The Imperial Irrigation District (IID) is an irrigation district that serves the Imperial Valley in Southern California. Established under the State Water Code, the IID supplies roughly 500,000 acres (200,000 ha) of Imperial Valley farmland with raw Colorado River water to support irrigation. In addition to providing irrigation, IID also supplies electrical energy to the valley.IID was formed in 1911 under the California Irrigation District Act to acquire the properties of the bankrupt California Development Company and its Mexican subsidiary. The IID was formed as a public agency, acquiring 13 mutual water companies in the valley which had developed and operated water distribution canals. The district is headquartered in Imperial, California.Prior to 1942, irrigation water delivered to the Imperial Valley was diverted from the Colorado River near Pilot Knob through Mexico to bypass the Imperial sand dunes west of Yuma and into the IID-operated Alamo Canal (also known as the Imperial Canal). Since 1942, water has been diverted at Imperial Dam on the Colorado River through the 82-mile All-American Canal, all of which the IID operates and maintains, although the structures are owned by the U.S. Bureau of Reclamation.Water from Imperial Dam serves the Yuma, Ariz. region as well as the Imperial Valley. The All-American Canal also delivers water from the dam to the Coachella turnout—a section east of Yuma that diverts water to the Coachella Valley Water District. Imperial Dam, located about 20 miles north of Yuma, contains four desilting basins which help remove silt and sediment from the river water so it can be delivered by gravity flow. The IID also remotely operates the Brock Reservoir, between El Centro and Yuma, by operating the inlet and outlet gates and regulating the amount of water diverted into the reservoir and returned to the main system.The IID is a key partner in the Quantification Settlement Agreement—a pack of several agreements among California water districts entered into in 2003 to help California live within its entitlement of 4.4 million acre-feet of Colorado River water a year. Water conserved through conservation projects under the QSA is made available for the Southern California Coastal communities (San Diego County Water Authority, Coachella Valley Water District and Metropolitan Water District of Southern California).In 2009 under the agreement, IID completed the 23-mile concrete lining project of the All-American Canal to recover about 66,700 acre-feet of water per year for use by the San Diego County Water Authority.IID's Energy Department provides electric power to more than 145,000 customers in the Imperial Valley and parts of Riverside and San Diego counties. Service to residents of the Imperial Valley and Coachella valleys includes the Imperial Valley cities of El Centro, Calexico, Holtville, Brawley and Coachella Valley cities including Mecca, Thermal, La Quinta, Coachella and Indio, Bermuda Dunes, Thousand Palms, Indio Hills and Sky Valley. As the third largest public power utility in California, IID controls more than 1,100 megawatts of power derived from a diverse resource portfolio that includes its own generation, and long- and short-term power purchases.Located in what's been referred to as the "renewable energy capital of the world", IID serves as a catalyst for renewable energy development in the Imperial Valley and is going to great lengths to enhance its energy infrastructure to be able to move renewable energy generated in the Imperial Valley to markets far and wide. The Energy Department has an aggressive transmission expansion plan and, over the next five years, intends to invest $1 billion in its energy infrastructure, which includes building a state-of-the-art energy battery storage unit in El Centro, which would provide back-up energy resources but also help the IID grid integrate the many megawatts of solar energy entering the IID grid during the day..
The moving rule of salt and water in cultivated land and saline wasteland during crops growth period in Hetao Irrigation District, Inner Mongolia has been studied. Based on the field measured data, the movement of salt and soil moisture in cultivaed land and saline westeland by using the HYDRUS-2D model has been simulated and analyzed.The results showed that function by strong evaporation, the salt will be accumulated in the soil surface,in the soil layers of 20,40 cmand 70 cm,the salt content will be increased 67.23%,62.37% and 37.2% respectively.Through examined, the simulation of soil moisture and salt content moving by the HYDRUS-2D model in horizontal and vertical direction indicated a high precision, reflected the rule of salt accumulated and soil moisture moving.
The Imperial Irrigation District is a large irrigation project in the western United States having a unique hydrogeologic structure such that only small amounts of deep percolation leave the project directly as subsurface flows. This structure is conducive to relatively accurate application of a surface water balance to the district, enabling the determination of crop evapotranspiration (ETc) as a residual of inflows and outflows. The ability to calculate ETc from discharge measurements provides the opportunity to assess the accuracy and consistency of an independently applied crop coefficient-reference evapotranspiration (K-c ET0) procedure integrated over the project. The accuracy of the annual crop evapotranspiration via water balance estimates was +/-6% at the 95% confidence level. Calculations using K-c and ET0 were based on the FAO-56 dual crop coefficient approach and included separate calculation of evaporation from precipitation and irrigation events. Grass reference ET0 was computed using the CIMIS Penman equation and ETc was computed for over 30 crop types. On average, K-c-based ET computations exceeded ETc determined by water balance (referred to as ETc (WB)) by 8% on an annual basis over a 7 year period. The 8% overprediction was concluded to stein primarily from use of K-c that represents potential and ideal growing conditions, whereas crops in the study area were not always in full pristine condition due to various water and agronomic stresses. A 6% reduction to calculated K-c-based ET was applied to all crops, and a further 2% reduction was applied to lower value crops to bring the project-wide ET predicted by K-c-based ET into agreement with ETc WB. The standard error of estimate (SEE) for annual ETc for the entire project based on K-c following the reduction adjustment, was 3.4% of total annual ETc, which is considered to be quite good. The SEE for the average monthly ETc was 15% of average monthly ETc. A sensitivity analysis of the Computational procedure for K-c showed that relaxation from using the FAO-56 dual K-c method to the more simple mean (i.e.. single) K-c curve and relaxation of specificity of planting and harvest dates did not substantially increase the projectwide prediction error The use of the mean K-c curves, where effects of evaporation from wet soil are included as general averages, predicted 5% lower than the dual method for monthly estimates and 8% lower on an annual basis, so that no adjustment was required to match annual ET derived from water balance. About one half of the reduction in estimates when applying the single (or mean) K-c method rather than the dual K-c method was caused by the lack of accounting for evaporation from special irrigations during the off season (i.e., in between crops).
Monolithic concrete pipe (also known as Concrete Pipe (CIPCP) or Cast-In-Place Pipe (CIPP)) is widely used in some regions for purposes such as storm, sewer, or irrigation pipelines. The earliest use of CIPCP was in 1922 in the Turlock Irrigation District of California. It is reported by The Sierra Group (Sierra, 1991) that there are over 15 million linear feet (4.6 million linear meters) of CIPCP under various applications. Nevertheless, many irrigation engineers, especially outside the U.S. are unaware of CIPCP. Monolithic concrete irrigation pipe is seldom mentioned in irrigation design literature.
Ova obtained from diploid grass carp females were inseminated with sperm from diploid and triploid males, during three consecutive spawning seasons (1986, 1987, 1988), with reproducible results. Fertilization success was significantly lower in diploid × triploid crosses (27, 38 and 25%) compared with diploid × diploid crosses (49, 84 and 82%). Hatching embryos from diploid × triploid crosses had significantly (P < 0.05) smaller body and yolk sac areas, and utilized their yolk more slowly than embryos from diploid × diploid crosses. Most diploid × triploid embryos surviving to hatch, suffered from notochord deformities and died before exogenous feeding began. Survival of juveniles from diploid × triploid crosses from hatching to 5 months was 0.21% and 0.125% for 1987 and 1988, compared with 95% and 84%, for diploid × diploid crosses. Coulter Counter ploidy determination for nine (five in 1987, four in 1988) diploid × triploid juvenile survivors revealed a diploid genome.
When injected with carp pituitary, triploid male grass carp Ctenopharyngodon idella produced milt that contained sperm of abnormal shape and variable size. Flow cytometry of this milt revealed three types of cells based on DNA content: 1.5n "haploid," triploid, and hexaploid. Hexaploid cells were interpreted to be spermatogonia in which premeiotic chromosome doubling had occurred; the coefficient of variation (CV = 100˙SD/mean) of DNA content in hexaploids was not different from the CV of DNA in other somatic cells. Meiotic triploid and 1.5n haploid cells from milt had CVs for DNA about 6–7% higher than those of somatic cell populations. This increase was consonant with the theoretical distribution expected from random segregation of the extra chromosomes of triploids. Therefore, both mean and relative variation of DNA content in aneuploid cells support the hypothesis that the third homologous chromosome segregates randomly during anaphase I of meiosis. Because the segregation of chromosomes follows the expected theoretical distribution, it is possible to estimate the probability that competent sperm types will be produced. This estimate can, in turn, be used as one component in estimating the likelihood that triploids will produce diploid offspring, which themselves will reproduce. The probability that a competent sperm from a single triploid male will unite with a normal egg and produce a reproductively capable offspring is conservatively estimated to be 4 × 10−11 for every meiotic reduction of hexaploid spermatogonia.
