Coupled mechanism of unsystematic Damming and Climate Change effect on the rivers of the Great Plains of Kansas

Abstract:

Damming the natural flow regime is responsible to drive away native species from the aquatic ecosystem and it becomes potentially damaging when it concerns the drought-prone areas in particular. Drought cycles are common in the Great Plains, which have given native fish species adapted strategies for coping with extreme variation in flow regimes. However, native populations have crashed as these stream networks became heavily fragmented beginning in the post-depression water reclamation era and continued into the 1960’s boom in flood control dam construction.

This study is an attempt to understand and assess the cumulative impacts of river network fragmentation and climate change on the river ecosystem, geomorphology and hydrology of the Smoky-Hill River Basin of North-West Kansas. The vast majority of the basin does not overly significant groundwater resources and is thus reliant on water supplied from precipitation, runoff, and shallow alluvial storage zones strongly connected to surface water systems, which is now fragmented by the construction of both small farm-ponds as well as big flood reservoir structures. Thus, there is a high probability of stream network segments to be dissociated (from the main channel during dry periods) and/or completely depleted (in case of a series of drought cycles) in this area. This paper would identify such vulnerable network segments and assess the impact of extreme climatic conditions – as a single event or scenario of cyclic droughts that can drive the native fishes out of the Smoky-Hill River Basin – by comparing modeled future flow regime projections with historic flow regimes in the fragmented river structure. The study will further address structural and functional connectivity of the river and would contribute to the understanding of fragmentation and its effect to the stream ecology at a higher scale, where a larger aquatic population can get affected by a single drought event.