Rainy season arrives

Stage = 59cm, Ta = 20.3C, Tw = 15.8C

This year the rainy season is late in arriving in the Niigata region. The hydrograph below shows a series of rainfall events and peaks during early July. After the first peak, river stage quickly returns to low flow levels, but subsequent rains are more prolonged and we can see the baseflow levels between floods are rising as the soils become more and more saturated and groundwater levels rise. The river flow is swelled by a mix of warm surface runoff and colder deeper groundwater circulation which reduces the temperature of the river, and produces a mist above the water as the warm humid air condenses.