By taking the extra time to shovel the walkway you can burn more calories than you would by standing behind a snow blower. Regular activities burn a lot of calories too, and are great for reaching your goals.
For example a 150lb person will burn 100 calories shoveling snow for 15 minutes. So how does that translate into your weight management goals? If it takes you 30 minutes to shovel and if you shovel 20 times in a winter you would burn 4000 calories, or 1.14 lbs worth of calories.