Schwarz, G.E. and Alexander, R.B. 19950901 1.1 Series_Name Open-File Report Issue_Identification 95-449 Reston, VA U.S. Geological Survey http://water.usgs.gov/lookup/getspatial?ussoils USSOILS is an Arc 7.0 coverage containing hydrology-relevant information for 10,498 map units covering the entire conterminous United States. The coverage was compiled from individual State coverages contained in the October 1994 State Soil Geographic (STATSGO) Data Base produced on CD-ROM. The geo-dataset USSOILS.PAT relates (on the basis of a map unit identifier) the 10,498 map units to 78,518 polygons. The scale of the geo-dataset is 1:250,000. The INFO attribute table USSOILS.MUID_ATTS contains selected variables from the STATSGO data set for 10,501 map units (an extra 3 map units are contained in the attribute table that are not in the geo-dataset - see the 'Procedures' section below), including: the map unit identifier, a 2-character state abbreviation, available water capacity of the soil, percent clay in the soil, the actual k-factor used in the water erosion component of the universal soil loss equation, the organic material in soil, soil permeability, cumulative thickness of all soil layers, hydrologic characteristics of the soil, quality of drainage, surface slope, liquid limit of the soil, share of a map unit having hydric soils, and the annual frequency of flooding. To facilitate mapping the attribute data, the narrative section below contains instructions for transferring the information contained in the attribute table USSOILS.MUID_ATTS to the polygon attribute table USSOILS.PAT. STATSGO United States Soil Water Capacity Clay Organic material Permeability Infiltration Drainage Hydric Flood frequency Slope The USSOILS coverage was originally compiled to support a national model of water quality. The model uses the soil characteristics contained in this coverage to mediate deliveries of nonpoint source pollution to stream and river segments in the RF1 data base. The National Resource Conservation Service (NRCS) recommends that any maps using NRCS STATSGO data show the source and date, and provide the following statement: "STATSGO is designed to support regional, multistate, State, and river basin resource planning, management and monitoring." Procedures_Used: The individual State coverages are from the State Soil Geographic (STATSGO) CD-ROM data base, issued by U.S. Department of Agriculture, NRCS National Cartography and GIS Center, P.O. Box 6567, Fort Worth, Texas 76115-0567, 1-800-672-5559 (U.S. Department of Agriculture, 1991). The CD-ROM coverage for New Mexico was defective and was not used. A corrected copy of the New Mexico coverage was obtained from Norman Bliss of the EROS Data Center ((605) 594-6034). The STATSGO State-based coverages were merged together into a national coverage using the Arc MAPJOIN command. All nodes along merged boundaries were checked and edited to remove any superfluous nodes created during the mapjoin process, and to ensure arcs properly merged along and across State boundaries. The joining process preserved all State boundaries. To understand the procedures used to create the attribute table USSOILS.MUID_ATTS, it helps to have an understanding of the STATSGO data structure. The smallest spatial entity mapped within the STATSGO dataset is called a map unit, of which there are 10,498 broken out into 78,518 polygons within the conterminous United States. Each map unit consists of up to 21 components. Components are used to apportion different characteristics of a map unit and do not represent a separate spatial entity. To help understand this, consider a map unit that has only two components. Suppose 30 percent of this map unit contains soil of type A and the remaining 70 percent contains soil of type B. Thus, component 1 of the map unit would have soil type A and component 2 would have soil type B. The data base would record the soil type for each component, along with the percentage of the map unit represented by each component (in this example, 30 percent for component 1 and 70 percent for component 2). The specific locations of soil types A and B are not spatially defined in the data base. Each component is further delineated into a maximum of 6 layers, corresponding to distinct soil layers. Soil characteristics recorded for a layer typically consist of a high and low value, which describes a range for that characteristic within that layer. Included among the characteristics of the soil layer is the thickness of the layer. In developing the USSOILS.MUID_ATTS table, it is necessary to aggregate the layer and component information up to the level of a map unit. To aggregate layer information to the component level, we first construct a simple average of the high and low values of a characteristic for each layer. We then construct a weighted average across all layers of the layer-specific characteristic averages, the weights being the thickness of the layer relative to the total thickness of all layers. For component-level information that is expressed as a range, we construct a simple average of the high and low values defining the range. These steps reduce layer-specific information and ranges of component-specific information into a single datum of component-specific information for each characteristic in the data base. Finally, to obtain map unit information, we construct a weighted average across all components of the component-specific information, the weights being the component percentages given for the map unit. Included in the Notes section below are the computer programs used to construct the USSOILS.MUID_ATTS data base, along with an AML program for transferring this information to the polygon attribute table USSOILS.PAT. We ask the reader to refer to the documentation contained in these programs to obtain detailed information on the methods used to construct each data item. The following is a brief description of how the programs were used. The AMLs "layer_out.aml" and "comp_out.aml" were run using the UNIX batch program "batch.prog" to write data from the STATSGO State INFO layer and comp files into ascii files. The ascii files were read by the SAS program "setussoils.sas" to aggregate data from the layer and component level to the map unit level. If there is no information available to determine a characteristic's value in a given map unit, the characteristic is given the value -0.1 to indicate a missing value. The program "setussoils.sas" creates an ascii, comma-delimited file and a SAS file of the aggregated, map unit data containing information for 10,470 map units. The comma-delimited, ascii file is then read back into ARC/INFO using the aml "ussoils_muid_atts.aml" to create the attribute table USSOILS.MUID_ATTS. Note that there is a discrepancy between the number of map units contained in the combined COMP and LAYER files (10,470) and the number contained in the polygon attribute table (PAT) USSOILS.PAT (10,498 broken out into 78,518 polygons). The discrepancy arises because 3 map units in the COMP and LAYER files were not included in the PAT (these are - VT029, UTWA1 (not in LAYER file either), and NE165 (not in LAYER file either)), while 31 map units in the PAT coverage were not in the COMP or LAYER files. The 31 map units missing from the COMP and LAYER files are all "water" designated map units for which the values of all items are missing. To assure that the attribute table is complete, the program 'ussoils_muid_atts.aml' appends the missing MUIDs from USSOILS.PAT to USSOILS.MUID_ATTS and sets the attribute values (except for STATE) to missing. Thus, the total number of map units contained in USSOILS.MUID_ATTS is 10,501 (10,470 + 31). We made no attempts to correct the USSOILS.PAT file for the 3 missing map units contained in the COMP and LAYER files and in the attribute table USSOILS.MUID_ATTS. To assist the user in mapping the attribute information, we include the program 'ussoils_atts.aml' in the "Notes" section. This program relates the attribute information for the 10,498 "mapped" map units (10,501 - 3) to the 78,518 polygons contained in the polygon attribute table USSOILS.PAT. This program may be run as an AML from the command line in ARC by entering the command: &r ussoils_atts. Revisions: 1.0 Original Version 1.1 Changed the documentation and coverages in accordance with comments received from reviewers. Created the INFO file USSOILS.MUID_ATTS containing the attribute information for 10,501 map units. Deleted this information from the polygon attribute table USSOILS.PAT. Changed the programs and documentation to reflect this change in file structure. Reviews_Applied_to_Data: Summary of review by Ken Lanfear, Network Info Products Coordinator, Reston, VA, August 21, 1995. Ken reviewed the metadata for the State Soil Geographic (STATSGO) Data Base for the Conterminous United States, and the associated coverage, ussoils. He viewed the coverage on a computer screen to ensure arcs were present for the 48 conterminous States and the District of Columbia (included in Maryland). He selected several States by Mapping Unit ID (MUID) and plotted polygons to check that the states were complete and that mapping units plotted in the correct state. He also examined the polygon attribute table, USSOILS.PAT, to note record counts and verify the format. He spot checked one mapping unit (TX118) against the original data (which was on line) and verified that the HYGRP and DRAIN items were computed correctly. He read the procedures included under supplementary information, and concurs with the overall processing steps. However, time did not permit him to check details of the coding. Ken found one possible discrepancy: There are 10,499 (actually 10,498 if we exclude the null map unit consisting of the "outer" polygon to the coverage) unique MUID's in the USSOILS.PAT file, but only 10,470 in the SOIL_ATTS file. He inquired where the 29 extra units came from? Ken emphasized that the narrative portion should be modified to make it clear that each mapping unit can be comprised of several polygons. This caused him some confusion initially. Ken had a suggestion for reducing the size of the coverage. Instead of appending all the items of SOIL_ATTS to USSOILS.PAT, why not just rename SOIL_ATTS to USSOILS.SOIL_ATTS ? This file would export with the coverage. By copying to the .PAT, the values are repeated an average of about 7.8 times. However, since the current form of ussoils is large but workable, he made this suggestion optional. Summary of review by Barb Ruddy, Hydrologist, Lakewood, CO, August 31, 1995. Barb looked at the programs to make sure they made sense. She found the programs to be well documented and the procedures to be appropriate for aggregating the comp and layer information to a single map unit value. She checked the values for the variable hygrp and found they were comparable to the analysis that she and Bill Battaglin had done. She also looked at how the data plotted nationally and it checked. Barb's main concern was the inefficient storage of the attribute information. Because each map unit is repeated multiple times in the PAT file, she suggested that the attribute data could be more efficiently stored in an info file. Related_Spatial_and_Tabular_Data_Sets: None Other_References_Cited: U.S. Department of Agriculture, National Resource Conservation Service, National Soil Survey Center, 1991, "State Soil Geographic (STATSGO) Data Base: Data use information," Miscellaneous Publication Number 1492, 110 p. (Revised July 1994.) Notes: The AMLs and SAS programs used to create USSOILS.MUID_ATTS and to transfer the attribute information to the polygon attribute table USSOILS.PAT are given below. Please refer to the documentation contained in these programs for information on variable descriptions, and computation methods. 1. The AML "layer_out.aml" used to unload selected items from the individual STATSGO State layer files into a single ascii data set. /*---------------------------------------------------------------------- /* /* Command name: LAYER_OUT.AML /* Language: AML /* /*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: /* /* Purpose: Program outputs soil LAYER data for processing in SAS. /* /*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: /* /* Comments: /* 1. Item description: /* LAYDEPH,LAYDEPL = layer depth high,low values /* AWC = available water capacity (inches/inch) /* CLAY = clay content of soil (% of soil < 2mm in size) /* KFFACT = soil erodibility f-factor /* OM = organic matter content (% by weight) /* PERM = permeability rates (inches/hour) /* LL = liquid limit of the soil (%moisture by weight) /* /*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: /* /* History: /* Author/Site, Date, Event /* ------------------------------------------------------------ /* R. Alexander/G. Schwarz 04/18/95 CREATED /*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: &sv STATEUP := [TRANSLATE [response 'ENTER STATE']] &DATA arc info ARC /* CALC $NM = 1 CALC $COMMA-SWITCH = -1 CALC $PRINTER-SIZE = 200 /*====================================================================== /* SEL LAYER OUTPUT /srv3/bsa/gschwarz/statsgo/LAYER.%STATEUP% INIT PRINT MUID,SEQNUM,LAYDEPH,LAYDEPL,AWCH,~ AWCL,CLAYH,CLAYL,KFFACT,OMH,OML,~ PERMH,PERML,LLH,LLL /* Q STOP &END &RETURN 2. The AML "comp_out.aml" used to unload selected items from the individual STATSGO State component files into a single ascii data set. /*---------------------------------------------------------------------- /* /* Command name: COMP_OUT.AML /* Language: AML /* /*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: /* /* Purpose: Program outputs soil COMP data for processing in SAS. /* /*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: /* /* Comments: /* 1. Output data are averages of high and low values /* /* 2. Item description: /* MUID = Mapunit identifier /* SEQNUM = component identifier /* COMPNAME = Name of the component /* COMPKIND = Description of the kind of component /* COMPPCT = Percent of mapunit represented by component /* DRAINAGE = Drainage quality (1=well drained to 7=poorly drained) /* HYDGRP = soil index variables (1=well drained to 4=poorly drained) /* HYDRIC = hydric soil indicator (1 if hydric) /* ANFLOOD = Annual flood frequency (1 = frequent (>50% chance) /* 2 = occasional (5-50% chance), 3 = rare (<5% chance)) /* SLOPE = Slope of surface (percent) /* /*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: /* /* History: /* Author/Site, Date, Event /* ------------------------------------------------------------ /* R. Alexander/G. Schwarz 04/18/95 CREATED /*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: &sv STATEUP := [TRANSLATE [response 'ENTER STATE']] /* &DATA arc info ARC /* CALC $NM = 1 CALC $COMMA-SWITCH = -1 CALC $PRINTER-SIZE = 200 /*====================================================================== /* SEL COMP CALC SLOPE = ( SLOPEL + SLOPEH ) / 2 /* OUTPUT /srv3/bsa/gschwarz/statsgo/COMP.%STATEUP% INIT PRINT MUID,SEQNUM,COMPNAME,COMPKIND,~ COMPPCT,DRAINAGE,HYDGRP,HYDRIC,~ SLOPE,ANFLOOD /* Q STOP &END &RETURN 3. The program "batch.prog" is used to run the AML's "layer_out.aml" and "comp_out.aml" to create individual layer and comp files for each state. The resulting state files will be read by the SAS program "setussoils.sas." #./bin/ksh ################################################################# # PROGRAM : BATCH.PROG # # DATE : 04/18/95 # # PURPOSE : THIS PROGRAM PROCESSES STATSGO AML OUTPUT PROGRAMS# # FOR EACH OF THE STATES. # # THE PROGRAM CHANGES THE READ/WRITE ATTRIBUTES OF # # THE STATSGO STATE DIRECTORIES AND # # DIRECTS THE LOOP VALUES TO THE AML # ################################################################# for state in al ar az ca co ct de fl ga ia id il in ks ky la ma md me mi \ mn mo ms mt nc nd ne nh nj nm nv ny oh ok or pa ri sc sd tn tx ut va vt \ wa wi wv wy; do #chmod 755 /srv3/bsa/gschwarz/statsgo/data/$state/spatial/info/* #chmod 755 /srv3/bsa/gschwarz/statsgo/data/$state/spatial/$state/* cd /srv3/bsa/gschwarz/statsgo/data/$state/spatial /gis2/esri70/arcexe70/programs/arc<<-:::: &r /srv3/bsa/gschwarz/statsgo/layer_out $state &r /srv3/bsa/gschwarz/statsgo/comp_out $state q :::: done 4. The SAS program "setussoils.sas" used to read the ascii files created by "layer_out.aml" and "comp_out.aml", perform averages of the data, merge the information from the layer file into the component file, and aggregate the component level information into a file having mapunit as the unit of observation. The resulting "map unit" file is output as both an ascii, comma-delimited file and a SAS file. /* Program to read the conterminous state statsgo ascii info files, comp.state and layer.state, and calculate summary statistics by muid. The program prints an ascii file which is then passed back to info in a latter step. Program written by Greg Schwarz, 4/24/95. The program uses the SAS macro language to perform iterative appends to the main database. Two database files are created, an ascii file ussoils.dat containing comma-delimited data, and a SAS dataset, ussoils.ssd. To iteratively build the files, we use the mod option of the file statement for the ascii file, and proc append for the SAS file. The program reads in the layer.state file (where state refers to the state name and is updated as the program iterates through the do loop. The variables taken from this file are: muid character map unit identifier (first two characters are the state abbreviation). seqnum integer sequence number identifying the component (there are up to 21 components in a map unit). laydeph integer depth of lower boundary of the layer (in inches). There are no more than 6 layers to a component laydepl integer depth of upper boundary of the layer (in inches). awch float high range of available water capacity (in inches per inch) for the given layer/component/mapunit. awcl float low range of available water capacity (in inches per inch). clayh float high range of percent of soil consisting of clay (in percent of material less than 2mm in size). clayl float low range of percent of soil consisting of clay (in percent). kffact float actual k factor used in universal soil loss equation to calculate soil loss by water. llh float high range of liquid limit of soil layer (in percent moisture by weight). lll float low range of liquid limit of soil layer (in percent moisture by weight). omh float high range of organic material in the soil (in percent by weight). oml float low range of organic material in the soil (in percent by weight). permh float high range of the permeability of the soil (in inches per hour). perml float low range of the permeability of the soil (in inches per hour). First, we compute the average of the high and low values for those variables expressed as a range. We then average the varaiables over all layers using the layer thickness (laydeph - laydepl) as weights. The final summary layer file contains a single weighted value for each component of each mapunit. The program then reads in the component file comp.state for each state. The variables read in are: muid character the map unit identifier seqnum integer the component number compname character the name of the component (contains useful information for tagging certain types of components as explained below). compkind character a one character code useful for tagging certain types of components as explained below. comppct integer the percent of the mapunit covered by the particular component. drainage character a two character code identifying the quality of the drainage for the component. The codes are E = excessive, SE = somewhat excessive, W = well drained, MW = moderately drained, SP = somewhat poorly drained, P = poorly drained, and VP = very poorly drained. These codes are converted into numeric values and assigned to the variable drain as follows: E = 1, SE = 2, W = 3, MW = 4, SP = 5, P = 6 and VP = 7. hydgrp character a three digit code identifying the hydrologic characteristics of the soil. The codes are defined in the Statsgo information guide. We convert the character codes into numeric codes according to Battaglin's methods. The numeric codes are assigned to the variable hygrp. The codes are A = 1, B = 2, C = 3, D, A/D, B/D, and C/D = 4. Also, we subselect areas and assign values for hygrp. Miscellaneous areas (denoted by M in compkind) and labeled as Dumps, and Gullied Land in compname are assigned the hygrp = 2.5 if the hydgrp value is missing. Areas denoted as Pits, Rock Outcrops, Terrace Escarpments, and Urban land with missing hydgrp are assigned a hygrp of 4. hydric character Hydric soil rating, Y = hydric, N = non-hydric. slope float The slope of the component (in percent). The value read in from the comp.state file is an average of the high and low range values stored in the INFO comp file for that state. anflood character Frequency of annual flooding. Three classes, frequent (FREQ) - greater than 50%, occasional (OCCAS) 5-50% chance, and rare (RARE) less than 5% chance. The layer file and the comp file are merged together by muid and seqnum. Water denoted components (from compname) are assigned missing values for all characteristics except comppct. The numeric variables are then averaged over all components within a mapunit using the comppct as weights. The final file gives one observation per map unit. Note that any remaining missing values are assigned the value of -.1. */ libname dir ''; filename outfile '/srv3/bsa/gschwarz/statsgo/ussoils.dat' ; /* Define the states for dynamically allocating files */ %let state1 = al ; %let state2 = ar ; %let state3 = az ; %let state4 = ca ; %let state5 = co ; %let state6 = ct ; %let state7 = de ; %let state8 = fl ; %let state9 = ga ; %let state10 = ia ; %let state11 = id ; %let state12 = il ; %let state13 = in ; %let state14 = ks ; %let state15 = ky ; %let state16 = la ; %let state17 = ma ; %let state18 = md ; %let state19 = me ; %let state20 = mi ; %let state21 = mn ; %let state22 = mo ; %let state23 = ms ; %let state24 = mt ; %let state25 = nc ; %let state26 = nd ; %let state27 = ne ; %let state28 = nh ; %let state29 = nj ; %let state30 = nm ; %let state31 = nv ; %let state32 = ny ; %let state33 = oh ; %let state34 = ok ; %let state35 = or ; %let state36 = pa ; %let state37 = ri ; %let state38 = sc ; %let state39 = sd ; %let state40 = tn ; %let state41 = tx ; %let state42 = ut ; %let state43 = va ; %let state44 = vt ; %let state45 = wa ; %let state46 = wi ; %let state47 = wv ; %let state48 = wy ; /* Begin the macro */ %macro loopy ; /* Iterate over conterminous states */ %do iter = 1 %to 48 ; option dquote ; /* Dynamically define the layer and comp files for processing (by state) */ filename indatal "~/statsgo/layer.&&&state&iter" ; filename indatac "~/statsgo/comp.&&&state&iter" ; /* Read in the layer specific data for each state */ data one ; infile indatal missover ; input muid $ 2-8 seqnum 10-11 laydeph 13-14 laydepl 16-17 awch 19-22 awcl 24-27 clayh 29-30 clayl 32-33 kffact 35-38 omh 40-43 oml 45-48 permh 50-54 perml 56-60 llh 62-64 lll 66-68 ; /* Compute the thickness of each layer and the thickness weighted values of awc, clay, kffact, om, and perm. If a range is given for a variable, then take the average of the range */ thick = laydeph - laydepl ; awc = thick*(awch + awcl)/2 ; clay = thick*(clayh + clayl)/2 ; kffact = thick*kffact ; om = thick*(omh + oml)/2 ; perm = thick*(permh + perml)/2 ; ll = thick*(llh+lll)/2 ; /* m(varname) stores the thickness of layers in which missing values for varname are encountered. This information is necessary to ensure we normalize the weights correctly later in the program */ if awc = . then mawc = thick ; else mawc = 0 ; if clay = . then mclay = thick ; else mclay = 0 ; if kffact = . then mkffact = thick ; else mkffact = 0 ; if om = . then mom = thick ; else mom = 0 ; if perm = . then mperm = thick ; else mperm = 0 ; if ll = . then mll = thick ; else mll = 0 ; keep muid seqnum thick awc clay kffact om perm ll mawc mclay mkffact mom mperm mll ; proc sort ; by muid seqnum ; /* Compute the sum of the thickness*varname over all layers. Also accumulate the thickness of layers where varname is missing */ proc means noprint ; var thick awc clay kffact om perm ll mawc mclay mkffact mom mperm mll ; by muid seqnum ; output out = layer sum = thick awc clay kffact om perm ll mawc mclay mkffact mom mperm mll ; /* Read in the state component files */ data comp ; infile indatac missover ; input muid $ 2-7 seqnum 10-11 compname $ 13-42 compkind $ 44 comppct 46-48 drainage $ 50-54 hydgrp $ 62-64 hydric $ 66 slope 68-69 anflood $ 71-74 ; proc sort; by muid seqnum ; data comp ; merge comp layer ; by muid seqnum ; /* Recode the hydgrp data to numeric values (see Battaglin) */ if hydgrp = 'A ' then hygrp = 1 ; else if hydgrp = 'B ' then hygrp = 2 ; else if hydgrp = 'C ' then hygrp = 3 ; else if hydgrp = 'D ' then hygrp = 4 ; else if hydgrp = 'A/D' then hygrp = 4 ; else if hydgrp = 'B/D' then hygrp = 4 ; else if hydgrp = 'C/D' then hygrp = 4 ; else hygrp = . ; /* Recode the drainage data to numeric values */ if drainage = 'A ' then drain = 4.0 ; else if drainage = 'E ' then drain = 1.0 ; else if drainage = 'E,MW ' then drain = 2.5 ; else if drainage = 'E,P ' then drain = 3.5 ; else if drainage = 'E,SE ' then drain = 1.5 ; else if drainage = 'E,W ' then drain = 2.0 ; else if drainage = 'MW ' then drain = 4.0 ; else if drainage = 'MW,A ' then drain = 4.0 ; else if drainage = 'MW,P ' then drain = 5.0 ; else if drainage = 'MW,SE' then drain = 3.0 ; else if drainage = 'MW,SP' then drain = 4.5 ; else if drainage = 'MW,W ' then drain = 3.5 ; else if drainage = 'P ' then drain = 6.0 ; else if drainage = 'P,A ' then drain = 5.0 ; else if drainage = 'P,SP ' then drain = 5.5 ; else if drainage = 'P,VP ' then drain = 6.5 ; else if drainage = 'PD,A ' then drain = 5.0 ; else if drainage = 'SE ' then drain = 2.0 ; else if drainage = 'SE,E ' then drain = 1.5 ; else if drainage = 'SE,MW' then drain = 3.0 ; else if drainage = 'SO ' then drain = 5.0 ; else if drainage = 'SP ' then drain = 5.0 ; else if drainage = 'SP,A ' then drain = 4.5 ; else if drainage = 'SP,E ' then drain = 3.0 ; else if drainage = 'SP,MW' then drain = 4.5 ; else if drainage = 'SP,P ' then drain = 5.5 ; else if drainage = 'SP,VP' then drain = 6.0 ; else if drainage = 'SP,W ' then drain = 4.0 ; else if drainage = 'SW ' then drain = 4.0 ; else if drainage = 'VP ' then drain = 7.0 ; else if drainage = 'VP,P ' then drain = 6.5 ; else if drainage = 'VP,SP' then drain = 6.0 ; else if drainage = 'W ' then drain = 3.0 ; else if drainage = 'W,A ' then drain = 3.5 ; else if drainage = 'W,E ' then drain = 2.5 ; else if drainage = 'W,MW ' then drain = 3.5 ; else if drainage = 'W,SE ' then drain = 2.5 ; else if drainage = 'W,SP ' then drain = 4.0 ; else if drainage = 'W,VP ' then drain = 5.0 ; else if drainage = 'WD ' then drain = 3.0 ; else drain = . ; /* Recode the anflood data */ if anflood = 'FREQ' then afldfreq = 1 ; else if anflood = 'OCCA' then afldfreq = 2 ; else if anflood = 'RARE' then afldfreq = 3 ; else if anflood = 'NONE' then afldfreq = 4 ; else afldfreq = . ; /* Recode the hydric data */ if hydric = 'Y' then ifhyd = 1 ; else if hydric = 'N' then ifhyd = 0 ; else ifhyd = . ; /* Assign default values to components denoted as Miscellaneous areas */ if compkind = 'M' then do ; if compname = 'BEACHES' then do ; if drain = . then drain = 6 ; end ; if compname = 'COASTAL BEACHES' then drain = 6 ; if compname = 'COASTAL DUNES' then clay = 1 ; if compname = 'DUMPS' then do ; if hygrp = . then hygrp = 4 ; end ; if compname = 'GULLIED LAND' then do ; if hygrp = . then hygrp = 2.5 ; end ; if compname = 'LAVA FLOWS' then do ; if clay = . then clay = 0 ; end ; if compname = 'PITS' then do ; if clay = . then clay = .5 ; if hygrp = . then hygrp = 2.5 ; end ; if compname = 'ROCK OUTCROP' then do ; if hygrp = . then hygrp = 4 ; end ; if compname = 'TERRACE ESCARPMENTS' or compname = 'URBAN LAND' or compname = 'URBANLAND' then hygrp = 4 ; end ; /* Set numeric data to missing if the component is WATER */ if compname = 'WATER' then do ; thick = . ; awc = . ; clay = . ; kffact = . ; om = . ; perm = . ; hygrp = . ; drain = . ; slope = . ; ll = . ; ifhyd = . ; afldfreq = . ; end ; /* Compute the component weighted values, and normalize for thickness. Set the variable to missing if thickness equals m(varname). Other- wise, normalize the layer weights by dividing by the total non- missing thickness of all the layers. */ if mawc = thick then awc = . ; else awc = comppct*awc/(thick - mawc) ; if mclay = thick then clay = . ; else clay = comppct*clay/(thick - mclay) ; if mkffact = thick then kffact = . ; else kffact = comppct*kffact/(thick - mkffact) ; if mom = thick then om = . ; else om = comppct*om/(thick - mom) ; if mperm = thick then perm = . ; else perm = comppct*perm/(thick - mperm) ; if mll = thick then ll = . ; else ll = comppct*ll/(thick - mll) ; thick = comppct*thick ; hygrp = comppct*hygrp ; drain = comppct*drain ; slope = comppct*slope ; ifhyd = comppct*ifhyd ; afldfreq = comppct*afldfreq ; /* m(varname) stores the component pct of components in which missing values for varname are encountered. This information is necessary to ensure we normalize the weights correctly later in the program */ if awc = . then mawc = comppct ; else mawc = 0 ; if clay = . then mclay = comppct ; else mclay = 0 ; if kffact = . then mkffact = comppct ; else mkffact = 0 ; if om = . then mom = comppct ; else mom = 0 ; if perm = . then mperm = comppct ; else mperm = 0 ; if ll = . then mll = comppct ; else mll = 0 ; if thick = . then mthick = comppct ; else mthick = 0 ; if hygrp = . then mhygrp = comppct ; else mhygrp = 0 ; if drain = . then mdrain = comppct ; else mdrain = 0 ; if slope = . then mslope = comppct ; else mslope = 0 ; if ifhyd = . then mifhyd = comppct ; else mifhyd = 0 ; if afldfreq = . then mafldf = comppct ; else mafldf = 0 ; keep muid seqnum comppct awc clay kffact om perm thick hygrp drain slope ll ifhyd afldfreq mawc mclay mkffact mom mperm mll mthick mhygrp mdrain mslope mifhyd mafldf ; /* Sum the comppct*varname over components Accumulate the missing comppct for each varname */ proc means data = comp noprint ; var comppct awc clay kffact om perm thick hygrp drain slope ll ifhyd afldfreq mawc mclay mkffact mom mperm mll mthick mhygrp mdrain mslope mifhyd mafldf ; by muid ; output out = mapunit sum = comppct awc clay kffact om perm thick hygrp drain slope ll ifhyd afldfreq mawc mclay mkffact mom mperm mll mthick mhygrp mdrain mslope mifhyd mafldf ; data mapunit ; set mapunit ; /* Normalize the averaged data for comppct. Set the variable to missing if comppct equals m(varname). Other- wise, normalize the comppct weights by dividing by the total non- missing comppct of all the components. */ if mawc = comppct then awc = . ; else awc = awc / (comppct - mawc) ; if mclay = comppct then clay = . ; else clay = clay / (comppct - mclay) ; if mkffact = comppct then kffact = . ; else kffact = kffact / (comppct - mkffact) ; if mom = comppct then om = . ; else om = om / (comppct - mom) ; if mperm = comppct then perm = . ; else perm = perm / (comppct - mperm) ; if mthick = comppct then thick = . ; else thick = thick / (comppct - mthick) ; if mhygrp = comppct then hygrp = . ; else hygrp = hygrp / (comppct - mhygrp) ; if mdrain = comppct then drain = . ; else drain = drain / (comppct - mdrain) ; if mslope = comppct then slope = . ; else slope = slope / (comppct - mslope) ; if mll = comppct then ll = . ; else ll = ll / (comppct - mll) ; if mifhyd = comppct then ifhyd = . ; else ifhyd = ifhyd / (comppct - mifhyd) ; if mafldf = comppct then afldfreq = . ; else afldfreq = afldfreq / (comppct - mafldf) ; /* Extract the state abbreviation from the muid */ state = substr(muid,1,2) ; /* Set missing values to -.1 */ if awc = . then awc = -.1 ; if clay = . then clay = -.1 ; if kffact = . then kffact = -.1 ; if om = . then om = -.1 ; if perm = . then perm = -.1 ; if thick = . then thick = -.1 ; if hygrp = . then hygrp = -.1 ; if drain = . then drain = -.1 ; if slope = . then slope = -.1 ; if ll = . then ll = -.1 ; if ifhyd = . then ifhyd = -.1 ; if afldfreq = . then afldfreq = -.1 ; com = ',' ; /* Append the state's map unit data to the ascii ussoils dataset */ file outfile mod ; put muid $ 1-7 com $ 8 state $ 9-10 com $ 11 awc 12-16 .2 com $ 17 clay 18-21 .1 com $ 22 kffact 23-27 .2 com $ 28 om 29-32 .1 com $ 33 perm 34-38 .2 com $ 39 thick 40-43 .1 com $ 44 hygrp 45-48 .1 com $ 49 drain 50-53 .1 com $ 54 slope 55-58 .1 com $ 59 ll 60-64 .1 com $ 65 ifhyd 66-69 .1 com $ 70 afldfreq 71-74 .1 ; drop _type_ _freq_ com mawc mclay mkffact mom mperm mll mthick mhygrp mdrain mslope mifhyd mafldf ; /* Append the state's map unit data to the SAS ussoils dataset */ proc append base = dir.ussoils data = mapunit ; %end ; %mend loopy ; /* Execute the macro */ %loopy ; 5. The AML "ussoils_muid_atts.aml" used to read the ascii file created by the SAS program and create the PAT coverage "ussoils.muid_atts." /*---------------------------------------------------------------------- /* /* Command name: USSOILS_MUID_ATTS.AML /* Language: AML /* /*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: /* /* Purpose: Program creates the INFO attribute table USSOILS.MUID_ATTS /* from the computed averages of STATSGO variables created by /* the SAS program setussoils.sas. /* /*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: /* /* Comments: /* 1. Item description: /* AWC = available water capacity (inches/inch) /* CLAY = clay content of soil (% of soil < 2mm in size) /* KFFACT = soil erodibility f-factor /* OM = organic matter content (% by weight) /* PERM = permeability rates (inches/hour) /* THICK = total thickness of all sampled soil layers (inches) /* HYGRP = soil index variables (1=well drained to 4=poorly drained) /* DRAIN = soil index variable (1=well drained to 7=poorly drained) /* SLOPE = average slope (%) /* LL = liquid limit (percent moisture by weight) /* IFHYDRIC = hydric soil indicator (1 if hydric) /* AFLDFREQ = annual flood frequency (1 = frequent (>50% chance) /* 2 = occasional (5-50% chance), 3 = rare (<5% chance)) /* /* 2. Relate the USSOILS.PAT file to USSOILS.MUID_ATTS to determine map unit /* identifiers for map units that are in USSOILS.PAT but not in /* COMP or LAYER files, and thus not in USSOILS.MUID_ATTS. These /* missing MUIDs are then written to a temporary file, where they are /* summarized (to eliminate redundancies from multiple polygons in /* USSOILS.PAT having the same MUIDs), and then added to /* USSOILS.MUID_ATTS. /* /* 3. The missing MUIDs added into USSOILS.MUID_ATTS have no attribute /* information. We reselect these MUIDs and assign missing values to /* all the items, except for STATE. To fill in STATE, we create the /* redefined item STID that consists of the first two characters of /* MUID. We then move this value into the value for STATE. /* /*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: /* /* History: /* Author/Site, Date, Event /* ------------------------------------------------------------ /* R. Alexander/G. Schwarz 04/24/95 CREATED /* R. Alexander/G. Schwarz 09/08/95 Modified to create /* USSOILS.MUID_ATTS only /* and to include missing /* MUIDs in the /* USSOILS.MUID_ATTS file. /* /*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: /* &DATA arc info ARC /* CALC $NM = 1 CALC $COMMA-SWITCH = -1 CALC $PRINTER-SIZE = 200 /*====================================================================== /* DEFINE USSOILS.MUID_ATTS MUID,7,7,C STATE,2,2,C AWC,4,5,F,2 CLAY,4,4,F,1 KFFACT,4,5,F,2 OM,4,4,F,1 PERM,4,5,F,2 THICK,4,4,F,1 HYGRP,4,4,F,1 DRAIN,4,4,F,1 SLOPE,4,4,F,1 LL,4,5,F,1 IFHYDRIC,4,4,F,1 AFLDFREQ,4,4,F,1 /* ADD FROM /srv3/bsa/gschwarz/statsgo/ussoils.dat SEL USSOILS.MUID_ATTS SORT MUID /* /* Create temporary file FILE1 to hold missing values. /* SEL USSOILS.MUID_ATTS REDEFINE 1 STID 2 2 C MODIFY FILE1 /* /* Find missing MUIDs in USSOILS.PAT and put in FILE1 /* SEL USSOILS.PAT RELATE USSOILS.MUID_ATTS 1 MUID ORDER RESEL MUID NE $1MUID RESEL MUID NE '' RELATE FILE1 2 MUID INIT MOVE MUID TO $2MUID SEL FILE1 SORT MUID /* /* Relate FILE1 to USSOILS.MUID_ATTS by MUID and do SUMMARY /* RELATE USSOILS.MUID_ATTS 1 MUID SUMMARY /* /* set all MUID not in COMP files with water designation to missing /* CALC $1AWC = -0.1 CALC $1CLAY = -0.1 CALC $1KFFACT = -0.1 CALC $1OM = -0.1 CALC $1PERM = -0.1 CALC $1THICK = -0.1 CALC $1HYGRP = -0.1 CALC $1DRAIN = -0.1 CALC $1SLOPE = -0.1 CALC $1LL = -0.1 CALC $1IFHYDRIC = -0.1 CALC $1AFLDFREQ = -0.1 MOVE STID TO $1STATE /* /* Delete the temporary file FILE1 /* SEL FILE1 ERASE FILE1 Y SEL USSOILS.MUID_ATTS SORT MUID /* Q STOP &END DROPITEM USSOILS.MUID_ATTS USSOILS.MUID_ATTS STID 6. The AML 'ussoils_atts.aml' which may be used to transfer the attribute infor contained in the attribute table USSOILS.MUID_ATTS to the polygon attribute tabl USSOILS.PAT to permit mapping the attribute information. /*---------------------------------------------------------------------- /* /* Command name: USSOILS_ATTS.AML /* Language: AML /* /*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: /* /* Purpose: Program creates attribute information for the national /* coverage USSOILS.PAT. The attribute information is taken from the /* info file USSOILS.MUID_ATTS. /* /*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: /* /* Comments: /* 1. Item description: /* AWC = available water capacity (inches/inch) /* CLAY = clay content of soil (% of soil < 2mm in size) /* KFFACT = soil erodibility f-factor /* OM = organic matter content (% by weight) /* PERM = permeability rates (inches/hour) /* THICK = total thickness of all sampled soil layers (inches) /* HYGRP = soil index variables (1=well drained to 4=poorly drained) /* DRAIN = soil index variable (1=well drained to 7=poorly drained) /* SLOPE = average slope (%) /* LL = liquid limit (percent moisture by weight) /* IFHYDRIC = hydric soil indicator (1 if hydric) /* AFLDFREQ = annual flood frequency (1 = frequent (>50% chance) /* 2 = occasional (5-50% chance), 3 = rare (<5% chance)) /* /* 2. Items are ADDED to USSOILS.PAT, then we RELATE to USSOILS.MUID_ATTS /* on the basis of MUID. Note that there are 3 MUIDS contained in /* USSOILS.MUID_ATTS that are not in USSOILS.PAT. /* /*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: /* /* History: /* Author/Site, Date, Event /* ------------------------------------------------------------ /* R. Alexander/G. Schwarz 09/08/95 CREATED /*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: /* ADDITEM USSOILS.PAT USSOILS.PAT STATE 2 2 C ADDITEM USSOILS.PAT USSOILS.PAT AWC 4 5 F 2 ADDITEM USSOILS.PAT USSOILS.PAT CLAY 4 4 F 1 ADDITEM USSOILS.PAT USSOILS.PAT KFFACT 4 5 F 2 ADDITEM USSOILS.PAT USSOILS.PAT OM 4 4 F 1 ADDITEM USSOILS.PAT USSOILS.PAT PERM 4 5 F 2 ADDITEM USSOILS.PAT USSOILS.PAT THICK 4 4 F 1 ADDITEM USSOILS.PAT USSOILS.PAT HYGRP 4 4 F 1 ADDITEM USSOILS.PAT USSOILS.PAT DRAIN 4 4 F 1 ADDITEM USSOILS.PAT USSOILS.PAT SLOPE 4 4 F 1 ADDITEM USSOILS.PAT USSOILS.PAT LL 4 5 F 1 ADDITEM USSOILS.PAT USSOILS.PAT IFHYDRIC 4 4 F 1 ADDITEM USSOILS.PAT USSOILS.PAT AFLDFREQ 4 4 F 1 /* &DATA arc info ARC /* CALC $NM = 1 CALC $COMMA-SWITCH = -1 CALC $PRINTER-SIZE = 200 /*====================================================================== /* SEL USSOILS.PAT RELATE USSOILS.MUID_ATTS 1 MUID ORDER MOVE $1STATE TO STATE CALC AWC = $1AWC CALC CLAY = $1CLAY CALC KFFACT = $1KFFACT CALC OM = $1OM CALC PERM = $1PERM CALC THICK = $1THICK CALC HYGRP = $1HYGRP CALC DRAIN = $1DRAIN CALC SLOPE = $1SLOPE CALC LL = $1LL CALC IFHYDRIC = $1IFHYDRIC CALC AFLDFREQ = $1AFLDFREQ /* Q STOP &END &RETURN 0000 ground condition Complete As Needed -127.88685968 -65.34551784 48.24566548 22.94132336 None State Soil Geographic (STATSGO) Data Base for the Conterminous United States inlandWaters None Conterminous U.S. None None None None None The National Resource Conservation Service recommends that the data not be used to describe soil characteristics for regions smaller than a multi-county area. Gregory E. Schwarz U.S. Geological Survey, Water Resources Div. (WRD) Economist, Branch of Systems Analysis mailing address

12201 Sunrise Valley Drive, MS 410

Reston VA 20191 USA 1-888-275-8747 703-648-5295 gschwarz@usgs.gov 9:00am-5:00pm EST Please contact thru email http://water.usgs.gov/GIS/browse/ussoils.gif Illlustration of data set GIF See References None Unclassified None dgux, 5.4R3.10, AViiON UNIX, ARC/INFO version 7.0.4 U.S. Dept. of Agriculture, Soil Conservation Service, National Coop. Soil Survey October 1994 map ARC/INFO 7.0 Coverage on CDROM See Entity_Attribute_Information See Explanation Attribute accuracy is described, where present, with each attribute defined in the Entity and Attribute Section. Polygon topology present. Unspecified 0000 250,000 Unspecified 0000 Unspecified Unspecified Unspecified GSCHWARZ MAPJOIN /SRV3/BSA/GSCHWARZ/STATSGO/USSOILS POLY NONE None 19950419 1840 None GSCHWARZ ARCEDIT /SRV3/BSA/GSCHWARZ/STATSGO/USSOILS None 19950420 1154 None GSCHWARZ BUILD /SRV3/BSA/GSCHWARZ/STATSGO/USSOILS POLY None 19950420 1213 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950717 1413 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950717 1454 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950717 1536 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950717 1708 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950718 0959 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950719 1506 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950725 1219 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950725 1613 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950726 1457 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950726 1502 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950726 1519 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950802 0931 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950802 1422 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950803 1457 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950803 1538 None GSCHWARZ DOCUMENT USSOILS DELETE GSCHWARZ None 19950803 1538 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950803 1558 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950803 1611 None GSCHWARZ DOCUMENT USSOILS DELETE GSCHWARZ None 19950803 1611 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950803 1711 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950804 1530 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950804 1535 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950804 1538 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950804 1553 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950804 1612 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950804 1615 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950804 1619 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950804 1622 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950804 1627 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950808 1059 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950808 1105 None GSCHWARZ DOCUMENT USSOILS DELETE GSCHWARZ None 19950811 0931 None GSCHWARZ EXPORT COVER USSOILS USSOILS None 19950811 1551 None GSCHWARZ COPY /SRV3/BSA/GSCHWARZ/STATSGO/USSOILS /SRV3/BSA/GSCHWARZ/NEWS None 19950911 1044 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950911 1210 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950911 1356 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950911 1401 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950911 1427 None GSCHWARZ EXPORT COVER USSOILS USSOILS FULL None 19950911 1531 None GSCHWARZ DOCUMENT USSOILS UPDATE GSCHWARZ None 19950918 1522 None MNEGRI IMPORT COVER /SCRATCH_AREA1/MNEGRI/USSOILS.E00 USSOILS None 19950920 1552 None MNEGRI EXPORT COVER /DSDL1/CUSA/TILES/CUSA/USSOILS USSOILS.E00 NONE None 19950926 1325 None MNEGRI EXPORT COVER /DSDL1/CUSA/TILES/CUSA/USSOILS USSOILS.E00 None 19960708 1158 None Not Applicable Vector Point 78518 String 241658 GT-polygon composed of chains 78519 Albers Conical Equal Area 29.5 45.5 -96 23 0.00000 0.00000 coordinate pair 1.0 1.0 METERS North American Datum of 1927 Clarke 1866 6378206.4 294.98 USSOILS.PAT Selected items of hydrologic relevance from the STATSGO Data Base STATSGO Data Base ARC/INFO 7.0 Coverage CD-ROM, October 1994 - Selected items of hydrologic relevance from the STATSGO Data Base STATSGO Data Base ARC/INFO 7.0 Coverage CD-ROM, October 1994 - unspecified unspecified AREA Area of poly in square coverage units Computed Positive real numbers unspecified unspecified PERIMETER Perimeter of polygon in coverage units Computed Positive real numbers unspecified unspecified USSOILS# Internal feature number Computed Sequential unique positive integer unspecified unspecified USSOILS-ID User-assigned feature number User-defined Integer unspecified unspecified MUID Mapunit Identification code - used to reference observations STATSGO, October 1994 Character unspecified unspecified STATE 2-character State abbreviation Created from first two characters of muid in STATSGO data base Character unspecified unspecified AWC Available water capacity (inches per inch) Created from AWCH and AWCL in STATSGO (10/94) layer file - see narrative Positive real numbers, missing value indicator = -0.1 unspecified unspecified CLAY Percent clay in soil (percent of material less than 2mm in size) Created from clayh and clayl in STATSGO (10/94) layer file - see narrative 0 to 100, missing value indicator = -0.1 unspecified unspecified KFFACT Actual k factor used in water erosion component of universal soil loss equation Created from STATSGO (10/94) component file - see narrative. Non-negative real, missing value indicator = -0.1 unspecified unspecified OM Organic material in soil (in percent by weight) Created from omh and oml of STATSGO (10/94) layer file - see narrative 0 to 100, missing value indicator = -0.1 unspecified unspecified PERM Permeability of the soil (in inches per hour) Created from permh and perml of STATSGO (10/94) layer file - see narrative Non-negative real, missing value indicator = -0.1 unspecified unspecified THICK Cumulative thickness of all soil layers (in inches) Created from laydeph and laydepl of STATSGO (10/94) layer file - see narrative Positive real, missing value indicator = -0.1 unspecified unspecified HYGRP Hydrologic characteristics of soil Created from hydgrp item of STATSGO (10/94) component file - see narrative 1-4:1=High infiltration,2=Mod infil,3=Slow infil,4=Very slow infil,-0.1=Miss unspecified unspecified DRAIN Soil drainage Created from drainage in STATSGO (10/94) component file - see narrative 1-7:1=excess,2=mod excess,3=well,4=mod well,5=mod poor,6=poor,7=v poor,-.1=miss unspecified unspecified SLOPE Surface slope (in percent) Created from slopeh and slopel of STATSGO (10/94) component file - see narrative 0 to 100, missing value indicator = -0.1 unspecified unspecified LL Liquid limit of soil (in percent moisture by weight) Created from llh and lll of STATSGO (10/94) layer file - see narrative 0 to 100, missing value indicator = -0.1 unspecified unspecified IFHYDRIC Share of map unit components with hydric soils Created from hydric of STATSGO (10/94) component file - see narrative 0 to 1 (1=all components hydric), missing value indicator = -0.1 unspecified unspecified AFLDFREQ Annual flood frequency Created from item anflood of STATSGO (10/94) component file - see narrative 1-4: 1=greater than 50 pct, 2=5 to 50 pct, 3=0 to 5 pct, 4=none, -0.1=missing unspecified unspecified The attribute table, USSOILS.MUID_ATTS, contains the following items for each map unit: Label Type Description muid character Map unit identifier (first two characters are the state abbreviation). state character 2-character State abbreviation. awc float Available water capacity (in inches per inch). Computed as a layer thickness weighted average, across soil layers, of a simple average of awch and awcl contained in the STATSGO layer file. Missing value .FALSE. clay float Percent of soil consisting of clay (in percent of material less than 2mm in size). Computed as a layer thickness weighted average, across soil layers, of a simple average of clayh and clayl contained in the STATSGO layer file. Missing value indicator = -0.1. kffact float Actual k factor used in universal soil loss equation to calculate soil loss by water. Computed as a layer thickness weighted average, across soil layers, of the variable kffact contained in the STATSGO layer file. Missing value indicator = -0.1. ll float Liquid limit of soil layer (in percent moisture by weight). Computed as a layer thickness weighted average, across soil layers, of a simple average of llh and lll contained in the STATSGO layer file. Missing value indicator = -0.1. om float Organic material in the soil (in percent by weight). Computed as a layer thickness weighted average, across soil layers, of a simple average of omh and oml contained in the STATSGO layer file. Missing value .FALSE. perm float Permeability of the soil (in inches per hour). Computed as a layer thickness weighted average, across soil layers, of a simple average of permh and perml contained in the STATSGO layer file. Missing value .FALSE. thick float Depth of soil layers (in inches). Computed as the sum of the differences between laydeph and laydepl for each soil layer in the STATSGO layer file. Missing value .FALSE. hygrp float A code identifying the hydrologic characteristics of the soil. The character codes defined in the STATSGO component file are converted into numeric codes according to Bill Battaglin's methods (Battaglin, written communication dated March 8, 1995). The coding transformations are A = 1 (high infiltration, deep soils, well drained to excessively drained sands and gravels), B = 2 (moderate infiltration rates, deep and moderately deep, moderately well and well drained soils with moderately coarse textures), C = 3 (slow infiltration rates, soils with layers impeding downward movement of water, or soils with moderately fine or fine textures), D = 4 (very slow infiltration rates, soils are clayey, have a high water table, or are shallow to an impervious layer), Mixture codes A/D, B/D, and C/D are assigned the value 4. Also, we subselect certain areas and assign values for hygrp based on the area type. Miscellaneous areas (denoted by M in compkind) and labeled as Dumps, and Gullied Land in compname are assigned the hygrp = 2.5 if the hydgrp value is missing. Areas denoted as Pits, Rock Outcrops, Terrace Escarpments, and Urban land with missing hydgrp are assigned a hygrp of 4. See the documentation of the SAS program "setussoils.sas" for additional details. The transformed data are averaged across components using the component percentage as weights. The missing value indicator is - 0.1. drain float A code identifying the quality of soil drainage. The two character code from the STATSGO component file is converted to a numeric value according to the following translation: E = 1 (excessive), SE = 2 (somewhat excessive), W = 3 (well drained), MW = 4 (moderately drained), SP = 5 (somewhat poorly drained), P = 6 (poorly drained), and VP = 7 (very poorly drained). The values are averaged across components using the component percentage as weights. The missing value indicator is -0.1. slope float The slope of the map unit (in percent). Slope values contained in the STATSGO component file are averaged using the component percentage as weights. The missing value indicator is -0.1. ifhydric float Share of map unit with hydric soils (1 = entire map unit has hydric soils). Computed by summing the component percentage for each component designated as having hydric soils according to the variable hydric in the STATSGO component file. Missing value .FALSE. afldfreq float Annual flood frequency code. Flood frequency designations contained in the variable anflood in the STATSGO component file are converted to numeric codes according to the following translation: 1 = greater than 50%, 2 = 5% to 50%, 3 = 0% to 5%, and 4 = no flood. Translated variables are averaged across components using the component percentage as weights. The missing value indicator is -0.1. Not Available U.S. Geological Survey Ask USGS - Water Webserver Team mailing

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Reston VA 20192 1-888-275-8747 (1-888-ASK-USGS) http://answers.usgs.gov/cgi-bin/gsanswers?pemail=h2oteam&subject=GIS+Dataset+ussoils Although this data set has been used by the U.S. Geological Survey, U.S. Department of the Interior, no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data and related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of this data, software, or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Export Region 01 New England zipped 155 http://water.usgs.gov/GIS/dsdl/ussoils_01.e00.gz Export Region 02 Mid-Atlantic zipped 349 http://water.usgs.gov/GIS/dsdl/ussoils_02.e00.gz Export Region 03 South Atlantic-Gulf zipped 702 http://water.usgs.gov/GIS/dsdl/ussoils_03.e00.gz Export Region 04 Great Lakes zipped 369 http://water.usgs.gov/GIS/dsdl/ussoils_04.e00.gz Export Region 05 Ohio zipped 257 http://water.usgs.gov/GIS/dsdl/ussoils_05.e00.gz Export Region 06 Tennessee zipped 90 http://water.usgs.gov/GIS/dsdl/ussoils_06.e00.gz Export Region 07 Upper Mississippi zipped 310 http://water.usgs.gov/GIS/dsdl/ussoils_07.e00.gz Export Region 08 Lower Mississippi zipped 307 http://water.usgs.gov/GIS/dsdl/ussoils_08.e00.gz Export Region 09 Souris-Red-Rainy zipped 101 http://water.usgs.gov/GIS/dsdl/ussoils_09.e00.gz Export Region 10 Missouri zipped 656 http://water.usgs.gov/GIS/dsdl/ussoils_10.e00.gz Export Region 11 Arkansas-White-Red zipped 377 http://water.usgs.gov/GIS/dsdl/ussoils_11.e00.gz Export Region 12 Texas-Gulf zipped 389 http://water.usgs.gov/GIS/dsdl/ussoils_12.e00.gz Export Region 13 Rio Grande zipped 171 http://water.usgs.gov/GIS/dsdl/ussoils_13.e00.gz Export Region 14 Upper Colorado zipped 144 http://water.usgs.gov/GIS/dsdl/ussoils_14.e00.gz Export Region 15 Lower Colorado zipped 138 http://water.usgs.gov/GIS/dsdl/ussoils_15.e00.gz Export Region 16 Great Basin zipped 167 http://water.usgs.gov/GIS/dsdl/ussoils_16.e00.gz Export Region 17 Pacific Northwest zipped 414 http://water.usgs.gov/GIS/dsdl/ussoils_17.e00.gz Export Region 18 California zipped 241 http://water.usgs.gov/GIS/dsdl/ussoils_18.e00.gz SDTS Region 01 New England zipped 148 http://water.usgs.gov/GIS/dsdl/ussoils_01.sdts.tgz SDTS Region 02 Mid-Atlantic zipped 306 http://water.usgs.gov/GIS/dsdl/ussoils_02.sdts.tgz SDTS Region 03 South Atlantic-Gulf zipped 584 http://water.usgs.gov/GIS/dsdl/ussoils_03.sdts.tgz SDTS Region 04 Great Lakes zipped 316 http://water.usgs.gov/GIS/dsdl/ussoils_04.sdts.tgz SDTS Region 05 Ohio zipped 230 http://water.usgs.gov/GIS/dsdl/ussoils_05.sdts.tgz SDTS Region 06 Tennessee zipped 92 http://water.usgs.gov/GIS/dsdl/ussoils_06.sdts.tgz SDTS Region 07 Upper Mississippi zipped 264 http://water.usgs.gov/GIS/dsdl/ussoils_07.sdts.tgz SDTS Region 08 Lower Mississippi zipped 257 http://water.usgs.gov/GIS/dsdl/ussoils_08.sdts.tgz SDTS Region 09 Souris-Red-Rainy zipped 95 http://water.usgs.gov/GIS/dsdl/ussoils_09.sdts.tgz SDTS Region 10 Missouri zipped 541 http://water.usgs.gov/GIS/dsdl/ussoils_10.sdts.tgz SDTS Region 10 Missouri zipped 541 http://water.usgs.gov/GIS/dsdl/ussoils_10shp.zip SDTS Region 11 Arkansas-White-Red zipped 309 http://water.usgs.gov/GIS/dsdl/ussoils_11.sdts.tgz SDTS Region 12 Texas-Gulf zipped 310 http://water.usgs.gov/GIS/dsdl/ussoils_12.sdts.tgz SDTS Region 13 Rio Grande zipped 153 http://water.usgs.gov/GIS/dsdl/ussoils_13.sdts.tgz SDTS Region 14 Upper Colorado zipped 134 http://water.usgs.gov/GIS/dsdl/ussoils_14.sdts.tgz SDTS Region 15 Lower Colorado zipped 130 http://water.usgs.gov/GIS/dsdl/ussoils_15.sdts.tgz SDTS Region 16 Great Basin zipped 158 http://water.usgs.gov/GIS/dsdl/ussoils_16.sdts.tgz SDTS Region 17 Pacific Northwest zipped 370 http://water.usgs.gov/GIS/dsdl/ussoils_17.sdts.tgz SDTS Region 18 California zipped 218 http://water.usgs.gov/GIS/dsdl/ussoils_18.sdts.tgz None. This dataset is provided by USGS as a public service. 20041108 U.S. Geological Survey Ask USGS -- Water Webserver Team mailing

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Reston VA 20192 1-888-275-8747 (1-888-ASK-USGS) http://answers.usgs.gov/cgi-bin/gsanswers?pemail=h2oteam&subject=GIS+Dataset+ussoils FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998