Spatial Trends of AMSR-E Soil Moisture across Agro-Climatic Zones of Pakistan 2003-2010

This study has been conducted to assess the spatial trends of soil moisture across different agro-climatic zones of Pakistan in the recent decade. The analysis have been performed annually and in the cropping seasons i.e. Kharif and Rabi using available monthly soil moisture AMSR-E satellite data from 2003-2010. The monthly precipitation and temperature (mean, maximum and minimum) data has also been analyzed during the study period. The AMSR-E has strong correspondence with observed precipitation records across Pakistan. The annual analysis showed significant decreasing trends of soil moisture in agriculture fields (sub humid – arid) from 2003-2010. The Kharif season soil moisture variability is closely associated with the monsoon precipitation (Jul-Aug) in the rain fed areas of Pakistan. The Kharif cropping season analysis has shown the increasing trends of soil moisture in the years (2003, 2005, 2006 and 2010) when substantial amount of monsoon precipitation occurred in the rain fed (humid-semi arid) areas of Pakistan. However, noticeable decreasing trend of soil moisture has been observed during 2004 and 2009 when monsoon precipitation was suppressed during Kharif season. The Rabi season analysis initiate just after the Kharif season and availability of soil moisture is equally vital for the sowing period. The Rabi season analysis showed the increasing trends of soil moisture from 2003-2010 with the exception of 2004 and 2009 in which slight decrease in soil moisture has been found in the agriculture cropland (semi arid- arid). It has been noticed that success and failure of monsoon generally affects the amount of soil moisture both annually and seasonally. Therefore it is expected that the erratic precipitation patterns may enhance the soil moisture stress in agriculture lands of Pakistan leading to agriculture drought.