SECTION 3 



DIURNAL MONITORING OF PONDS 



Introduction 



Diurnal studies were carried out at Peck, Pryse and Barbizon evaporation ponds in 

 March and August 1989. The studies comprised bihourly analysis of water samples from the 

 ponds, and half-hourly data acquisition of weather conditions. Water samples were collected 

 from one site at Barbizon and Pryse ponds, while Peck pond was sampled at two sites in March 

 and three in August. Of the three samples at Peck pond during the August study, one was taken 

 from a pool containing brine shrimp (BS), and another from a brackish pool containing salts (SP). 

 The third sample was taken from an adjacent cell containing less saline water. 



Methodology 



Water Che mistr\' Parameters 



Pond water was collected at regular intervals at selected locations in 1 L Nalgene 

 polyethylene bottles. Chemical parameters (Table 3.1) were measured and recorded on-site. 



Table 3.1 Instruments used for measuring Pond Water Chemical Parameters in Diurnal Study 



O Temperature and pH Markson Model 90 pH/Temperature meter, Markson 



combination electrode 



O Eh Markson Model 90 Meter with Markson Pt electrode 



3 DO YSI Model 54A Oxygen Meter and Probe 



a Conductivity YSI Model 32 Conductivity Meter, YSI 3417 Dip-Type 



Cell, YSI 400 Series Temperature Probe 



Density Fisherbrand specific gravity hydrometer range 1.000- 



1.225 and cylinder 



Evaporation Parameters 



Diurnal monitoring for evaporation data at the agricultural drainage evaporation ponds 

 was accomplished using instrumentation developed by Campbell Scientific. The principal 

 device was a CR-21 battery-operated data-logger connected to various weather instruments 

 described later. 



Five parameters were monitored every half hour during a 24-hour period. First, wind 

 speed was measured with a Met One 014 wind cup anemometer. Wind direction was monitored 

 using a Met One wind vane. Gross solar radiation was measured using a Lichor pyranometer 

 from Campbell Scientific. Relative humidity was measured using a Physical-Chem instrument 

 also from Campbell Scientific. Additionally, temperature was recorded using a Campbell 

 Scientific temperature probe. 



Instrumentation was set up on a pipe and stand cross-bar (Figure 3.1). The wind-speed 

 and the wind-direction instruments were placed 2 m above ground level on one of two cross-bars. 

 All other instruments were attached onto the other cross-bar 1 m above ground level. Due to the 

 extreme heat of the summer monitoring trip, the temperature probe was kept shaded. The CR- 

 21 unit was kept out of direct sunlight and also protected from dew-point moisture by wrapping 

 it in a plastic bag. 



piige 3.1 



