3.5. Example 5: The Temperature Distribution Along a First-order Stream [19] In streams and rivers water temperature is of importance to ecological processes, and may also be useful to determine inputs of both surface and groundwaters to streams. In this case after (Brusense, Brugg, Switzerland) was installed in the Maisbich, a groundwater-fed firs-order stream in Luxembourg and read with the DTS (Sentinel DTS-LR, Sensomet, London, England) Egure6) The data shown taken on sunny day that transitioned to a clear sky night. . Groundwater were a inputs and confluences are apparent, giving temperature measurements of unprecedented precision and resolution both temporally and spatially-These data open many opportunities for quantifying stream processes. For instance, by choosing specific times at which stream temperature does not change at the point of known groundwater input (see the 100 PM trace of a Figure 6 at position 150 m for example) it is possible identify the local groundwater inflow to temperature. Using gauges of surface water flux along the flow path, the changes in temperature a points of groundwater input allows for accurate estimates of point-wise groundwater inputs based On an energy balance.