Shifting of agro‐climatic zones, their drought vulnerability, and precipitation and temperature trends in Pakistan

Abstract

Agro‐climatic classification helps to determine the different features of a region. This climatic classification provides a useful insight for a farmer to grow their crops according to the conditions of their region. This study identifies the shifting of moisture index from average values in different agro‐climatic zones of Pakistan. Unpredictable climate remains dominant over long periods. Observational data of precipitation and evapotranspiration were used to determine the agro‐climatic zone during the period 1951–2010. This study reveals that almost 87% of Pakistan is in extremely arid to semi‐arid zones, a 5% decrease in over the last 30 years (1981–2010). The largest decrease of 8% and increase of 5% were observed in the extremely arid and humid zones, respectively. The semi‐arid zone is more vulnerable to drought, while intensity and severity are greater in the extremely arid region. An agro‐climatic regional analysis identifies 1952, 1969, 2000, 2001 and 2002 as years when the most severe droughts were observed during the study period. The trends of precipitation and temperature were performed at 95% significance level on a monthly, seasonal and annual basis over the entire agro‐climatic zone of Pakistan during 1951–2014. The annual precipitation trends show a significant increase of 0.828 mm year−1 in arid regions, whereas the maximum temperature trends shows a significant increase of 0.014 °C year−1 and 0.018 °C year−1 in extremely arid and humid regions, respectively. The trend of minimum temperature shows an increase over the whole region, which may place pressure on the water demands of crops.

Comparing Multiple Precipitation Products against In-Situ Observations over Different Climate Regions of Pakistan

“…Four locations were selected for a regional scale comparison as shown in Figure 1b. These regions were selected based on variations in climate, elevation and land cover ( Table 1), following the classification of [48] for the study region. The climate descriptions in Table 1 correspond to the climate zones 'Wet Semi-Arid,' 'Sub Humid,' 'Arid' and 'Extremely Arid' as described in Reference [48].The dominant features of the selected regions such as, the land cover, climate and precipitation pattern typically remain the same.…”

“…These regions were selected based on variations in climate, elevation and land cover ( Table 1), following the classification of [48] for the study region. The climate descriptions in Table 1 correspond to the climate zones 'Wet Semi-Arid,' 'Sub Humid,' 'Arid' and 'Extremely Arid' as described in Reference [48].The dominant features of the selected regions such as, the land cover, climate and precipitation pattern typically remain the same. The main seasons in the study region were classified as winter (December, January, February and March), pre-monsoon (April, May and June), monsoon (July, August and September) and autumn (October and November) following [35,37].…”

“…Two precipitation patterns are observed in Pakistan, the first is due to disturbances of westerlies in the winter and pre-monsoon season and the South Asian monsoon, which is the primary driver of the hydrological cycle in the region [37,48]. The GPPs clearly showed these two precipitation patterns, with a slight deviation from the mean; however, during the winter and autumn seasons, MSWEP and CHIRPS captured higher precipitation values in the northwest which could be associated with relatively higher grid size resolution of these two GPPs.…”

Benefits of the Successive GPM Based Satellite Precipitation Estimates IMERG–V03, –V04, –V05 and GSMaP–V06, –V07 Over Diverse Geomorphic and Meteorological Regions of Pakistan

“…The total area is 803,940 km 2 where elevation as varies from a maximum of 8011 m at K2 (second elevated peak on earth) to about 0 m at the Arabian Sea. Climatologically, the study area is very diverse in space and time, and it is divided into different climatic zones [34]. For the present study, four regions are considered to assess SPEs performance over variable geomorphic and meteorological contexts ( Table 1).…”

Classification of precipitation regimes in Pakistan using wet and dry spells

“…Given the precipitation climatology of Pakistan, an arid type of precipitation regime is one that receives less than 300 mm of precipitation annually, a semi‐arid type of precipitation regime receives precipitation between 300 and 1000 mm annually, whereas humid type of precipitation regime is characterized as a region which receives more than 1000 mm of precipitation annually. Similar precipitation ranges were obtained for the three precipitation regimes using different number of weather stations and observation time period lengths, in earlier studies (see, for instance, Siddiqui et al, ; Khan et al, ; Sadiq and Qureshi, ; Mazhar et al, ; Adnan et al, ).…”