INTEGRATED DRAINWATER MANAGEMENT IN IRRIGATED AGRICULTURE

Drainwater management strategies include source control, reuse, treatment, and evaporation ponds; questions of interest are efficient management, policy instruments, and sustainability. A high level of source control is indicated absent reuse due to the relatively high cost of evaporation ponds; this is accomplished largely through high uniformity/high cost irrigation systems. With reuse, the primary form of source control is reduction in land area devoted to freshwater production; the released land goes to reuse production. Reuse appears as an economically promising solution to the drainage problem. A high level of net returns is achieved while maintaining overall hydrologic balance in the system. Economic efficiency and hydrologic balance may be attained through pricing or market schemes. With pricing, growers are charged for deep percolations flows, while reuse and evaporation pond operators are paid for extractions. With markets, permit supply is generated by extractions from the water table, while permit demand is generated by deep percolation. Competitive equilibrium exists, is efficient, and implies hydrologic balance. The analysis suggests that a high level of agricultural production may be possible for some period of time while still maintaining environmental quality.Resource /Energy Economics and Policy,

Feasibility Analysis of South Bay Salt Pond Restoration, San Francisco Estuary, California

228pp. (pdf contains 257 pages

A validation of the model for effluent disposal using land irrigation (MEDLI)

Biological waste produced by intensive livestock farming is a valuable and useful product used in the agricultural industry for irrigation of crops. Manure and liquid effluent contains nutrients that can be effectively utilised in commercial cropping of livestock feed. It provides farmers with a low cost organic material and fertilizer, resulting in high yielding crops if carefully managed. The downside of using effluent in crop irrigation is the potentially high concentrations of chemicals and pathogens in effluent can, if mismanaged, reach toxic levels in the soil. This can lead to crop failure and in worst cases, land and water contamination. It is a requirement of Queensland law that before an enterprise irrigates with effluent it must first obtain a regulation certificate. To fulfil this obligation an effluent irrigation scheme must be designed and modelled to the satisfaction of the regulatory authority. There are tools available which aid the designer of the effluent irrigation scheme in conducting water and nutrient balances. The software package recommended by the Queensland Government is; The Model for Effluent Disposal using Land Irrigation (MEDLI). The purpose of this program is to model; effluent volumes, concentrations of chemical constituents in effluent, point of deposition soil chemistry and nutrient uptake by plants. Due to the absence of previously completed program validation, this research aimed to conduct validation of MEDLI software. Modelling scenarios were entered into the program using input variables that had been established from data collected from three beef cattle feedlots. Scenarios were set-up to try and best mimic site conditions, so a comparisons could be drawn between the simulated and observed datasets. Results of the comparisons for all three sites found, often significant variation in the values of simulated and observed conditions. Weak correlation of the datasets could not be conclusively attributed to systematic errors in the model. Analytical errors such as; improperly defined inputs and inadequacy of sample sizing may have contributed to the bias found between datasets. A particularly notable conclusion of the analysis was that far greater definition is required around the required estimations of the pre-treatment and anaerobic pond chemistry inputs. A recommendation is; MEDLI literature which is supplied with the program, should provide considerably more detailed guidance on deriving accurate estimation of these input variables

Improving decision support system in identifying vulnerability rating and prioritizing the best interventions for sustainable watersheds in Pakistan, Nepal, and Sri Lanka

Quantification of watershed vulnerability rating and prioritization of the best watershed management intervention is always a challenge for multidisciplinary experts in developing consensus. Consequently, the lack of a decision support system (DSS) negatively affects the adoption of promising interventions leading to reduced watershed communities’ resilience to climate change. Therefore, a DSS has been developed to integrate local multi-disciplinary knowledge in identifying the watershed vulnerability ratings and prioritizing the best site-specific watershed management interventions. The DSS developed was applied to selected watersheds using 25 local experts each in Pakistan, Nepal, and Sri Lanka. The results showed the DSS is conveniently applicable and effective in developing consensus among multidisciplinary experts. The DSS recommended that the best interventions for the selected watersheds should primarily reduce the existing accelerated land and water degradation through engineering and biological actions, namely the control the rainwater run-off losses through appropriate harvesting systems and their subsequent efficient utilization for improving food security, climate change resilience and livelihood of vulnerable watershed communities. The DSS developed can be helpful in developing local adaptation plans and strengthening the policy support for promoting sustainable watersheds in Pakistan, Nepal, and Sri Lanka. However, the system needs further refinement through the incorporation of the design, specifications and costing of the interventions and making the data acquisition and analysis automatic using an online electronic system for quicker results and appropriate resource allocation for stimulated adoption.Quantification of watershed vulnerability rating and prioritization of the best watershed management intervention is always a challenge for multidisciplinary experts in developing consensus. Consequently, the lack of a decision support system (DSS) negatively affects the adoption of promising interventions leading to reduced watershed communities’ resilience to climate change. Therefore, a DSS has been developed to integrate local multi-disciplinary knowledge in identifying the watershed vulnerability ratings and prioritizing the best site-specific watershed management interventions. The DSS developed was applied to selected watersheds using 25 local experts in Pakistan, Nepal, and Sri Lanka. Results showed that DSS is conveniently applicable and effective in developing consensus among multidisciplinary experts. The DSS recommended that the best interventions for the selected watersheds should primarily reduce the existing accelerated land and water degradation through engineering and biological actions. These actions may include controlling the rainwater run-off losses through appropriate harvesting systems and their subsequent efficient utilization for improving food security, climate change resilience and livelihood of vulnerable watershed communities. The DSS developed can be helpful in developing local adaptation plans and strengthening the policy support for promoting sustainable watersheds in Pakistan, Nepal, and Sri Lanka. However, the system needs further refinement through the incorporation of the design, specifications and costing of the interventions and making the data acquisition and analysis automatic using an online electronic system for quicker results and appropriate resource allocation for stimulated adoption

Workshop on computer applications in water management: proceedings of the 1995 workshop

Compiled and edited by L. Ahuja, J. Leppert, K. Rojas, E. Seely.Also published as: Great Plains Agricultural Council publication, no. 154.Includes bibliographical references.Presented at the Workshop on computer applications in water management: proceedings of the 1995 workshop held on May 23-25, 1995 at Colorado State University in Fort Collins, Colorado

Ground water and surface water under stress

Presented at Ground water and surface water under stress: competition, interaction, solutions: a USCID water management conference on October 25-28, 2006 in Boise, Idaho.Includes bibliographical references.The A&B Irrigation District in south-central Idaho supplies water to irrigate over 76,000 acres. The district's 14,660-acre Unit A is supplied with water from the Snake River. Unit B is comprised of 62,140 acres of land irrigated by pumping groundwater from the Eastern Snake Plain Aquifer (ESPA) using 177 deep wells. Pumping depths range from 200 to 350 feet. Water from Unit B wells is distributed to irrigated lands via a system of short, unlined lateral canals averaging about 3/4-mile in length with capacities of 2 to 12 cfs. During the period from 1975 to 2005, the average level of the ESPA under the A&B Irrigation District dropped 25 ft and as much as 40 ft in some locations. This has forced the district to deepen some existing wells and drill several new wells. To help mitigate the declining aquifer, the district and its farmers have implemented a variety of irrigation system and management improvements. Improvements have involved a concerted effort by the district, landowners, and local and federal resource agencies. The district has installed variable speed drives on some supply wells, installed a SCADA system to remotely monitor and control well pumps, and piped portions of the open distribution laterals. This has permitted farmers to connect farm pressure pumps directly to supply well outlets. Farmers have helped by converting many of their surface irrigation application systems to sprinklers, moving farm deliveries to central locations to reduce conveyance losses, and installing systems to reclaim irrigation spills and return flows

Ground water and surface water under stress: competition, interaction, solutions

Presented at Ground water and surface water under stress: competition, interaction, solutions: a USCID water management conference on October 25-28, 2006 in Boise, Idaho.Includes bibliographical references.Overview of the Pecos River basin -- Integrating water management in Egypt: from concept to reality -- Evaluation of the Pecos River Carlsbad Settlement Agreement using the Pecos River Decision Support System -- Collaborative solutions to complex problems: a Pecos River basin, New Mexico case study -- Development of replacement water supplies by the Lower Arkansas Water Management Association -- Integrated water management in the Bear River basin -- Looking for trouble: anticipating impacts of changing allocation of irrigation water -- AgriMet: a tool for irrigation water management -- Application of MODIS and Landsat based evapotranspiration for western states water management -- Calibrating satellite-based vegetation indices to estimate evapotranspiration and crop coefficients -- Reducing Ogallala withdrawls by changing cropping and irrigation practices in the Texas High Plains -- Evaluating cotton yield potential in the Ogallala aquifer region -- A fully automated center pivot using crop canopy temperature: preliminary results -- Deficit irrigation in alfalfa as a strategy for providing water for nonagricultural uses -- An infrastructure management system for enhanced irrigation district planning -- Gila River Indian Community Water Resources Decision Support System - a modeling system for managing a multi-source conjunctive use water supply for long-term sustainability -- Groundwater analysis tool: a component of the Water Resources Decision Support System for the Gila River Indian Community -- Effective water management through farmer participation -- Improving canal water management through participatory approach: a case study on secondary canal (Potho Minor), Sindh, Pakistan -- Groundwater management improvements to mitigate declining groundwater levels - a case study -- An on-line advisory program for optimum irrigation management -- Institutional reforms in the water sector of Pakistan -- Matching irrigation supply and demand in Egypt -- Drought risk management for irrigated potato production in Idaho -- Case study - statistical forecasting techniques for evaluating an interruptible supply contract -- Managing across groundwater and surface water: an Australian 'conjunctive licence' illustration of allocation and planning issues -- Decentralized flow monitoring in Egypt -- High rate irrigation for groundwater recharge -- Impervious synthetic lining of deteriorated concrete canals - what are the real cost and benefits to irrigation districts? -- Design and installation of a flume to monitor spring discharge at the headwaters of the Verde River -- Optimal allocation of limited water supply for a large-scale irrigated area -- Assessment of the environmental sustainability of irrigated agriculture in a large-scale scheme - a case study

Ground water and surface water under stress

Presented at Ground water and surface water under stress: competition, interaction, solutions: a USCID water management conference on October 25-28, 2006 in Boise, Idaho.Includes bibliographical references.The METRIC evapotranspiration (ET) estimation model was applied using MODIS (Moderate Resolution Imaging Spectroradiometer) satellite images in New Mexico to evaluate the applicability of MODIS images to ET estimation and water resources management. With the coarse resolution of MODIS (approximately 1km thermal resolution), MODIS was not found to be suitable for field-scale applications. In project and regional scale applications, MODIS has potential to contribute to ET estimation and water resources management. MODIS based ET maps for New Mexico were compared with Landsat based results for 12 dates. Average ET calculations using MODIS and Landsat applications were similar, indicating that MODIS images can be useful as an ET estimation tool in project and regional scale applications

Water Development, Consumptive Water Uses, and the Great Salt Lake

Great Salt Lake (GSL) covers 5500 km2 (2100 mi2) at its unimpacted elevation and is the eighth largest saline lake in the world. Its highly productive food web supports millions of migratory birds and the economic value of the lake is estimated at $1.5 billion US dollars in 2019. Droughts and wet cycles have caused huge fluctuations in lake level, area, and salinities, and this variation has masked anthropogenic impacts. Recent work, however, has determined that consumptive water uses in the watershed have depleted inflows by approximately 39$14–96 million ($5–32 per person). Water conservation paired with water markets reduce costs further, costing between$2 and $16 per person. Descriptions of potential solutions to reduce consumptive water uses and stabilize GSL level are a starting point to encourage discussion. Strategies have yet to be prioritized or thoroughly evaluated. Quantifying water diversions from rivers that feed GSL and consumptive water uses will allow Utahns to make defensible decisions to manage water resources and the lake’s biology for long-term ecological, recreational, and economic benefit