Pakistan lies between 24°N to 37°N latitudes and 61°E to 77°E longitudes. Major part of the country lies within the tropics, i.e. up to 30°N, beyond 30°N is extra tropical region. Pakistan has diversified climate, which comprises of mostly arid and semi arid regions besides some hyper arid region on account of natural deserts within 25°N to 30°N as well as considerable areas of irrigated land with insignificant forest cover. Total area under irrigation in Pakistan is about 15 million hectares out of which 9.6 million hectare is arid, 3.8 million hectare is semi arid, 1.0 million hectare is sub humid and remaining 0.6 million hectare is in transitional climate zones. The extensive and continuous use of surface irrigation has altered the hydrological balance of the Indus basin by substantially raising the ground water table. The water table has risen up to 6feet over 25% of the basin and up to 10 feet over one third of the entire Indus plain. More than 40,000 hectares of irrigated land are lost each year to agriculture production due to water logging and salinity. The Thal desert stretches over an area of 2-6 Mha in Khushab, Mianwali, Bakar, Leiah, Muzafargarh and Jhang districts of the Punjab. The Thar desert is located between latitudes 24° and 28° north and between longitudes 68° to 71° East in the Sindh province it comprises eastern parts of Tharparker, Sangar, Nawabshah, Khairpur, and Sukker districts. The desert is bounded by in the north Punjab province; in the west by eastern Nara; in the south by Arabian Sea and in the east by Rajhastan (India). Area of desert is 2.65 million ha out of which 1/4th to 1/3rd is cultivated. Coastal sandy belt extending over 560km from Karachi to Jiwani.
Floods have been recognized as a major natural calamity and the country has a long history of flooding from the Indus river and its tributaries. Floods of 1928, 29, 55, 57, 59, 73, 76, 88, 92, 95, 96 & that of 1997 are the sad yet memorable events entailing tremendous damages to the life and property. The need for establishing an early flood forecasting and warning system was thus recognized soon after the creation of Pakistan in 1947. The devastating floods of 1973 in Pakistan aroused the feeling that the flood forecasting arrangements in the country were still inadequate and did not meet the country requirements. These floods, thus, paved way to full-fledged activities for the further strengthening of the flood forecasting system (FFS). The subsequent floods of 1988, 92, 96 & 1997 again revealed many serious system discrepancies pertaining to areas of flood forecasting and dissemination and it was badly felt that the system still needed to be further enhanced. The system went through many improvements and is now sufficiently comprehensive but efforts are still underway to make it more self-contained.