Trophic state index derivation through the remote sensing of case-2 water bodies in the Mediterranean region

Abstract

The main goal of this study is the derivation of Carlson's Trophic State Index (TSI) through the remote sensing of four different Case-2 waters in the Mediterranean region such as Cyprus and Greece. TSISD is derived through extensive field ground campaign of Secchi Disk Depth measurements for the Asprokremmos Dam, located in Paphos District in Cyprus; Alyki Salt Lake, located in Larnaca District in Cyprus; and in Karla Lake, located in Volos District in Greece; and finally to three coastal water areas in the Limassol coastal area. Several regression models have been applied in order to develop the best regression model between the TSISD and in-band reflectance values for Landsat TM/ETM derived from spectroradiometric measurements using a GER-1500 field spectroradiometer over the main case study area in Asprokremmos Dam in Cyprus. Finally, we apply several regression models for Asprokremmos Dam for retrieving the suitable Landsat TM/ETM band or band combinations (obtained from field spectroradiometric measurements) in which TSISD can be determined. Indeed, the best regression model has been obtained by correlating 'TSI Versus Band2/Band3', with R2=0.89. All field TSISD and in-band reflectance values from the four different water bodies have been used to develop the best fitted model for the established TSISD Versus Band2/Band3 model. We find that the exponential regression model provides the best fitted equation over the four different water bodies.