by Treetop » Thu Mar 07, 2013 1:24 pm
there are many issues here rolled into one. Managing resources as we are now, water WILL be a looming issue over the decades. No doubt about that. It does not HAVE to be though! Not at all. Look at the actual raw data for the southwest, this isnt a major drought at all. Various factors from our land management however are magnifying it.
Also that desertification video is weak, we can do multiples better then that.
The largest factor in all this is pulling ground water for cities and irrigation. To maintain the massive yields per acre american farmers enjoy many crops need lots of irrigation. If we lower this irrigation crop types or yields will indeed change. So how could we possibly lower yields per acre while also keeping pace with increasing populations? Its easier then you think! Just takes a perspective change.
This is a big topic so bear with me here. ultimately we have to have our water tables balance out, in that we want as much water making it to our water tables as we take out. Do this in the dry areas specifically and the rivers and aquifers in such places will still go low at times but never dry.
Again several factors here but one thing we can do is turn large tracts of desert land into production or magnify what production is there. It gets tricky for me to explain this because there are so many variables. Heres an example, you grow mesquite in southern cali, AZ, texas new mexico etc. Once established this can produce as much ethanol per acre as corn does, with less inputs. which of course allows us to not need as much corn for our ethanol mandates while also having more efficent and thus cheaper ethanol while also allowing more water into the soil especially if it was once open land we are talking about. You can take this even further, if you did a one time earth works project before you planted the mesquite you can set up the landscape to direct the bulk of the water into depressions where youll be planting the trees. Even just a gentl sloping dip of a few feet where each tree is will be a feature that lasts as long as the orchard and will give more water to your trees, it will also let the water get deeper intot he soil since more of it is in one place (even if most of that concentration happens undergound as it often will) and since it gets deeper into the soil less evaporates and more gets to the water table. Do this over a large enough area that it balances out with the amount people are taking from those water tables. Getting that balance within every single water table might be tricky with the high concentrations of people in some areas but we could atleast get most of it covered if we wanted. Taking this further simply add a layer of stones around all the trees, and now your blocking all the wind and direct sunlight from the soil surface as well as slowing evaporation. From there you could go several routes, Id probably take the fallen leaves and other brush to my ranches though, and start building the soil there which again will help the soil retain the water and increase the amounts that get to the water table.
So lets say we did all that, we now dont need to use any corn for ethanol. We are now able to raise higher amounts of cattle per arid acre (which depends on how many variable we alter it can get pretty extreme) and we are now producing more ethanol then we ever could otherwise while using lands we already use poorly.
Example two. So now lets use similar methods of magnifying the amount of water a landscape concentrates and then retains to grow a range of trees in the high desert. There is a surprising amount of crops and cattle grown in the high desert and for most of the crops they are irrigated. So let switch to mainly tree crops here as well. Such areas could readily grow almost all tree crops under the right methods. There are even less pest and disease issues to deal with or breed through. This can ALSO include our animal feeds! There are a full range of reliable sources of nutrients we could be using in our animal feeds where we use soy and corn now. So all without irrigation we can actually turn to crops that are MUCH more productive per acre while retaining MORE water in our soil and again in this case potentially drastically lowering the amounts of other staples humans need to grow all without yet having to alter our diets. Done well these crops could be cheaper by the way, so Id expect them to work their ways s fillers into processed foods as well. Siberian peashrub is an example of this, matches soy on protein, its like a bland bean, makes a great filler and dwarfs standard beans which are already cheap in reliability and production all with much less inputs.
So now we have the low desert retaining as much or more water then it uses while producing more beef and fuels and they could be producing a few types of wood as well. We have the high desert able to produce much more beef as well, as well as replacing the bulk of our animal proteins and if we wanted the bulk of the nations treecrops. All without irrigation. We now need a fraction of the yields out of our main cropping areas, and can now switch to dryland methods and their lower yields on our staple crops without any issues. With the lower yields comes lower inputs and so profits for said farmers shouldnt suffer.
I tried to simplify all this so its easier to digest, but we DO have options here. This part is a bit taboo, but large cities in dry areas can also readily recycle their water and in fact many do to a degree. Albuquerque a few years back bought the rights to some very brackish water. They process it several times before they can use it. The cities engineers apparently pushed for simply rerouting the cities waste water back into the city, and that this could have been done cheaper with a better quality water then what they were getting from the brackish stuff. But it sounds gross to people even though they already do this with the waste water from cities upstream they get out of the river.
Greywater is also a wasted resource. Many folks out there by law have elaborate expensive septic systems. There are greywater system designs that not only allow us to get more use from the water it also can be cheaper with less pressure on the septic. Not really my area of expertise, but its silly to waste it especially in dry areas.
We also have storm run off. In dry areas specifically it isnt even difficult to get it to sink into the soil instead of letting most of it evaporate as I see so often out here. Our sidewalks and roads concentrate all this water, it wouldnt be hard to set it up so over the areas in question more water ends up in the soil then if we had never built the road instead of less water in the soil since we did build the road which is the case now.
We will only have future water issues if we continue to mis manage the resource. If we wise up a bit we will be perfectly fine. It would cost a bit more for some aspects of such methods then we pay now and less in others. With the land management changes especially, all of these will pay for themselves. So it actually has a chance of getting done if people realize we DO have options and act on them. Lots more to it of course, but we do indeed have options and ways to address these issues. Unfortunately humans as a group seem to only learn AFTER we face the consequences so we may indeed have increasing issues in the future but only if we dont adapt.