Abstract:
Soil salinity is among the cruelest and vicious environmental factor, affecting
yield of most of the salinity sensitive crops due to excessive concentration of salts in the
soil. Throughout the globe more than 100 countries are facing salinity problems and no
continent is totally free of it. Hence it is important to devise a method for assessing and
mapping soil salinity that are both rational and reliable. The current study was conducted
on Shorkot and Toba Tek Singh tehsil of Central Punjab. Laboratory analysis data was
acquired for 32 different soil samples from the study area and a relationship was
developed between ground data and satellite data. Laboratory analysis for Electrical
Conductivity (EC) and Sodium Adsorption Ratio (SAR) were performed for the selected
samples. Landsat satellite (i.e., Landsat 4-5 and Landsat 8 OLI) imageries were used for
indices development. Based on the ground data set (EC & SAR) and indices of 2020, the
EC and SAR values for the past years (1996-2020) were calculated and classified into
different classes. Inverse Distance Weighed (IDW) technique was used for mapping and
soil classification was performed based on the ranges set earlier. The results after
mapping confirm a major rise in salinity which disclose that the maximum EC and SAR
values, in 1996 and 2020 were 4.94 dS/m and 10.01 mmol, and 8.23 dS/m and 59.73
mmol respectively. The minimum values of EC and SAR in 1996 were 3.44 dS/m and
7.16 mmol respectively, while oppositely in 2021 the minimum values analyzed were
5.28 dS/m and 11.11 mmol. On the other hand, the mean values of EC and SAR during
1996 were 4.74 dS/m and 23.24 mmol. A rapid increase in salinity level was observed
during 2020 as the mean value of EC and SAR were 6.58 dS/m and 27.22 mmol. Overall,
the percentage change in the mean value of EC and SAR were 38.8% and 17.2%
respectively
