Time example: storage reservoir

The various time series analytical methods were applied to the same environmental example - a series of nitrate concentrations in a storage reservoir. A comparison of the power of time series methods is, therefore, possible. 

Regression techniques are most frequently used for detection of trends in a series. For evaluating nonparametric trend tests see BERRYMAN et al. [1988]. This example series concerning the nitrate concentrations in the storage reservoir will be tested for any trends over the Ml time of observation. 

In the time series example it is fortunate that the nitrate concentration of the feeder stream in the storage reservoir system is known. Now we have to test if this parameter can explain the nitrate concentration in the storage reservoir. Approximately 70% of the total amount of water which is flowing into the storage reservoir system was measured as originating from the feeder stream from the Lawitz gauge. 

The time series example used in this section requires one to determine the time lag between the storage reservoir feeder stream and the drinking water storage reservoir. The cross-correlation function was then calculated between the nitrate concentrations in the... 

Weida storage reservoir —Autoregression prediction from feeder stream Fig. 6-18. Autoregression fit of the example time series... 

Earths land reservoirs play an important role in long-term carbon storage. In fact, they store carbon for very long periods of time. The carbon in limestone, for example, may remain in a land reservoir for thousands of years. The carbon in a fossil fuel may be stored for millions of years. 

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