70 
appendix 
Chlorophyll a 
Assessment Protocol 
STEP 1. CALIBRATING DATAFLOW CRUISE-TRACKS 
1. Locate the CPB segments where DATAFLOW cruise-track points are located 
using GIS. Although VIMS and Hampton Roads Sanitation District (HRSD) 
have cruise-tracks organized by segment, the ends of cruise-tracks “spill” over 
into adjacent segments. Points need to be regrouped prior to calibration since 
each segment has its own regression equation. 
2. Organize records for verification stations by segment and season (spring and 
summer). Each verification station should have extracted and YSI chlorophyll for 
each sampling date, along with turbidity and temperature data. 
3. A calibration equation should be determined for each segment-season combina¬ 
tion by calculating a log-ratio (logExtracted - logYSI) for each verification 
event, regressing it over concomitant temperature and turbidity values to deter¬ 
mine a predicted log-ratio, and multiplying the backtransformed predicted 
log-ratio by the YSI chlorophyll to estimate the extracted chlorophyll for cruise- 
track points. 
STEP 2. SETTING UP THE DATA SET 
4. Compile a chlorophyll database for the assessment period containing records 
from the following stations: 
a. Long-term CBP stations (records stored in CIMS database) 
b. DFLO verification stations (records stored in CIMS database) 
c. VA DEQ stations (records stored in VA DEQ CEDS database) 
d. DFLO cruise-tracks (records stored by VIMS/HRSD). 
5. Database should contain station name, UTM Easting and Northing coordinates 
(NAD83), laboratory-extracted chlorophyll values (ug/1), sampling date, 
sampling depth (only depths less than or equal to 1.0 m should be used), and 
appendix g 
Chlorophyll a Assessment Protocol 
