The prediction of the time to ponding following commencement of rainfall is fundamental to hydrologic prediction of flood, erosion, and infiltration. Most of the studies to date have focused on prediction of ponding resulting from simple rainfall patterns. This approach was suitable to rainfall reported as average values over intervals...
A study was conducted to compare snow accumulation and melt during rainfall in adjacent forest and clearcut plots in the
transient snow zone of the western Cascade Range in Oregon. Snow accumulation differences were determined by comparing the water equivalents of forest and clearcut snowpacks. During rain-on-snow periods, energy balances...
One-minute rainrates were measured during two winter rainy
seasons in western Oregon to gain insights into the time-structure of
Oregon rainstorms. The averages of three non-dimensional relative
variance statistics were greater on the coast than inland. Rainrate
distributions showed that a greater portion of the total rain fell, at
higher...
The WSR-57 weather radar operated by the National
Weather Service at Sacramento, California, plus a network
of precipitation gages provided data for this comparison
of radar reflectivity with precipitation rates. Located
in a valley with mountains within range of the radar on
three sides, this radar has varying sensitivity for...
This study examines in detail a continuous drop-size distribution
recorder and selected data gathered with this recorder at
various locations on 6, 15, and 31 May 1966. The drop-size distribution
recorder consists of a self-contained, mobile unit able to
operate without electric power. This recorder utilizes "Ozalid 105
SZ" filter...
A large rainfall simulator was used to study infiltration on six
soil plots. Water content and capillary pressure were measured during
steady rainfall at rates less than required to produce runoff. The
equipment and procedures used to make these measurements are discussed.
Water content and capillary pressure data obtained as...
Climate changes. That’s what climate does. It is a natural and dynamic process. The National Weather Service (NWS) recognizes on-going climate change by publishing new figures for average climate every ten years. Climate averages for precipitation, temperature, and other weather parameters are computed on a 30 year basis but only...
Interception of precipitation by forest canopies has been found previously to reduce rainfall intensity, but this effect is poorly understood. The goal of this research is to quantify the attenuation of rainfall intensity by forest canopy interception, with the specific objective of estimating the contribution of this attenuation to hillslope...
We propose a novel, accurate quantification of precipitation and evaporation, as needed to understand fundamental hydrologic processes. Our system uses a collection vessel placed on top of a slender rod that is securely fixed at its base. As the vessel is deflected, either by manual perturbation or ambient forcing (for...