Late winter

Snowmelt water is crystal clear. Stage = 58cm.

Takiya River stage hydrograph (Nov 2012 to Mar 2013)

Today I serviced all the snow lysimeters, and also downloaded the river water level data enabling me to plot the stage hydrograph for the entire winter season as above. This winter is notable for the absence of any large rain-on-snow events during January and February as cold conditions continued. Precipitation is predominantly snow from mid-December to the end of February. Warmer conditions early March have given two moderate peaks already. Interestingly, the winter minimum low flow of about 40cm stage is roughly the same as the summer low flow stage of last September. Generally we expect the winter low flow to be a little higher due to basal melt of the snowpack and minimal ET during winter.

We are just about to enter the snowmelt season, and mountain snowpacks reach their peak during the month of March, at least in the Takiya River catchment. I was surprised to see that the water level was already a little high at 58cm - likely due to rain-on-snow over the previous weekend, though a trace of new snow had also fallen.

Early this morning temperatures plummeted to -6.5 degrees C for the tributary young cedar site (coldest temperature recorded there all winter). Must have been even colder in the valley bottoms. Clear skies, low humidity and still conditions gave extreme radiative cooling overnight, but warm air moved in during the day and temperatures reached the teens. However, in the shady spots the snowpack remained frozen solid all day. Lots of fresh monkey tracks in the snow.

Larch lysimeter

Mature cedar lysimeter

Young cedar lysimeter

View towards Japan Sea (left) and Miomote River (centre) at about 300m asl

Same viewpoint looking north across lower part of Takiya catchment (right-hand peak about 640m asl)