A Non-Topographic Photogrammetric Approach to Monitoring Total Suspended Solids (TSS)in Environmental Control Dams in the Ahafo Ano District of Ghana

Terrestrial-based remotely sensed data were utilized in this study to monitor Total Suspended solids (TSS) in Environmental Control Dams and the Tano River at Ahafo-Kenyasi in Ghana. Two algorithms were used to relate TSS with Spectrum Reflectance computed from DN values which were extracted from digital photographs. The geometric mean Reflectance extracted for three bands (red, blue and green) was used in this analysis. A modified optical model that accounted for backscattering and also a polynomial Regression model were modeled using reflectance and in-situ TSS values. Validation was made by finding correlation of estimated TSS with measured TSS. The high correlation coefficients (0.95 with a standard deviation of 2.03mg/l) for the modified optical model and (0.92 with standard deviation 2.08mg/l) obtained for the polynomial model showed that non-topographic photogrammetry (Simple Digital Camera) can be used for water quality measurements. A method was developed based on both models to compute or predict TSS values from image data. These values were compared with EPA threshold of 50mg/L, to warn on the safety of decanting the water trapped in these dams into streams and rivers. TSS maps of a water dam, upstream and downstream of the Tano River was also produced for planning and environmental monitoring.