Histogram based water quality assessment in satellite images

Water is one of the most precious resources of our environment. This water body is often faced the quality questions because of being polluted by ammonia, chemical wastes, sulfur dioxide from power plants, fertilizers containing nutrients— nitrates and phosphates, sediment, phytoplankton, etc. So, it is very necessary to assess quality of different water bodies. In this study, satellite images have been used for water quality measurement using histogram comparisons. A satellite image has been chosen to use as the original image whose water body has been considered as a standard of clear water body. Then this clear water body has been separated from other features using clustering at first to be used as standard ones and their number of pixels in percentage has been counted. Those images which contain the same percent of water bodies as the perspective standard ones can be verified by comparing their histograms. Euclidean distance has been measured between the standard and tested image's histograms. A tolerance level has been taken to assess the water quality as excellent, better, good, bad and poor. Finally if the distance falls within the tolerance level the water body can be categorized as excellent, better, good, bad or poor based on their degree of purity.