SATELLITE IMAGE BASED EVIDENCE OF POSITIVE IMPACT OF FRESHWATER FLOODING IN INDUS DELTA, PAKISTAN

Abstract

Focusing on the ten year’s mangroves cover change analysis of Kharo Chann taluka, Indus Delta, this study contributed for understanding the changes in distribution and total area of mangroves. Satellite Remote Sensing (SRS) techniques were used to assess the ecological impact of flooding on mangroves growth/change. Object based image analysis being most recent and advanced classification technique was adopted to quantify the density cover of the mangrove’s spread. Multitemporal (2001 and 2011) images of Terra (ASTER) satellite were used to analyze the extent of mangrove cover, various algorithms were incorporated for hierarchical rule set classification. An increase of 2,568 ha in mangroves, particularly in Avicenna marina was observed in this study. Accuracy of the developed forest cover maps was 92.7 % with kappa value of 0.88. Validation of the results was done by ground truthing and an increasing trend in the mangroves from the last 3 to 4 years was seen during analysis. This increase was attributed to plantation activities and natural regeneration as well which was mainly due to the increase in the fresh water flow, downstream from Kotri barrage through floods.