Abstract:
Pakistan having the highest urbanization rate (3% per year), population growth rate (1.8%
per year), high vulnerability (8th rank according to IPCC) to climate change and inadequate
drainage network is highly prone to urban flooding. Recurrent monsoon floods in Pakistan with
huge disruption in urban centers is a clear manifestation of increased frequency and intensity of
urban floods in Pakistan.
ICT and Rawalpindi tehsil being the ethnic, political, commercial and educational hub of
Pakistan face exponential increase in population (9.13% and 49.3% in ICT and Rawalpindi tehsil
respectively) due to migration from villages and rest of the country. The LULC dynamics reveal
that from 1990 to 2022, urbanized area increased from 97.07 km2
to 577.65 km2
(14.7%),
agricultural land increased from 0.60 km2
to 310.6 km2
(8.96%), bare land increased from 1250.21
km2
to 1476.41 km2
(9.54%) and vegetation decreased from 1971.92 km2
to 853.84 km2
(32.31%).
Water remain almost constant depending upon the seasonal fluctuations. Further it was concluded
that from 1990 to 2022, the LULC class which transformed the most into other classes was
vegetation i.e. 80.3%, and total 27.6%, 20.6% and 47.6% area got converted into agriculture, urban
communities and bare land respectively from 1990 to 2022.
Unpredictable and uncontrolled urbanization has resulted in encroachments. Encroachment
started after 1995 and rose to 200.5 km2
in 2022. Maximum urbanization has taken place in zone
A (105.9 km2
) i.e. within 30m on both sides of the rivers and storm water ways. In zone B (50 m)
total encroachment was 28.7 km2
, 39.7 km2
and 26.2 km2
in zone C (80 m) and zone D (100m)
respectively. This significantly decreased the storm water drainage capacity. Based on the results
of LULC dynamics, temporal analysis of floods and encroachment; the 3 hotspots which faced
frequent urban flooding in the past were identified i.e. E-11, Islamabad, Gawal mandi and Soan
bridge, Rawalpindi. In E-11, Islamabad; encroachment increased from 0.008 km2
to 0.1 km2
. In
Gawal mandi and its vicinity it increased from 0.15 km2
in 1990 to 0.23 km2
in 2022. While,
encroachment in Soan Bridge and its vicinity has increased to 1.19 km2
in 2022 from 0.15 km2
in
1990.
