Environmental numerical data

1. Green dam supporting water circulation

1) Forest situation with "green dam" function to cultivate water sources

【Graph 1】 Changes in areas of natural forest and artificial forest

【Graph 1】 Changes in areas of natural forest and artificial forest
  • The graph tells us
Natural forests are said to have both excellent underground water retention and purification capabilities, as they are excellent as diverse habitats for surface and underground organisms. From this point of view, whether the forest around the water source is a natural forest has a great significance for the water cycle. Niseko Town relies on springs for many of its water resources, it is very important that natural forests around the water resources be preserved. According to the graph, the number of natural forests in Niseko Town is decreasing. However, the area of natural forest is still larger than that of planted forest, so it is necessary to stop the decreasing trend in order to conserve rich water resources.

2. Influence of agriculture on water circulation function

1) Paddy field area of ​​the middle mountainous area contributing to downstream groundwater recharge

【Graph 2】 Changes in the area of ​​cultivated cultivated paddy fields and field crops

【Graph 2】 Changes in the area of ​​cultivated cultivated paddy fields and field crops
  • The graph tells us
In the paddy field, in addition to the function to recharge the downstream groundwater, there is a denitrifying effect that the microorganisms in the soil change nitrogen contents such as ammonia and nitric acid dissolved in water into nitrogen gas. In this respect, rice paddies planting rice paddies and fallow fields filled with water have a positive effect on water circulation.
According to the graph, although the cultivated land area of ​​paddy fields is on a downward trend, the reduction rate of the field exceeds it. From this, it seems that the groundwater recharge function has declined.
According to the soil diagnosis, the field soil of Niseko is characterized by a slightly lower pH, excessive potash component, and lack of lime.

2) Inflow of livestock waste into rivers and groundwater

【Graph 3】 Changes in livestock head number

【Graph 3】 Changes in livestock head number
  • The graph tells us
Inappropriate treatment of manure and wastewater from domestic animals is highly likely to contaminate nearby rivers and groundwaters, so the pH, BOD, COD, SS, the number of E. coli groups, nitrogen and phosphorus emissions Standards have been set.
In recent years, the number of dairy cattle head per household has increased sharply, so we have actively promoted improvement of livestock manure compostors so far. In FY 2002, maintenance of almost all livestock farmers will be completed. Also in FY 2003, we are planning to develop a "compost center" that composts cow dung, kitchen waste garbage (raw garbage) and sewage sludge discharged from livestock farmers together.

Inquiries regarding information on this page

Planning Environment Division Eco-Model City Promotion Section
TEL:0136-44-2121
FAX:0136-44-3500