Showing posts with label water. Show all posts
Showing posts with label water. Show all posts

Friday, 19 October 2012

Lights, Camera, Action ... Heat, Dehydration, Crash

It was never that bad :)
I found myself on a film set the other day. This might sound glamorous, but it's a lot of waiting around, being told what to do and then doing it over and over again. You can't go very far and you don't really know when it's going to end. When working on a film set, knowledge of the human body and application of survival skills can get you through the day. With lots of down time and unpredictable events in a hot and largely resource free environment, it's easy to to get overheated, fatigued and dehydrated. Using your head and being opportunistic is the only way to ensure you're on form and not exhausted at the end of it all. This article is not about film set survival, more an insight into managing yourself in an situation over which you have little control.

Sunday, 29 April 2012

Ways of Seeing Two

Take a look at this photo again, what do you see?

If you are wondering about the "again", then it might be worth reading Ways of Seeing One first.


Hopefully, you've zoned in on the different habitats here; woods, water, waterside, meadow and pathway. In addition, you'll have noted the fringes and transitions which support their own set of species. This is the major zoning method associated with foraging and identifying diversity in a local area, so what's next?

There are many factors which affect biodiversity. From a global perspective, climate is a huge distinguishing factor, so much so that if you were in a food library, climate zones would each have their own sections with almost no crossover, apart from at the transitions, of course. Climate is a sort of super habitat which is itself subdivided into the habitat zones we have learnt previously, albeit with some climate zone specific habitats.

An additional global modifier is altitude. With altitude, comes changes in temperature, moisture and prevailing weather, all of which affect plant growth. Here in lies the beginning of a huge area of study which we will sidestep for two reasons. The first is that in a recreational or survival foraging perspective, you're likely to be stuck in one of these super zones and have no real opportunity to change that, the other is that no matter where you are, the ways of seeing still apply. With that in mind, we'll stay local, but keep hold of altitude, more specifically how local altitude changes.

When we look around, local altitude makes the world stand up in three dimensions. A few specific features of altitude can give us many clues about the plant life and natural resources available. Let's start with Slope. Firstly, the direction of slope will define the direction of water flow. Water flows down hill, be it above or below ground. So if need water, follow the slope down, simple.

Unlike the contours on a map, which define a locus of points of common altitude, we will be taking a slightly different approach to zoning altitude. Let's start with the most simple case. If we keep walking up hill, eventually, we'll come to the top. This might seem like an over clarification, but at the top of a hill, all directions lead down. At this point, we are exposed to the elements from all directions. We are unlikely to find rich vegetation here, and often no trees either. Sometimes we don't even find soil. If anything, other than grass, we're likely to find hardy plants such as heather or gorse. Of course, if we walk up, we might get to the top of a hillock which is not actually that exposed as it has neighbouring higher hills. This is a local maxima, in mathematical terms, and though it has important qualities from a water flow perspective, it may not from a weather viewpoint. From a zoning perspective, you may wish to ignore minor local maxima.

The opposite of a local maxima or a local minima. This point on the landscape is a place where every direction is up hill. Chances are, of you're stood at a local minima, your feet are wet. If you're not stood in a lake or tarn, it's almost certainly going to be boggy and if not, a bit of digging may bring water. Open your eyes a little more and chances are you'll see another general trend down hill, this will lead to another local minima, likely larger and ultimately, if taken to its extreme, the minima which is the sea; global minima. There are regions of land which are below sea level, but these are likely to be marsh, such as the Fens in the UK (4m below) or parts of much wider arid regions which present a much more interesting survival challenge.

Typical Snowdonia
Ridges and Local Minima
Assuming we are not at one of these extremes, there will be a general trend down hill and one of three configurations. If we have slopes up on both sides, then we are in a Valley. A valley represents the most likely route for rivers and even if the valley floor is dry, then digging will generally expose ground water. There is likely to be lush vegetation in valleys.

The deeper and steeper the valley, the more shaded it will be. This will make for cold mornings and evenings. Additionally, valleys afford protection from the elements, unless of course, the wind direction is up or down it, in which case the wind can funnel, dramatically increasing speed, brrr! There are some temperature considerations with valleys, but they get quite nerdy, what with temperature inversions and all and deserves an article of its own.

The opposite of a valley is a Ridge, which is where there is a general trend up or down hill which drops off on both sides. This area of high exposure is normally the easiest route from one local maxima to another. Visibility is good here, but as with maxima, plant life can be limited.

Stick with me reader, this does have a point, I assure you. Our third and final situation is that we are merely mid slope, neither at the top or bottom in any direction. Some might argue that there is "flat", but in reality, that's just a special case of one of the above where the gradient is small. Gradient represent how steep a slope is. Where gradient is very high (steep), even at low altitude, soil doesn't hold and rocks are exposed. This can be seen clearly in the above pictures. Maximum gradient is represented by a cliff, which is essentially vertical. "Flat" zones, be they large or some small localised area, are often moist, since there is little chance for ground water to run off. They universally make poor sites for shelter. Better to find a slight gradient.

I promised a point, and so here it is. We don't need to concern ourself with actual altitude when zoning our vista, rather, we should be looking at whether or not areas are maximally high, like the tops of hills or ridges or low, like valley floors and dips. A ridge presents pretty much the same habitat factors at 100m as it does at 300m. It's not a matter of actual altitude, it's more about shape. Hill tops and ridges are exposed, valleys and dips are wet. In addition, we concern ourselves with gradient as this has an effect on soil. All of these factors have their own effect on vegetation.

Altitude Zones

Habitat and Altitude

We can now return to our original photo. I've zoned this area into high, middle, low, flood plain, waterside and basically, wet. This is because it's clearly visible, but at a distance, we might only see hight to low. We are not worried about the prevailing slope only that we can see the shapes of the area and understand what each feature presents. There are not many large areas of high gradient, but the meadow is really quite "flat".

Our original article allowed us to see the world in basic habitats. Now let's overlay a slightly improved version of that on our altitude zone map and see what we end up with.

Here you can see that altitude defines some habitat and the zones match, but elsewhere, the two form a patchwork across the landscape. Add in to this view the habitat fringes and transitions, together with extremes of steep and shallow gradient and you have a new way of looking at your environment.



In terms of recreational foraging or in a genuine survival situation, being able to make an assessment of the local environment is very important. Not only does it help us define what sort of plants might be available, but also sources of water, sites for shelter and routes to take, should be need to make a move. Basic Habitat and Altitude zones are two simple, visual dimensions which allow us to make assessments like "that meadow is going to be boggy", "there is likely to be a stream there and those trees very close are probably willow", "I bet there is rocks and pennywort over there", or "there's a section of land suitable for shelter building in those woods" all without taking a step.

Take time to notice the changes in trees and plants with respect to altitude shapes and see where water runs and settles. Combine all of this with the trees, plants and fungi we've covered on the course. A useful exercise is to take the knowledge you've learnt on your local patch and try to apply it to a brand new one. If you've made a concious effort to look and learn, your new environment will be much less unfamiliar.


Monday, 16 April 2012

Wet & Dry

I pop on the forums quite a lot and there are many ideas about what should and should not be carried as trail food. Not normally a survival consideration, trail food is more of a preparation; and what do we concern ourself with when preparing for the trail? Weight! To this end, I see a lot of talk about carrying ration packs, dried meals, dry ingredients, partially dried or cured foods and this got me thinking. What sort of food should we pack for the trail? Well, tins and jars are out for a start.

One of the most influential factors in this area is that of provision of water and the most importantly whether or not there is water available at the point where cooking will happen. If no water is available, then you have no choice but to carry it, and that's where we'll begin.

A chap walks for a day on a trail which is not scorching, but has no sources of water available. He takes a couple of litres for drinking, a couple of snack bars, some beef jerky, some rice, two packet soups, a bread roll (acquired from the breakfast buffet at the B&B) and some instant coffee. Like me, he has his coffee black, so no worries about milk or other nasty alternatives. The plan is to much a bit of jerky and the snack bars on the trail, soup & bread for lunch, and a bit of jerky soup with rice for tea.

Jerky is dried and salted and needs extra water to digest, so has some dehydrating qualities, though a little salt intake after sweating is a good thing. Some snack bars are really quite dry also. If we were good trekkers, we would counter this with some extra liquid and so this begs the question, why are we bothering carrying dried stuff at all? Why not carry a nice moist chicken breast and half a malt loaf, I wonder? I know, I know, you can't really have malt loaf without real butter.

Instant soups are super simple because they don't need cooking. A simple introduction to boiling water and you're all done. Hardly any washing up too, just a simple wipe around with the bread roll and it's a very efficient meal indeed. That is, if the roll survives the walk and doesn't become a pancake.

The last meal is rather cunning. Rice and pasta, when cooked from dry need more water to cook than then consume in the hydration, that is, unless you're into pilafs and can get the quantities perfect and not burn it over a fire. Good luck with that. So instantly, we need extra water. The trick with this meal is that the extra water is then not only used to hydrate a bit of jerky, but make a thick soup too. Voilà, dinner. Not much washing up again. Wash out with a splash of water, make a brew and you're set. How could we possibly improve on that?

There is something very simple going on here. If someone took some water out of the food we're carrying, then we're going to have to put the same about back in to eat it. We can't take this out of our drinking ration, since that'll dehydrate us, so we have to carry it as extra. Generally speaking, cooking and washing up needs more water, so the whole business of carrying dried food on trips where there's no water is really a bit of a waste of time. Better to just carry wet food and have done with it. Here's some I prepared earlier.

This is me, particularly late, having dinner in the dark. This often happens on courses in the winter. Note the use of the kettle as the reheating vessel. This is for good reason; I wanted a brew, and as the food was nicely contained, there was no danger of it mingling with my coffee. Two birds with one stone, no plates and no washing up. Decent! Yeah, the portions can sometimes be small, but if you supplement with a precooked rice pouch, then that's a meal right there.

Yes, there was water on site, and so I could have had one of those dehydrated pasta meals, but frankly, they taste awful! I've tried supermarket ones, trekker branded ones (which taste just as bad but cost twice as much), ration packs (no comment) as well as dehydrated veg and stock. Some come with a "make in the packet" option, avoiding washing up, but really, they're pants.

My friend who finds herself all over the world has an interesting diet. What she does is preprepare her own meals and take them with her. She seals them all in boilable bags using one of these units.

As another instructor, she too finds herself eating at odd times in short time periods. She too has tried many options and has found this is the best way of making gluten free, lactose free, other stuff free food and cooking it conveniently.

I'm so getting one!

Anyway, I digress. I'm sure you can see that the benefits of dried or partially dehydrated foods are a bit of a fallacy when water is very short on the trail and this leaves us with one of two conclusions. The first is simply that you might as well take wet food, certainly if it comes in boiler bags and the second is ... why the hell are you not planning your route around water?

So remember, water is a major consideration when carrying food and provision of such is very important from a planning perspective. Ultimately, if you're somewhere where there is no water to be had, you might as well take a nice juicy steak over a dehydrated version, since you're going to have to balance it out with water anyway.


This has got me thinking about trail food in general and I'm presently compiling some research in order to determine the best types of food to be taking should we be able to acquire water en route. Keep an eye out for follow-ups.

Monday, 27 February 2012

Igloo Man


Swedish man was/was not trapped in his car for two months/a bit living on only snow, but maybe other stuff

Peter Skyllberg may or may not have survived an ordeal which may or may not have been a miraculous survival story.



Frankly I don't care if this recent survival story is true or not, but it does raise some interesting survival questions. Let's take them in a pretty standard order of priority; that is to say, let's deal first with the things that would kill us first.

Stuck?


Apparently, he was stuck in the car, under two feet of snow. Well, it wasn't an avalanche, so I have to wonder how he managed to get stuck inside during even the heaviest of snow storm. Might have been worth checking the weather forecast to if there was an indication of such a storm for him to have been so quickly snowed in. Maybe packing a snow shovel would have been an idea. There was no mention of him being knocked out, and even if he slept through his snow storm, it's not beyond the wit of man to open or even break a window and poke your way out. He had to have some form of ventilation, or he'd had suffocated.

Temperature

They say the temperature went down to -30°C, but let's assume that's the press playing the statistics cards. I had a quick look at the statistics for the area and it turns out.
The month of January is characterized by essentially constant daily high temperatures, with daily highs around -3°C throughout the month, exceeding 3°C or dropping below-12°C only one day in ten. Daily low temperatures range from -12°C to -10°C, falling below -22°C or exceeding -1°C only one day in ten.
February wasn't much different. That's not actually that exciting. Yeah, you wouldn't want to stand outside in your birthday suit, but it's not exactly Arctic conditions. Given that the guy had a sleeping bag, we can assume that he also had some sensible clothes too. Pretty good preparation, I'd say.

Shelter


What's immediately apparent about a car, is that it's already wind and waterproof, which is nice. Something else that's useful about a car, is that's it's insulated from the ground rather well, it being not only raised off the ground, but held up by inflated rubber tyres. So far, so good.


My former colleague was quoted in the Telegraph as saying that trying to survive in a car was going to be gruelling, since it was made of metal. If this was an isolated fact, it would be true, since a metal shelter is highly conductive of heat and quickly evens out the inside and outside temperatures, basically, making the inside temperature fall to that of the surrounding environment. I imagine the quote was taken from a quick phone call, which is the normal way the press gets a sound bite for a story.

It turns out, if you have a look at the press photos, that there was a good 50cm of snow on the top of the car and given that he was dug out, we can assume that was covering the whole car. Snow is about 80%, which makes it a great thermal insulator. Snow has a thermal conductivity (k) of around 0.16 W/m K, which is better than brick (0.18), but not quite good as wood (about 0.12) but it's about 7 times better than glass (1.1), 250 times that of steel (55) and 1400 times better than Aluminium (237). We can assume the car had some form of meagre insulation, but we all know how quickly a car gets chilly after you've stopped blowing warm air into it.

Heat transfer is inversely proportional to thickness of material, that is to say that twice the thickness of material yields half the heat transfer and hence half the heat loss over the same period of time. Standard  maximum roof insulation is around 270mm thick, which is around half the thickness of our snow. The materials vary, but it has a conductivity of around 0.04, which if four times better than snow. That makes good roof insulation only twice as good as the snow. So, that's not all bad either.

Other than the igloo and snow hole, another example of snow insulation is that of Uruguayan Air Force Flight 571 which famously crashed in the Andes and became the subject of a book and the film Alive. Other than the well publicised cannibalism, an avalanche covered the fuselage of the plane, killing nine, but arguably aiding the survival of the remainder.

So, what's heating up the air in the car? Well, as far as I can tell, there was only one heat source available, and that was our guy. We humans emit energy at a rate of about 100 Watts, normally, which is why a party in a small room always get a bit warm. A cheap bathroom heater is about 400W and a car is a rather a lot smaller than even my tiny bathroom. As the air in the now insulated car heats up, we cool down more slowly, so burn less calories keeping warm, unlike standing outside, where we just keep loosing heat to the largely constant temperature air and ground. 

All in all, the snow covered car is not a bad shelter at all.

Fire

Our hapless 'igloo man' was next to a wood. I still don't think he was stuck in it, so I'm going to assume he could have got out. Now let me think ... I'm cold and next to a wood. I know, I'll light a fire. Bit a no brainer. 

"But what if he didn't have anything to light a fire with?" you may ask. Well, other than the quite difficult "rubbing two sticks together" methods, he had a car, and there are loads of ways of lighting a fire with bits of car. More realistically, however, someone who travels out to photograph Elk (as it seems he was) in those conditions, should be carrying something to light fires with. If not, then frankly, get out of my gene pool. That's basic preparation.

Sat by a fire by day, sleep in the car by night. That the most efficient way of keeping warm if you don't have the skills to keep a fire going all night.

Rescue

Our chap was obviously remote and said to be about 1km from a road. This road was described as "main" and there were reportedly hundreds of mapped snowmobile tracks. I don't really understand how he could not have signalled for help or gotten to the road. Either he didn't bother, or he didn't want to get rescued, or he wasn't there for long at all. Hmmm.

Sensible solutions for someone wanting to get noticed from an off road position are signs and smoke signals. That's a blog post by itself, but he obviously missed a trick there.

Water

So, snow, that's water right? Well yes, but it's cold. This chap was said to have survived by "eating snow and ice". Good old Daily Mail, but even the Telegraph alluded to the same. More likely, he would have eaten melted snow, see above for methods of melting. 

What's wrong with eating snow? Well, consuming snow directly means that you have use energy to melt it. Even if we use body heat to melt it in advance, we're still using our own energy, albeit not from the core directly. Even if we let the nice warm air in our car warm it up, we're still taking heat from the air we heated up ourself which we'll then have to heat up all over again we have to find another way.

I'm just going to assume the car wouldn't start, because that would be a sensible way of melting snow, even if you were trapped in the car. Would also keep you nice and warm for a bit. I reckon even a little Fiesta would idle for 30 hours or so on a half tank.

Food

He had a bit of food, but it would have run out. Snow doesn't have any nutritional value, nor does any part of a regular car. So, let's play along with the whole "trapped in the car" lark. What's going to happen here? Well, first we'll consume the sugars stored in muscles and the liver, then we're going to burn lean muscle and fats. The rule of thumb is that we can last about month without any food and make a complete recovery. There are a few contributing factors to this, largely environmental, but also some biological. 

So how did he last that long? Well, I'm going to assume that he had a bit of food kicking around, he kept as warm as possible, he had a little more fat than the average guy and was just one of those people who last longer. 

He was reportedly malnourished, which you'd expect. There is also a possibility that's he's had permanent internal damage, but at least he's alive.

Hibernation

Some sources suggested he went into a state akin to hibernation. Really? Come on!

Escape

This section is left for an exercise for the reader.


All in all, I don't buy it. It seems to be that the chap did not make the effort to try to survive, just curled up and waited to die. Maybe there was something more psychological going on. Maybe he wasn't really there for two months. Maybe he wasn't really trapped in the car. Who knows. It was interesting exploring the possibilities though.

Give some thought to the preparation you might now make, if you risked ending up in the same situation and the actions you might take to get yourself out of the situation in a more timely fashion.


Saturday, 4 February 2012

All Things Being Inequal

I'm sat here watching Hugh's Three Hungry Boys, which is a slightly disappointing incarnation of a "get from A to B without any money" challenge where, at least in my expectation, there should be a lot more foraging and a lot less scavenging and working in exchange food. However, working for your food itself brought to mind an important concept in survival; that of the inequality.

In mathematics, an inequality describes the relationship between two quantities, stating that one is either less then or greater than the other. So simple is this concept, that we use it every day. If the temperature is less than is comfortable, we turn the heating up. If the amount of money in your pocket is less than the bus fare, tough luck. These are luxuries we might not have in a genuine survival situation, but there is one day to day inequality from the human biology which is extremely important in survival:
calories taken in compared to calories expended
If calories in is greater than calories out, then we put on weight, if less, then we lose weight. From a dieting perspective, the latter makes sense meaning we either eat less to reduce calories in or work harder, increasing calories out. Either way, we're trying to tip the inequality the other way, thus losing weight. In addition, the greater the difference between these two quantities, the greater the rate of weight loss or gain.

In survival situation, it would be unusual for us to find ourself concerned with weight gain, more likely weight loss and more concerningly, rate of weight loss. Loss can be mitigated by reducing calorie expenditure by doing less work, keeping warm and generally sleeping as well as eating more, but here in lies another inequality dressed in a question.
At what cost is in calories is my food coming?
That is to say, are the calories I gain from the food I eat greater than the calories expended getting it? If it costs you more in calories to get the food than you gain from it, then that's a net loss, which is a bad thing. I remember Bear Grylls climbing a huge tree to get a single egg, which is not only a massive risk of injury, but a net loss in calories, which didn't help his cause. An example from the show is that the three chaps did fifteen hours of weeding in exchange for five pounds of vegetable. Was it worth it? Let's see.

Weeding costs about 300 to 350 calories an hour, depending on how much you weigh and how hard you work. The chaps worked pretty hard, so they probably expended about 5000 calories each over the 15 hour period.

I seem to remember the box containing, leeks, turnips, chard, spinach, potatoes and beetroot amongst other, so an average of, say, 50 calories per 100g. That's about 1200 calories in total which doesn't seem to offset the work. The boys were in luck, however, as they were subsequently given a kilo of honeycomb. Whilst standard, jarred honey is around 30 calories per 100g, honeycomb is more like 400. So that's 4000 calories for the kilo. Giving us a total of 5200. Hurrah, we might think, until we realise they had to share it between the three of them, making about 1400 calories each. Damn! Back to a loss.

But, you might argue, they would have used a certain amount of calories anyway. This is true. Each of the  chaps would have burned around 80 calories per hour just sitting around. So, assuming that's not been taken off of the weeding rate already, that's about 1200 calories. How are we doing so far?
calories in = 1400
extra calories out  = 5000 - 1200 = 3800 
so far
calories in are less than extra calories out
For those who saw the show, you might remember that they said one of the advantages of weeding is that you can collect wild food on the way. The really observant amongst you will have noticed one of them with a stalk of chickweed. They also had some stable in the van. So, if we want to flip the equation around, we'd need another 2400 calories in wild food, rice and spuds, which about the amount that an average male needs per day.

In summary, even with the honey and some wild food, they would have been better off, calorie-wise, just sitting on their arses.

This might seem like a contrived, TV example, as is the case with the egg up the tree, but it illustrates an important point about calorie expenditure in a survival situation. It's important to ensure that we waste as little of our calories as possible, by making sure we're always on the look out for foragable food whilst, for instance, combining gathering food with getting water and checking traps. We might consider placing our camp nearer to such daily resources as water, wood and food, in order that we expend less calories walking, which takes up about three times as much as sitting.

In cold weather, we should ensure we make small, efficient fires we can sit close to and reflect the heat in, rather than huge fires we have to constantly go searching for wood for. There's another inequality there. Are the calories I'm wasting keeping myself warm internally greater or less than those I'd expend gathering wood for a fire? If you're walking around all day getting wood for a fire you're not sat next to, you're collecting wood for nothing and wasting even more calories.

This same concept can be applied to water in a low water environment. We use water all the time, but sometimes more than others. Rather than sweat a litre of water in the mid day sun collecting from a small drying stream, it would be better to wait until it's cooler. Is it worth using the water you have to cook rice, or is it better to just drink it, staving off dehydration rather than hunger? Another inequality:
if water in is less than water used then you will dehydrate
The greater the difference, the faster you'll dehydrate and the quicker you'll die.

There's no need for a calculator and calorie counter in a genuine survival situation, just use your head. Limit and combine activities, work efficiently and think. Consciously applying this simple concept of comparing benefit an loss to your actions might save your life.