spontaneous fire.

So I saw smoke coming from my backyard and went out to investigate. The ground had a big black ring and smoke was spewing out. Should I be concerned? I did pour water all over it and it has stopped. However am kinda stressed about it. Should I call the fire department? Should I water my whole yard? Is this due to the ground being so dry? Sorry for all the questions. I just need some advice in general.. I am located in the alief area.