Inferring Anthropogenic Trends from Satellite Data for Water-sustainability of US Cities Near Artificial Reservoirs

Abstract:

Impact of anthropogenic activities on water cycle and water supply has different effects at global and regional spatial scales, ensuing the need for a design and water management approach that considers anthropogenic inputs. One of the major inputs in local-to-regional availability of water and the water cycle are land use land cover change as a result of urbanization, artificial reservoirs and irrigation activity. This study employed a multi-factorial approach involving population trends, water use (and demand), streamflow; and various satellite derived water-relevant variables. These variables are: daily precipitation (from TRMM, 3B42.V7), Normalized Difference Vegetation Index-NDVI (from MODIS-MOD13A1), land surface temperature-LST (from MODIS-MOD11A2), and land cover (MODIS-MCD12Q1). Long terms exhibited by such data were used to understand temporal and spatial trends in impounded watersheds hosting a large and growing city in its proximity. The selected cities are: City of Atlanta-Georgia and Buford dam; Columbia-South Carolina and Saluda dam; Columbus-Ohio and Alum Creek dam; Montgomery-Alabama and Jordan dam; Tulsa-Oklahoma and Keystone dam; Tuscaloosa-Alabama and Tuscaloosa dam were selected. our study reveals that daily mean stream flow has been decreasing in all but one (Tulsa) of the areas selected. Satellite data trends between 2000 and 2012 showed a steady decrease in precipitation and NDVI; while LST has gradually increased. We attribute the NDVI (i.e., gradual decrease in vegetation cover) to LST rather than precipitation trends. The results of this research suggested that future temperature projection from climate models can be used in understanding vegetation activity and water availability over the study areas. Cities with larger upstream watershed area are potentially more sustainable and resilient (than those with small watersheds) as a result of spatial variability of water resources’ response to climate change. Inter-basin water resources transfer is a possible solution to vulnerable cities in the future. The study results stressed the need to establish a sustainable and resilient water resources management system that includes narrowing information and perception gap between the engineering community and the general public.