Analysis of historic agricultural irrigation data from the Natural Resources Conservation Service monitoring and evaluation for Grand Valley, Lower Gunnison Basin, and McElmo Creek Basin, western Colorado, 1985 to 2003

Abstract

Front cover: Top left, typical weather station measuring wind run, solar radiation, maximum-minimum temperatures, relative humidity, and precipitation; top right, pressure transducer to measure air pressure. Middle left, Datapod and housing box; middle right, Datapod, interface, and signal conditioner for a magnetic induction pipeline flow sensor. Bottom right, typical inflow installation with a stilling well and float potentiometer. For more information on the USGS-the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment, visit http://www.usgs.gov or call 1-888-ASK-USGS. Analysis of Historic Agricultural IrrigationFor an overview of USGS information products, including maps, imagery, and publications, visit http://www.usgs.gov/pubprodTo order this and other USGS information products, visit http://store.usgs.gov Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner.Suggested citation: Mayo, J.W., 2015, Analysis of historic agricultural irrigation data from the Natural Resources Conservation Service monitoring and evaluation for Grand Valley, Lower Gunnison Basin, and McElmo Creek Basin, western Colorado, 1985 to 2003: U.S. Geological Survey Open-File Report 2014-1261. ISSN 2331ISSN -1258 iii Acknowledgments While the USGS study found discrepancies in some of the results of the NRCS evaluation, the author of the USGS study respectfully recognizes the work performed by the NRCS staff to complete such a complex and long-running effort of field data collection and data analysis. The number of site-years evaluated over three salinity control units, with each site often requiring daily visits, would be very difficult to replicate today. Given the time frame that the evaluation was begun (early 1980s), electronic data collection instruments and office computer technologies were then in their infancy. The analysis software for the NRCS evaluation was hand coded in the Basic programming language and run on an early Tandy home computer. If errors in definitions in the analysis software occurred at the beginning of the evaluation, it would have been difficult to recognize those errors, and even more difficult to have the software modified later. The pioneering efforts by the staff of the NRCS evaluation to overcome many technical obstacles along the way led to the successful completion of a complex and worthwhile project. Overall, the results of the NRCS evaluation have been accurate and consistent and have provided real value to the salinity control activities in the Colorado River Basin.Thanks are extended to Frank Riggle, NRCS, former Assistant State Conservationist for Water Resources (retired), NRCS, Denver, Colo. The original project was envisioned by Frank, a...