154 research outputs found
Effects of Sprinkler, Partial Sprinkler/Drip, and Drip Only Irrigation on Strawberry Transplants 2010-2011
The purpose of the project is to develop an analysis of the current irrigation practices of the strawberry growers on the Central Coast of California. The primary research evaluation is during the establishment of transplants where sprinklers are typically used even though drip irrigation is available. Growers have been selected from Oxnard, Santa Maria, and Watsonville to provide a good cross section of the different strawberry growing areas.
The specific objectives of the project are to: (1) set up a research areas and control plots on a demonstration scale, (2) determine the key factors that affect the problems in early growth of transplanted strawberries, (3) determine relationships between the use of irrigation water and the control of salinity, and (4) provide a multi-year analysis to determine long term salinity impacts on yields.
This project examines the motives, methods, and need for sprinklers on strawberries. The overall goal of the project is to conserve water by minimizing or eliminating sprinkler use on strawberries. The project is designed to study the current practice and determine the conditions where growers can change these practices. By minimizing sprinkler use, water is conserved, money is saved by pumping less water, and runoff is reduced. This project targets drought management as well as target runoff as a potential source on contaminants reaching waterways
Underground Pipe Locating Demonstration at Arvin-Edison Water Storage District
A presentation/demonstration of some of the latest underground pipe locating equipment was conducted on August 13, 2003 at the Arvin-Edison Water Storage District. All the techniques shown were non-destructive pipe locating procedures that provide approximations to the depth and location of underground-buried pipe.
3 types of technology were shown at the demonstration: Acoustic pipe locators Leak detectors Ground penetrating radar
Each form of technology has its own merits and advantages. Acoustic technology is effective in locating single, small diameter pipes with pressurized flow located within about 500-ft of the sound (sonde) units. Leak detection technology is more accurate in locating leaks and pipelines than acoustic technology. Leak detectors can also locate pipes at deeper depths than can acoustic detectors, but require water flowing through the pipe during instrument operation and are also more costly. Ground penetrating radar is highly accurate in locating and approximating the depths of buried objects; this radar technology is also faster and requires less skill to operate and interpret readings than the other types of pipe location. However, the effectiveness is dependent on soil types, depth of pipes, and soil salinity. It is crucial to remember, though, that underground pipe locating technology is only a tool for finding approximate locations and depths of buried pipes, not exact positions. For optimum pipe location, the site conditions must first be evaluated to determine the proper underground pipe locating instrument
Effects of Sprinkler, Partial Sprinkler/Drip, and Drip Only Irrigation on Strawberry Transplants 2011-2012
The Cal Poly Irrigation Training and Research Center (ITRC), in collaboration with academic, water district, and industry partners, proposes to evaluate new strategies for drip irrigation on strawberries to minimize runoff during transplant establishment.
The most common method used for irrigating strawberries is a mix of sprinkler irrigation and drip. Growers use sprinkler irrigation for bed preparation and salinity control, then eventually switch to drip irrigation after transplanting, but continue to use sprinkler irrigation as an insurance policy (for bonding between plant roots and soil bonding, washing off the leaves, controlling salinity, and frost). However, field observations have shown that only a small portion of the water applied by sprinklers actually infiltrates through the plastic mulch to the deeper plant roots.
The purpose of the project is to develop an analysis of the current irrigation practices of the strawberry growers on the Central Coast of California. The primary research evaluation period is during the establishment of transplants where sprinklers are typically used even though drip irrigation is available. Growers have been selected from Oxnard, Santa Maria, and Watsonville to provide a good cross section of the region’s strawberry growing areas. The specific objectives of the project are to: (1) set up research areas and control plots on a demonstration scale, (2) determine the key factors that affect the problems in early growth of transplanted strawberries, (3) determine relationships between the use of irrigation water and the control of salinity, and (4) provide a multi-year analysis to determine long-term salinity impacts on yields. This project examines the motives, methods, and need for sprinklers on strawberries. The overall goal of the project is to conserve water by minimizing or eliminating sprinkler use on strawberries. The project is designed to study the current practice and determine the conditions where growers can change these practices. By minimizing sprinkler use, water is conserved, money is saved by pumping less water, and runoff is reduced. This project targets drought management as well as target runoff as a potential source of contaminants reaching waterways
Implementation and Field Calibration Pipeline Doppler Meters in Northern California
The Tehama-Colusa Canal Authority (TCCA) has been using SonTek Doppler flow meters at approximately 30 installations for about 3 years. TCCA is located in northern California with its headquarters in Willows. The Cal Poly ITRC compared the accuracy of the flow measurement readings from the new Doppler flow meters to the venturi meters that were installed by the US Bureau of Reclamation (USBR). The venturis were used as the historical standard for flow measurement for TCCA. TCCA has opted to move away from the existing technology for a variety of reasons, especially due to the issue concerning access requirements for an enclosed space. TCCA has opted to use the Doppler meter as the replacement. In past studies, ITRC has used the R-Squared statistic to set the minimum number of data points for calibration. This paper evaluates the technique used by USGS to report the calibration of a meter
Strawberries: Effects of Modifying Irrigation Methods for Transplant Establishment 2009-2010
The purpose of the project is to develop an analysis of the current irrigation practices of the strawberry growers on the Central Coast of California. The primary research evaluation is during the establishment of transplants where sprinklers are used even though drip irrigation is available. This project has targeted the impacts of salinity on the young strawberry transplants.
The specific objectives of the project are to: (1) Set up a research areas and control plots on a demonstration scale, (2) determine the key factors that affect the problems in early growth of transplanted strawberries, (3) determine relationships between the use of irrigation water and the control of salinity, and (4) provide a multi-year analysis to determine long term salinity impacts on yields.
This project examines the motives, methods, and need for sprinklers on strawberries. The overall goal of the project is to conserve water by minimizing or eliminating sprinkler use on strawberries. The project is designed to study the current practice and determine the conditions where growers can change these practices. By minimizing sprinkler use, water is conserved, money is saved by pumping less water, and runoff is reduced. This project targets drought management as well as target runoff as a potential source on contaminants reaching waterways
Broad-Crested Weir Application on 15,000-Acre Farm
Growers in California have been subjected to increasing pressure to account for water used on the farm due to limited water supplies and increasing energy costs. Water measurement capability provides for equitable distribution of assigned costs and enables effective water management to be accomplished. Broad-crested weirs are proven water measurement devices, especially when applied to on-farm applications. The broad-crested weirs and published data were developed by the USDA Agricultural Research Service in Phoenix, Arizona. This paper is a discussion of an application of these weirs
Structural and stochastical modelling of possible contaminant pathways below nuclear installations
Structural and stochastical modelling of possible contaminant pathways below nuclear installations
1Richard Haslam, 1Stuart Clarke, 1Peter Styles & 2Clive Auton
1Earth Sciences and Geography, School of Physical and Geographical Sciences, Keele University, Keele, Staffordshire, ST5 5BG, United Kingdom
2British Geological Survey, Murchison House, West Mains Road, Edinburgh, EH9 3LA, United Kingdom
Dounreay Nuclear Power station is situated on the northern coast of Caithness, Scotland on complex normally faulted Devonian sedimentary rocks with a thin, intermittent cover of superficial deposits, predominantly comprising glacial tills of varying provenance.
Bedrock structure, fracture patterns and the relationships between bedrock and the superficial deposits have a considerable impact on the transmissivity of any possible contaminants. Consequently, an understanding of the bedrock-superficial boundary and how fractures and faults influence and control the transport of fluids are a key concern. The principal aims of this work are to gain an understanding of the processes and controls on fluid flow pathways within such complex geological terrains, and develop methods of stochastatically evaluating likely contamination transport within the subsurface.
This work focuses on the near-surface bedrock geology and superficial deposits. The near surface geology of the Dounreay site comprises cyclic sequences of lacustrine rocks; their cyclicity has enabled a reference stratigraphy to be created and correlated across the site. This stratigraphy, the coastal exposures and the extensive amount of borehole data available, provide a unique opportunity to construct and constrain a three-dimensional bedrock model; the interpretive element of which has been robustly test using structural restoration techniques.
In the bedrock of Dounreay, three principal fracture sets have been identified. The first two sets of fractures are approximately orthogonal, trending north-northwest and west-southwest respectively; they represent the regional fracture set. It is proposed that these fractures where produced during loading and burial of the Devonian sediments. The final fracture set is predominantly parallel to bedding of the laminated sediments; it gives the Caithness Flagstones their ‘flaggy’ nature.
The regional fracture sets are approximately constant over the site area and vary little with depth, whereas the bedding parallel fracture set shows a marked decrease in the number of fractures per meter with depth, on a logarithmic trend. This relationship is also visible in the Rock Quality Designation (RQD) values and hydraulic conductivity data from boreholes. It follows that the bedding parallel fractures are the major controlling factor of flow in the shallow subsurface and that the RQD values can be used as a proxy for fracture density. RQD values are a commonly collected during borehole drilling and the relationship between hydraulic conductivity and RQD values offer a method for stochastically populating a 3D geological model with hydraulic conductivity values.
Current geological interpretations of the superficial deposits are based primarily on their genesis. Consequently, subdivisions based on the origin of the sediments do not relate directly to their fluid transmissivity. The superficial deposits generally have a very low hydraulic conductivity, compared to that of the bedrock, impeding the flow of water from the surface to the groundwater system at depth. A combination of driller’s description and comparisons of grain-size distribution enables subdivisions of the Quaternary strata to be established based on their properties instead of their genesis. These properties can then be stochastically interpolated throughout the 3D geological model.
This work provides a framework from which likely contamination scenarios can be modelled, both in the well-constrained subsurface of Dounreay, and at other nuclear installations where the nature of the subsurface is less well constrained
ITRC Weir Stick
The Irrigation Training and Research Center, working under a technical service agreement with the United States Bureau of Reclamation (USBR) Mid-Pacific Region, has developed a new weir rule for open-channel flow rate measurement
Telog PR-31 Water Level Tracker
The Irrigation Training and Research Center, working under a technical service agreement with the United States Bureau of Reclamation (USBR) Mid-Pacific Region, has undertaken a performance review of advanced electronic water level measurement technologies in irrigation applications. An example is the Telog PR-31 Level Tracker
Field Evaluation of Non-Contact Flow Measurement Devices - GCID
The Irrigation Training and Research Center (ITRC) has analyzed the data from several non-contact volumetric flow meter models under various conditions. This testing was done with support from technical services contracts with the California Department of Water Resources (DWR) and the United States Bureau of Reclamation (USBR)
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