Water Quality Monitoring in Baltimore Watersheds

Overview

For this assignment, I worked with data from the water quality monitoring efforts of Blue Water Baltimore, a nonprofit organization dedicated to safeguarding the health of Baltimore's waterways. The area that the data is collected from encompasses four key watersheds: Jones Falls, Gwynns Falls, Baltimore Harbor, and Herring Run. With a total land area of 194 square miles and 454 miles of streams, the watersheds are a vital ecological system supporting diverse aquatic life and serving as critical resources for the surrounding communities.

I chose this data not only because I am a Baltimore native and someone who is passionate about environmental stewardship but also because I have personally contributed to Blue Water Baltimore's data through volunteer work with the organization. In Spring of 2023, I was a waterkeeper volunteer where I collected and processed the data in the Blue Water Baltimore laboratory.

Data & Methodology

The data utilized in this analysis was sourced from Blue Water Baltimore's water quality monitoring program, spanning the years 2009 to 2022. This dataset comprises tens of thousands of individual data points, collected and synthesized to assess the health of Baltimore's waterways.

Monitored Parameters

Blue Water Baltimore monitors the following parameters in water:

Nitrogen levels

Phosphorus levels

pH levels

Temperature

Dissolved oxygen levels

Water clarity

Fecal bacteria

Chlorophyll

Conductivity

Focus: Water Temperature

I opted to concentrate on water temperature for this analysis. Temperature plays a crucial role in aquatic ecosystems, influencing the health and vitality of aquatic flora and fauna. Deviations from optimal temperature ranges can have significant implications for aquatic organisms, potentially leading to stress, mortality, or displacement from their habitats. Temperature fluctuations can impact other key water quality indicators, such as dissolved oxygen levels, further highlighting its importance in ecosystem health assessment.

GIS Analysis

To analyze temporal trends in water temperature across the tidal and non-tidal segments of Baltimore's waterways, I used a combination of geoprocessing tools, including Aggregate, Spatial Statistics, and Spatial Join. These tools facilitated the comparison of temperature data collected from the watersheds, allowing for the identification of patterns and variations spanning the 2009–2022 period.

In addition to the geoprocessing tools, I also created the maps and generated two bar graphs from the temperature datasets, providing visual insights into temperature trends and variations observed within the watersheds.

Water Quality Monitoring in Baltimore Watersheds — maps of tidal and non-tidal monitoring stations with temperature data bar charts — Water Quality Monitoring in Baltimore Watersheds — Left: tidal and non-tidal monitoring station locations across Jones Falls, Gwynns Falls, Baltimore Harbor, and Herring Run watersheds. Right: bar charts showing tidal and non-tidal water temperature data from 2009–2022.

Key Findings

Tidal vs. Non-Tidal Temperature Differences

The temperature of water in tidal water is higher than the average temperature in non-tidal waterways. These findings are consistent with the raster and aggregate temperature data that are also displayed on the map.

Watershed Health Indicators

Temperature patterns across the four watersheds reveal how urban heat island effects and land use impact aquatic ecosystem health, with implications for dissolved oxygen levels and species viability.

Spatial Analysis Insights

By identifying these gaps, local governments and organizations can prioritize resources for monitoring and remediation in the most impacted areas of Baltimore's watershed system.