Premium
Quantifying the regional water footprint of biofuel production by incorporating hydrologic modeling
Author(s) -
Wu M.,
Chiu Y.,
Demissie Y.
Publication year - 2012
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/2011wr011809
Subject(s) - environmental science , water use , watershed , corn stover , hydrology (agriculture) , evapotranspiration , footprint , irrigation , water resource management , soil and water assessment tool , biofuel , drainage basin , geography , streamflow , agronomy , engineering , geotechnical engineering , cartography , archaeology , machine learning , computer science , ecology , biology , waste management
A spatially explicit life cycle water analysis framework is proposed, in which a standardized water footprint methodology is coupled with hydrologic modeling to assess blue water, green water (rainfall), and agricultural grey water discharge in the production of biofuel feedstock at county‐level resolution. Grey water is simulated via SWAT, a watershed model. Evapotranspiration (ET) estimates generated with the Penman‐Monteith equation and crop parameters were verified by using remote sensing results, a satellite‐imagery‐derived data set, and other field measurements. Crop irrigation survey data are used to corroborate the estimate of irrigation ET. An application of the concept is presented in a case study for corn‐stover‐based ethanol grown in Iowa (United States) within the Upper Mississippi River basin. Results show vast spatial variations in the water footprint of stover ethanol from county to county. Producing 1 L of ethanol from corn stover growing in the Iowa counties studied requires from 4.6 to 13.1 L of blue water (with an average of 5.4 L), a majority (86%) of which is consumed in the biorefinery. The county‐level green water (rainfall) footprint ranges from 760 to 1000 L L −1 . The grey water footprint varies considerably, ranging from 44 to 1579 L, a 35‐fold difference, with a county average of 518 L. This framework can be a useful tool for watershed‐ or county‐level biofuel sustainability metric analysis to address the heterogeneity of the water footprint for biofuels.