Historical Trends in Pollutant Loadings to Lake Erie

摘要

This paper investigates historical trends in pollutant loadings to Lake Erie. The first of two sections of this report analyzes information on the amount of sediments delivered to Lake Erie and discusses historical trends in sediment yield. There are two primary sources of data: (1) measurements of suspended sediment load made in some of the tributary rivers and (2) analyses of shoreline erosion and sedimentation rates in Lake Erie. These lead to a subsequent analysis of the sediment budget. Since the loading of contaminants to the lake is manifested by sedimentation, results are presented of analyses of contamination inputs from bottom coring. Trends in precipitation, runoff, and lake levels have been analyzed and are presented followed by the calculation and tabulation of the average surface water runoff to Lake Erie. The second section of the report deals primarily with the sources and inputs of the two nutrients, phosphorus and nitrogen, to Lake Erie. There is little specific information on those inputs, and, therefore, information has been assembled from other locations on the sources of these nutrients. The historical growth in population in the Lake Erie Basin has also been traced.