We investigated scaling of conservative solute transport using temporal moment
analysis of 98 tracer experiments (384 breakthrough curves) conducted in 44 streams
located on five continents. The experiments span 7 orders of magnitude in discharge
(10⁻ ³ to 10³ m³/s), span 5 orders of magnitude in longitudinal scale (10¹ to 10⁵ m), and
sample different lotic environments—forested headwater streams, hyporheic zones, desert
streams, major rivers, and an urban manmade channel. Our meta-analysis of these data
reveals that the coefficient of skewness is constant over time (CSK ¼ 1:1860:08,
R² > 0:98). In contrast, the CSK of all commonly used solute transport models decreases
over time. This shows that current theory is inconsistent with experimental data and
suggests that a revised theory of solute transport is needed. Our meta-analysis also shows
that the variance (second normalized central moment) is correlated with the mean travel
time (R² > 0:86), and the third normalized central moment and the product of the first two
are very strongly correlated (R² > 0:96). These correlations were applied in four different
streams to predict transport based on the transient storage and the aggregated dead zone
models, and two probability distributions (Gumbel and log normal)