Determining Flow Systems Using Chemical Data and GIS in Cuatro Cienegas, Coahuila, Mexico. Shanna Evans December 2, 2004. Importance. The basin was set aside as a preserve by the Mexican government in 1994 More than 70 endemic and/or endangered species inhabit the basin (DFWC, 2003)
Determining Flow Systems Using Chemical Data and GIS in Cuatro Cienegas, Coahuila, Mexico
December 2, 2004
The basin was set aside as a preserve by the Mexican government in 1994
More than 70 endemic and/or endangered species inhabit the basin (DFWC, 2003)
It has a spring density of 12-15 pozas (spings) per square kilometer (Winsborough, 1990)
Water levels have dropped approximately 30-60 cm in the past five years (Lesser, 2001)
Where is the water coming from and where is it going?
Blue points on Cuatro Cienegas Map are springs within the basin
Water samples and corresponding GPS locations were collected at 35 sites during April and June, 2004.
Samples were analyzed for major anions and cations
Conductivity, pH, DO, ORP, Temperature, and alkalinity were measured in the field
Poza Juan Santos
Each pink point is a sample site containing chemical data, but the data was stored in 4 layers!
Spline and kriging methods were not accurate in their interpretation.
Inverse Distance Weighted method was most accurate
IDW and Spline Temperature Map
Kriging Temperature map
5 flow systems most likely exist in the basin
Higher conductivities were at the end of flow paths and toward the center of the basin
Evaporation controls chemical evolution
This is consistent with the proposed flow systems
Conductivity map of the basin
Higher temperatures were at the source of the spring and toward the end of the flow paths
Interesting, but not necessarily helpful
Temperature map of the basin
Alkalinity in the basin may be an indicator of separate flow systems
The Anteojo and Hundidos systems had the highest alkalinities
Alkalinity map of the basin