Assessing spatio-temporal changes of soil moisture: a case study at Karachi, Pakistan

Abstract

The soil moisture is an important component in the plant’s growth that decreases with time. Soil moisture content relies on climate change, urban heat island (UHI), and population. The purpose of the investigation is based on the soil moisture changes that are with different prospective in which soil moisture index (SMI) with normalized difference vegetation index (NDVI), SMI with land surface temperature (LST), and SMI with LST and NDVI involved. Similarly, the satellite images of Landsat 8 OLI/TIRS (Operational Land Imager/Thermal Infrared Sensor) and Landsat 4-5 TM (Thematic Mapper) were based on examination and co-operate the RS/GIS techniques. All satellite data images were downloaded from the website of earthexplorer. The ERDAS IMAGINE 9.2, Microsoft Excel, and ArcGIS 10.3.1 software from diverse techniques were adopted like LST, SMI with LST, SMI with LST and NDVI, NDVI, SMI with NDVI, and LST with NDVI and all of the graphs were developed except LST and LST with NDVI. The study concludes that the SMI with LST decreased reasons of LST increased plus SMI with NDVI and SMI with LST and NDVI both increased in the review area, and all changes were examined from the images (1992 and 2019) comparisons. Furthermore, all of the changes graphically observed the high values of the no-change classes.