Pfafstetter Basin Codification

1
Pfafstetter Basin Codification

• What is it?
• A topological system for codification of basins.
• Based on topology of the river network.
• References
• Pfafstetter, 1989
• "Classification of hydrographic basins coding
  methodology", unpublished manuscript, Departmento
  Nacional de Obras de Saneamento, Rio de Janeiro
• Verdin, 1997
• http//edcdaac.usgs.gov/gtopo30/hydro/P311.html
• Why use it?
• Hydrologically ordered
• Provides a unique ID for each FFMP small basin
• Efficiency of digits

2
Pfafstetter Basin Codification
First, identify the four tributaries with the
highest flow accumulations (largest drainage
areas) along the main stem. These are assigned
even digits from downstream to upstream.
8
6
4
2
3
Pfafstetter Basin Codification
Next, assign odd digits to the interbasins along
the main stem. Note In the Pfafstetter
system, basin 9 is defined as a main stem basin
and has a higher flow accumulation value than
tributary 8.
8
9
7
6
4
5
2
3
1
4
Pfafstetter Basin Codification
Subdivision of Tributaries
8
9
7
29
6
26
4
5
22
25
28
27
2
23
3
24
21
1
5
Pfafstetter Basin Codification
Subdivision of Interbasins
8
9
79
78
7
77
6
76
4
5
72
75
2
74
3
73
71
1
6
Pfafstetter Basin Codification
Codification when there are less than four
tributaries
9
9
9
6
4
2
5
2
4
3
2
3
1
1
1
Note Basin 9 is always the main stem basin.
7
Pfafstetter Basin CodificationThe Pfaf_id
Attribute

• The Pfaf_id attribute is a 13-character string
• The first four digits represent the 8-digit HUC
  basin
• For example, each Pfaf_id for FFMP basins in HUC
  03010102 will begin with "1150".
• 8-digit HUC Basin First 4 digits in the Pfaf_id
• 03010102 1150XXXXXXXXX
• 03010103 1151XXXXXXXXX
• 03010104 1152XXXXXXXXX
• 03010105 1153XXXXXXXXX
• . .
• . .
• etc. etc.

8
Pfafstetter Basin CodificationThe Pfaf_id
Attribute

• The last nine digits represent the "local"
  Pfafstetter ID internal to the HUC
• The first digit of the "local" Pfafstetter ID is
  generally a "2", but can be any other digit if
• More than one outlet exists in the HUC basin
• The HUC basin is along the coast
• The HUC basin is closed or contains natural
  sinks.
• Note The actual Pfafstetter ID begins with the
  6th digit of the 13-digit Pfaf_id.
• The combination of these 13 digits ensures a
  unique Pfaf_id for each small basin in the
  country.

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Pfafstetter Basin CodificationExample - HUC
05010002
1st Division
10
Pfafstetter Basin CodificationExample - HUC
05010002
2nd Division (Basin 6)
11
Pfafstetter Basin CodificationExample - HUC
05010002
3rd Division ( Basin 6)
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Pfafstetter Basin CodificationExample - HUC
05010002
Add a leading "2" and trailing zeros to create
the 9-digit "local" Pfafstetter ID.
Local Pfafstetter ID "2" "699" "00000"
13
Pfafstetter Basin CodificationExample - HUC
05010002
Add the 4-digit HUC identifier to create the
13-digit Pfaf_id.
13-digit Pfaf_id "1459" "269900000"
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Pfafstetter Basin Codification
Pfafstetter Ids along the coasts and Mexican and
Canadian borders are assigned in a clockwise
manner.
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Pfafstetter Basin CodificationBorder Example -
HUC 15080302
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Pfafstetter Basin CodificationCoastal Example -
HUC 03020106