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.
HYDLCA.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 HYDLCA# 4 5 B -
29 HYDLCA-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 20 20 C -
101 HYD_FEATURE_ID 6 6 I -
107 COURSE_CL 1 2 C -
Coord_source, hyd_feature_id, and course_cl are user defined items.
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.
Coord_source provides information on the source of vertices and arcs
in the data. In this case, all coordinate source is USGS 100k DLG
data. Currently, valid values for coord_source are 100K DLG, VIS EST,
arb ext, ctypca (a county data coverage), and vis est. Hyd_feature_id
is an internal ID number used to tie arcs that make up a river to the
name of the river - stored in Info and an Informix table. Current
values for hyd_feature_id are integers in the range 1 through 1547.
Course_cl indicates if the arc is a stream center line (value of 'y')
created in areas of lakes, resevoirs, and double bank streams.
HYDLCA.RATWATER_COURSE:
COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME
1 WATER_COURSE# 4 5 B -
5 WATER_COURSE-ID 4 5 B -
9 HYD_FEATURE_ID 6 6 I -
15 NAME 52 52 C -
Data file hydlca.ratwater_course is the routes attribute file for the
water_course route data. These routes are built on item hyd_feature_id
in the hydlca.aat arc arc attribute file. Item hyd_feature_id is
identical to that in hydlca.aat data file above. Item name actually
contains the stream name. The valid domain for this item is stream
names in California - too long to list here. The item name may be used
through the routes for analysis or for symbolization and naming of
streams and rivers on cartographic products.
HYDLCA.SECWATER_COURSE:
COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME
1 ROUTELINK# 4 5 B -
5 ARCLINK# 4 5 B -
9 F-MEAS 4 12 F 3
13 T-MEAS 4 12 F 3
17 F-POS 4 12 F 3
21 T-POS 4 12 F 3
25 WATER_COURSE# 4 5 B -
29 WATER_COURSE-ID 4 5 B -
Data file hydlca.secwater_course is only an internal section file
used by Arc/Info in creating the water_course route data file
described above.