CLIMATE CHANGE AND ITS IMPACT ON AGRICULTURE IN ARID REGION OF PAKISTAN (1961-2000)

Abstract

This study is aimed at the climate change and its impact on the agriculture sector in the arid region of Pakistan between 1961 and 2000 (40 years) taking into account the secondary data of temperature and precipitation of 21 weather stations of the Pakistan Meteorological Department. The agriculture data were collected from the Pakistan Agriculture Research Council, whereas the primary data sources are questionnaire survey, and personal interviews. Five international publications were published from the current research and placed in the last of dissertation. Physiography and location of the study area with respect to sea are the key factors that control the climate. There are a number of factors that have their influence on the cropping pattern in the area apart from climate. They include the type of soils, availability of irrigation water, government policies, socio-economic condition, advance technologies, market value and human demand etc. The soil of irrigated plain in lower Punjab and Sind is more suitable for the agriculture as compared to other parts, where the water is insufficient for cultivation. The results obtained through trend analysis of annual temperature indicate warming of 1.6oC from 1961 to 2000. The mean monthly temperature shows rise and fall after an interval of five, ten, fifteen and twenty years. There is a negative trend during summer because of an increase in the monsoon precipitation, while it remains positive in winters. Five temperature zones have been identified including hot, warm, mild, cool, and cold. There is a slight increase in temperature in cold, pre-monsoon, monsoon season, and decrease in the post-monsoon season that adversely affect the agriculture sector in the arid region. The precipitation trend shows decrease throughout the series and depletion in the flow of the Indus and its tributaries causing change in landuse pattern, growing season, yield per acre, and make the agriculture sector more vulnerable. Palmer Drought Severity Index shows the dry condition prevailed over the arid region of Pakistan (1871 to 2000). The meteorological data from 1961 to 2000 reveal a slight change after every five years, medium in ten and fifteen years and long term oscillation after 20 years. The decline in the winter precipitation is higher as compared to the summer season. This decrease is maximum in cold and pre-monsoon season, whereas it is minimum in monsoon and post monsoon season. The change in precipitation decrease yield in rabi season in the rainfed as well as in the irrigated plain of lower Punjab and Sind, while the production of the kharif crops remain stable due to increase in the monsoon lows, cultivated area, and human demand. The isohyets reveal heavy rains in the southern Sind in monsoon season, while in winter, it shifts towards northwest Baluchistan. Generally, the isohyets of the southern arid region reveal a shift in the boundary towards northwest. Resultantly, Quetta and the adjoining areas of Afghanistan fell into arid climate during 1961 to 2000 and aridity prevailed over most of Baluchistan, Sind and lower Punjab. The flow of the Indus and its tributaries seem to have direct relationship with the precipitation fluctuation. The impact is not visible on the flow of the Kabul river, but it is more prominent on the Indus, Chenab, Sutlej, Ravi and rivers in Baluchistan.