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Grid Square System

National Survey on the Natural Environment uses the Grid Square System (3rd grid)
To compile and analyze data from the All-Species Survey and the Environmental Indicator species survey as well as the results of various other specific surveys.
The "Grid Square System" is based on the Administrative Management Agency's Announcement No. 143 of July 12, 1973: "The Grid Square System and Grid Codes for Statistical Use" which uses lines of longitude and latitude to section an area into a grid.

The first area section is based on a difference of one degree of longitude and forty minutes of latitude. The second area section divides the first into 8 parts of equal length and breadth and the third area section divides the second into 10 equal parts. Generally, it is the third section that is referred to as the "Standard Area Grid" or "3rd grid." A grid five times the size of the 3rd grid can also be used depending on the character of the target data.


"The Grid Square System" [*1] uses longitude and latitude to section an area into a grid.
The first area section (1st grid) is based on a difference of one degree of longitude and 40 minutes of latitude.
The second area section (2nd grid) divides the first into 8 parts of equal length and breadth. The third (3rd grid) divides the second by 10 equally.
Generally, the third area section is called the "Standard Area Grid"
The method of using grids to show information (called the grid approach) is a good way of exhibiting statistical data, topography, features of the natural environment, administrative districts, roads, railways, public facilities, the location and scale of cultural assets and so forth in quantitative form. It is widely used.

[*1] Administrative Management Agency Announcement No.143, "The Grid Square System and Grid Codes for Statistical Use"




Grid Units and Size
Grid Units
Scope and Size
The first area section
(1st grid)กห

Longitudinal difference 1 degree,
latitudinal difference 40 minutes
Corresponds to a 1:200,000 scale topographical map
About 80 X 80Km*
The second area section
(2nd grid)
Longitudinal difference 7 minutes 30 seconds,
latitudinal difference 5 minutes
Corresponds to a 1: 25,000 scale topographical map
About 10 X 10km
The third area section
(3rd grid, Standard Area Grid)
Longitudinal difference 45 seconds,
latitudinal difference 30 seconds.
Corresponds to each of ten equal divisions of the 1:25,000scale topographical map
About 1 X 1km
Multiple - 5 Area Grid
Longitudinal difference 3 minutes 45 seconds,
latitudinal difference 2 minutes 30 seconds.
Corresponds to each of four equal divisions of the 1:25,000 scale topographical map.
About 5 X 5km
* Different grids have different length in the east-west direction depending on latitude. Okinawa's is 1.3 times as long as Hokkaido's.


Area Grid Count By Prefecture
Prefectures, Towns,
Villages

No. of Cities,
Wards(*1)

1st Area section
2nd Area Section
3rd Area Grid
All Japan
3,383
174
4,866
386,555
01. Hokkaido
02. Aomori
03. Iwate
04. Miyagi
05. Akita
06. Yamagata
07. Fukushima
08. Ibaraki
09. Tochigi
10. Gunma
11. Saitama
12. Chiba
13. Tokyo
14. Kanagawa
15. Niigata
16. Toyama
17. Ishikawa
18. Fukui
19. Yamanashi
20. Nagano
21. Gifu
22. Shizuoka
23. Aichi
24. Mie
25. Shiga
26. Kyoto
27. Osaka
28. Hyogo
29. Nara
30. Wakayama
31. Tottori
32. Shimane
33. Okayama
34. Hiroshima
35. Yamaguchi
36. Tokushima
37. Kagawa
38. Ehime
39. Kochi
40. Fukuoka
41. Saga
42. Nagasaki
43. Kumamoto
44. Oita
45. Miyazaki
46. Kagoshima
47. Okinawa

226(*2)
67
62
75
69
44
90
88
49
70
92
80
65
58
112
35
41
35
64
121
99
75
103
69
50
54
67
99
47
50
39
59
78
93
56
50
43
70
53
109
49
79
98
58
44
96
53
39
8
7
5
6
6
6
5
4
5
4
5
21
4
7
4
5
4
3
8
6
7
6
4
4
5
2
6
5
4
4
9
6
4
7
4
2
5
6
5
4
10
5
5
5
18
15
1,127
152
192
111
156
123
175
89
85
91
54
79
85
46
192
63
77
71
65
175
137
115
77
94
56
76
36
122
52
74
61
115
99
117
107
61
48
111
109
87
42
130
110
95
100
204
110
91,385
10,411
15,966
7,855
12,164
9,583
13,848
6,088
6,465
6,470
3,853
5,285
2,669
2,581
13,038
4,376
4,488
4,417
4,494
13,548
10,596
7,839
5,274
6,073
3,541
4,781
2,030
8,540
3,712
4,854
3,624
6,880
7,192
8,734
6,584
4,192
2,214
6,239
7,147
5,121
2,526
5,477
7,519
6,396
7,547
9,825
2,874

(Note) The grid count includes the four northern islands (claimed by Japan). The island of Takeshima in Oki Gun, Goka Village, Shimane Prefecture is not included. The area grids for each prefecture are summed to a total. Thus the grid count for the whole country and the total count by prefecture do not agree.

*1 Special wards in Tokyo and cities designated by ordinance are counted as wards.
*2 The six villages on the northern islands (Shikotan, Tomari, Ruyobetsu, Rubetsu, Shana, Shibetori) are included.