Yes. Walking is a form of exercise. When you exercise, you burn the calories/fat that centers around your waist. It isn't the best way. It is slow process and it will take time to show results.
Ways to reduce fat in the abdomen include lowering fat in the diet or getting exercise. Talking to your doctor about alternative weight loss cases can also be helpful if the issue is extreme.
Any sort of cardiovascular exercise combined with a proper diet will lead to a caloric deficit that can cause an overall reduction in body fat, some of which will be on the stomach.
This is a really simple exercise and you can do it anywhere. When you can, just move your jaw up and down, tensing as you do that. Do it 100 times a day or so, and the fat will melt off your...