ISLAMABAD: A joint report of the United Nations Food and Agriculture Organisation (FAO) and Pakistan Space and Upper Atmosphere Research Commission (Suparco) has blamed the design of Left Bank Outfall (LBOD) spinal drainage for inundation of large swathes of land in Tando Mohammad Khan, Badin and Mirpurkhas districts and displacement of a large number of people in rural Sindh.
According to the report, the runoff water does not find any inlet into the LBOD. The rainwater either overtops the banks of the drain or farmers breach them to drain their fields because of the disadvantage of lower riparian.The design of LBOD spinal drainage has become controversial because of devastation caused by floods in parts of rural Sindh. It is a man-made fault which is responsible for the devastation.
The design does not take into account the current flows of water and, as a result, the excess water overflows the banks of the drain and floods fields. The latter, which are carrying crops, are then breached by farmers to let the water out. This has led to the inundation of large areas in Tando Muhammad Khan, Badin and Mirpurkhas.
The LBOD spinal drain with a capacity of 4,600 cusecs was designed to carry 2,000 cusecs to Shakoor lake and the remaining 2,600 cusecs to the Arabian Sea through Badin.
Suparco says that change detection based on multi-temporal and multi- resolution satellite imagery was used to ascertain the location of breaches, their sizes and damage to other infrastructure. Various base layers such as settlements, irrigation network, roads, railway lines and bunds were overlaid on flood extent map for assessment of infrastructural damage and mapping.
The LBOD design has come under severe criticism by politicians belonging to rural Sindh. Speaker of the National Assembly Dr Fehmida Mirza, who belongs to Badin, recently said the current devastation was because of inherent fault in the design. According to the Suparco report, several breaches in protective bunds of canals have also been noticed in Sindh. The most prominent breaches have been identified and delineated in Badin, Mirpurkhas, Umerkot, Tando Muhammad Khan, Thatta, Tando Allah Yar and Sanghar.
The stagnant runoff water damaged a large number of cotton and rice crops in Mirpurkhas, Benazirabad, Sanghar, Ghotki, Tando Muhammad Khan, Tando Allah Yar, Badin and other districts. However, rice crop benefited from rains in some districts and losses are expected to be offset by gains in other areas. The overall impact on rice crop is expected to be positive.
Sugarcane crop is almost 11 months old in Sindh and height of the crop flooding is 6-8 feet. Generally, sugarcane crop is not damaged by flash floods. Some damages can accrue by lodging and uprooting of the crop. However, the sugarcane productivity is likely to increase because of availability of additional water from rains.
Kharif vegetables are at the fag end and major harvests have already been made. The damage on this account is, therefore, ignorable.
Rabi vegetables are being sown. Vegetables like onion and tomato may have to be re-sown in the flood-affected areas. Chillies in Kunri may be affected by prolonged flooding.
Official land utilisation statistics show that the cultivated area in Sindh is 4.89 million hectares. The net shown area over a year is 2.81 million hectares and fallow area is 2.08 million hectares.
This is almost a ratio of 60 per cent cropped area and 40 per cent fallow area. However, Suparco assessment suggests that cropped area is 70 per cent and fallow area 30 per cent.