Urban Expansion as an Incursive Factor for Food Security: An Assessment of Spatio-Temporal Variations in Punjab

Abstract

An agriculture based country, Pakistan is a sixth highly populated (188.9 million) country in the world (United Nations, 2015). Among the four provinces of Pakistan, Punjab is the major contributor to national food supply with over 80% contribution of wheat. However, overpopulation and urbanization have resulted in great changes in land use and land cover pattern of Punjab creating the issue of food insecurity in the country. The division-wise spatio temporal variations in the agricultural lands of the Punjab due to urbanization has been identified in current study using medium resolution satellite imageries of Landsat 7 and 8 of year 2000 to 2014, respectively. Supervised classification technique was adapted to monitor land use land cover (LULC) changes and NDVI technique was used to classify Wheat cropped area using ground information and expert knowledge on the growing patterns of the crops to differentiate wheat from different seasonal crops. The results indicate that over 313 km² of Punjab cultivated land area is converting into built-up every year resulting in approximately 4387 km² of this conversion in last 14 years. The overall growth rate of cultivated area in Punjab is just 3% in comparison with over 27% increase in both built-up area and population during the study period. The estimated increase in population and built-up area will be 50% and 43% respectively till 2025 with just 5% increase in cultivated lands in comparison with year 2000 which will worsen the food security condition in the country. It is an alarming situation for decision makers to device sustainable development strategies by using the already bare lands for the development of urban societies to keep intact existing cultivated lands and adopt sustainable agricultural practices to increase crop yield keeping in view the increasing gap between population expansion and decreased food supply due to urbanization to curb the issue of food security in the country.