Characterization and classification of agro-climates of Pakistan
2002
Roohi, R. (National Agricultural Research Centre, Islamabad (Pakistan). Water Resources Research Programme) | Ahmad, S. | Ashraf, A.
The countryþs geographical area covers around 88.2 mha including the areas. Ecologically, the country has diversified physiography and climate. To analyze the diversified status of the resources, a large data- set is required and analyze. GIS, being an accepted computer age management tool, describe agricultural environments in Pakistan. For defining the agro-environment, as a first step, the annual climatic data was classified according to the seasonality i.e. winter and summer. The country experiences two distinct season namely winter (Rabi) and summer (Kharif). The summer is wet due to rains originating from the east while in winter the western fronts moisture. The seasonal aridity and crop growth indices were used to characterize and classify the agro-environments. The aridity index refers to the ratio of 50 % probability of rainfall and actual crop evapotranspiration. The aridity classes humid to hyper-arid. Based on the seasonal aridity classes, 18 zones were delineated. The crop growth index reflects the temperature availability for crop growth and is estimated as a ratio of growing degree-days available to those required by a particular crop. The crop growth classes defined ranged from deficit to excess. A total of 9 zones were defined by superimposing the seasonal crop growth maps. These two indices contributed to the classification of 57 agro- climates in Pakistan.
显示更多 [+] 显示较少 [-]