Soil moisture probe

Presented at Irrigated agriculture responds to water use challenges - strategies for success: USCID water management conference held on April 3-6, 2012 in Austin, Texas.Includes bibliographical references.Throughout the American West irrigated agriculture has been targeted to increase water use efficiency. Soil moisture sensors offer a method to achieve efficiency improvements but have found limited use due primarily to high cost and lack of soil specific calibration equations. In this paper we examine the ECH2O EC-20 soil moisture sensor, a low cost capacitance sensor and develop a unique laboratory calibration method. Field and laboratory calibration equations were developed for 6 soil types in the Middle Rio Grande Valley. The average absolute error in volumetric water content for field calibration was 0.43 m³/m³, and 0.012 m³/m³ for the laboratory calibration. The factory calibration equation for the EC-20 was also evaluated and found to yield an average absolute error of 0.049 m³/m³. We found that the EC-20 is a reliable, cost effective, and accurate sensor, and recommend that the laboratory calibration method presented here be used to obtain maximum accuracy. We also recommend that the field calibration of the EC-20 soil moisture sensor be foregone, as this type of calibration exhibits large error rates. Additionally, it was found that the field calibration method was time consuming, covered a small range of moisture content values and was destructive to the area around installed sensors, which could lead to measurement errors

USCID fourth international conference

Presented at the Role of irrigation and drainage in a sustainable future: USCID fourth international conference on irrigation and drainage on October 3-6, 2007 in Sacramento, California.Includes bibliographical references.Water is the lifeblood of the American West and the foundation of its economy, but it remains its scarcest resource. The explosive population growth in Western United States, the emerging additional need for water for environmental uses, and the national importance of the domestic food production are driving major conflicts between these competing water uses. Irrigated agriculture in particular is by far the largest water user of diverted water – 80% country wide and 90% in the Western U.S. — and since it is perceived to be comparatively inefficient user, it is frequently asked to decrease its water consumption (Oad and Kullman, 2006). The case of the Middle Rio Grande illustrates the problem very well. The river is the ecological backbone of the Chihuahuan Desert region in the western United States, and supports its dynamic and diverse ecology, including the fish and wildlife habitat. The Rio Grande Silvery Minnow is federally listed as endangered species, and the irrigated agriculture in the Middle Rio Grande has come under increasing pressure to reduce its water consumption while maintaining the desired level of service to its water users. This paper will present our on-going research on options to make irrigation system operations more efficient in the Middle Rio Grande Conservancy District. Specifically, it will describe formulation and implementation of a Decision-Support System (DSS) that can assist the MRGCD managers to more efficiently plan and implement their water delivery operations, thereby reducing river diversions. Since year 2000, MRGCD has been modernizing their physical water delivery network, and the DSS will be used in tandem with SCADA software in making water delivery decisions based on real-time knowledge of available water supplies and crop water requirements. In irrigation systems, the conceptual problem addressed by the DSS is how best to route water supply in a main canal to its laterals so that the required water diversion is minimized. The MRGCD DSS uses linear programming to find an optimum water delivery schedule for canal service areas in the MRGCD irrigation system. For the past three years, the model has been validated in the field and the evaluation indicates that the model recommendations are realistic and represent ditch-rider practices

Emerging challenges and opportunities for irrigation managers

Presented at Emerging challenges and opportunities for irrigation managers: energy, efficiency and infrastructure: a USCID water management conference held on April 26-29, 2011 in Albuquerque, New Mexico.Includes bibliographical references.Scheduled water delivery (SWD) provides the opportunity to increase overall irrigation system performance and define legitimate water use in regions without adjudication. A well-managed program of scheduled water delivery is able to fulfill seasonal crop water requirements in a timely manner, but requires less water than on-demand water delivery. In order to successfully realize SWD in an irrigation district, several components need to be addressed and developed simultaneously. This paper will present results of on-going research in the Middle Rio Grande Conservancy District (MRGCD) related to implementation of scheduled water delivery supported by a decision-support system (DSS) and modernization of irrigation infrastructure. A DSS developed over the last four years uses linear programming to find an optimum water delivery schedule for all canal service areas in the MRGCD irrigation system. The DSS has been developed for the entire MRGCD and a significant validation effort of input parameters and model logic has been completed. The second component for implementing scheduled water delivery is a program of irrigation infrastructure modernization with Supervisory Control and Data Acquisition (SCADA) system. Over the past six years, the MRGCD has modernized canal infrastructure and developed a SCADA system with the focus being to improve water use efficiency. The third component in implementing scheduled water delivery is its acceptance by all water users as a matter of district policy and practice. To gain acceptance and disseminate information regarding SWD, a public outreach program was formulated that includes providing water users information through newsletters, websites, and public meetings. It also included training related MRGCD staff in the concepts and practice of scheduled water delivery and the use of related decision-support systems

Scheduled water delivery

Presented at Meeting irrigation demands in a water-challenged environment: SCADA and technology: tools to improve production: a USCID water management conference held on September 28 - October 1, 2010 in Fort Collins, Colorado.Includes bibliographical references.Scheduled water delivery (SWD) provides the opportunity to increase overall irrigation system performance and define legitimate water use in regions without adjudication. A well-managed program of scheduled water delivery is able to fulfill seasonal crop water requirements in a timely manner, but requires less water than on-demand water delivery. In order to successfully realize SWD in an irrigation district, several components need to be addressed and developed simultaneously. This paper will present results of on-going research in the Middle Rio Grande Conservancy District (MRGCD) related to implementation of scheduled water delivery supported by a decision-support system (DSS) and modernization of irrigation infrastructure. A DSS developed over the last four years uses linear programming to find an optimum water delivery schedule for all canal service areas in the MRGCD irrigation system. The DSS has been developed for the entire MRGCD and a significant validation effort of input parameters and model logic has been completed. The second component for implementing scheduled water delivery is a program of irrigation infrastructure modernization with Supervisory Control and Data Acquisition (SCADA) system. Over the past six years, the MRGCD has modernized canal infrastructure and developed a SCADA system with the focus being to improve water use efficiency. The third component in implementing scheduled water delivery is its acceptance by all water users as a matter of district policy and practice. To gain acceptance and disseminate information regarding SWD, a public outreach program was formulated that includes providing water users information through newsletters, websites, and public meetings. It also included training related MRGCD staff in the concepts and practice of scheduled water delivery and the use of related decision-support systems

Canal seepage losses

Presented at Emerging challenges and opportunities for irrigation managers: energy, efficiency and infrastructure: a USCID water management conference held on April 26-29, 2011 in Albuquerque, New Mexico.Includes bibliographical references.Seepage from earthen irrigation canals represents substantial water loss in irrigation districts. Historically, the determination of canal seepage was accomplished using the inflow-outflow method with propeller and electromagnetic type flow meters. This method was difficult, time consuming, and limited by measurement device accuracy. In recent years, advances in technology have led to the widespread use of Acoustic Doppler Current Profilers (ADCP) for discharge measurements in streams and rivers. Even though ADCP use has become widespread for stream discharges, studies to determine canal seepage using this new technology are limited. Using an ADCP, extensive field measurements were conducted in the Middle Rio Grande Conservancy District. This paper describes the ADCP measurement protocol used to measure irrigation canal seepage and presents predictive equations for determining canal seepage based on flow rate and canal geometry

Scheduled water delivery

Presented at the fifth international conference on irrigation and drainage, Irrigation and drainage for food, energy and the environment on November 3-6, 2009 in Salt Lake City, Utah.Includes bibliographical references.Scheduled water delivery (SWD) provides the opportunity to increase overall irrigation system performance and define legitimate water use in regions without adjudication. A well-managed program of scheduled water delivery is able to fulfill seasonal crop water requirements in a timely manner, but requires less water than on-demand water delivery. In order to successfully realize SWD in an irrigation district, several components need to be addressed and developed simultaneously. This paper will present results of on-going research in the Middle Rio Grande Conservancy District (MRGCD) related to implementation of scheduled water delivery supported by a decision-support system (DSS) and modernization of irrigation infrastructure. A DSS developed over the last four years uses linear programming to find an optimum water delivery schedule for all canal service areas in the MRGCD irrigation system. The DSS has been developed for the entire MRGCD and a significant validation effort of input parameters and model logic has been completed. The second component for implementing scheduled water delivery is a program of irrigation infrastructure modernization with Supervisory Control and Data Acquisition (SCADA) system. Over the past six years, the MRGCD has modernized canal infrastructure and developed a SCADA system with the focus being to improve water use efficiency. The third component in implementing scheduled water delivery is its acceptance by all water users as a matter of district policy and practice. To gain acceptance and disseminate information regarding SWD, a public outreach program was formulated that includes providing water users information through newsletters, websites, and public meetings. It also included training related MRGCD staff in the concepts and practice of scheduled water delivery and the use of related decision-support systems

Improving irrigation system performance through scheduled water delivery in the Middle Rio Grande Conservancy District

This dissertation examines improving irrigation system performance in the Middle Rio Grande Valley in central New Mexico. Historically, the Middle Rio Grande Conservancy District practiced continuous on demand water delivery, which resulted in large diversions from the Rio Grande. Due to pressure related to the endangered Rio Grande silvery minnow (Hybognathus amarus), the Middle Rio Grande Conservancy District has been forced to manage water more effectively. To reach this goal while still providing farmers with adequate supplies, the Middle Rio Grande Conservancy District has employed scheduled water delivery. Scheduled water delivery introduces significant management challenges that can be addressed using Decision Support Systems (DSS). This dissertation presents the development, validation and implementation of a DSS in the Middle Rio Grande Conservancy District to facilitate scheduled water delivery. The development of the DSS represents a four year effort during which data were collected throughout central New Mexico to develop a real time model capable of predicting crop water demand and distributing irrigation water. This research verified the hypothesis that real time modeling using a Decision Support System is capable of predicting crop water demand and developing water delivery schedules to meet those demands. The field study conducted during the validation effort defined input parameters for the DSS and also had the contribution of quantifying farmer practices in the Middle Rio Grande Valley, which prior to this research were poorly understood. The implementation of the developed DSS was successful during the 2009 irrigation season and improved water delivery operations, while reducing the required water supply by 27%. Overall, the DSS provides the Middle Rio Grande Conservancy District with a powerful tool that can be used to schedule water delivery, determine legitimate water use, improve reservoir operations and sustain irrigated agriculture in the face of future water management challenges