Recording temperature probes donated for use by AECOS Consultants are monitoring stream temperatures in Kawa Stream. Information on the Optic StowAway temperature logger is available at Onset Computer Corporation website. Sampling interval is set at once every 15 minutes.
The following table summarizes long-term monitoring results from the Optic StowAway temperature logger. To better reveal seasonal trends, the measurements are analyzed by month. Details of temperature probe placements are presented in the descriptions of the monitoring runs that follow. Temperature data are summarized as mean, standard deviation, range, number of data points (in parentheses) and total days (or partial days) in situ for the month indicated. These results may be compared with simultaneous recordings made by the Makawai Stream Restoration Aliance in Waiahole Stream.
| Kawa Stream | 1999 | |||
| Sta. 007 | NOVEMBER | 22.70 oC +/- 1.21 | 20.2 - 25.8 oC | (1567) ~ 17 |
| DECEMBER | 22.32 oC +/- 1.05 | 19.7 - 25.3 oC | (2976) ~ 31 | |
| 2000 | ||||
| JANUARY | 21.39 oC +/- 1.25 | 18.3 - 25.5 oC | (2977) ~ 31 | |
| FEBRUARY | 22.53 oC +/- 1.52 | 19.6 - 26.9 oC | (2784) ~ 29 | |
| MARCH | 22.80 oC +/- 1.68 | 20.0 - 27.9 oC | (2977) ~ 31 | |
| APRIL | 22.38 oC +/- 1.83 | 17.9 - 28.5 oC | (2880) ~ 30 | |
| MAY | 24.32 oC +/- 2.24 | 21.4 - 30.9oC | (2977) ~ 31 | |
| JUNE | 25.58 oC +/- 2.45 | 22.19 - 32.83 oC | (2880) ~ 30 | |
| JULY | 25.26 oC +/- 1.97 | 22.36 - 32.05 oC | (2976) ~ 31 | |
| AUGUST | 25.39 oC +/- 2.07 | 22.69 - 31.28 oC | (2262) ~ 28 | |
Run No. 1 ~ Recording probe (S/N 295496) placed in about 10 cm of water (shaded by a concrete block) within Kawa Stream on November 14, 1999. An air temperature recorder (S/N 302212) was established nearby in a shaded location (under an eave on the north corner of a house) on November 19. It appears that although the range for air temperatures is expectedly much broader, mean water temperature in Kawa Stream tracks mean air temperature fairly closely in the winter months (Table 2). In the summer months, mean stream temperature tends to be around 1 Co cooler than mean air temperature, with the transition (in 2000, at least) between winter and summer temperatures occurring in March/April.
MONTH |
AIR TEMP.(oC) |
RANGE |
STREAM TEMP.(oC) |
RANGE |
| 1999 | ||||
| November | 23.9 | 20.0 - 30.5 | 22.7 | 20.2 - 25.8 |
| December | 22.5 | 15.2 - 28.6 | 22.3 | 19.7 - 25.3 |
| 2000 | ||||
| January | 21.4 | 14.4 - 27.5 | 21.4 | 18.3 - 25.5 |
| February | 22.6 | 15.5 - 30.1 | 22.5 | 19.6 - 26.9 |
| March | 23.4 | 17.0 - 31.8 | 22.8 | 20.0 - 27.9 |
| April | 22.9 | 16.9 - 32.8 | 22.4 | 17.9 - 28.5 |
| May | 25.3 | 19.7 - 32.8 | 24.3 | 21.4 - 30.9 |
| June | 26.3 | 20.8 - 33.6 | 25.6 | 22.2 - 32.8 |
| July | 26.3 | 22.3 - 33.0 | 25.3 | 22.4 - 32.0 |
| August | 26.4 | 22.2 - 32.8 | 25.4 | 22.7 - 31.3 |
Run No. 2 ~ Recording probe (S/N 344029) placed in about 5 cm of water (beneath a rock in a shaded forest) within the upper west branch (PUR) of Kawa Stream on July 28, 2000. This location is approximately 50 m upstream of water quality Sta. 08L and was selected because too little water was present above Sta. 08R (central branch; UMR) in July. Intended for only short-term monitoring, recordings from this probe are compared with recordings at Station 07 to demonstrate temperature rise as water flows towards the stream mouth.
For the summer time period between July 28 and August 24, 2000 (2599 measurements) the average difference between roughly simultaneous (within minutes) temperature measurements made in the upper west branch of Kawa Stream and Sta. 07 is -1.8 Co.