Hokkaido Lakes Catalog

Data and photo sources

Sources of the data, 1970s aerial photos and 3D views in this catalog, and how the figures were chosen.

Lake data

The 127 lakes and ponds in this catalog are those in Hokkaido covered by the lake survey carried out in 1991 by the Environment Agency of Japan (now the Ministry of the Environment). Figures are taken from the newest source available, in this order:

  1. Area: Geospatial Information Authority of Japan, Area Statistics of Prefectures and Municipalities 2026 (as of July 1), appendices 1 and 2 (Japanese). It lists only lakes of 1 km² or more; this catalog uses it for 30 lakes.
  2. Surface elevation and maximum depth: the reference water level and depth in the Geospatial Information Authority of Japan, List of surveyed lakes (Japanese), used for 26 lakes.
  3. All other data: Environment Agency of Japan, 4th National Survey on the Natural Environment: Lake Survey Report (national edition), March 1993 (Japanese). Origin, lake type, fresh or brackish water, average depth, transparency, freezing, unmodified status and lake number are as of the 1991 survey.

The report contains a few apparent errors, such as listing brackish Lake Akkeshi as freshwater; those we noticed have been corrected. Locations were checked with the GSI address search, and the municipalities of Lake Tachibana and Oyunuma Pond (Noboribetsu City) and Lake Hangetsu (Kutchan Town) were corrected. Natural parks are shown under their current names.

Lake descriptions

Each description contains only facts confirmed in materials published by public bodies: the Ministry of the Environment's Ramsar Site leaflets and national park pages, the Japan Meteorological Agency's catalogue of active volcanoes (caldera volcanoes), and the lake survey report and its data appendix (species recorded in the 1991 survey). The sources for each lake are listed under its description. Where we compared the 1970s aerial photo with recent imagery, that is noted as a source. The English descriptions are translations of the Japanese ones; all sources are in Japanese.

1970s aerial photos

The photo on each lake page is an aerial photo taken by the Geospatial Information Authority of Japan (GSI) in the 1970s, published on the GSI Maps and Aerial Photo Service. It is shown with attribution in accordance with the GSI content terms of use. The whole frame, including the film edge and instruments, is shown resized; thumbnails in the lists are cropped.

Source: aerial photos taken by GSI (date shown on each page).

3D view of today

The 3D view on each lake page is built in your browser from GSI Tiles (elevation tiles and the latest seamless aerial photos). The year of the aerial imagery varies by location. For lakes on flat land, height is exaggerated so the terrain is visible, and the factor is shown under the view.

Maps

The maps use GSI Tiles (pale map) and OpenStreetMap.