Technical Note: Testing an improved index for analysing storm discharge–concentration hysteresis
- 1School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
- 2School of Geographical Sciences, University of Bristol, University Road, Bristol, BS8 1SS, UK
- 3Department of Sustainable Soils and Grassland Systems, Rothamsted Research, North Wyke, Okehampton, EX20 2SB, UK
Abstract. Analysis of hydrochemical behaviour during storm events can provide new insights into the process controls on nutrient transport in catchments. The examination of storm behaviours using hysteresis analysis has increased in recent years, partly due to the increased availability of high temporal resolution data sets for discharge and water quality parameters. A number of these analyses involve the use of an index to describe the characteristics of a hysteresis loop in order to compare storm behaviours both within and between catchments. This technical note reviews the methods for calculation of the hysteresis index (HI) and explores a new more effective methodology. Each method is systematically tested and the impact of the chosen calculation on the results is examined. Recommendations are made regarding the most effective method of calculating a HI which can be used for comparing data between storms and between different water quality parameters and catchments.