Monitoring Ungauged Manchar Lake (Pakistan) using ICESAT-2 Data

Abstract

Inland water is crucial for global water and food security, particularly in developing nations with growing populations. Lakes are central in meeting the world's increasing water demands, making them a vital component of inland water resources. However, developing an efficient and continuous monitoring system is essential for water authorities to ensure the effective management of water resources. This study employed ICEsat2, a satellite laser altimetry technology, to monitor Manchar Lake in Dadu district, Sindh, Pakistan. Multiple satellite altimetry missions, such as Sentinel 3, ICESat2, and Jason3, traverse Pakistan's largest natural lake, providing valuable data for monitoring purposes. It is worth noting that Sentinel 3 has previously been validated for monitoring water levels in the Indus River. In the absence of an in-situ gauge in Manchar Lake, Sentinel 3 and Jason 3 were employed for comparison with the findings of ICESat2. Jason3 Sentinel 3 data were acquired, respectively, from Dahiti and Earth Console. ICESat2 data were downloaded from NASA's official website, which had allowed open altimetry access. They utilized permanent water surfaces from Hydro Lakes for masking the Manchar Lake area. The correlation coefficient (R=0.534/0.928 Dahiti/S3), root mean square error (RMSE=0.443 m/0.4717 m Dahiti/S3), and mean square error (MSE=0.196/0.22258 Dahiti/S3) were calculated as validation metrics. This study has limitations, including the short time series of ICESat2 due to its low temporal resolution. Another limitation is the lack of exact matching satellite data acquisition dates, which could be addressed by installing in-situ gauges in the Lake. Reevaluating ICESat2 data in the future using in-situ gauges can significantly enhance the validation of this dataset.