该代码从USGS的NLCD2016土地覆盖数据集中加载了一个影像，并剪切为感兴趣区域。然后，将其添加到地图上进行可视化，并将其导出为GeoTIFF图像进行下载。您需要将代码中的lat1、lon1、lat2和lon2替换为所需区域的经纬度坐标，并根据需要调整其他参数（例如可视化参数和导出名称）。

// Load the land cover data
var landCover = ee.Image('USGS/NLCD/NLCD2016');

// Select a region of interest
var roi = ee.Geometry.Rectangle([lon1, lat1, lon2, lat2]);

// Clip the land cover data to the region of interest
var clippedLandCover = landCover.clip(roi);

// Define the visualization parameters for the land cover data
var visParams = {
  min: 0,
  max: 95,
  palette: [
    '476ba1', 'd1def8', 'decaca', 'd99482', 'ee0000', 'ab0000',
    'b3aea3', '68ab63', '1c6330', 'b5ca8f', 'a68c30', 'ccba7d',
    'e3e3c2', 'caca78', '99c247', '78ae94', 'dcdcaa', 'fbff13',
    'b6ff05', '27ff87', 'c24f44', 'c9c3b4', 'ffffff'
  ]
};

// Display the clipped land cover data on the map
Map.addLayer(clippedLandCover, visParams, 'Land Cover');

// Export the clipped land cover data as a GeoTIFF image
Export.image.toDrive({
  image: clippedLandCover,
  description: 'land_cover_data',
  scale: 30,
  region: roi
});