Shoreline erosion in Deep Creek Lake, Maryland: Patterns, trends and economic implications.

摘要

Deep Creek Lake, Maryland was constructed in the 1930s as a reservoir for a hydro-electric project, but it also has been used for recreational purposes. Property ownership is attractive, but lakefront properties in particular are exposed to shoreline erosion. A particular issue is the State of Maryland's ownership of the shoreline and the buffer strip. While most of shoreline erosion occurs technically on state-owned land, not the lakeshore private property, erosion's most visible effects are property improvements damage or gradual decrease in the distance between the lake and the property improvement. In order to understand the magnitude of the problem, to observe patterns for shoreline erosion and to help better planning of development in the region, one of the objectives of the present study was to map and, to the extent possible, to quantify shoreline erosion on Deep Creek Lake. Another objective of the study was to collect information about actual erosion directly from owners of lakefront properties and to assess their experiences and perceptions of shoreline erosion hazards on their property. In order to achieve the first objective, the study used historical aerial photographs. The highest water marks on previously rectified aerial photographs were traced in ArcView 9.1. Digitized shorelines from multiple years were overlain, followed by the spatial adjustment of vectorized shoreline. For the second objective of the study, a survey of lakefront property owners was conducted. The result of the digitization procedure showed that in many sectors the shoreline receded from the original location, whereas in some sectors the shore protracted. The findings from the owners' survey (sample size=323; return rate: 67.4 percent) suggest that almost 70 percent of properties have undergone some form of erosion and that those owners who reported such events are more likely to be aware of potential causes and mechanisms of erosion on the shoreline of their property. The limitations of the study include the fact that a qualitative analysis of shoreline change cannot be descriptive enough if changes are only on a small scale and that self-reported data can overestimate the location and/or extent of erosion. The study found that there is erosion in Deep Creek Lake and the property owners are aware of the process, but additional information is needed in order to quantify the erosion, to map it and establish its patterns.