Modeling and Mapping Temperature, Secchi Depth, and Chlorophyll-a Distributions of Zinav Lake by Using GIS and LANDSAT-7 ETM+ Imagery
Temperature, secchi depth, and chlorophyll-a (in relation to secchi depth) of Zinav Lake in Turkey were modeled and mapped by using Geographic Information Systems (GIS) and Remote Sensing (RS). Temperature (oC), secchi depth (m), and chlorophyll-a (mg/l) field data were collected from the geo-referenced 5 stations on the lake between September- 2011 and October-2012. Secchi depth was measured by Hidrobios brand secchi disc with 25 cm diameter. A multi-measuring device (YSI-556MPS) was utilized to determine temperature values. Chlorophyll-a was measured by using Helios-? model UV-Vis spectrophotometer and monochromatic method. Utilizing geo-referenced field data and the digital number (DN) values of thermal (6.1) band of Landsat-7 ETM+ image (date: 27 April 2012 and pat/row: 175/32), temperature raster map of Zinav Lake was developed. Relationships between secchi depth and band1/band3 values of Landsat-7 ETM+ image, and between secchi depth and chlorophyll-a were modeled by curve fit analysis. Running the produced models in GIS, secchi depth, temperature and chlorophyll-a raster maps of Zinav Lake were developed. The results showed that the lake has anoxic conditions and it exhibits eutrophic characters
GIS, modeling, clorophyll-a, temperature, secchi depth, remote sensing.