Temporal and spatial trends in nutrient and sediment loading to Lake Tahoe, California-Nevada, USA

Journal of the American Water Resources Association
By: , and 

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Abstract

Since 1980, the Lake Tahoe Interagency Monitoring Program (LTIMP) has provided stream-discharge and water quality data—nitrogen (N), phosphorus (P), and suspended sediment—at more than 20 stations in Lake Tahoe Basin streams. To characterize the temporal and spatial patterns in nutrient and sediment loading to the lake, and improve the usefulness of the program and the existing database, we have (1) identified and corrected for sources of bias in the water quality database; (2) generated synthetic datasets for sediments and nutrients, and resampled to compare the accuracy and precision of different load calculation models; (3) using the best models, recalculated total annual loads over the period of record; (4) regressed total loads against total annual and annual maximum daily discharge, and tested for time trends in the residuals; (5) compared loads for different forms of N and P; and (6) tested constituent loads against land use-land cover (LULC) variables using multiple regression. The results show (1) N and P loads are dominated by organic N and particulate P; (2) there are significant long-term downward trends in some constituent loads of some streams; and (3) anthropogenic impervious surface is the most important LULC variable influencing water quality in basin streams. Many of our recommendations for changes in water quality monitoring and load calculation methods have been adopted by the LTIMP.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Temporal and spatial trends in nutrient and sediment loading to Lake Tahoe, California-Nevada, USA
Series title Journal of the American Water Resources Association
DOI 10.1111/1752-1688.12461
Volume 52
Issue 6
Year Published 2016
Language English
Publisher Wiley
Contributing office(s) Nevada Water Science Center
Description 19 p.
First page 1347
Last page 1365
Country United States
State California, Nevada
Other Geospatial Lake Tahoe