Reaeration Measurement in an Estuary

Measurements of surface reaeration are presented for the Sacramento-San Joaquin Delta. Estimates of reaeration were computed from observed diurnal dissolved oxygen changes in the estuary. The reaeration constants computed in this manner varied between 0.16 and 3.91 grams per cu m per hr at 0% saturation. Independent in-situ measurements using gasometeric and disturbed equilibrium methods were conducted for comparison. Reaeration constants varied from 0.64 to 2.84 gm per cu m per hr using the gasometeric method. The disturbed equilibrium method yielded reaeration constants between 0.62 and 1.70 gm per cu m per hr. The independent methods showed reaeration constants to be highly variable. Surface turbulence proved to be the most important mechanism controlling reaeration constants in the estuary. Wind velocity was the singularly most significant parameter in causing surface turbulence.