The colors are wonderful, and it is a beautiful scene. It may have been helped by using a grad ND filter to better balance the light. The bright areas of the sky seem to have caused the landscape to be a bit underexposed and therefore a bit noisy.
What ISO were you using? I can't find the value in the EXIF data.

I notice what seem to be numerous dust spots on the sensor in the sky (probably in other places, but the rest is too dark for them to be easily seen on the web.)