A comprehensive research on open surface drinking water resources in Istanbul using remote sensing technologies

Area of Science:

• Environmental Science
• Remote Sensing
• Urban Hydrology

Background:

• Istanbul's rapid population growth and urbanization increase water demand.
• Drinking water resources are critical for megacities like Istanbul.
• Understanding water resource dynamics is essential for sustainable urban planning.

Purpose of the Study:

• To analyze changes in drinking water surface areas in Istanbul's eight major basins.
• To investigate the relationship between water surface area changes, meteorological factors, and urbanization.
• To assess the impact of land use/land cover changes on water resources.

Main Methods:

• Utilized Sentinel-1 SAR and Sentinel-2 optical satellite imagery on the Google Earth Engine platform.
• Applied the Normalized Difference Water Index (NDWI) to determine monthly water surface areas.
• Generated water frequency maps and analyzed Land Use/Land Cover (LULC) changes using ESRI data.

Main Results:

• Significant urbanization increase (1-91.43%) observed in watersheds from 2017-2022.
• Seven out of eight water resources showed decreased surface areas (1-12.35%) between 2016-2022.
• Overall total water surface area decreased by 0.70% (62.33 ha) from 2016-2022.

Conclusions:

• Urbanization is a significant driver of drinking water resource reduction in Istanbul.
• Remote sensing techniques effectively monitor water resource dynamics and LULC changes.
• Integrated water resource management strategies are needed to address increasing urban water demands.