Toward Sustainable Groundwater in Agriculture –
An International Conference Linking Science and Policy.
Univ. California – Davis and the Water Education Foundation, San Francisco, June 15-17, 2010.
Agricultural Groundwater and Energy Nexus
(Session D1), Christopher Scott, Session Chair
A National View of the Irrigation Resources to Grow Biofuel and the Groundwater Role [pdf]
Noel Gollehon, Natural Resources Conservation Service – USDA, Noel.Gollehon@wdc.usda.gov, (202) 720-8676
Irrigated cropland and associated water supplies, including groundwater resources, are currently being used for biofuel production. This presentation provides a national view of water and land resources used for irrigation, with an emphasis on groundwater use. The focus of the data-driven presentation is on current biofuel production in the form of corn-based ethanol, but implications will be drawn for possible future cellulosic ethanol feedstock. The presentation utilizes secondary data sources from the U.S. Department of Agriculture and U.S. Geological Survey to provide a national view of the water (surface and groundwater) and land resource activities. State- and crop-level data are used to illustrate the consequences of ramping up biofuel feedstock production on crop water applications with implications for the utilization of groundwater resources.
Can Electricity Pricing be a Tool for Efficient, Equitable and Sustainable Use of Groundwater in Indian Agriculture? [pdf]
Dinesh Kumar, Institute for Resource Analysis and Policy, firstname.lastname@example.org, +91 40 42617392/ +91 97050 15640
Om Prakash Singh, Banaras Hindu University, email@example.com/ firstname.lastname@example.org, +91 94503 92935
Flat rate and heavily subsidized prices for electricity in the farm sector ruin both groundwater and energy economy in many groundwater-scarce regions in India. But, many scholars have theoretically argued that pro rata pricing of electricity in the farm sector is socio-economically unviable and politically infeasible. This paper analyzes the potential impacts of energy pricing on efficiency, equity and sustainability in groundwater use. The analyses use empirical data on water productivity in agriculture for crops, dairying and farms for north Gujarat, eastern UP and south Bihar. For north Gujarat, the analysis uses data from well owners who pay flat rate tariff, and well owners who pay pro rata tariff. For eastern UP and south Bihar, the analysis uses data from well owners and water buyers from diesel and electric well commands. Analysis shows that introducing marginal cost for electricity motivates farmers to use water more efficiently at the farm level through careful use of irrigation water; use of better agronomic inputs; optimize costly inputs; optimize livestock composition and carefully select crops and cropping patterns, which give higher return from every unit of water and grow low water consuming crops. It also shows that higher cost of irrigation water will not lower net return from every unit of water used as the farmers will modify their farming system accordingly. Further, change in the structure of power tariff from flat rate to pro-rata will not have any adverse effects on access and equity in groundwater use. Nor will it increase the monopoly power of well owners. The number of potential water sellers and not the number of potential buyers of water govern the price of water. Pro rata pricing reduces cost of groundwater pumping per unit of land. It also reduces aggregate pumping, which is disproportionately higher than the reduction in net returns per unit of land. This leads to more sustainable groundwater use. This means that in water scarce regions, it would be possible to introduce metering and higher electricity tariff without compromising on the economic prospects of farming. Raising power tariff in the farm sector to achieve efficiency, equity and sustainability in groundwater use is socially and economically viable.
(Program title: Simulating hydrologic and biologic response to land use and climate change – Randy Hunt, USGS)
Biofuel Production Effects on Gw-Sw Connection. Groundwater-Lake Interaction in
Ag Settings (Quality and/or Quantity) [pdf]
Hydrologic measurements and models are well-suited for characterizing groundwater and surface water systems, but simple abiotic indicators may not answer the hydroecological questions related to changes in land use and climate. Thus, understanding how changes in the hydrological system might ripple to the biological system is a critical topic for understanding and protecting groundwater dependent ecosystems, both for present day and potential future conditions. In this work, the effect on the biotic system was evaluated using simulated changes in hydrograph shape metrics (also referred to as hydrologic indices or hydrologic condition metrics). In this approach, the hydrograph is characterized using many different criteria (e.g., low-flow duration, stormflow recurrence), which are then summarized into a set of statistical metrics. Others have shown that some hydrologic metrics responded to urbanization and related to both water quality and biologic field data, and that such relations held for watersheds evaluated in the conterminous United States and internationally. Such results are promising because climate change predictions are commonly reported in abiotic terms, yet societal concerns are often ecosystem focused. The USGS coupled hydrologic model GSFLOW was used to simulate two watersheds in Wisconsin, USA. Model results are processed using the Nature Conservancy Index of Hydrologic Alteration (IHA) software suite to assess possible biological response to present day and changed streamflow resulting from climate and/or land-use change. The low pulse frequency count, defined as the number of flow events where the flow drops below a low-flow threshold, related well to current climate biological field data. In one watershed the relation established between both macroinvertebrate abundance and richness and the low pulse frequency counts simulated using a current-conditions calibrated groundwater-surface water model was then extrapolated to change scenario conditions. The increased temperature scenarios resulted in decreases in expected invertebrate abundance, with the lowest expected quality at a stream site that was periodically dry during some change scenarios. Results from both watersheds suggest that hydrographic shape metrics hold promise for helping translate future changes in climate or land use to ecosystem health
Groundwater and Energy Emerging Challenges, Directions and Opportunities [pdf]
Water and energy are interdependent. Water is used extensively in energy development as cooling water in thermoelectric power generation, in oil and alternative transportation fuels refining and in biofuels production. At the same time, water and waste water pumping, treatment, and distribution is one of the largest energy use sectors in the country. At a time when fresh water availability is becoming limited in many regions from changing precipitation patterns, increased ecological and environmental water demands, and concerns over sustainable groundwater withdrawal, water demands by the energy sector could triple over the next two decades. Emerging competition for water from the energy sector could significantly impact and change how surface and groundwater resources are developed and utilized. This presentation will provide an overview of emerging trends in how the energy and groundwater development sectors are becoming even more closely linked due to new energy development trends and water needs. The presentation will also discuss some of the emerging energy and biofuels related issues that are expected to drive future groundwater development and utilization.