Monitoring heavy metal concentrations in turbid rivers: Can fixed frequency sampling regimes accurately determine criteria exceedance frequencies, distribution statistics and temporal trends?

Reconstruction of Sparse Stream Flow and Concentration Time‐Series Through Compressed Sensing

“…Streamflow and water quality monitoring data are needed to characterize stream physical and ecological regimes, responses to climate and land use change, impairments, and pollutant loads for regulatory oversight and management (Bremer et al., 2020; Burns et al., 2019; Crawford et al., 2015; Pellerin et al., 2014; Pluth et al., 2021; Reynolds et al., 2016; Skeffington et al., 2015; Smith et al., 1997). Many studies agree that high‐frequency or even near‐continuous sampling is necessary to capture the dynamics of flow and concentration and to effectively estimate pollutant loads (Cassidy & Jordan, 2011; Gao et al., 2020; Jones et al., 2012; Kerr et al., 2018; Minaudo et al., 2017; Pellerin et al., 2014; Reynolds et al., 2016; Skeffington et al., 2015; Thompson et al., 2021). However, despite recent advances in sensor technology (Rode et al., 2016), high‐frequency sampling remains prohibitive and stream assessment still relies heavily on infrequent grab sampling, especially for emerging contaminants.…”