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Flood inundation maps provide valuable information towards flood risk preparedness, management, communication, response, and mitigation at the time of disaster, and can be developed by harnessing the power of satellite imagery. In the present study, Sentinel-1 Synthetic Aperture RADAR (SAR) data and Otsu method were utilized to map flood inundation areas. Google Earth Engine (GEE) was used for implementing Otsu algorithm and processing Sentinel-1 SAR data. The results were assessed by (i) calculating a confusion matrix; (ii) comparing the submerge water areas of flooded (Aug 2018), non-flooded (Jan 2018) and previous year's flooded season (Aug 2016, Aug 2017), and (iii) analyzing historical rainfall patterns to understand the flood event. The overall accuracy for the Sentinel-1 SAR flood inundation maps of 9th and 21st August 2018 was observed as 94.3% and 94.1% respectively. The submerged area (region under water) classified significant flooding as compared to the non-flooded (January 2018) and previous year's same season (August 2015-2017) classified outputs. Summing up, observations from Sentinel-1 SAR data using Otsu algorithm in GEE can act as a powerful tool for mapping flood inundation areas at the time of disaster, and enhance existing efforts towards saving lives and livelihoods of communities, and safeguarding infrastructure and businesses.

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11This paper explores the link between the anomalous warming hole in the Southeastern U.S. and 12 a major land use/land cover (LULC) change in the region. Land surface and satellite 13 observations were analyzed to estimate the net radiative forcing due to LULC change. Albedo 14 and latent energy were specifically addressed for the dominant LULC change of agriculture to 15 forests. It was assumed that in the energy limited environment of the region, the partition of 16 changes in available energy due to albedo will mostly impact the sensible heat. The results 17 show that in the Southeastern U.S. for the period of 1920 to 1992 the changes in sensible (as a 18 result of albedo) and latent energies are in direct competition with each other. In the spring 19 Revised Manuscript (non-LaTeX) Click here to download Manuscript (non-LaTeX) Revision2.docx 2 and early summer months, the croplands are in peak production and the latent energy 20 associated with their ET is comparable to that of the forests so the decrease in radiation due to 21 albedo dominates the signal. However, during the late summer and fall months most major 22 crops have matured thus reducing their transpiration rate while forests (particularly 23 evergreens) maintain their foliage and with their deep roots, are able to continue to transpire 24 as long as atmospheric conditions are favorable. This later influence of latent energy appears to 25 more than offset the increased radiative forcing from the spring and early summer. Overall, a 26 mean annual net radiative forcing resulting from a LULC change from cropland to forests was 27 estimated to be -1.06 W/m 2 ; thus, a probable contribution to the 'warming hole' over the 28 Southeast during the majority of the 20th century. 29 30