It is strongly recommended that these data be aquired directly from the U.S. Bureau of Land Management and not indirectly through some other source which may have changed the data. It is also strongly recommended that careful attention be paid to the content of the metadata file associated with these data. Users are cautioned that digitial enlargement of these data to scales larger than that at which they where originally mapped can cause misinterpretation. Users are further cautioned that these data and interpretations derived from them do not eliminate the need for onsite survey and evaluation of specific sites for intensive uses.
The U.S. Bureau of Land Management should be cited as the data source in any products derived from these data.
HYDPCA.PAT:
COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME
1 AREA 8 18 F 5
9 PERIMETER 8 18 F 5
17 HYDPCA# 4 5 B -
21 HYDPCA-ID 4 5 B -
25 GNISNAME 45 45 C -
70 MAJOR1 6 6 I -
76 MINOR1 6 6 I -
82 MAJOR2 6 6 I -
88 MINOR2 6 6 I -
94 MAJOR3 6 6 I -
100 MINOR3 6 6 I -
106 MAJOR4 6 6 I -
112 MINOR4 6 6 I -
118 NAME 52 52 C -
170 HYD_FEATURE_ID 6 6 I -
176 ELEV_FEET 5 5 I -
181 ELEV_METER 5 5 I -
186 NAVIGABILITY 1 1 C -
187 FEATURE_TYPE 32 32 C -
219 HYDRO_CLASS 14 14 C -
Name and hyd_feature_id are user defined items. Hyd_feature_id
is an internal ID number used to tie polygons to the
name of the water body - stored in Info and an Informix table. Current
values for hyd_feature_id are integers in the range 1 through 1547.
Name contains the name of the water body. Item gnisname is the name
of the water body from the USGS GNIS database. Major and Minor 1
through Major and Minor 4 are the original USGS DLG major and minor\
code pairs for each arc in the data set. Items elev_feet and elev_meter
are obtained from the attributes stored in the USGS DLG data and
are the elevation of the surface of the water body. Item navigability
is a code from the DLG data which indicates whether the water body
is navigable or not. Current values are u for unknown, and y for yes.
Item feature_type provides a short description of the type of water
body. Current values are alkali flat, aqueduct, area to be submerged,
bay; bays, estuaries, gulfs, oceans, seas, ditch or canal; duck pond,
fish hatchery or farm, flats, gravel pit or quary with water, industrial
water impoundment, inundation area, lake, marsh wetland swamp bog, none,
ocean, reservoir, salt evaporator, sand in open water, sewage pond or
filtration bed, soda evaporator, spillway, stream, tailings pond, wash
or ephemeral drain. Item hydro_class is also from the DLG data and
provides information regarding the frequency of water in the water body.
Current values are dry ,intermittent, or perennial.
HYDPCA.AAT:
COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME
1 FNODE# 4 5 B -
5 TNODE# 4 5 B -
9 LPOLY# 4 5 B -
13 RPOLY# 4 5 B -
17 LENGTH 8 18 F 5
25 HYDPCA# 4 5 B -
29 HYDPCA-ID 4 5 B -
33 MAJOR1 6 6 I -
39 MINOR1 6 6 I -
45 MAJOR2 6 6 I -
51 MINOR2 6 6 I -
57 MAJOR3 6 6 I -
63 MINOR3 6 6 I -
69 MAJOR4 6 6 I -
75 MINOR4 6 6 I -
81 COORD_SOURCE 80 80 C -
161 COAST_FEATURE 12 12 C -
Data file hydpca.aat is the arc attribute file for the water body
data set. Item coord_source provides information on the source
of the data coordinates which define the shape of the arc. Current
values of coord_source are 100kdlg, VIS EST, hydp, rdsleh37, and
vis est. Item coast_feature provides information as to whether
the arcs along the coast are on the coast, or on a bay. Current
values for coast_feature are bay and coast.
HYDPCA.ATTS:
COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME
1 HYDPCA-ID 4 5 B -
5 HYD_NAME_ID 5 5 I -
Data file hydpca.atts is a data file which is an info file. This
data set is only to relate features with their names through the
use of the hyd_name_id code. Current values for this item are
integers from 307 to 483.