Great shots Abraxas, especially the Green in #1. I just love it. Regarding the #2, is that the reflecting colour you captured? It very good and the pattern you got is excellent. More shots of the same river please,.........
The 'reflected' color in the first is a combination of sky reflection and the sand at the bottom of the river. The water is about a foot deep and very clear at this point.
The second shot is what happens when water 'sheets' over a large surface of sand. Saturation occurs, currents develop, and braiding, or interweaving takes place. The water is about 4 inches deep toward the top of the photo (where the current is strongest) and only about 1 inch deep at the bottom (where the water slows and begins "sheeting"). This slight channeling will change every couple hours or so.
The river flows mainly underground at this point, so as the weather warms and the flow sinks back into the sand, this is a very likely place for quicksand to develop.
The first one was taken from a bridge overlooking the river. I got to do a little creative trespassing and got busted. The bridge goes across to a cement processing plant and is heavily fenced. I just drove in and parked at the spot where most figure out they shouldn't be there and turn around. After about 20 minutes, a very expensive looking black car pulled up and the driver asked what I was doing? I just said taking pictures of the river, smiled and then said, it's very beautiful- The car drove off.
The second photo was about a mile downstream. The river is sort of thrashed with trash and off-road vehicle tracks. I had to get a shot of this specific location though as it is an historic pioneer crossing- wagons were brought through in the mid-late 1800's. I found the cross currents fascinating.
Here's the shot I'm going to use to illustrate the location of the actual crossing. As far as I can tell, the wagon trains would come down off the opposite bank and pass directly over where I was standing to a dry wash (creek) behind me.
A little bit of trespassing to get this shot was involved also