How do Source to Sink Systems influence patterns of human settlement in the Indo-Gangetic Basin?

The source-to-sink (S2S) river systems in the Indo-Gangetic Basin (IGB) construct alluvial landscapes which have hosted some of the earliest human civilizations. These landscapes provide the vital sustaining resources  acting as a lifeline for settlement and agriculture. The factors contributing to its richness are climate, political security, and the alluvial landscapes formed by Indus, Ganga, and Yamuna rivers. Given the significant changes that have happened due to human exploitation of landscape, an understanding of the impact of geomorphic landscapes on human settlement patterns is lacking, hence it is important to understand changes in these source to sink landscapes over a range of spatial and temporal scales. For instance, given the risk to people on river floodplains due to natural processes such as flooding, it is important to understand the impact of geomorphic landscapes on human populations.

Here, we aim to investigate the impact of  the source to sink system on the human settlement patterns in the Indo Gangetic Plains at decadal and centennial historic timescales. Historical maps along with LANDSAT images are used for detailed mapping of the S2S landscape elements and study the long term changes in the river morphology. Previous studies mainly exploited the optical data like LANDSAT and MODIS data to map the urban areas. To investigate changes at short timescales, we use DMSP-OLS stable nightlights data to study changes in urban settlement patterns in the Gangetic basin from 1992-2013. Earlier research have demonstrated usefulness of nightlights data for urban settings for the assessment of the economic, demographic and environmental purposes. We are integrating these data sets with mapping of geomorphic elements in the Gangetic basin as well as the river network extracted from the SRTM-DEM. We use these data sets to evaluate the links between the nightlights and geomorphic features thus highlighting possible connections between population growth and geomorphic elements in the IGB.

The overall aim of this study is to provide new quantitative insights between the dynamics of human habitation and river morphodynamics in the Indo-Gangetic basin over a range of scales.