Description: <DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN><SPAN>Groundwater pumping chronically exceeds natural recharge in many agricultural regions in California.</SPAN></SPAN></P><P><SPAN><SPAN>A common method of recharging groundwater — when surface water is available — is to deliberately</SPAN></SPAN></P><P><SPAN><SPAN>flood an open area, allowing water to percolate into an aquifer. However, open land suitable for this</SPAN></SPAN></P><P><SPAN><SPAN>type of recharge is scarce. Flooding agricultural land during fallow or dormant periods has the potential</SPAN></SPAN></P><P><SPAN><SPAN>to increase groundwater recharge substantially, but this approach has not been well studied. Using data</SPAN></SPAN></P><P><SPAN><SPAN>on soils, topography and crop type, we developed a spatially explicit index of the suitability for</SPAN></SPAN></P><P><SPAN><SPAN>groundwater recharge of land in all agricultural regions in California.</SPAN></SPAN></P><P><SPAN STYLE="font-weight:bold;"><SPAN>Date: </SPAN></SPAN><SPAN><SPAN>2015</SPAN></SPAN></P><P STYLE="font-weight:bold;"><SPAN><SPAN>Point of Contact:</SPAN></SPAN></P><P><SPAN><SPAN>Toby O’Geen</SPAN></SPAN></P><P><SPAN><SPAN>Professor & Soil Resource Specialist in Cooperative Extension</SPAN></SPAN></P><P><SPAN><SPAN>Dept. of Land, Air and Water Resources, UC Davis</SPAN></SPAN></P><P><SPAN><SPAN>atogeen@ucdavis.edu</SPAN></SPAN></P><P><SPAN><SPAN>530-752-2155</SPAN></SPAN></P><P STYLE="font-weight:bold;"><SPAN><SPAN>Field Definitions:</SPAN></SPAN></P><P><SPAN><SPAN>areasymbol </SPAN></SPAN><SPAN STYLE="font-style:italic;"><SPAN>– </SPAN></SPAN><SPAN><SPAN>symbol representing the SSURGO survey area</SPAN></SPAN></P><P><SPAN><SPAN>spatialver – number used to denote the serial version of the SSURGO spatial data for a soil survey</SPAN></SPAN></P><P><SPAN><SPAN>musym – symbol used to identify the soil map unit in the SSURGO soil survey</SPAN></SPAN></P><P><SPAN><SPAN>mukey – string used to uniquely identify the SSURGO map unit</SPAN></SPAN></P><P><SPAN><SPAN>mukey_num – same as mukey field, but in numeric format</SPAN></SPAN></P><P><SPAN><SPAN>acres – area in acres of the mapped polygon</SPAN></SPAN></P><P><SPAN><SPAN>mukey_1 – duplicate of mukey field</SPAN></SPAN></P><P><SPAN><SPAN>cokey – string used to identify the dominant component of the SSURGO map unit</SPAN></SPAN></P><P><SPAN><SPAN>deep_perc – suitability score (0-100) for the deep percolation SAGBI factor</SPAN></SPAN></P><P><SPAN><SPAN>rt_zn_res_ – suitability score (0-100) for the root zone residence time SAGBI factor</SPAN></SPAN></P><P><SPAN><SPAN>toxicity – suitability score (0-100) for the toxicity SAGBI factor</SPAN></SPAN></P><P><SPAN><SPAN>topo_rest – suitability score (0-100) for the topographic restrictions SAGBI factor</SPAN></SPAN></P><P><SPAN><SPAN>surf_cond – suitability score (0-100) for the surface condition SAGBI factor</SPAN></SPAN></P><P><SPAN><SPAN>restrictns – description of the dominant component’s restrictive layers</SPAN></SPAN></P><P><SPAN><SPAN>sagbi – overall SAGBI suitability score (0-100)</SPAN></SPAN></P><P><SPAN><SPAN>rat_grp – rating group associated with the SAGBI score</SPAN></SPAN></P><P><SPAN><SPAN>slope_l – slope gradient (low value) of the dominant component</SPAN></SPAN></P><P><SPAN><SPAN>slope_h – slope gradient (high value) of the dominant component</SPAN></SPAN></P><P><SPAN><SPAN>compname – name of the dominant soil component</SPAN></SPAN></P><P><SPAN><SPAN>taxsubgrp – the taxonomic subgroup of the dominant component</SPAN></SPAN></P><P STYLE="font-weight:bold;"><SPAN><SPAN>Suggested Symbology:</SPAN></SPAN></P><P><SPAN><SPAN>SAGBI Score Rating Group RGB values</SPAN></SPAN></P><P><SPAN><SPAN>85 – 100 Excellent 38, 115, 0</SPAN></SPAN></P><P><SPAN><SPAN>69 - 85 Good 152, 230, 0</SPAN></SPAN></P><P><SPAN><SPAN>49 - 69 Moderately Good 255, 255, 0</SPAN></SPAN></P><P><SPAN><SPAN>29 - 49 Moderately Poor 255, 170, 0</SPAN></SPAN></P><P><SPAN><SPAN>15 - 29 Poor 255, 85, 0</SPAN></SPAN></P><P STYLE="margin:0 0 0 0;"><SPAN STYLE="font-size:16pt"><SPAN>0 - 15 Very Poor 168, 0, 0</SPAN></SPAN></P></DIV></DIV></DIV>
Copyright Text: O'Geen A, Saal M, Dahlke H, Doll D, Elkins R, Fulton A, Fogg G, Harter T, Hopmans J,
Ingels C, Niederholzer F, Sandoval Solis S, Verdegaal P, Walkinshaw M. 2015. Soil suitability index
identifies potential areas for groundwater banking on agricultural lands. Calif Agr 69(2):75-84.
Available online at http://calag.ucanr.edu/archive/?article=ca.v069n02p75