Rapid water inundation and submerged crop fields mapping using satellite remote sensing

Floods have utterly destroyed Pakistan. At least 350 of the 1,200 fatalities were children. At the time of this report on September 3, 2022, about 33 million people had been impacted by the recent flooding, and tens of millions were forced to leave their homes. 

A significant proportion of the Sindh, Balochistan, and Punjab provinces are classified as arid climate zone. Agriculture contributes to ca. 24% of the country's GDP. The floodplain of Chenab and Indus Rivers are the primary grain producers of Pakistan. Nearly three times higher rainfall (than 30 years average) has caused flooding conditions in vast areas, including a majority of the croplands. Prolonged water inundation has resulted in enormous crop damage.

A rapid analysis was done using the ESA (European space agency) satellite images (Sentinel-1 A & B microwave images). We used modified Otsu's thresholding to capture the waterlogged/ inundated areas in the Google Earth Engine. The ESRI LULC map was employed to highlight the cropland affected due to the waterlogging. The following figures indicate the dominant water inundation in the western part of Sindh province. The flooding impacted the major rice-growing districts such as Jacobabad, Kashmore, Shikarpur, Qambar Shahadkot, Larkana, Dadu and Naushahro Feroze.