Hydrological feedbacks in groundwater dominated systems in northern
India: approaches, challenges and projections of future change
Ana Mijic, Imperial College London
Land-use change and related changes in water use are key drivers of
changes in the regional water cycle. This is especially the case for large-scale
changes from bare and forested land into irrigated agriculture. Over the last
decades, the Gangetic plains in northern India have undergone the world’s
largest and fasted increase in irrigated agriculture. It is well known that
groundwater extraction for irrigation is extensively decreasing the region’s
water table levels, thus putting potential pressure on local water resources.
However, determining the risks of water scarcity at a local scale, and
predicting future trends requires a much more detailed assessment of local
water fluxes. Land use change is affecting the partitioning of water fluxes,
thus driving changes in recharge and runoff. These changes will affect surface
and groundwater resources, while changes in evapotranspiration and soil
moisture may feed back to atmospheric processes. Given the interactions
between different hydrometeorological processes, a systems approach is
needed.
This talk will present a modeling setup that implements an integrated systems
approach to simulating the hydrometeorological cycle of the Ganges basin,
which is needed to resolve local and regional feedbacks to the water cycle
that determine water resources and risks. Both the technical and scientific
challenges to integrate modeling components dealing with groundwater,
surface water, atmospheric and irrigation processes will be discussed. Some
of the major challenges include the assimilation of heterogeneous data, model
component evaluation and improvement, and uncertainty quantification.
The project is part of a concerted effort to improve our understanding about
historic and future changing water cycle, coordinated by the eponymous UK
research council funding initiative. The projects funded under this programme
jointly explore the complex interactions between various components in the
hydrological cycle and changes as a consequence of climate and land use
drivers.