Supplementary information

A hotspot analysis of water footprints and groundwater decline in the High Plains aquifer region, U.S.

Sebastian Multsch1, Markus Pahlow2, Judith Ellensohn1, Thomas Michalik1, Hans-Georg Frede1 and Lutz Breuer1

1Institute for Landscape Ecology and Resources Management (ILR), Research Centre for BioSystems, Land Use and Nutrition (IFZ), Justus Liebig University Giessen, Heinrich-Buff-Ring 26, 35392 Giessen, Germany, (, , , )

2 Water Management Group, Twente Water Centre, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands, ()

* Corresponding author: Sebastian Multsch, , Heinrich-Buff-Ring 26, 35392 Giessen, Germany, phone: +49 641 99 37384


Fig. 1 Irrigated and rainfed cropland in the High Plains Aquifer region.


Fig. 2 Alpha value of the Priestley-Taylor equation (own illustration, data from (Cristea, 2012)).

Fig. 3 Average climatic condition during the period 1990-2012. (a) Annual accumulated rainfall. (b) Average daily temperature. (c) Annual accumulated potential evapotranspiration. [own illustration, data source: Copyright ©2013, PRISM Climate Group, Oregon State University, http://prism.oregonstate.edu/, Map created 01.10.2014 ]


Fig 4 The boxplots illustrate the extent of (a) water level change, (b) green WFarea and (c) blue WFarea in each cluster.

Table 1 Input data for SPARE:WATER.

Description / Unit / Reference / Description
Crop coefficients (1) / [-] / (1) / Commonly applied dataset from FAO56 guidelines
Crop coefficients (2) / [-] / (2, 3) / Local dataset
Growing seasons (1) / [days] / (1) / Commonly applied dataset from FAO56 guidelines
Growing seasons (2) / [days] / (2, 3) / Local dataset
Rooting depth / [cm] / (1)
Crop height / [cm] / (1)
Crop salt tolerance / [dS m-1] / (5)
Sowing / [date] / (15) / Early and late dates have been considered.
Harvest / [date] / (15)
Irrigation quality / [dS m-1] / 1 dS m-1
Irrigation efficiency / [%] / (2) / 80%
Irrigation method / [-] / (6) / centre pivot technology and sprinkler systems
Digital elevation model / [m] / (7) / GTOPO30–Model, 30 arcsec (~1km)
Solar radiation / [MJ m-2] / Calculated / Calculated according to Allen et al. (1998) from temperature
Precipitation / [m³ha-1] / (8) / 2.5 arcmin, (~4km), monthly, 1990-2013
Humidity / [%]
Temperature / [°C]
Yield per crop / [t ha-1] / (9–16)
(17-18) / USDA statistics, annual
Harvest area / [ha yr-1] / see SI 5

1. Allen RG, Pereira LS, Raes D, Smith M (1998) Crop evapotranspiration-Guidelines for computing crop water requirements-FAO Irrigation and drainage paper 56. FAO, Rome 300:6541.

2. Howell TA, et al. (2006) Crop coefficients developed at Bushland, Texas for corn, wheat, sorghum, soybean, cotton, and alfalfa. Proc World Environ and Water Resour Congr, Omaha, NE:21–24.

3. Mauget S, Leiker G (2010) The Ogallala agro-climate tool. Computers and electronics in agriculture 74(1):155–162.

4. Ayers RS, Westcot DW (1994) Water quality for agriculture. FAO Irrigation and Drainage Paper 23 Rome, Italy.

5. USDA (2010) Field crops usual plating and harvesting dates.

6. Hornbeck R, Keskin P (2014) The Historically Evolving Impact of the Ogallala Aquifer: Agricultural Adaptation to Groundwater and Drought. American Economic Journal: Applied Economics 6(1):190–219.

7. USGS (2012) Global 30 Arc_second Elevation (GTOPO30). Available at: https://lta.cr.usgs.gov/GTOPO30.

8. PRISM Climate Group (2013) Climate Data (Precipitation, Max Temp., Min Temp, Dew point for 1990- 2012) (Oregon State University) Available at: http://prism.oregonstate.edu/ [Accessed June 11, 2013].

9. USDA (1993) Crop Production 1992 Summary (National Agricultural Statistics Service, US Department of Agriculture) Available at: http://usda.mannlib.http://usda.mannlib.cornell.edu/usda/nass/CropProdSu//1990s/1993/CropProdSu-01-00-1993.pdf.edu/usda/nass/CropProdSu//2010s/2013/CropProdSu-01-11-2013.pdf.

10. USDA (1996) Crop Production 1995 Summary (National Agricultural Statistics Service, US Department of Agriculture) Available at: http://usda.mannlib.cornell.edu/usda/nass/CropProdSu//1990s/1996/CropProdSu-01-00-1996.pdf.

11. USDA (1999) Crop Production 1998 Summary (National Agricultural Statistics Service, US Department of Agriculture) Available at: http://usda.mannlib.cornell.edu/usda/nass/CropProdSu//1990s/1999/CropProdSu-01-12-1999.pdf.

12. USDA (2001) Crop Production 2000 Summary (National Agricultural Statistics Service, US Department of Agriculture) Available at: http://usda.mannlib.cornell.edu/usda/nass/CropProdSu//2000s/2001/CropProdSu-01-11-2001.pdf.

13. USDA (2004) Crop Production 2003 Summary (National Agricultural Statistics Service, US Department of Agriculture) Available at: http://usda.mannlib.cornell.edu/usda/nass/CropProdSu//2000s/2004/CropProdSu-01-12-2004.pdf.

14. USDA (2007) Crop Production 2006 Summary (National Agricultural Statistics Service, US Department of Agriculture) Available at: http://usda.mannlib.cornell.edu/usda/nass/CropProdSu//2000s/2007/CropProdSu-01-12-2007.pdf.

15. USDA (2010) Crop Production 2009 Summary (National Agricultural Statistics Service, US Department of Agriculture) Available at: http://usda.mannlib.cornell.edu/usda/nass/CropProdSu//2010s/2010/CropProdSu-01-12-2010.pdf.

16. USDA (2013) Crop Production 2012 Summary (National Agricultural Statistics Service, US Department of Agriculture) Available at: http://usda.mannlib.cornell.edu/usda/nass/CropProdSu//2010s/2013/CropProdSu-01-11-2013.pdf.

17. Monfreda C, Ramankutty N, Foley JA (2008) Farming the planet: 2. Geographic distribution of crop areas, yields, physiological types, and net primary production in the year 2000. Global biogeochemical cycles 22(1).

18. Siebert S, Henrich V, Frenken K, Burke (2013) Global Map of Irrigation Areas version 5. Rheinische Friedrich-Wilhelms-University, Bonn, Germany / Food and Agriculture Organization of the United Nations, Rome, Italy 2(4):1299–1327.

Table 2 Growing seasons and crop coefficients.

Growing stages / Crop coefficients
Crop / Initial (Lini) / Growth (Ldev) / Mid (Lmid) / End (Lend) / Total / Kcini / Kcmid / Kcend
Alfalfa1 / 60 / 60 / 160 / 84 / 364 / 0.4 / 1.2 / 0.6
Corn2 / 30 / 40 / 50 / 30 / 150 / 0.3 / 1.2 / 0.45
Cotton2 / 30 / 50 / 60 / 55 / 195 / 0.35 / 1.17 / 0.6
Sorghum2 / 20 / 35 / 40 / 30 / 125 / 0.3 / 1.05 / 0.55
Soybeans2 / 20 / 35 / 60 / 25 / 140 / 0.4 / 1.15 / 0.5
Wheat2 / 30 / 140 / 40 / 30 / 240 / 0.7 / 1.15 / 0.3

1. Howell TA, et al. (2006) Crop coefficients developed at Bushland, Texas for corn, wheat, sorghum, soybean, cotton, and alfalfa. Proc World Environ and Water Resour Congr, Omaha, NE:21–24.

2. Mauget S, Leiker G (2010) The Ogallala agro-climate tool. Computers and electronics in agriculture 74(1):155–162.

Table 3 Crop water balance and water footprint of the entire High Plains Aquifer (HPA) and of each cluster (Peff – effective rainfall, ETc – crop specific evapotranspiration, IRR - irrigation water requirement, green WFcrop - green crop water footprint, blue WFcrop - blue crop water footprint, total WFcrop - total crop water footprint, green WFarea - green regional water footprint, blue WFarea - blue regional water footprint, total WFarea - total regional water footprint).

Region / Crop / Peff / ETc / IRR / Green
WFcrop / Blue
WFcrop / Total
WFcrop / Green
WFarea / Blue
WFarea / Total
WFarea
mm growing season-1 / m3 t-1 / km3 yr-1
HPA / Alfalfa / 556 / 1094 / 559 / 640 / 619 / 1259 / 2.02 / 2.14 / 4.17
HPA / Corn / 356 / 630 / 344 / 427 / 410 / 837 / 9.63 / 7.10 / 16.73
HPA / Cotton / 306 / 988 / 680 / 5325 / 11719 / 17044 / 2.27 / 5.14 / 7.40
HPA / Sorghum / 264 / 519 / 282 / 631 / 675 / 1306 / 1.36 / 1.58 / 2.94
HPA / Soybeans / 382 / 626 / 290 / 1355 / 1030 / 2385 / 2.42 / 1.64 / 4.05
HPA / Wheat / 199 / 640 / 437 / 877 / 1831 / 2709 / 3.27 / 7.15 / 10.43
20.97 / 24.75 / 45.71
Class Slight / Alfalfa / 673 / 1000 / 397 / 757 / 446 / 1203 / 0.04 / 0.02 / 0.07
Class Low / Alfalfa / 486 / 1213 / 744 / 544 / 802 / 1346 / 0.12 / 0.17 / 0.29
Class Moderate / Alfalfa / 455 / 1275 / 830 / 488 / 876 / 1364 / 0.04 / 0.07 / 0.12
Class Significant / Alfalfa / 493 / 1226 / 759 / 519 / 801 / 1320 / 0.14 / 0.19 / 0.33
Class Severe / Alfalfa / 441 / 1288 / 855 / 458 / 887 / 1345 / 0.05 / 0.09 / 0.13
Class Slight / Corn / 483 / 589 / 227 / 538 / 253 / 791 / 0.75 / 0.35 / 1.10
Class Low / Corn / 338 / 662 / 385 / 395 / 448 / 843 / 0.69 / 0.72 / 1.41
Class Moderate / Corn / 310 / 659 / 401 / 391 / 507 / 898 / 0.47 / 0.63 / 1.10
Class Significant / Corn / 342 / 657 / 378 / 401 / 451 / 852 / 0.66 / 0.71 / 1.37
Class Severe / Corn / 286 / 657 / 414 / 374 / 552 / 926 / 0.52 / 0.75 / 1.28
Class Slight / Cotton / 0.00 / 0.00 / 0.00 / 0.00 / 0.00 / 0.00 / 0.00 / 0.00 / 0.00
Class Low / Cotton / 300 / 1021 / 740 / 5185 / 11956 / 17142 / 0.10 / 0.23 / 0.33
Class Moderate / Cotton / 326 / 990 / 659 / 5727 / 11411 / 17138 / 0.15 / 0.31 / 0.46
Class Significant / Cotton / 294 / 993 / 720 / 5116 / 12473 / 17589 / 0.78 / 1.89 / 2.67
Class Severe / Cotton / 321 / 964 / 645 / 5639 / 11244 / 16883 / 0.79 / 1.64 / 2.43
Class Slight / Sorghum / 372 / 478 / 158 / 706 / 300 / 1006 / 0.04 / 0.02 / 0.06
Class Low / Sorghum / 257 / 540 / 285 / 632 / 684 / 1315 / 0.20 / 0.23 / 0.43
Class Moderate / Sorghum / 224 / 493 / 299 / 588 / 771 / 1360 / 0.21 / 0.28 / 0.49
Class Significant / Sorghum / 185 / 525 / 321 / 516 / 874 / 1390 / 0.19 / 0.28 / 0.47
Class Severe / Sorghum / 204 / 493 / 310 / 545 / 814 / 1359 / 0.22 / 0.32 / 0.54
Class Slight / Soybeans / 414 / 615 / 252 / 1399 / 852 / 2251 / 0.25 / 0.15 / 0.40
Class Low / Soybeans / 336 / 695 / 371 / 1492 / 1695 / 3187 / 0.04 / 0.04 / 0.08
Class Moderate / Soybeans / 295 / 709 / 426 / 1403 / 2097 / 3500 / 0.01 / 0.01 / 0.02
Class Significant / Soybeans / 300 / 709 / 421 / 1348 / 1673 / 3020 / 0.06 / 0.06 / 0.12
Class Severe / Soybeans / 265 / 709 / 454 / 1394 / 2404 / 3798 / 0.03 / 0.05 / 0.07
Class Slight / Wheat / 285 / 470 / 201 / 1113 / 786 / 1899 / 0.01 / 0.01 / 0.02
Class Low / Wheat / 191 / 641 / 453 / 818 / 2044 / 2862 / 0.72 / 1.56 / 2.28
Class Moderate / Wheat / 189 / 695 / 508 / 877 / 2498 / 3375 / 0.50 / 1.32 / 1.82
Class Significant / Wheat / 203 / 695 / 486 / 947 / 2292 / 3239 / 0.38 / 0.85 / 1.23
Class Severe / Wheat / 206 / 757 / 552 / 996 / 2736 / 3732 / 0.42 / 1.12 / 1.54
8.58 / 14.07 / 22.65

Table 4 Median as well as 10% and 90% Percentile of groundwater level decline, green and blue WFarea in each cluster.

Item / Cluster / Median / 10% Percentile / 90% Percentile
Groundwater level decline [m] / Slight / -2.4 / -4.1 / -1.6
Low / -4.3 / -13 / -1.8
Moderate / -21.4 / -33 / -14.1
Significant / -9.5 / -19 / -2.6
Severe / -41.9 / -51.9 / -28.5
Green WFarea [mmyr-1] / Slight / 460 / 426 / 476
Low / 229 / 174 / 316
Moderate / 228 / 205 / 283
Significant / 271 / 234 / 362
Severe / 265 / 214 / 293
Blue WFarea [mmyr-1] / Slight / 234 / 212 / 247
Low / 408 / 302 / 539
Moderate / 444 / 390 / 516
Significant / 461 / 348 / 686
Severe / 515 / 430 / 600

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