Evaluation of soil salinity based on satellite image indices: a case study from Valikamam East Divisional Secretariat Division of Jaffna

Abstract

Soil salinity is one of the most important issues affecting the environment. It is triggered by natural factors and human activities. Excessive salinity in the soil negatively affects the plant growth and productivity. Therefore, in order to reduce the increasing soil salinity, it is necessary to monitor, mapping and manage the soil salinity at an early stage and take appropriate management measures in the future. In that way, this study aims to compute salinity indices using different wavelength bands of satellite images, identify soil salinity based on the salinity indices, measures EC and pH in field from selected samples, and analyses the interaction between the value of field measurement and salinity indices. The secondary and the primary data from various sources were collected to achieve the aforesaid objectives; secondary data was collected from satellite images and Divisional Secretariat report, and the primary data was collected through the field measurement. The data was thorough analyzed by laboratory and GIS method. Soil salinity based on satellite Remote Sensing indices and based on field measurement data are found to be appropriately correlated. Thus the distribution of spatial soil salinity through both methods is high in the east and low in the west of the study area. Therefore, the Remote Sensing Technique may be better than traditional methods to assess soil salinity