboratory and in the field. The effects of compaction on infiltr...

Understanding how spring runoff is generated in East Siberia during the spring thaw is important to predicting river flows. To evaluate the snowmelt runoff generated, a simple runoff model was developed. The model involves processes of water and energy balance within the snowpack and energy balance within soil, snowmelt infiltration into the frozen ground, and surface runoff. The model reproduc...

Atrazine transport through packed 10 cm soil columns representative of the 0-10 cm soil horizon was observed by measuring the atrazine recovery in the total leachate volume, and upper and lower soil layers following infiltration of 7.5 cm water using a mechanical vacuum extractor (MVE). Measured recoveries were analyzed to understand the influence of infiltration rate and delay time on atrazine...

Predicting infiltration rates is among the most important aspects in planning, designing, and managing groundwater recharge systems, flood water retention basins and other infiltration systems. Knowledge of soil infiltration rates determines the capacity of the soil to receive water and ultimately how much land surface will be required to meet the infiltration demand of the engineered system. T...

Computer models help identify agricultural areas where P transport potential is high, but commonly used models do not simulate surface application of manures and P transport from manures to runoff. As part of an effort to model such P transport, we conducted manure slurry separation and soil infiltration experiments to determine how much slurry P infiltrates into soil after application but befo...

This paper describes the scientific principles of Darcy’s law and hydraulic resistance as they relate to the in-ground dispersal of onsite wastewater effluent. A clear understanding of how water moves into the ground via dispersal trenches is needed to facilitate proper system design and effect some standardization of dispersal trench sizing and design. Hydraulic conductivity of the media, hydr...

Phytophthora root rot of avocado, a soilborne disease caused by Phytophthora cinnamomi Rands, continues to be devastating to the cultivation of avocados despite more than 70 years of research on control methods. Phytophthora root rot has been estimated to be present in two-thirds of the avocado groves in California, causing losses of almost 30% of the total value of the crop (5). P. cinnamomi m...

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 ...