variable names Julian day (YYDDD) & date 



DISPtAY OF RINCON PRQ, 

 'Upper plot: ~ White pt ^al Rincon sup^ 

 ftower plot 

 X White Point tide 

 \cCBay tide 



Rincon gage stage 

 Lunar declinat:j.6n 

 wind I wind below, circle = 10 m/s 

 vector .^ I DATE 98317 Nov 1 



apoq periq 



rainfall 



Calallen flow 



declination 

 range 



Lunar icon 



salinity 



Flow in 

 Rincon 

 channel 



lunar 

 ^ ^efclination 



tide (stage) 

 level 



pengee 

 range 



tide datum 

 end-of-month marker 



mnemonic line for key control options 



Figure 1 : Display Screen for BAION. 



All three stage records are referenced to the same ("arbitrary") consistent datum. (Also, the 24-hr mean values 

 of the Rincon stage had to be re-computed to reference these to GMT, which is the averaging period for all of 

 the other hydrographic data.) On this same panel, lunar declination is plotted as a faint blue covet. Although 

 declination is indicated by the vertical position of the lunar icon on the left panel, it can be hard to follow in 

 relation to the water level, requiring one eyeball to be fixed on the lower left panel while the other follows one 

 of the traces in the right panel. The vertical lines demarcate months. 



The upper panel displays "hydrography", including the salinity variation m upper Nueces Bay, the super- 

 elevation of Rincon gauge over White Point, and the measured discharge in the Rincon diversion channel 

 (starting in May 1996), as well as Calallen flow and regional rainfall. The Rincon discharge is generally about 

 10% of the flow at Calallen, so it is scaled tenfold to be plotted on the same axis (scale on the right side of 

 panel). The salinity data is from CBI SALT03 gauge, which turns out to be situated due south of White Point, 

 but in the center of the bay about equidistant from the moutli of the Rincon and the mouth of the Nueces. It 

 therefore responds to flows in both conveyances. 



Daily rainfall is plotted as a light blue bar, positive downward from the top of the panel. This is a composite 

 data set, consisting of the measiurement at the USGS gauge back to May 1996, and the Corpus Christi airport 

 measurement prior to this. The Calallen flow is plotted as a bar graph at the "back" of the panel. This slows 

 down the display, because more time is required to "paint" the record, but this strikes me as a clearer depiction 

 of flow conditions. (Note the jazzy shadows of the data points when a trace crosses a flood hydrograph.) 



One problem with the record of super-elevation is that both the White Point and the USGS Rincon gauge peg 

 at low water. The Rincon gauges is especially problematic. For these data, any day with more than 25% of the 

 data (5 measurements) at the low pegged value was deleted from the record. For those days with 5 or less such 

 pegged values, a daily mean was computed using the peg values. (To omit them would overestimate the mean 

 stage.) Approximately 16% of the data at the Rincon gauge proved to be pegged values. Fortunately these 

 were confined to winter or summer low flows, in the absence of significant river flow, so there should be littie 



B-4 ♦ Hydrography of the Nueces Delta and Estuaty: 1992-1999 



