Analyzing the Influence of Anthropogenic Heat on Groundwater Using Remote-Sensing and In Situ Data.

Area of Science:

• Environmental Science
• Remote Sensing
• Urban Planning

Background:

• Urbanization leads to increased impervious surfaces, replacing natural landscapes and altering thermal dynamics.
• Urban heat transfer affects subsurface aquifers, impacting groundwater temperature.

Purpose of the Study:

• To map land use/land cover (LULC), land surface temperature (LST), and anthropogenic heat flux (H_as) changes in Bangalore City.
• To validate satellite-derived data with in situ measurements of LST and groundwater temperature (GWT).
• To analyze the impact of urban expansion on thermal indicators and their correlation with GWT.

Main Methods:

• Utilized Landsat optical and thermal satellite data for LULC, LST, and H_as mapping from 1999 to 2017.
• Employed in situ sensor-based measurements for LST and GWT validation.
• Performed correlation analysis between H_as, LST, and GWT.

Main Results:

• Built-up area increased from 7.61% to 28.78%, with significant LST rise, especially in formerly green areas (~6 °C).
• Anthropogenic heat fluxes increased substantially (above 65 W/m²).
• Strong correlations found between in situ GWT and H_as (R² = 0.83) and LST (R² = 0.78).

Conclusions:

• Bangalore's urban expansion significantly impacts LST, H_as, and GWT.
• Satellite-derived urban heat indicators can be used for sustainable land use planning and urban ecosystem preservation.
• High collinearity allows for periodic monitoring of thermal changes using Landsat data for policy-making.