Time series analysis of the world's longest fluvial nitrate record: evidence for changing states of catchment saturation |
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| Authors: | Fred Worrall Nicholas J K Howden Tim P Burt |
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| Institution: | 1. Department of Earth Sciences, Science Laboratories, Durham, UK;2. Department of Civil Engineering, University of Bristol, Bristol, UK;3. Department of Geography, Science Laboratories, Durham, UK |
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| Abstract: | Processes that drive the occurrence of nitrate concentrations in surface waters are known to operate over many decades longer than the available observations. This study considers the world's longest water quality record of nitrate concentrations in the River Thames (1868–2009) in order to understand whether the nature of the time series has changed with time and such external drivers as climate change and land use of hydrology. The study considers the linear trend, the seasonality, the memory and the impulsivity relative to river flow of the time series for moving windows of 6 years in length. The study can show that:
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| Keywords: | saturation impulsivity seasonality land‐use change |
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