René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Question about R-LOADEST confidence intervals","articleBody":"I have been recently using R-LOADEST to estimate loads at the Connecticut River- in a tidal part of the river where we have an Acoustic Doppler Side Looker that computes our discharge.\r\n\r\nMost of the loading work I am doing is based on using measurements of uv-nitrate, and turbidity to predict total nitrogen.  We have periods of missing record, and I have been using RLOADEST to backfill the holes in the data, for daily LOADS.\r\n\r\nIn order to do this, I ran LOADEST for the entire period.  I was able to make predictions for daily load, as well as annual load.  I am confused however as to how the confidence intervals are calculated for annual load estimates, as they seem to be much smaller than the confidence intervals from the daily load estimates- which makes sense.\r\n\r\nI had always assumed that the annual numbers were based on some average of the daily estimates, but I realize I am not correct.\r\n\r\nWondering if you have any thoughts on this?  I have used LOADEST for many years, but never worked much with the daily outputs.\r\n\r\nSee the difference in confidence intervals below.  I guess I am interested in how the annual confidence intervals are calculated.\r\n\r\nThanks for any thoughts,\r\n\r\n\r\nSee below\r\n\r\n**Output from the annual water year LOADEST model**\r\n\r\n-------------------------------------------\r\n \r\nWARNING: The minimum estimation data set steamflow exceeds the minimum\r\ncalibration data set streamflow. Load estimates require extrapolation.\r\n \r\n \r\n-------------------------------------------------------------\r\nConstituent Output File Part IIb: Estimation (Load Estimates)\r\n Load Estimates for 2008-12-06 to 2014-09-30\r\n---------------------------------------------------------------\r\n \r\nFlux Estimates, in metric tons/d, using AMLE\r\n----------------------------------------\r\n \r\n   Period Ndays     Flux   Std.Err       SEP      L95      U95\r\n1 WY 2009   299       NA        NA        NA       NA       NA\r\n2 WY 2010   365 **35.79537** 0.8031539 0.9129524 **34.03918 37.61769**\r\n3 WY 2011   365 52.60603 0.9648709 1.1402695 50.40633 54.87595\r\n4 WY 2012   366 37.88657 0.6920841 0.8021472 36.33856 39.48282\r\n5 WY 2013   365 38.72842 0.5725083 0.7078853 37.35939 40.13420\r\n6 WY 2014   365 33.78798 0.7151103 0.8206135 32.20798 35.42458\r\n \r\n\r\n****In this version, I summarized the results from the daily output, taking the mean of the\r\ndaily loads and the daily confidence intervals by water year.****  \r\n\r\nStatistics on daily output from the same LOADEST model.\r\n  waterYear     mean  meanL95  meanU95      sum    sumL95   sumU95  NObs\r\n1      2009 38.31362 26.50062 53.64662 11455.77  7923.686 16040.34   299\r\n2      2010 **35.79537** **24.85938 49.95111** 13065.31  9073.675 18232.15   365\r\n3      2011 52.60603 36.56946 73.35049 19201.20 13347.852 26772.93   365\r\n4      2012 37.88657 26.35149 52.80251 13866.48  9644.645 19325.72   366\r\n5      2013 38.72842 26.96705 53.92551 14135.87  9842.974 19682.81   365\r\n6      2014 33.78798 23.48650 47.11421 12332.61  8572.571 17196.69   365","author":{"url":"https://github.com/jmusgs","@type":"Person","name":"jmusgs"},"datePublished":"2017-03-29T18:09:09.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/20/rloadest/issues/20"}