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Full-Text Articles in Engineering
Reconstructing The Natural Hydrology Of The San Francisco Bay - Delta Watershed, P. Fox, P.H. Hutton, D.J. Howes, A.J. Draper, L. Sears
Reconstructing The Natural Hydrology Of The San Francisco Bay - Delta Watershed, P. Fox, P.H. Hutton, D.J. Howes, A.J. Draper, L. Sears
BioResource and Agricultural Engineering
We evaluated the impact of landscape changes on the amount of delta outflow reaching San Francisco Bay. The natural landscape was reconstructed and water balances were used to estimate the long-term annual average delta outflow that would have occurred under natural landscape conditions if the climate from 1922 to 2009 were to repeat itself. These outflows are referred to as natural delta outflows and are the first published estimate of natural delta outflow. These natural delta outflows were then compared with current delta outflows for the same climate and existing landscape, including its re-engineered system of reservoirs, canals, aqueducts, and …
Rating Rectangular Farm Delivery Meter Gates For Flow Measurement, Daniel J. Howes, Charles M. Burt
Rating Rectangular Farm Delivery Meter Gates For Flow Measurement, Daniel J. Howes, Charles M. Burt
BioResource and Agricultural Engineering
Traditional meter gates for farm delivery flow measurement from an open channel conveyance have traditionally incorporated round canal gates (Armco type) for control. In recent years, some irrigation water agencies (i.e., irrigation districts) have replaced deteriorating round gates with lower-cost rectangular gates that cover round holes. Similar to the situation described in a companion paper, where round gates were examined, there have been no investigations into flow measurement uncertainty using the existing rating tables for these gates. In this study, two commonly used rectangular gate sizes, 0.46 m (18-in.) and 0.61 m (24-in.), were tested under scenarios of various gate …
Accuracy Of Round Meter Gates For On-Farm Deliveries, Daniel J. Howes, Charles M. Burt
Accuracy Of Round Meter Gates For On-Farm Deliveries, Daniel J. Howes, Charles M. Burt
BioResource and Agricultural Engineering
Recent California legislation requires irrigation water agencies larger than 25,000 acres to measure volumetric water deliveries within specified levels of relative uncertainty. Although the meter gate is one of the most widely used flow measurement devices in California, little investigation has been conducted into the accuracy, limitations, and uncertainties of the rating tables developed over 60 years ago. A meter gate testing facility was constructed at the Cal Poly Irrigation Training and Research Center’s Water Resources Facility capable of testing gates up to 0.76 m (30 in.). The facility was constructed with gates oriented perpendicular to the supply channel flow …
Improving Flow Measurement Accuracy At Farm Delivery Gates In California, Charles M. Burt, Daniel J. Howes
Improving Flow Measurement Accuracy At Farm Delivery Gates In California, Charles M. Burt, Daniel J. Howes
BioResource and Agricultural Engineering
ITRC, through a CSU ARI grant, constructed a meter gate testing facility and tested five gates of various sizes and designs. The gate testing was conducted by varying the multiple parameters including upstream and downstream head, supply channel velocity, gate opening, and head above the gate. Data was also collected at various locations on the downstream side of the gate. In total, ITRC staff collected over 10,000 points of data during this evaluation. Using the new rating tables for the three gates examined, the relative uncertainty is less than ±5 to ±7% at the 95% confidence level with the new …
Drip Hydraulics Program, Garret Blocher
Drip Hydraulics Program, Garret Blocher
BioResource and Agricultural Engineering
This senior project report lays out the production of drip hydraulics software composed in Microsoft Excel and backed by coding in Visual Basic for Applications. The program performs 2 main functions useful in the design of irrigation systems. The first is based on performing single hose computations under three different circumstances. It can solve for the average emitter flow rate given the hose inlet pressure, the inlet pressure given the average emitter flow rate, and can model hose pressures and flow rates while flushing. The second function is to place a manifold in the hydraulically optimum location on a slope. …
Installation, Evaluation, And Modification Of Adcon Telemetry Systems, Caitlin Held
Installation, Evaluation, And Modification Of Adcon Telemetry Systems, Caitlin Held
BioResource and Agricultural Engineering
No abstract provided.
Evapotranspiration From Natural Vegetation In The Central Valley Of California: Monthly Grass Reference-Based Vegetation Coefficients And The Dual Crop Coefficient Approach, Daniel J. Howes, Phyllis Fox, Paul H. Hutton
Evapotranspiration From Natural Vegetation In The Central Valley Of California: Monthly Grass Reference-Based Vegetation Coefficients And The Dual Crop Coefficient Approach, Daniel J. Howes, Phyllis Fox, Paul H. Hutton
BioResource and Agricultural Engineering
Restoration activities in the Central Valley of California and elsewhere require accurate evapotranspiration information, which can then be used for a wide variety of surface and subsurface hydrologic evaluations. However, directly measuring evapotranspiration can be difficult or impossible depending on the evaluation’s time frame. Transferability of measured evapotranspiration in time and space is also necessary but typically requires a weather-based reference. For nonagricultural vegetation, there is at present time no standard reference, which makes the evaluation of a variety of vegetation types from different sources difficult and time-consuming. This paper examines several methods used to estimate evapotranspiration from native vegetation, …
Practical Guide For Metergates, Charles M. Burt, Daniel J. Howes
Practical Guide For Metergates, Charles M. Burt, Daniel J. Howes
BioResource and Agricultural Engineering
This document contains brief instructions on the use of special round canal gates called “metergates” for flow measurement.