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Mathematical programming models of agricultural production in the Colorado River Upper Basin were integrated with a hydrology model of the Colorado River to assess the impacts of transferring water from irrigation uses in the Upper Basin to urban users in the Lower Basin. One strategy involved a long-term lease of irrigation water on an annual basis. The other assessed a lease-option strategy by the Lower Basin to take Upper Basin water only when needed. The economic impacts measured were changes in regional income, agriculturally generated income, crop production, land use, and input expenditures. Environmental impacts considered were changes in river salinity levels and increased hydropower production resulting...
Improving seasonal to annual predictions of climate variability and water available at the catchment
Improving seasonal to annual predictions of climate variability and water available at the catchment, credited to Switanek, Matthew B, published in 2008.
The demand for water is increasing in the western United States. Coupled with growing emphasis on development of the western resources, the limited supply of water will create an expanding competitive market for water by agricultural, energy, industrial, and municipal users. The Upper Colorado River Basin is faced with a question of what water-conservation measures in the agricultural and energy sectors can be instigated without reducing agricultural output. If the decision is made to adopt water-conservation-technology measures, this study addresses the impacts in the private and public-investment sectors under alternative public policies, i.e., regulation or non-regulation of salinity, to invest or not to invest...
Water is essential to life because its unique properties facilitate a vast number of biochemical processes that enable all organisms to exist. Maintenance of proper water concentration in the body is thus a vital activity. Colonization of terrestrial habitats placed organisms in desiccating environments that emphasized problems of water balance. The procurement and economical use of water has since been a central organizing theme in biology and has shaped the morphology, physiology, behavior, and spatial distribution of organisms. In hot, and environments like North American deserts, organisms are faced with especially challenging abiotic conditions characterized by variable and often extreme temperatures, intense...
Categories: Publication;
Types: Citation,
Thesis Citation;
Tags: Anatomy & physiology,
Animals,
Zoology
Changes in the hydrologic equilibrium of a river basin resulting from resource development also produce changes in the quality pattern. since the burden of quality maintenance must be shared by users (just as are quantities) predictions are needed for quality changes which might result from contemplated development at any specified location within the river system. This study reports the development of a computer simulation model of the water and salt flow systems within the Upper Colorado River Basin. Because of the close relationship between the hydrologic and salinity flow systems, an understanding of the hydrologic system is essential to successful management of the salinity system. In this study development...
Categories: Publication;
Types: Citation,
Thesis Citation;
Tags: colorado river basin,
computer models,
flow,
forecasting,
irrigation efficiency,
Water quality models in the Colorado River Basin have been developed for the basin, river, and individual reservoirs. They are used to support water quality programs within the basin. The models are periodically reviewed and updated to improve the accuracy of simulations. Improving the usefulness of the Lake Powell model, one of the key reservoirs in the basin, is the subject of this study. Lake Powell is simulated using a hydrodynamic and water quality model, CE-QUAL-W2. Previously the model has been used at Lake Powell to simulate hydrodynamics, temperature, and total dissolved solids with a reasonable degree of accuracy. An additional parameter, dissolved oxygen, will be added to the simulations and then calibrated...
The Colorado River system recently experienced the worst five year drought in 100 years of measured streamflows. The vast network of reservoirs that sustain and fuel development were drawn below 50% of system capacity to historic lows. The dry period also impacted water quality, increasing salinity concentration as a result of low flows. Paleo reconstructions of streamflow in the basin indicate that such dry spells are not uncommon. Interestingly, a compact to share water resources among the basin states, developed during wet periods of the early 1920s, is under stress as the states confront economic growth under limited water resources. Given these factors, the key question for this research is how to plan for...
Broom snakeweed (Gutierrezia sarothrae) is a widespread suffrutescent shrub in large areas of the semiarid rangeland of the western U. S., southern Canada, and northern Mexico. It is considered a major weed problem in the southwestern U.S. It causes poisoning to grazing and browsing animals and competes with desirable species, especially warm season grasses, essentially eliminating them from the plant community. Its population fluctuates according to localized or regional weather patterns. If soil water is adequate in the fall and winter, snakeweed will remain evergreen and use much of the available soil water during the period when warm season grasses are dormant. In the early spring when grasses start growing,...
We tested the adequacy of standard 30 m riparian buffers for semi-aquatic vertebrate species, using the boreal toad (Bufo boreas boreas) as an example. We monitored toad populations in south-central Utah using radio telemetry during the summers of 2003 and 2004. We found 30 m buffers inadequate for protecting boreal toads and suggest this is likely true for other species as well. Managers must consider several factors when constructing buffers: (1) Buffer requirements may vary by time of year. While we located toads most often in wet habitats, toads commonly utilized upland habitats in late summer, occasionally at distances greater than 100 m from water. (2) A single year’s observation may not be sufficient to...
A grassland restoration project was conducted in Canyonlands National Park on an area recently disturbed due to construction. Two native grasses (Oryzopsis hymenoides and Stipa comata) were seeded with 18 different soil treatments. Stipa density and relative mycorrhizal colonization were measured. None of the soil treatments resulted in significantly greater Stipa density than the control treatment of seeding only plus water. There was very little correlation between Stipa density and mycorrhizal colonization based on the treatments (r2= 0.011 p = 0.05). Three treatments produced 3 to 5 times the VAN colonization as the control including spring cryptobiotic soil crusts, with and without sugar, and fall soil crusts...
Categories: Publication;
Types: Citation,
Thesis Citation;
Tags: Revegetation,
Vesicular-arbuscular mycorrhizas
Arid-land deserts comprise up to 30% of global land surface area and experience degradation by anthropogenic land use demands. Sixteen of the 19 climate models used by the International Panel on Climate Change predict increased temperature and prolonged periods of drought for much of the arid southwest US. Soil microfauna consume organic-bound nitrogen and excrete soluble inorganic and dissolved organic nitrogen that is available for plant uptake or as substrate for microbial saprotrophs. However, the growth and activity of nematodes and protozoa is restricted to periods of adequate temperature and moisture. The objective of this dissertation research project is to determine the possible effects of predicted climate...
The ability of downy brome to successfully infest crop lands is partially due to its prolific nature. To better understand its reproductive biology, studies investigating (1) effects of temperature and photoperiod on flowering, (2) prevention of downy brome seed information with herbicides, and (3) effects of drought on reproduction, were conducted. Seedling vernalization was more effective than seed vernalization in promoting downy brome flowering. Vernalizing imbibed downy brome caryopses at 3 C for 0 to 30 days did not induce rapid flowering. Downy brome seedlings were exposed to six photoperiod/temperature treatments. After transfer to long days, plants from the short da/3 C treatment flowered within 30 days....
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