Note: When reading any chart or graph, please keep in mind that space and software limitations may create misleading spatial relationships. For example, in time series graphs on the Atlas, each sample date is plotted at regular spatial intervals, but time intervals between the sample dates may vary widely. In these cases, the X-Axis is not providing a spatial relationship of time, but merely presenting sample dates in an easy-to-read format. Also, the Y-Axis may not necessarily start at zero, further distorting spatial relationships among the data. Furthermore, if multiple samples were taken on the same date at different locations on the water body, multiple values are plotted for that date. This presentation of the data explains the appearance of vertical lines on some of the graphs. If you need to see accurate spatial relationships, we highly recommend that you use the Data Download section, download the available data, and graph according to your needs.