Abstract:
Shorelines are becoming increasingly fragile due to the combined effects of climate
change and natural disasters, leading to erosion and flooding in coastal areas. This
study used satellite imagery data spanning 20 years to analyze the changes in five
coastal regions: Karachi, Manora, Jiwani, Kemari, and Gwadar. The Random Forest
classification algorithm achieved high accuracy (95% to 99%) in classifying images,
supported by a kappa coefficient of 0.85 to 0.90. Additionally, a time series model was
employed, showing a mean absolute percentage error of 4.5% to 4.95%. The findings
revealed dynamic changes in the coastlines of the studied regions from 2000 to 2020.
Karachi experienced significant accretion at a rate of 20 meters per year from 2000 to
2006, followed by erosion of -10 meters per year in 2014. However, the shoreline has
since experienced accretion, with an annual increase of 15 meters per year until 2020.
Similarly, Kemari initially witnessed severe erosion of -11 meters per year from 2000 to
2006, leading to substantial accretion. This trend improved in 2014, with an erosion
rate of -22 meters per year. From 2014 to 2021, the shoreline consistently experienced
an annual increase in the accretion rate of 11 meters per year.
The study reveals varying trends in coastline change across different locations, with
a mix of expansion and erosion. Future coastal management should address these
changes and their impacts. Regions experiencing negative trends (Manora, Kemari, Ji-
wani) may need erosion mitigation strategies, while areas with positive trends (Karachi,
Gwadar) should focus on sustainable development. Comprehensive coastal manage-
ment is crucial to protect ecosystems while accommodating human activities, consid-
ering the dynamic nature of coastlines.
