Money, E., G. Carter, M.L. Serre. 2008. Covariance models for directed tree river networks, UNC-BMElab Technical Report 2008-08, Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7431, pp. 18. - 1 - Covariance models for directed tree river networks Eric Money 1 , Gail Carter 2 , and Marc L. Serre 1* 1 Univ. of North Carolina – Chapel Hill 2 New Jersey Dept. of Environmental Protection * marc_serre@unc.edu , Phone: 919-966-7014 BMElab Technical Note No 2008-08 Published: August 2008 (Last editing/formatting updates on March 2009) Department of Environmental Sciences and Engineering The University of North Carolina at Chapel Hill Rosenau Hall CB 7431 Chapel Hill, NC 27599-7431 Abstract: In this technical note we describe two classes of covariance models that are permissible for river networks which can be represented as directed trees. These two classes of permissible models are, namely, the isotropic covariance models, and the flow-weighted covariance models. This material is provided as supplementary information to the following paper Money, E., G. Carter, M.L. Serre. Using River Distances in the Space/Time Estimation of Dissolved Oxygen along Two Impaired River Networks in New Jersey, Water Research, accepted 22 January 2009. Available online 21 February 2009, doi:10.1016/j.watres.2009.01.034