Integrating Long-Term InSAR Monitoring Into Local Groundwater Management: Insights From the Hollywood Basin, California

Abstract

We demonstrate the effectiveness of long-term continuous interferometric Synthetic Aperture Radar (InSAR) monitoring for local resource management. Sustainable yield is a key concept in groundwater management to ensure sustainable, low-impact groundwater extraction. This study proposes to estimate sustainable yield using InSAR, combined with local groundwater production data. We apply this method to the Hollywood Basin in Los Angeles, California, leveraging nearly 30 years of InSAR data (1992–2023) to investigate ground deformation linked to groundwater extraction. High spatial InSAR measurements reveal deforming regions linked to anthropogenic activities previously not well-characterized by in situ observation networks. By integrating InSAR data with production records, we estimate the sustainable yield for the basin to be 1.44 to 1.67 million cubic meters per year, significantly lower than the current operating safe yield of 3.70 million cubic meters per year. Utilizing Independent Component Analysis, we are able to distinguish hydrological signals originating from the deep and shallow aquifers in the Hollywood Basin. Our findings demonstrate the effectiveness of InSAR for long-term monitoring of anthropogenic deformation and for supporting urban planning and resource management.