River gauging using a transparent velocity head rod (TVHR)

OXUS
Three Women, One River
OXUS
Three Women, One River
OXUS
Three Women, One River
OXUS
Three Women, One River
OXUS
Three Women, One River

River gauging using a transparent velocity head rod (TVHR)

There are three common definitions of the true source of a river: the source which is furthest
from the sea; the source which is at highest altitude; and the source which contributes the
greatest volume of water to the river basin. It is straightforward to collect data to compare
sources against the first two definitions, using a GPS and altimeter; but calculating water flow is
more complex and time-consuming.

Sophie measuring flow depth with the TVHR

Preparing for the Oxus Expedition, Sophia and I looked at a wide range of different gauges, which could be used to measure velocity and/or the total water flow in a channel. Some were prohibitively expensive or heavy; others required an external power source or internet
connection. We needed something simple but rugged. Thankfully, Nick Everard, Senior Hydrometric Scientist at the UK Centre for Ecology & Hydrology (UKCEH) suggested somesimple, viable options, including the transparent velocity head rod (TVHR). The TVHR was developed by hydrologists at INRAE in France. It is a low-tech way to measure both the depth of a river and the velocity of the water at surface level. By taking these measurements at multiple point across a channel and inputting the data into a spreadsheet, you can visualise a cross-section of the river and calculate the average flow. I ordered two TVHRs, one to use in the field and the other as a back-up, in case the primary gauge broke or was washed away. None of the expedition team has a background in hydrology, and it is important to use the equipment correctly in order to get accurate measurements. I communicated at length with staff at INRAE, in particular the ever-helpful Mickaël Lagouy;
watched the instruction video on YouTube; and co-opted two much more knowledgeable friends, Matt and Jack, to give the TVHR a trial run in Wiltshire.

The Ebble and the Nadder are very different rivers to those we will be measuring in the Wakhan. However, the basic skills for using the TVHR and inputting data are the same. I got togged up in enormous waders on one of July’s hottest, sweatiest days, and jumped in at the two easily/acceasible test sites we’d chosen in Broad Chalke and Wilton. Step one is to measure the width of the channel. In the trials we used a 10 m tape measure, but I’ve subsequently bought a laser distance meter, We decided to take measurements at 50 cm intervals, so 10-12 sets for each river. In essence, the TVHR is a transparent Perspex metre stick. Standing downriver, you put it in the water until it touches the bottom, turn it side on to the direction of the river flow, and read off the flow depth from the centimetre rule. The TVHR is a metre long but it works reliably up to 120 cm, and possibly beyond: you’d just need a longer pole to measure the depth and be very careful not to get swept away. Once you’ve recorded the depth, you twist the TVHR 90 degrees: you now feel the water pushing at the flat side of the gauge. Looking closely, you’ll see that the water level on the upriver side of the gauge is higher than on the downriver side. You slide the millimetre rules — one transparent, one red — to align with each of these levels, then read off the difference between them. This is the velocity head. INRAE provides a spreadsheet to input data, pre-set with equations and three options for the edge co-efficient. You choose which option is most applicable for the angle of the riverbank, add your figures to the table, and voila! It automatically calculates the discharge, area, and mean velocity, and plots the shape of the channel and thd percentage of discharge at each point measured on the graph.

Sophie and Jack testing the TVHR in the River Nadder

The TVHR is incredibly simple to use, even for amateurs. It won’t be possible to use it in large, fast-flowing rivers, but I am excited to put it to use in the smaller mountain streams of the Wakhan Corridor. It will be interesting to see how the surface velocity data we get from the TVHR compares with the video velocimetry data we will also be collecting. I will report back on that later in the summer.

Sophie and Matt uploading measurements to the TVHR spreadsheet

Training for the Oxus Expedition

OXUS
Three Women, One River
OXUS
Three Women, One River
OXUS
Three Women, One River
OXUS
Three Women, One River
OXUS
Three Women, One River

HOW I AM TRAINING FOR THE OXUS EXPEDITION

In a few weeks I head to Tajikistan for the first leg of the Oxus expedition, with the aim of climbing a beautiful (unforgiving) remote mountain range in the Pamirs, located in Afghanistan and to find the source of the Oxus river.

There will be some things on the mountain that I can’t control such as the weather, the snow conditions and the way my body reacts to the high altitude. I am therefore focused now on the things I can control, to help me prepare as best I can.

I was under no illusion that preparing for an expedition to the Pamir mountains was going to be easy. It requires physical and mental preparation, developing skills and experience in navigation, mountain travel and being able to recognise and avoid steep rocky terrain. The necessary tick-list I received when I started this journey was a definite reality check. I knew that there was a big challenge ahead of me and that I would need to push far beyond my comfort zone to achieve it. The key to my success was going to be my training.

An important part of my training was to find and create a tailored training plan to build my endurance, strength and cardiovascular fitness. After several conversations with other mountain climbers and hours of research I came to the conclusion that stamina and endurance are the most important facets of physical training since the majority of a mountaineering expedition will involve steadily hiking uphill with a rucksack over a long period of time – usually consecutive hours without a chance to stop.

Behind the beauty of the Wakhan pass and the Pamir Mountains is isolation and danger. Its landscape is a testament to the forces of nature and it’s a full body workout to navigate the large ridges, steep mountains and valleys that cut through the terrain. I was told that a high-altitude, low-oxygen environment dramatically suppresses one’s appetite, and as a result, mountaineers struggle to take in enough calories. So a big part of my training preparation was long-duration workouts over many hours at a low intensity on an empty stomach.

I started my training a year ago. Before work I go for early morning runs. It started off as jogging to 5km runs for three months to regular 10km runs. I have been doing this at least 5 times a week now and it has helped me stay concentrated, manage a steady pace, improve my breathing and increase my fitness levels ahead of the expedition. I even managed to complete a half marathon in Tashkent in April! I ran  21.2km in 4 hours! It was my first marathon in the soaring heat, but I managed to pull through and it was a proud moment. Along with endurance training, climbing conditioning is another important aspect of preparing for a mountaineering expedition. Climbing conditioning exercises often work as endurance exercises, but as i was told by many veteran mountaineers, the main point of them is to strengthen all of the muscle groups that will be required to make steady and steep ascents, some of which are not commonly used in day-to-day activities.

Most of us, including me, don’t have the opportunity to go to the mountains on a regular basis. So instead I tried to simulate the physical challenges that i would encounter when climbing a mountain, such as climbing stairs with a weighted backpack, which i would aim to do at least once a month. Climbing and mountaineering require far more endurance than they do sheer strength. So another aspect of my training focused on strengthening my core and mimicking ranges of motions that would be used for mountaineering. This would include 2 hour sessions of yin and hot yoga on the weekends to stretch my muscles to develop strength and balance. Another main reason for this flexibility training was to also reduce soreness and lower my recovery time.

My primary goal is to achieve a basic level of fitness and carry out regular exercise that would fit in my lifestyle and that would work best for my body. Another key part of my training is mental training. Developing mental toughness has been an equally important part of my training which  includes practising visualisation exercises, breathing exercises and meditation.

Those who know about my plans have asked why? Why do I want to push myself so hard? And why do I want to put myself in a risky environment? These are questions that I ask myself and I’m not sure that I have the full answer yet. But I know that I feel strongly on three beliefs:  Don’t let your dreams be just dreams; I wanted to challenge myself to achieve something that I didn’t know would be possible for me; and life is far too short to wait for the perfect moment, we need to take the moment and make it perfect.

It is often easier to be focused on the menial day to day and get through the to do lists. Sometimes this is essential because of things that are impacting our personal lives. But when we can dream, and work to turn those dreams into plans and then into reality, we can push ourselves to do far more than we ever imagined we could. Whilst I worry about aspects of what lies ahead, I would worry far more if I didn’t push myself, if I didn’t take a chance. I know it will be hard, I know there will be moments during the training and on the expedition where I feel it is impossible but I also know that there will be moments of pure joy, wonder and delight and I believe it will make me a better person at the end of it.

We can always think of reasons not to do things or to delay doing things. I could wait another year, to improve my skills further, or to train more. But there is unlikely to ever be a perfect moment to do things. The last few years have taught me that life is far too short. We are so lucky to be able to have time in our wonderful world and we should maximise that to the full.