Inundation Risk to Marginalized Communities in the Floodplains of Indus River Basin, Pakistan

Abstract

The Indus basin is subject to modifications – from the development of canals in Kashmir (8th century) to the development of a complex irrigation system (19th century). These developments have increased the illegal encroachment of floodplains. The rivers wreak havoc on these people in the form of floods. To mitigate the flood risks, it is important to effectively manage the Indus River system, which requires knowledge of current river geomorphology and flood management practices. The present study provides a systematic analysis of the river planform dynamics in the context of flooded duration and cultivated land loss. MODIS dataset was used to map the districts flood duration (2000-2020). The river planform characteristics were systematically mapped using the Landsat NDVI images (2000-2020). The district flooded duration reached a maximum of ~48 to ~91 days. The average width calculated for Indus is ~1,594 m, ~893 m for Jhelum, ~687 m for Chenab, and ~331 m for Sutlej. Accretion and erosion analysis indicated that Indus (~1,034 km2 ) and Jhelum (~130 km2 ) rivers gained net land, while the Chenab River lost (~919 km2 ) on both banks. The Sutlej River experienced net land gain on the right bank (~161 km2 ) and loss on its left bank (~16 km2 ). Additionally, Indus, Jhelum, Chenab, and Sutlej rivers eroded ~1,995 km2 , ~477 km2 , ~643 km2 , and ~463 km2 of cultivated land respectively. Regression analysis provided a statistically significant relationship between river planform dynamics and districts flood duration. The Indus floods and the constantly altering river planform dynamics are causing constraints on agricultural production in the region. The study also provides an elaborative flood management analysis which highlights that a loophole is present in the flood management strategy which needs to be outlined and plugged on a priority basis to reduce the detrimental effects of floods on the country.