Physico- Quimical
Water quality monitoring consists of both spot measurements as well as daily measurements. Spot measurements are taken at 23 sampling sites using portable YSI equipment, whereas daily measurements are taken 6 sampling sites using YSI data loggers.
We used a multi-parameter YSI 6600V2 sonde to make spot measurements of temperature, specific conductance (conductivity corrected to 25° C), dissolved oxygen, and pH/ORP. The following graphs show results from the spot measurements since 2006 for some of the sites and key parameters. To compare conditions in the Ciénega we have grouped sampling sites into those sites within the open water and dense cattail areas, which we refer to sites inside the Ciénega. We also group sites along the edges of the Ciénega, where areas tend to be shallower. The following graphs show Mean TDS for these areas.
For TDS we report values calculated in the lab from the analysis of a water sample. The Total Dissolved Solids is calculated in the lab by using a well-mixed water sample, which is filtered through a standard glass fiber filter, and the filtrate is evaporated to dryness in a weighed dish and dried to constant weight at 180°C. The increase in dish weight represents the TDS.Calculated TDS (mg/l) at the Bypass measured at the Ciénega (in blue) and measured at the Southerly International Border (in red) by the U.S. Bureau of Reclamation, and at the Riito-Santa Clara drain (in green) through December 2010. The gaps in the time series represent lack of data for those months. The gaps are for the following months: February 2006, December 2006, August 2007, November 2007, January 2008, July 2008, August 2009. Cattail growth thresholds according to Glenn et al., 1995.
Mean calculated TDS (mg/l) inside the Ciénega (sites 1,2,3). Cattail growth thresholds according to Glenn et al., 1995. Salinity of 3.2 corresponds to a TDS of 3700 ppm, and salinity of 6 ppt corresponds to a TDS of 6900 ppm, using our data from 2006.
Mean calculated TDS (mg/l) inside the Ciénega at new monitoring sites (sites 4, 17, 18, 19, 20, and 23). Cattail growth thresholds according to Glenn et al., 1995. Salinity of 3.2 corresponds to a TDS of 3700 ppm, and salinity of 6 ppt corresponds to a TDS of 6900 ppm, using our data from 2006. Note: The value for August for site #4 was checked and found to be correct.
Mean calculated TDS (mg/l) at the edge site of the Ciénega (site 7). Site 7 has the longest time series. Note the adjustment in the scale to show range of values. Cattail growth thresholds according to Glenn et al., 1995
Mean calculated TDS (mg/l) at the edge sites of the Ciénega at new monitoring sites (sites 10, 11, 13, 16, 22). Site 11 was 17,000 ppm in June and 30,000 in July. Note the adjustment in the scale to show range of values. Some of these sites were dry during the summer months and therefore no TDS measurement could be made. Cattail growth thresholds according to Glenn et al., 1995.
