Is the geomantic position of the lake convex or concave?

The feng shui by the lake is definitely a good place to sink in, because the wind by the lake is strong, but it doesn't get angry. However, it is in a concave place that the industry should pay attention to the shape of the lake. If the lake is pointing and murderous to the houses or houses on the shore, the operators should avoid it. In short, there should be mountain rings and water hugs on both sides.