摘要：Abstract Dissolved Oxygen (DO) is an important parameter to be monitored as far as water quality of rivers and streams are concerned. On the other hand, in rivers and streams, varying roughness occurs naturally but their contributions to DO availability is yet unknown. This paper examines the effects of varying roughness of different sizes and arrangement patterns on DO and also reveals how Error Correction Methodology as a modelling technique can be applied in river studies rather than using the traditional ordinary least square method with velocity (V), Froude number (Fr), roughness coefficient (K) and dispersion coefficient (d) captured as explanatory variables. The findings of this study revealed that roughness coefficient (K) had no effect on DO i.e. negative relationship with coefficient value of −0.796, with corresponding t-statistics (t = 0.615) suggesting its non-significance. In addition, Froude number (Fr) and dispersion coefficient (d) also showed negative relationships respectively (−77.71 and −2.039) with DO but with sharp significance as revealed by the corresponding t-ratio (t-ratio = −2.75 and −4.08). Thus, the study suggests that dispersion coefficient or its dimensionless number as a variable is important and should be included in the modelling, otherwise, the spread of pollutants (BOD) in the transverse and vertical directions rather than their single centre point values are essential to improve the outcome of DO and reaeration coefficient (k2) modelling.
关键词：pollution ; river management ; tracer studies ; dispersion coefficient ; water quality
