Objective 1: Identify the factors that are known to influence N and P levels in waterways of the Lake Erie watershed, Ontario.

These factors were identified using literature that discusses the known factors that affect N and P levels in waterways. These factors were chosen because they have been shown through previous research to be correlated with N and P levels and are also present in the Lake Erie watershed, Ontario.

Factor 1 - Agriculture

Agriculture is known to increase N and P levels in nearby waterbodies because fertilizers placed on fields are enriched in N and P and there are high levels of N and P in manure (Chen & Lu, 2014).

Factor 2 - Urban Areas

Urban areas can lead to increased N and P levels because of the impervious structure of built-up areas leads to increased run off into nearby waterbodies (Chen & Lu, 2014; Mainali & Chang, 2018; Pratt & Chang, 2012).  

Factor 3 - Forests

Forests have been shown to act as sinks for N and P as the vegetation in this type of land covers will uptake the N and P before it reaches the waterbodies (Basnyat et al. 2000; Chen & Lu, 2014; Pratt & Chang, 2012).

Factor 4 - Slope

Slope is an important factor for run off because the steeper the slope, the higher the erosion potential is which can lead to more N and P inputs into the downslope waterbodies. This increased erosion potential is caused by the increased speed of water running over a surface with a higher slope (Chen & Lu, 2014; Colborne et al. 2019).

Factor 5 - Soil Group

Different soil groups have different susceptibilities to erosion which can lead to increased sediment (and thus N and P) input into waterbodies that are surrounded by more erodible soil groups (Colborne et al. 2019). The Lake Erie watershed contains soils dominated by the Grey Brown Luvisol great group (National Soil Database, 2011).

Factor 6 - Hydraulic Conductivity (ksat)

Hydraulic conductivity is a property of soils, it explains the ease in which a fluid (in this case water) moves through the soils pore spaces and fractures (National Soil Database, 2011). 

Factor 7 - Precipitation

Precipitation can facilitate the movement of N and P from other sources like urban and agricultural land covers and thus influence N and P inputs (Pratt & Chang, 2012).

Factor 8 - Temperature

Increased temperatures result in increased water temperatures which effect zooplankton populations and their ability to control algal growth and therefore, increases the likelihood of eutrophication (Moss et al. 2011).