[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

Discharge observation by floats is more useful than other methods in rapid streams and torrential flows. The adjustment factor is required for obtaining discharge from float velocity. Various kinds of factors were already proposed by various organizations based on assumptions of the vertical distribution of flow. In this report, the linearity is assumed on the distribution, therefore the square rule of drug force of fluid is easily simplified. The calculated values of the adjustment factor are illustrated in Fig.3 with compared with those of WMO and Japanese standards. The reader can realize the trends between them.

View full abstract

[in Japanese]

View full abstract

Sapporo has relied on the Toyohira for most of its water resources. However, population increases have necessitated much water use. In recent years, some rivers have experienced drought and water quality deterioration.We researched the hydrologic and material cycles in Sapporo toward finding solutions to these water environment problems. The assessment revealed the following characteristics of the hydrologic cycle in Sapporo: 1) Sapporo depended on the Toyohira River for 80% of its water supply. However, 2/3 the volume of waste water discharge from its area is channeled into other rivers. 2) Two third of organic pollutant substance and total phosphorus and half of total nitrogen is drained to the other rivers. 3) We identified high-concentration organic pollutant and nutrient of the initial rainfall runoff water from sewerage system.

View full abstract