As to arid gardening conditions, long term incorperate plenty of organic matter to hold mosture in the soil
Short-lon term use a mulch of organic matter and/or black plastic sheetoing to reduce evaporation. The mulch will also attract plenty of invertibrates, a valuable protien source, which in turn will attract higher life forms (reptiles, rodents etc) that can suppliment your diet
Get a good field guid to you local flora and take a walk around your neighborhood (bring the kids), and start identifying the plants and fungi. Some will be edible, some usefull in other ways, some poisonous.
Take especial note of fruit/nut bearing trees. A mature nut tree can produce a large quantity of nutricious, easily stored fats and protien. All you have to is be around at the right time...research!
Other plants will bear fibre, medicine, saponin, and may also provide food or habitat for invertibrates, and larger animals that will act as bait or food
Beware. Never eat any plant or fungus unless you are SURE what it is
The Great Crack:
It is speculated that a portion of Hawai'i island could shear off causing a huge tsunami, large enough to wipe us all out.
We also have The Great Craic in Ireland, and it too could wipe us all out
But what a way to go!