Abstract
Hansen CH, Burian SJ, Dennison PE, Williams GP. 2019. Evaluating historical trends and influences of meteoorological and seasonal climate conditions on lake chlorophyll a using remote sensing. Lake Reserv Manage. 36:45–63. Evaluations of long-term water quality trends and patterns in lakes and reservoirs are often inhibited by irregular historical records. This study uses historical Landsat satellite imagery to construct a more complete historical record of algal biomass (measured via chlorophyll a [Chl-a]) and presents a framework for developing seasonal algal estimation models using open source tools for processing and model development. This approach is both physically based (using observed patterns of variability and algal succession in the lake) and data driven (relying on statistical methods for model development). We use a generalized linear regression modeling technique to develop lake-specific, seasonal models for each lake in the multilake Great Salt Lake system in Utah. The 32-yr constructed history of estimated Chl-a enables analysis of long-term trends within the lake system as well as evaluations of local climate influences on Chl-a concentrations. The estimated historical record exhibits a shift in seasonality (i.e., maximum Chl-a occurs earlier in the growing season), as well as increasing trends of extreme Chl-a concentrations. We also evaluated relationships between meteorological conditions and Chl-a using the enhanced historical record and found localized sensitivity to short-term weather events such as high wind, high temperatures, or precipitation events. Seasonal climate conditions including high winter precipitation, summer temperatures, and early spring snow water equivalent are consistent with higher Chl-a extremes in the historical record. Improved understanding of the trends and climate influences provides useful context and guidance for future monitoring efforts and management strategies.
| Original language | English |
|---|---|
| Pages (from-to) | 45-63 |
| Number of pages | 19 |
| Journal | Lake and Reservoir Management |
| Volume | 36 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 2 2020 |
| Externally published | Yes |
Funding
This article was developed under assistance agreement number 835866-01 awarded by the US Environmental Protection Agency to Dr. Michael Barber. It has not been formally reviewed by EPA. The views expressed in this document are solely those of the authors and do not necessarily reflect those of the agency. EPA does not endorse any products or commercial services mentioned in this publication. The authors thank Rob Baskin at the USGS, members of the JRFBWQC (now the Wasatch Front Water Quality Council), and Jake Van der Laan, Ben Holcomb, Marshall Baillie, and others at the UDWQ for providing feedback, assisting us in gathering historical data records, and collaborating on field sampling efforts.
| Funders | Funder number |
|---|---|
| Marshall Baillie | |
| UDWQ | |
| Wasatch Front Water Quality Council | |
| U.S. Environmental Protection Agency | |
| U.S. Geological Survey |
Keywords
- Algal blooms
- climate and water quality
- eutrophication
- remote sensing
