In January this year, the story that cartographers make deliberate errors made me catch my breath. You can read it in full here.
As long term readers of this blog will know from an earlier post, to walk from the mouth to the source of the Derwent River has required me to work across 17 maps. Because they were generated by a government agency I would like to believe they were accurate at the time of printing.
While my maps are scaled at 1:25,000 (I always wished they were finer in detail), I depended on them as much as I could. I registered that many were grossly out of date – too many were last printed in the 1990s and so I was cautious with my expectations. However I never once thought that a deliberate error might have been introduced.
For walkers like myself, trekking independently great distances from help and civilisation, having accurate maps seems a sensible requirement. Many readers will know that I always check with Google Earth imagery but again they are out of date – although not as old as some of the official maps I was using. I was fortunate to be flown in a small aircraft up and back along the Derwent so the photos taken contributed to understanding what the land was like below.
In recent days I have been horrified to learn that the Tasmanian State Government will never print further copies of the 1:25,000 scale maps and the common map for purchase in the future will be 1:100,000. People get lost in our dense bush, and some have died after wandering around for days. From a public safety perspective for tourists and locals who want to make their own way into our bush, where tracks are non-existent and using a compass and a map is the only means of knowing where you are, I am somewhat fearful for people in the future.
I think your concern about deliberate errors on printed maps is misplaced – the “errors” mentioned in the article are all merely labels, and inconsequential. No-one is going to be confused by the ‘addition’ of an imaginary locality name. Of more concern is errors in topographic data – roads, railways, rivers, elevations. These would have implications which could be significant, but you are unlikely to notice most. I very much doubt cartographers would deliberately introduce errors in topography. These organisations, particularly government instrumentalities, have rigorous checking procedures to protect themselves. The insurance and legal implications of a significant error could be horrendous.
I would be far more concerned with the universally available digital maps – I have come across many errors – roads where there are no roads, labels incorrectly placed, etc. One example was a fellow who noticed his street was shown incorrectly and wrongly labelled and sent an error message to Google Maps. When there was no response or change, he sent another message, The response was “we need to go through our checking procedures”. The fellow reporting the issue then pointed out that it should be really easy to check this error – he could see the Google office from his house a couple of miles away.
Another common mis-apprehension is that all GPS receivers are precise – not so! Depending on the type of receiver, how you are using it, the location, the weather, and even the degree of sunspot activity on the sun, your results can be quite imprecise. The classic example of mis-placed reliance on GPS readings was the guy who turned up at Cameron’s Corner, the intersection of the borders between NSW, Qld and SA (a survey marker was placed there in the 1880s, thereby fixing it forever) and, using his $200 handheld GPS receiver, declared that the survey marker was in the wrong place – “it should be 200 m over this way!”
Hi Mike Thanks for this thoughtful and informative response to my post. Like you I am doubtful that government created maps contain deliberate errors, and in fact I work on the assumption that they do not. However because all such maps (well those associated with the Derwent River) are very out of date, caution is required when interpreting the usage made by mankind. For example, without knowing the Derwent is rerouted through Tarraleah Canals 1 and 2 a casual reader of the maps might assume a raging river or at least one filled with water from Clark Dam to Wayatinah. That’s where the wise look at all sorts of guidance tools, amalgamate the knowledge and remain prepared for surprises. Nevertheless the idea that someone might play with any sort of map which is intended to inform others, had never occurred to me – so I found the idea interesting.