Climatic Zonation of Pakistan through Precipitation-Effectiveness Index

This paper attempts to describe the zonation of Pakistan using Precipitation-Effectiveness (PE) Index. In agriculture, soil moisture plays a key role that depends on the ratio of precipitation to evaporation, often expressed as the P/E ratio or PE index. PE index values for 46 stations for the period 1959-2008 have been calculated and analyzed. This study has shown that Pakistan is divided into four broad distinct Precipitation effective Index climatic Zones; first is Rain forest (Wet) where PE index values are between 50 to 148, second is Forest (humid) where index values ranges between 10-49, third is partly forest (less humid) with index values ranging from 20-33 and fourth one is Arid (dry) having values which are less than 20. Triple point area of NWFP, Punjab and Kashmir & its vicinity are in the climatic zone of rain forest. The surrounding of the same area covering some parts of upper Punjab and a very slight portion of Balochistan is considered to be as Forest (humid) zone. Some part of the northern Punjab, major part of southern NWFP and very little part of eastern Balochistan lies in partly forest (less humid) zone, while the rest of the country (southern Pakistan) lies in Arid (dry) climatic zone.