Author(s): Shaukat Ali Awan
Linked Author(s):
Keywords:
Abstract: Pakistan has unique flood forecasting problems, which can be appreciated only if the meteorological causes of the floods are first understood. Floods in Pakistan are mainly caused by the heavy monsoon rains during the summer monsoon period from July to September. Meteorologically there are two situations which cause flood producing rains in the upper catchments of the rivers. The two meteorological situations in relations to different conditions of intensity and movement of low/depression may produce three categories of floods. Category-I Floods: This is the situation when the seasonal low, which is a semi permanent weather system gets occasionally intensified and causes the moisture from the Arabian Sea to be brought up to the upper catchments resulting in the heavy downpour. Category-II& Category-III Floods: The second flood generating meteorological situation is the one linked with a monsoon low/depression. Such monsoon systems originate in the Bay of Bengal region and then moving across India in a general west/north westerly direction arrive over Rajasthan or any of the adjoining states of India. Flood management process in Pakistan is multi-functional involving a number of different organizations. The very first step in the process is the issuance of the flood forecast/warning. This function has been assigned to the Pakistan Meteorological Department (PMD) since the basic cause of the floods in Pakistan is the rainfall, which can be best, predicted and monitored by PMD utilizing the satellite cloud pictures and the quantitative precipitation measurement radar data, in addition to the conventional weather forecasting facilities. Digital terrain mapping through GIS technique is being carried out for effective floodplain management in the Indus river basin and co-related with the flood level expected and the depth of the area effected.
Year: 2002