A review of the assessment and mitigation of floods in Sindh, Pakistan

This paper lays emphasis on the riverine floods (natural hazards), which are more frequent than other types of flood affecting Sindh. Nevertheless, a brief description of the other types of floods is also included. River Indus and its tributaries cut across Pakistan. The river basin so evolved covers approximately 65 % of the total area of the country. The major part of the river basin in Pakistan lies in the province of Sindh, which is prone to floods. It poses a major environmental hazard, particularly when the flood waters overtop, a few km wide river channel; the natural floodplain, confined by the manmade levees (flood protective embankments/bunds), several kilometers apart, constructed on both sides of the channel, forms the riverine area (manmade flood plain). The latter, locally known as the katcha area, is spread over an area totaling about 8,500 km(2), and agricultural crops, which are the backbone of economic prosperity of Sindh, are partly grown in the flood plain of River Indus. The worst floods do not occur every year, but when they do, they play havoc in the riverine area, occupied by crops. Furthermore, there are three barrages constructed at Guddu, Sukkar, and Kotri, in which manmade feeder canals control the floods, as well as enabling the river water to irrigate over 60,000 km(2) of agricultural land, falling within the command area of these canals. It may be noted that there are other types of flood, including the pluvial floods, urban/stormwater floods, flash floods, and coastal, as well as groundwater floods that also occur in Sindh. A brief description of these floods is also included, and an attempt is made to make an assessment of occurrence of the riverine floods. Also, suggestions are put forward to mitigate the influence of these floods, and through light on participatory management practices considering safety, scientific, technical, social, and political dimensions, aimed at mitigating and controlling the flood hazards.