Impact of Spatio-Temporal Changes in Rainfall and Temperature on Different Crops in Selected Districts of Punjab, Pakistan

Abstract

Climate Change is undeniable fact with pronounced effects on human life especially food produce. Agricultural policy makers require accurate and timely information regarding crop performance, shifting of cropping patterns and allied information pertaining to changing climate. A method was developed to efficiently monitor and predict changes in crop pattern with the changing climate in the province of Punjab using satellite data process and GIS. In this research firstly, changes in temperature and rainfall from 1980 to 2015 were assessed at district level in comparison with the data of 1951 to 1980. Secondly, using multi-temporal remote sensing in combination with crop statistics crop area maps was developed. Thirdly, remote sensing based crop profiles were generated from 2000 till 2014. Lastly, the changes in crop performance were compared with temperature and rainfall variations. The outcomes demonstrated that increase in temperature influences production of crops and a critical adverse relationship on yield and production was found with temperature rise or fall. Punjab province was divided into three equivalent imaginary parts (Northern, Central and Southern divisions) and was found that the most extreme increment in the temperature occurred in the Southern division i.e. lower Punjab (DG khan, Rahim Yar Khan, Rajanpur). In Central portion i.e. Faisalabad, likewise raised temperature was observed. While in Northern Punjab temperature remained less than the normal range. As far as precipitation is concerned, increase in precipitation took place in Central Eastern and Northern segment i.e. Gujrat, Lahore, Sheikhupura and Kasur; while extreme decline in precipitation happened in Central Western and Southern potions i.e. Bahawalnagar, Sargodha, Chiniot and Pakpattan. Enormous negative effects of temperature increase were found on cotton crop in July and August. For maize, adverse effect of expanding temperature in the month of May was observed; while rain in the period of September positively contributed. Rise in November temperature has a positive impact on wheat; however, December temperature has a negative impact on wheat production. Major important facts like mentioned above can be easily derived from this study and may be taken as guide line for various agriculture departments to predict their crop production / yield very accurately at every stage of crop cycle through remote sensing images and GIS. Farmers and agriculturists may be educated about the effects of these variables i.e. temperature and rainfall on crop growth from sowing to harvesting, even on monthly basis. This would entail better crop monitoring, requirement of water at every stage of crop cycle, accurate estimation of yield and better adaption / mitigation strategies for the future.