The Ganges-Brahmaputra Delta is one of the largest deltas in the world. In Bangladesh alone, 160 million people live in the floodplains. The Ganges and Brahmaputra Rivers and their delta are strongly impacted by the Asian summer monsoon. Widespread hazards relate to the intense seasonal rainfall: flooding, river erosion and channel switches. The people of Bangladesh have adapted to this dynamic delta system, they have raised villages above the annual flood level and embanked agricultural land.
Still, the lowlands of the Ganges-Brahmaputra Delta are considered one of the regions most at risk from climate change, and particularly from sea level rise. About 75 million people live in the GB coastal zone (defined as the region <10 m.a.s.l). It is thought that the impact of relative sea-level change will be profound in Bangladesh where 32% of the country is already affected by tides, salinization, and cyclones/storm surges. At the same time, the Ganges-Brahmaputra river system drains tremendous amounts of sediment (sand, silt and clay) from its steep Himalayan hinterland. We ask: how does this amount of sediment change with a changing monsoonal climate? Does this sediment aggrade fast enough to help counteract rapid sea-level rise?
Classroom organization This lab replicates and improves upon simulations originally run by Frances Dunn and Stephen Darby, reported in Darby et al. 2015. This simulation is driven by climate predictions (daily temperature and precipitation) obtained from the Hadley Centre (HadRM3P) Regional Climate Model. The Q0 realization is utilized in this lab.
This lab will run HydroTrend simulation with Python Modeling Tool (Pymt). If you have never used the Pymt, learn how to use it: https://pymt.readthedocs.io/en/latest/install.html. The Pymt allows you to set up simulations and run notebooks.
You can create an account at CSDMS JupyterHub and test the Jupyter Notebook for this lab. Please follow the instruction at: https://github.com/csdms/pymt/blob/master/notebooks/README.md. If you are a faculty at an academic institution, it is possible to work with us to get temporary teaching accounts. Work directly with us by emailing: csdms@colorado.edu
Learning objectives Skills
use Pymt to run HydroTrend Model
familiarize with a basic configuration of the HydroTrend Model
make small changes to key input parameters
hands-on experience with visualizing output in Python
Key concepts
Simulation of the river discharge for Ganges River
Simulation of the suspended sediment discharge for Ganges River
Explore mean annual water discharge trends through time
Lab notes
Launch binder
You can launch binder to directly run the Jupyter Notebook for this lab through a web browser.
>> You will see that there are several example models. In this lab we will select the HydroTrend Ganges.
>> Click on the 'Launch Binder' box and it will allow you to see this lab as a Jupyter Notebook.
>> You can execute the Jupyter notebook code cells using shift -enter.
Requirements --
References
Kettner, A.J., and Syvitski, J.P.M., 2008. HydroTrend version 3.0: a Climate-Driven Hydrological Transport Model that Simulates Discharge and Sediment Load leaving a River System. Computers & Geosciences, 34(10), 1170-1183. doi: 10.1016/j.cageo.2008.02.008
Darby, S. E., Dunn, F. E., Nicholls, R.J., Rahman, M. and Riddy, L. 2015. A first look at the influence of anthropogenic climate change on the future delivery of fluvial sediment to the Ganges–Brahmaputra–Meghna delta. Environmental Science: Processes & Impacts. doi:10.1039/c5em00252d
