u.s. department of the interior u.s. geological survey 14 august 2013 agro-geoinformatics 2013...
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DESCRIPTIONIrrigated Agriculture in U.S. Over 23 m hectares (233 K km 2 ) of U.S. croplands are irrigated a) b)
U.S. Department of the Interior U.S. Geological Survey 14 August 2013 Agro-Geoinformatics 2013 Agro-Geoinformatics 2013 Variability and trends in irrigated and non-irrigated croplands in the Central U.S. Jesslyn Brown, USGS EROS Acknowledgments Shahriar Pervez (Inu tec) Susan Maxwell (Biomedware) Brian Wardlow (NDMCUNL) Karin Callahan (NDMCUNL) Ron Zelt (USGS Nebraska Science Center) Irrigation ground reference data providers: California Department of Water Resources Idaho Water Resources Board University of North Dakota Irrigated Agriculture in U.S. Over 23 m hectares (233 K km 2 ) of U.S. croplands are irrigated a) b) % Source: USDA NASS Source: USDA 2002 Census Irrigation is an agricultural practice Agricultural intensification Drivers for expansion in the U.S. (early to mid 20 th century) Climate uncertainty Rising demand for farm productsrising (urban) population, rising sophistication in diet Increasing crop yields (esp. in moisture limited environments like the American West) Raising farm revenues Federal policies to develop water supplies Development of new technologies for groundwater mining and irrigation equipment Gollehon, N., Quinby, W., Irrigation in the American West: Area, water and economic activity. International Journal of Water Resources Development 16, Requirement for Geospatial Data on Irrigation Status (Land Use Data) Irrigation status is a required data layer in drought monitoring In drought monitoring, we need to separate locations that receive supplemental moisture from those that dont Repeatable and reliable process Coast to coast coverage (48-state) Moderate resolution (able to resolve median irrigated field size in U.S.) Direct and spatially-detailed modeling strategy Source: USDA 2002 Census MODIS Irrigated Agriculture Dataset for the United States (MIrAD-US): Data and Methodology Model Inputs Irrigated area statistics from USDA NASS 2002 Census of Agriculture 2002 annual peak MODIS NDVI (250 m) 2001 NLCD MIrAD Model Assumptions Irrigated crops commonly exhibit higher annual peak NDVI values than non-irrigated crops in the same local area. The growing season peak NDVI, at any time it occurs, will vary for each crop and for each geographic region of the U.S. The difference in peak NDVI between irrigated and non-irrigated crops will be enhanced under non-optimal precipitation conditions (e.g., drought). MODIS 250-meter NDVI time series Annual Peak NDVI 2002 Drought Beans & Corn Blue line : Irrigated Red line : non-irrigated Peak NDVI for Separating Irrigated and Non-irrigated Crops Corn Dry Beans Pasture Crop Avg. Corn & Millet Model Approach Runs on a County Domain MODIS annual peak NDVI Area of 1 st peak > USDA irr. acg. Masking : Peak NDVI for agricultural land only NLCD Area of 2 nd peak > USDA irr. acg. Area of n th peak > USDA irr. acg. Area of last peak > USDA irr. acg. yes no yes Peak NDVI cells above or equal to threshold peak NDVI are identified as irrigated All the peak NDVI cells are considered irrigated The cumulative area for peak NDVI is compared with irrigated area reported by USDA by county Loop for defining peak NDVI threshold for irrigated crops Peak NDVI rank Desc. order Pervez & Brown (2010) Remote Sensing 2(10) 2002 MIrAD-US Vegetation Irrigated crop landLegend MIrAD-US Accuracy Error Matrix SiteCategory ProducersOverallKappaProducersOverallKappa California Irrigated Non-Irri.0.97 Great Plains Irrigated Non-Irri.0.80 Eastern Snake Plain Aquifer- Idaho Irrigated Non-Irri.0.98 Regional accuracies were over 88% Accuracy at national scale is unknown Spatial Change in Irrigated Lands between 2002 and 2007 U.S. Land Use Change: Irrigation Status In 2002, 22.4 million ha (55.3 million acres) were irrigated In 2007, 22.9 million ha (56.6 million acres) were irrigated Net increase of 2.3% nationally Nationally, the proportion of harvested croplands that are irrigated has increased slightly during the last 15 years, according to the USDA Agricultural Census. Irrigation Change (2002 to 2007) Top ten States Irrigated area in million Ha. Irrigation Consistency Top ten States State% changed (spatially) % net change Nebraska 3.68CA California 3.23ID Texas 2.02UT Arkansas 1.88NV Idaho 1.34AZ Kansas 1.17NE Colorado 1.13WY Montana 0.81CO Oregon 0.73WA Washington 0.71AR High Plains Aquifer The HPA underlies ~450 thousand km 2 (8 states: SD, WY, NE, CO, KS, OK, NM, TX) Most intensively used aquifer in the U.S. Ground water use primarily for irrigated agriculture More than 60% of the aquifer lies under one state, Nebraska Irrigation Change across the High Plains Aquifer State Irrigated area in ha Common area between 2007 and 2002 New in 2007Lost from 2002 Net Change in % in ha% % % NE3,422,0132,942,8562,220, ,201, , TX1,469,2881,451,419871, , , KS1,022,581969,206454, , , CO270,656270,413138, , , WY111,144116,64470, , , OK105,406103,85051, , , NM96,525125,53166, , , SD7,4005,4691, , , Total6,505,0125,985,3873,874, ,630, ,110, Irrigation Change Factors Causing Recent Irrigation Change in the HPA Economic incentives Rising commodity prices Rising land values Government policies (e.g. water reg.) Demand for corn (biofuels, livestock feed, food) Climate Corn Wheat Soybeans Sorghum Irrigation and 2012 Corn Yields Recent article from U.S. Department of State The 2012 drought the worst in more than 50 years for several U.S. states reduced yields in many states, but less so in Nebraska. It is expected to end its 2012 summer growing season with its eighth- largest grain yield in history while drawing down its aquifer just 1 percent, Lenton said. More than 65 percent of the High Plains Aquifer, the largest in North America, lies beneath the state. Read more: html#ixzz296ElvEHK html#ixzz296ElvEHK From 2002 to 2007, NE land values rose 48% on average, 51% for CP Irrigated Cropland. Demand for Corn Due to Ethanol Nebraska Water Policy Published by the Nebraska Department of Natural Resources Consequences of Irrigation Expansion Increased crop productivity Changing boundary layer energy and water exchange Changes in ET Groundwater storage Regional climate Water quality Fischer, B.C. et al. Digital map of the saturated thickness of the High Plains aquifer in parts of Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas and Wyoming, HPA Water Budget Components Stanton, J.S., Qi, S.L., Ryter, D.W., and others, 2011, Selected approaches to estimate water- budget components of the High Plains, 1940 through 1949 and 2000 through 2009: U.S. Geological Survey Scientific Investigations Report 20115183, 79 p. (Values enclosed in parantheses are given in million acre-feet per year.) Water level changes in the HPA Predevelopment to 2009 Average water level change ft McGuire, V.L., 2011, Water-level changes in the High Plains aquifer, predevelopment to 2009, 200708, and 200809, and change in water in storage, predevelopment to 2009: U.S. Geological Survey Scientific Investigations Report 20115089, 13 p. Water level changes in the HPA New irrigation in 2007 McGuire, V.L., 2011, Water-level changes in the High Plains aquifer, predevelopment to 2009, 200708, and 200809, and change in water in storage, predevelopment to 2009: U.S. Geological Survey Scientific Investigations Report 20115089, 13 p. Summary Regional variability in spatial change irrigated agriculture from Nationally +2.3% HPA +8.7% NE +16.3% Various causes and consequences Future monitoring will be important especially as it relates to sustainable water use (ground and surface water) References Brown, J.F. and Pervez, M.S., Merging remote sensing data and national agricultural statistics to model change in irrigated agriculture, Agricultural Systems, in review. Pervez, M.S. and Brown, J.F., 2010, Mapping irrigated lands at 250-m scale by merging MODIS data and national agricultural statistics, Remote Sensing, 2(10), ; doi: /rs Brown, J.F., Pervez, M.S., and Maxwell, S., Mapping irrigated lands across the United States using MODIS satellite imagery. In Remote Sensing of Global Croplands for Food Security, Eds., Thenkabail, P.S., Lyon, J.G., Biradar, C.M., and Turral, H., London, Taylor and Francis, Boca Raton, p Access to Geospatial Data 2002 and 2007 MIrAD-US can be downloaded from Questions? Extra slides Irrigation increased corn yields by Bu/Acre. 2009, 2010 saw historical high yields. In drought years (*): 80 100 Bu/Acre. * * * Detrending actually shows a recent decrease in the difference between irrigated and non-irrigated yields. U.S. Irrigation Water Use Irrigated Agriculture Methodology CountyCounty area (acres) Irrigated area (acres) % of Total County Area Dawes Peak NDVI Cell CountArea (sq m)Area (acre)Cumulative Area (acre) Process is iterative, performed one county at a time for 3,114 counties. Irrigated Agriculture Methodology CountyCounty area (acres) Irrigated area (acres) % of Total County Area Dawes Peak NDVI Cell CountArea (sq m)Area (acre)Cumulative Area (acre) Key StakeholdersIrrigation Status Plans/Opportunities 2012 is an Agricultural Census year. Updated statistics will be published late in Opportunity to produce MIrAD-US for 2012 and further land use change research. Experiment with modeling results at the Landsat scale Crop-specific irrigated agriculture maps % Source: USDA NASS % Source: USDA NASS % Source: USDA NASS