Location: Agricultural Systems ResearchTitle: Using ecologically relevant hydrologic indices to examine temporal changes in unregulated streams in Kansas Author
Submitted to: American Society of Agricultural and Biological Engineers
Publication Type: Abstract Only
Publication Acceptance Date: 11/23/2009
Publication Date: 6/23/2010
Citation: Aguilar, J.P., Koelliker, J.K., Chandler, D.G. 2010. Using ecologically relevant hydrologic indices to examine temporal changes in unregulated streams in Kansas. American Society of Agricultural and Biological Engineers. Paper No. 1009056. Interpretive Summary:
Technical Abstract: Demand for water, especially for agriculture, is one of the major reasons for dewatering the streams and lowering groundwater levels in the Great Plains region. As the conditions have worsened in many areas groundwater has ceased to supply the dependable baseflow to some perennial streams, thus making them intermittent. In addition, the level of connectivity and the natural flow regime of streams have been detrimental to the riverine ecosystem. Several researchers have shown that changes occurring in streams have adverse impacts on water quality of the freshwater ecosystem, and more specifically on fish species distribution. This study was done to document changes for 14 unregulated streams with 60 or more years of daily discharge data geographically distributed across Kansas were used. The analysis focused on hydrologic indices judged to be relevant to the lotic ecosystem. The state was divided into four regions, representing roughly the northwest, southwest, northeast and southeast sections. Log Pearson III method was used for computing flow probabilities. The Mann-Kendall test in conjunction with Sen’s slope estimator was used for trend analysis. Indicators of Hydrologic Alterations software was used to generate most hydrologic indices. Results show there is substantial difference in the streamflow characteristics between the western and eastern regions. Many streamflow aspects have changed over time, and a number of them show significant and important change. Most streams in western Kansas now have longer and more frequent dry periods. Moreover, the timing of these dry periods could adversely impact the spawning cycle of the fishes. Results of this study could be useful to decision makers, water users, watershed stakeholders, and environmental conservation advocates in addressing problems and concerns related to stream and river management.