Open access “1km-HydroJAPAN”

The research and development ground of Geosphere Environmental Technology Corporation has been working on the project of information service development. The aim of this project is to provide up to date information to the public via internet using the information generated by “1km-HydroJAPAN” model.“1km-HydroJAPAN” is a 3D numerical model, which is developed for the entire land area of Japan. Horizontal spatial resolution is 1km and vertical one is variable depending on the topographical and geological setting. For the convenience, the model is divided into several sections. 1km-HydroJAPAN consists of 6 sections (Hokkaido, Tohoku, Kanto, Kinki, Chugoku – Shikoku and Kyushu). Any third party can use their own data with “1km-HydroJAPAN” whenever they want to analyze the water environment of any interested area within the Japanese land.The following figure depicts our objective of the information service project which is based on “1km-HydroJAPAN”. The information service is planned to provide in future and it will contain followings:

  1. On-demand analysis service that allows users to run simulations based on their own requirements by using released open data by “1km-HydroJAPAN” or user’s own data.
  2. Hosting services to store user’s own data on the Web.
  3. National water circulation forecasting service to offer the up to date water situation of any location in the country comply with the national weather forecasting information.
  4. National water circulation information library service which can provide various water related thematic maps whenever third party request such information.

In the proposed information service, national scale spatial data can be provided to the users as a package in a user friendly PC interface via internet. Moreover, we would like to provide software services for our clients who can use our facilities and software for their requirements (Software as a Service – SaaS). The users of our facilities and software are charged according to amount they utilize within a specified time period. In this way clients do not need to buy software but they can rent them whenever they need.

1km×1km 3D Numerical Model of Japan

Geosphere Environmental Technology Corporation started to develop a 1km×1km 3D numerical model for Japan (excluding remote islands) as the first version. Using our own parallel computer system, we succeeded surface-subsurface coupled fluid-flow simulation.

1km 3D Numerical Grid Model of Japan

The 3D model was built by giving published open data of topography, precipitation, temperature, land use, geology to each of the 3D grid block. Precipitation and temperature data are averaged meteorological observation data of recent 20 years. The fluid system of the models was configured to 2-phases 3-componets, as a result of that, the seawater/fresh water interaction at coastal areas was able to visualize. The equilibrium state for the water circulation system of the country was achieved in the 1km-HydroJAPAN model. Specific local and regional water circulation patterns were identified through the generated numerical results. In this simulation the total land of Japan was divided into 6 districts as shown below. The water circulation information generated by the 1km-HydroJAPAN model (June 2010) is also displayed accordingly.


*Please Notice
The hydro-geological, meteorological, land use, GIS and whatever other relevant data for the 1km-HydroJAPAN model was obtained from the General Sources where anybody can access and use. During the simulation we simplified and unified the general data accordingly to compatible with the natural system. However, it is not mandatory to the results to reflect the country’s water circulation system perfectly. Future plans aim to upgrade the model with additional information as appropriate.The results of the 1km-HydroJAPN are figured into different categories and they are free to download. However we do not bear the responsibility of the accuracy of those figures if a third party uses them for any commercial or research purpose.

Application to Global Warming Issue

It is considered that 1km-HydroJAPAN model can be applied to wide ranges of water-related problems in the actual field. One of the applications of the 1km-HydroJAPAN is to estimate the future impact of global warming on natural water circulation system. The expected fluctuations of river flow rates, recharge and discharge of groundwater, groundwater levels and so on can be predicted by coupling the relevant localized time series meteorological data accordingly to the model.The spatial resolution of 1km grid-block might not be small enough to represent complicated topography and small streams and ponds. However, such constrains can be overcome by downscaling techniques where more detailed information are needed. Therefore optimizing the 1km-HydroJAPAN model in a prudent way local, regional and global level information can be produced for the water circulation.

Application to Global Warming Issue