Description

Irrigation water is a key resource in desert agriculture. Water for agriculture is, however, in direct competition with urban water use and therefore, at serious risk when dealing with long-term and intense drought situations that are expected to increase in many arid regions, including the Southwestern US (National Research Council, 2007). Risk to agriculture varies among regions because of different priorities of use. The overall goals of this study are to better understand how water use by crop type responds to drought conditions and to use this knowledge to support adaptive management in the agricultural sector and foster sustainable water use in an era of climate uncertainty and change. This project seeks to answer the underlying research questions: 1) How does vulnerability to drought vary by crop types based on a large spatial scale analysis?; 2) What is the impact of drought on agricultural water consumption at different spatial scales?; 3) What adaptive options are available through changes in crop mixes and limited time market driven water transfers? and 4) What are the economic cost-benefits of alternative adaptation strategies under different drought scenarios at the farm and watershed levels? The project will focus on a highly climate sensitive region within Southwestern US which is also subject to strong urbanization pressure: Phoenix Active Management Area (PHX AMA) in central Arizona. Nearly all crops in this region rely on irrigation with agriculture accounting for nearly forty percent of all water used. To address the above research questions, we have set the following objectives: (1) Identify different agricultural crop types in two wet years (i.e., 2001, 2005) and two drought years (i.e., 2000, 2002) over the selected study area using advanced image processing techniques and remotely sensed data (e.g., Landsat, QuickBird); (2) Determine evapotranspiration (ET) or water demand by crop type for the selected years using satellite-based SEBAL/MATIRC; (3) Generate water demand per crop per pixel and integrate with selected drought indicators (e.g., Gridded Standardized Precipitation Index - SPI, gridded Hydroclimatic index); (4) Examine statistical relations between water demand by individual crop types as well as agriculture land as a whole and drought index using spatial regression and analysis of variance tests; and (5) Estimate the economic impacts of drought at both farm and the watershed level and assess economic cost-benefits of alternative adaptation strategies under different drought scenarios using crop budget analysis. NOAA's goal is to "help society cope with, and adapt to, todays variations in climate and to prepare for tomorrows." By providing an accurate assessment of consumptive water use by crops and other vegetation in two typical dry and wet years, our project will identify current crop-specific and regionspecific vulnerabilities. This will help promote a better understanding of how to plan for and respond to drought. Examining, analyzing, modeling, and translating coupled climate (e.g., drought index, surface temperatures, rainfall, albedo) and agricultural data (e.g., crop types, ET, water demand, crop budgets, NDVI) will enable adaptive decision making options for sustainable water use by demonstrating where water can be saved and the associated economic impacts. Our proposed project is directly relevant to NOAA's five-year climate objectives as outlined by the NGSP - 1) Improved scientific understanding of the changing climate system and its impacts; 2) Assessments of current and future states of the climate system that identify potential impacts and inform science, service, and stewardship decisions; 3) Mitigation and adaptation choices supported by sustained, reliable, and timely climate services; and 4) A climate-literate public that understands its vulnerabilities to a changing climate and makes informed decisions.
StatusFinished
Effective start/end date8/1/127/31/16

Funding

  • DOC: National Oceanic Atmospheric Administration (NOAA): $285,000.00

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water use
agricultural land
drought
decision making
land use
crop
climate
water demand
agriculture
vulnerability
economic impact
evaluation
evapotranspiration
irrigation
farm
watershed
water
QuickBird
adaptive management
arid region