Question

1. a study taking place over several years will examine how increased storm activity from climate change impacts erosion rates along the padma river. in order to maintain data accuracy, which variable should be controlled? the water temperature on the days when data is collected the locations of the sites along the river where data is collected the height of the riverbanks before and after each storm event the density and particle size of soils at data collection sites along the river

Explanation:

In an experiment, a controlled variable is one that is kept constant to ensure that the relationship between the independent variable (storm activity) and the dependent variable (erosion rates) is accurately measured. The locations of the sites along the river where data is collected should be controlled. If the locations change, other factors (such as pre - existing soil conditions at different parts of the river that are not related to storm activity) could influence the erosion rates, making it difficult to determine the exact impact of storm activity on erosion.

• Water temperature is not directly related to the causal relationship between storm activity and erosion rates in this context.
• The height of the riverbanks before and after each storm event is a measured variable (related to the dependent variable of erosion), not a controlled variable.
• The density and particle size of soils could be factors, but if the sites are fixed (controlled by location), the soil characteristics at those specific locations (which are part of the system being studied in relation to storm activity) are accounted for as part of the natural conditions at those fixed locations. By controlling the location, we can more accurately attribute changes in erosion to storm activity rather than changes in sampling location.

Answer:

the locations of the sites along the river where data is collected