Maine Elevation Contours 20 Feet Feature

Maine Elevation Contours 20 Feet contains contour lines for Maine from USGS 1:24,000 scale quadrangles; in accordance with the source, units may be in feet or meters and intervals may be at 10 to 20 feet, or 3 meters. Additional supplementary contours exist on some of the quads. Due to the large number of arcs, elevation codes are spot checked from a representative sample. The contours are useful for determining drainage, determining slope and delineating watersheds. If used in hydrology, care should be given to cell size for modeling. It is recommended that in coastal plain areas, a cell size of no more than 22.5 meters be used. Please report any elevation coding errors to the Maine Office of GIS. The data retains the edgematching discrepancies existing in the source.20英尺精度缅因州高程等高线数据集包含源自美国地质调查局（United States Geological Survey，USGS）1:24000比例尺标准图幅的缅因州境内等高线。根据源数据规范，其高程单位可采用英尺或米，等高线间距可设为10至20英尺，亦可为3米。部分标准图幅中还包含额外补充等高线。由于矢量弧段总量庞大，高程编码仅通过代表性样本进行抽样核查。该等高线数据可用于水系分析、坡度测算及流域范围划定。若应用于水文学研究，建模时需谨慎选择栅格单元尺寸。针对沿海平原区域，建议栅格单元尺寸不超过22.5米。若发现高程编码错误，请上报至缅因州地理信息系统办公室（Geographic Information System，GIS）。本数据集保留了源数据中固有的边缘匹配偏差问题。