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<br />. <br /> <br />II. HYDRO-SALINITY MONITORING & EVALUATION <br /> <br />C\:l <br />f',) <br />~ <br />00 <br /> <br />A, Setting <br /> <br />The McElmo Creek Monitoring & Evaluation <br />Plan was established in August 1988 and revised <br />ApriI1994..,MQ.nitori!'g of on-farm hydro- <br />salini!}' has been scaled down to 3-5 sites with the <br />I!!!ent Qf mnving thpo c:itp.s, aq the M&E program <br />progre,s,!;l:S. M&li.!wsonnel monitored 5 <br />irrigalLqn sites during the 1995 irrigation season. <br />Ali sites selected for monitoring were located <br />south of Cortez in priority area one. <br /> <br />S- (;+''''' <br /> <br />B. Procedures <br /> <br />The main objective of the M&E program was to <br />estimate the amount of deep percolation on the <br />monitored sites. <br /> <br />Irrigation water data was gathered by reading <br />flow meters that were installed in the pipeline <br />delivery systems to individual farms or fields. <br />there are more than two hundred sites available <br />with this type of installation. These flow meters <br />were installed by the Bureau of Reclamation and <br />are part of the Montezuma Valley Irrigation <br />System, With the cooperation of the Montezuma <br />VaHey Irrigation Company, the Monitoring and <br />Evaiuation Team members are allowed access to <br />read these meters that are under lock and key. <br /> <br />Another adjusonenl in procedure was necessitated <br />at the beginning of the irrigation season, due to <br />the loss of the M&E Team Leader in Cortez. An <br />alternative plan was implemented and the Salinity <br />Irrigation Specialist was assigned to collect the <br />field data. Data was recnrnp.rI anti c:~"t to the <br />M&E Team Leader in the Roosevelt, Utah for <br />cornpihW.on. <br /> <br />Onp. remote sensinQ" weather ~tMinn bas been <br />installed in the area. The site is connected to a <br />telephone. The weather data is transferred to the <br />Roosevelt, Utah field office computer each night <br />The data from the weather stations is used to <br />calculate the evapotranspiration (El) for the sites. <br />ET is calculated using the Modified Penman <br />Equation. This method uses solar radiation, wind <br />speed, temperaMe, and relative humidity. <br /> <br />A crop simulation program from Utah State <br />University is also being used to give crop <br />coefficients. This has made the modeling of crop <br />water use more accurate, Colorado State <br />University and Utah State University have been <br />extremely helpful with hardware and software <br />"troubie shooting" for meteorological data <br />retrieval and crop modeling. <br /> <br />Calculations for ET, flow in, flow out, and deep <br />percolation, are made on a weekly basis for each <br />sile. Flows for the sprinkler systems are reduced <br />by ten percent to account for losses in droplet <br />evaporation. ET was adjusted downward when <br />the soil moisMe balance dropped to a level that <br />the plants would be in stress and using less water. <br /> <br />A graph has been developed using the data <br />gathered on each site. The graphs show the soil <br />moisMe, ET, flow in, and flow out of each field. <br />These graphs are included in Appendix A. <br /> <br />McElmo Creek Unit M&E 1995 Report <br />Page 5 <br />