Etymology and distribution of 一沢.

The Japanese surnames etymology dictionary.
https://play.google.com/store/apps/details?id=info.jigensha.jcedfreeGoogle Play で手に入れよう https://apps.apple.com/us/app/id1471109324
↑オフライン検索できるアプリもどうぞ
在日通名大全

日本初、在日通名の研究書「在日通名大全」発売中!
ネットの電話帳 住宅地図 マッポン!

「一沢」さんの名字の分布比率。

カンマ区切りで複数の名字を指定できます。

Etymology of 一沢

Distribution of 一沢
Ranking
1 San'nohe-gun San'nohe-machi(0.132%)
2 Higashiibaraki-gun Ibaraki-machi(0.102%)
3 Kuji-shi(0.0922%)
4 Isumi-gun Onjuku-machi(0.0392%)
5 San'nohe-gun Nanbu-machi(0.0162%)
6 Sakaiminato-shi(0.00942%)
7 Kyouto-shi Sakyou-ku(0.00808%)
8 Abiko-shi(0.00801%)
9 Yokohama-shi Minami-ku(0.008%)
10 Kyoutanabe-shi(0.008%)
11 Musashimurayama-shi(0.00772%)
12 Kyouto-shi Kita-ku(0.00717%)
13 Yokohama-shi Kounan-ku(0.00698%)
14 Kitami-shi(0.00574%)
15 Nabari-shi(0.00528%)
16 Kyouto-shi Kamigyou-ku(0.00509%)
17 Yokohama-shi Kanazawa-ku(0.00484%)
18 Akishima-shi(0.00482%)
19 Ishioka-shi(0.00481%)
20 Kyouto-shi Nakagyou-ku(0.00447%)
21 Nagoya-shi Meitou-ku(0.00404%)
22 Hachinohe-shi(0.00332%)
23 Kuki-shi(0.00315%)
24 Koutou-ku(0.00312%)
25 Yaidzu-shi(0.00299%)
26 Sakura-shi(0.0029%)
27 Oosaka-shi Hirano-ku(0.00273%)
28 Yokohama-shi Hodogaya-ku(0.00257%)
29 Sendai-shi Taihaku-ku(0.00252%)
30 Souka-shi(0.00242%)
31 Kamakura-shi(0.00242%)
32 Kyouto-shi Ukyou-ku(0.00239%)
33 Yokohama-shi Tsurumi-ku(0.00218%)
34 Yokohama-shi Totsuka-ku(0.0021%)
35 Yokohama-shi Kouhoku-ku(0.00197%)
36 Mito-shi(0.00173%)
37 Morioka-shi(0.00158%)
38 Kooriyama-shi(0.00147%)
39 Katsushika-ku(0.00136%)
40 Okazaki-shi(0.0013%)
41 Matsudo-shi(0.00116%)
42 Edogawa-ku(0.00105%)
43 Nerima-ku(0.00105%)