Why should house terrain xiangyang no shadow

The topography has the branch of Yin and Yang.ShanZhiNa, water of the north called Yang;Mountains in the north, south of water called Yin.The ancients originally many hills, many cities are at the water's edge mountains as well.For example, has a long history of henan province with Yang places have a lot of, still can see was established at the water's edge cities are: luoyang, puyang, huaiyang, biyang, QinYang, RuYang, etc.In terms of the general situation of terrain, xiangyang is table, is in shady place.House will make the sun, don't be in the shadow, the reason is that the sunny and dry, and just generally is very humid, is not conducive to living and health.