Mapping Turbidity Levels in the Lake’s Water using Satellite Remote Sensing Technique

Abstract

Haleji lake, Thatta, Sindh, has been affected by water pollution in the past decades. This study focuses on
mapping water pollution at Haleji lake using turbidity as the pollution indicator. In this study, an algorithm was
developed by correlating satellite reflectance data and in-situ turbidity measurements using regression analysis. The
determination coefficient R2 of the developed algorithm showed a value of 0.83 that is evidence of a good correlation
between field-based and mapped turbidity. Moreover, a temporal analysis was carried out using the same algorithm for
the years 1999 and 2011. Results of temporal analysis confirmed that the turbidity levels in Haleji lake have increased
from below 5 NTU to around 15 – 30 NTU. This is a clear sign of lake pollution in the interim of the past twelve years.