Rest during the day travel, hardest at dawn and dusk, try to keep a mouthful of water without swallowing it and breath through your nose.
Don't stop to dig for water unless there is clear signs of vegitative growth at which point you sould look for a seep.(water purification tablets normaly come with a soldiers standard kit odd that you don't have it here but drinking dirty water is better than not drining)
And whatever you do don't eat anything.
The rationale behind this in squence:
While nightvision gives you the ablitiy to see without giving out light it only allows you see in one colour which unfortunaly means you tend to miss things which in a desert which usualy contain plenty of noctunal venimous creatures can be bad so it's better to be careful at night.
A big problem with traveling through a desert is dry air this makes it harder for the oxygen to pass into your lungs and generaly means you need more water than normal to counter act this.
If you keep a decent amount of water in your mouth it will hydrate the air you breath in through your nose making breathing easier and lowering your water intake.
Besides dawn and dusk at the times of day when human beings tend to be least active and least aware.
It's a desert water is etheir very deep or not there so look out for large clusters of green plants.
Eating things involes breaking things down in your liver, breaking things down in your liver involes using up water.