Version History for Open-File Report 2009-1120 Paul A. Conrads and Matthew D. Petkewich Estimation of Missing Water-Level Data for the Everglades Depth Estimation Network (EDEN) ----------------------------------------------------- Posted online June 15, 2009 Revised September 15, 2009 ----------------------------------------------------- Gap Report Preface and Modifications Preface This report was originally released without a reference to the datum that data was stored in the National Water Information System (NWIS) database. The report has been revised with references to the datum for each station and the importance of using the correct datum to compute the correct estimation of water level. Modification to the report 1) Insert "Preface" in Table of Contents 2) Insert in Acronyms and Abbreviation on page iv NAVD 1988 North American Vertical Datum of 1988 NGVD 1929 National Geodetic Vertical Datum of 1929 NWIS National Water Information System 3) Insert paragraph after first paragraph on page 4 The estimation of missing data is computed after the data is retrieved from NWIS and prior to the pre-processing the data to generate daily water-level surfaces. The water-level data for a majority of stations in the National Water Information System (NWIS) are stored to North American Vertical Datum of 1988 (NAVD 1988). For the stations with water levels stored to National Geodetic Vertical Datum of 1929 (NGVD 1929), the data preprocessing program converts the water-level data to NAVD 1988. The estimation equations uses the datum used in the retrieval from NWIS and the datum of the stations are listed in Appendix 1 and 2. 4) Insert the sentences beginning with "Make sure" in the second to last paragraph on page 4 Find the station of interest, for example S146_H, a marsh structure in Water Conservation Area 2A (appendix 1). The three input stations, or predictors, are S144_H, S145_H, and S11A_H and are listed as P1, P2, and P3, respectively. Make sure that the data for the predictor stations are for the datum used for the gage (Appendix 1 and 2). The water-level estimation will be for the datum used for the gage. The three estimation equations are: 5) Add the sentences beginning with "Water levels" to the caption for figure 4. Figure 4. Measured and estimated water level for station S146_H using three input (predictor) stations for the period April 15, 2008, to June 15, 2008. Water levels for stations S146_H, S144_H, and S145_H are in NAVD 1988. Water levels for station S11A_H are in NGVD 1929. 6) Insert columns in Appendix 1 and 2 "Datum of data stored in NWIS" to specify the datum for the station. Table abbreviations need to include NWIS, NAVD 1988, and NGVD 1929. 7) Footnote for stations North_CA1, South_CA1, S150_T (SFWMD), and S150_T (USGS) "Prior to October 1, 2004 data stored in NGVD 1929." 8) Add footnote to Columns of Appendix 3 for Station name, Predictor number, Minimum observed, Maximum observed, and Average measured, in feet that reads "Datum of data as stored in NWIS. See Appendix 1 and 2 for a listing. Data for predictors must use the datum listed in Appendix 1 and 2. The water-level estimation will be for the datum used for the gage." Table abbreviations need to include NWIS. ----------------------------------------------------- Revised June 19, 2013 ----------------------------------------------------- The report number had transposed the "1120" with "1102" and this was corrected.