I am a research hydrologist. The focus of my research is the description and understanding of long-term variability and change in surface-water quality and streamflow. I develop and apply new statistical tools to help characterize these changes to gain the best possible understanding of the nature of the change and its implications from a policy perspective (for example with respect to water quality improvement, ecosystem restoration, flood hazard mitigation, water supply planning, or provision of in-stream flow). I served as Chief Hydrologist of the USGS from 1994-2008 and at that time returned to a career in hydrologic research. I am the lead developer of a software package called EGRET (Exploration and Graphics for RivEr Trends) which is now an approved USGS model (written in R - an open source computer language). The statistical method (Weighted Regressions on Time, Discharge, and Season - WRTDS) has been used in a number of studies of water quality trends in the US (Chesapeake Bay Watershed, Mississipi River Basin, Lake Champlain Basin, and elsewhere) to describe and better understand changing concentrations and fluxes of nutrients in river systems. I am also the author of the R package called EGRETci which extends the EGRET package by providing uncertainty information about the trends that are described by EGRET. I have also been working on the description of long-term trends in streamflow as related to changes in land use and climate. Both EGRET and EGRETci are freely available from the Comprehensive R Archive Network (CRAN).