caa a22 4500 467903891 CHVBK 20180406152827.0 cr unu---uuuuu 170328e20061001xx s 000 0 eng 10.1007/s10661-005-9163-8 doi (NATIONALLICENCE)springer-10.1007/s10661-005-9163-8 Predicting Water Quality Impaired Stream Segments using Landscape-Scale Data and a Regional Geostatistical Model: A Case Study in Maryland [Elektronische Daten] [Erin Peterson, N. Urquhart] In the United States, probability-based water quality surveys are typically used to meet the requirements of Section 305(b) of the Clean Water Act. The survey design allows an inference to be generated concerning regional stream condition, but it cannot be used to identify water quality impaired stream segments. Therefore, a rapid and cost-efficient method is needed to locate potentially impaired stream segments throughout large areas. We fit a set of geostatistical models to 312 samples of dissolved organic carbon (DOC) collected in 1996 for the Maryland Biological Stream Survey using coarse-scale watershed characteristics. The models were developed using two distance measures, straight-line distance (SLD) and weighted asymmetric hydrologic distance (WAHD). We used the Corrected Spatial Akaike Information Criterion and the mean square prediction error to compare models. The SLD models predicted more variability in DOC than models based on WAHD for every autocovariance model except the spherical model. The SLD model based on the Mariah autocovariance model showed the best fit (r2 = 0.72). DOC demonstrated a positive relationship with the watershed attributes percent water, percent wetlands, and mean minimum temperature, but was negatively correlated to percent felsic rock type. We used universal kriging to generate predictions and prediction variances for 3083 stream segments throughout Maryland. The model predicted that 90.2% of stream kilometers had DOC values less than 5 mg/l, 6.7% were between 5 and 8 mg/l, and 3.1% of streams produced values greater than 8 mg/l. The geostatistical model generated more accurate DOC predictions than previous models, but did not fit the data equally well throughout the state. Consequently, it may be necessary to develop more than one geostatistical model to predict stream DOC throughout Maryland. Our methodology is an improvement over previous methods because additional field sampling is not necessary, inferences about regional stream condition can be made, and it can be used to locate potentially impaired stream segments. Further, the model results can be displayed visually, which allows results to be presented to a wide variety of audiences easily. Springer Science+Business Media, Inc., 2006 dissolved organic carbon nationallicence geostatistics nationallicence hydrologic distance nationallicence streams nationallicence waterquality monitoring nationallicence Peterson Erin CSIRO Mathematical & Information Sciences, Queensland Bioscience Precinct, 306 Carmody Road, 4067, St. Lucia, QLD, Australia aut Urquhart N. Department of Statistics, Colorado State University, 80523, Fort Collins, CO, USA aut Environmental Monitoring and Assessment Springer Netherlands 121/1-3(2006-10-01), 615-638 0167-6369 121:1-3<615 2006 121 10661 https://doi.org/10.1007/s10661-005-9163-8 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10661-005-9163-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Peterson Erin CSIRO Mathematical & Information Sciences, Queensland Bioscience Precinct, 306 Carmody Road, 4067, St. Lucia, QLD, Australia aut NATIONALLICENCE 700 1- Urquhart N. Department of Statistics, Colorado State University, 80523, Fort Collins, CO, USA aut NATIONALLICENCE 773 0- Environmental Monitoring and Assessment Springer Netherlands 121/1-3(2006-10-01), 615-638 0167-6369 121:1-3<615 2006 121 10661 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer