SURVEYING What does our world really look like? An attempt is being made by volunteers all over the world to visit the confl uence points and document the scenery with pictures and narratives

RAINER MAUTZ

sually, us human beings tend The Confl uence project counting down numbers at the to cumulate in urban centres, displays of their GPS receivers. and if we go places, then to Fortunately, for the past decade an The time to reach confl uence points Uthose which we consider as attempt is being made by volunteers ranges from 10 visits in 1 day (as worthwhile a visit, such as the Tower all over the world to visit the I managed to do in Germany, a of Pisa or Old Faithful Geyser in confl uence points and document the country with dense infrastructure) Yellowstone National Park. Due to our scenery with pictures and narratives. up to 1 visit in 10 days for reaching unbalanced focus on certain areas, we All reports of visits are submitted the world’s highest confl uence have a distorted image of our world to the website www.confl uence.org at 5835m in Xizang (Tibet). – much more jam-packed of houses, where they are published. Now, roads and people than it actually is. exactly 10 years into the project with The disparity of infrastructure, several thousand people actively population density, and awareness participating, one might guess that of the project hampers the fulfi lment An approach to all points must have been visited. De of the project goal. Currently, there sample the world facto, only 26.9% of the project goal is a huge gap in completeness of the is fulfi lled at the time of writing. project between different regions in If we want to have an unbiased the world. Figure 1 shows the current view of our earth surface, we need Why is the progress so slow? achievement in all countries. On the to sample it that independently of The answer can be found when top of the list of best documented any existing human infrastructure, recalling that these points ignore countries is Luxembourg with its topography and accessibility. our built infrastructure: they let only confl uence point (50°N 6°E) One clever idea that realizes ‘confl uence hunters’ drive into being visited 13 times. Even in a true independency is simply to deserts, wade through swamps, larger country such as Germany, identify an evenly distributed set argue with land owners and run its 48 confl uence points have been of sample points by coordinates. for miles after their vehicle has got documented more than 5 times on stuck in the sand, thereby always average. On the other end, in areas A straightforward approach is to sample all the exact spots where an integer degree of latitude and an integer degree of longitude meet, such as 20°00’00”N 106°00’00”E. Those 64,442 points are referred here as confl uence points. Using the WGS84 datum the locations of those points are exactly defi ned. If we only knew what these sites – at least those 21,541 being on land – look like, the title question could be answered. Considering that pure satellite pictures do not give the true impression of the spot compared to the scene when actually standing on it, taking pictures of all confl uences means to go to the confl uence Figure 1: The completeness of confl uence point documentations for different points. This is quite an effort, since countries. The greyscale directly refl ects the ratio between the fraction of visited they form a grid with a cell size points of a country. White (greyscale 255) indicates that none visits have been of roughly 100 km. by 100 km. done, black (greyscale 0) specifi es that all confl uence points have been visited.

8 March 2006 Coordinates solving, timing, improvising, organising, geography, transportation and many more. • Discover the fascinating and intriguing sides of ordinary places not on the “must see” agenda of most travellers and discover the fascinating and intriguing sides of those places which are supposedly uninteresting. • Last, but not least, participate in the Degree Confl uence Project. Figure 2: Uneven distribution of visited confl uence points: There are few projects where Those marked red have already been documented. volunteers from all over the world are unifi ed by a common goal. where the people’s basic needs such confl uence 30°N 90°E where the as water, food and health are far visitors suffered a physical toll (one of After having personally visited from being satisfi ed, the search for them was rushed to the hospital after 82 confl uences in 24 countries confl uence points is not ranked high the trip) because the confl uence hunt I can clearly say that despite on the to-do-lists. The Democratic involved a 6-day, 75 km pack-horse the fact that places are very Republic of Congo (Zaire) is leading trip at altitudes continuously above different, each confl uence visit the list of incompleteness: not a single 5000 m without any villages or human involves the following steps: of the 189 confl uence points in Congo infrastructure. Sometimes negotiation has been visited nor even attempted. skills are required when points are The planning phase Clearly, most of the Congolese are not located in restricted areas, such as the aware of the project and not equipped last remaining virgin confl uence on It is essential to look at the available with the required instruments to the contiguous USA (37°N 116°W) time budget and estimate how long survey their nearby confl uence points. that resisted all attempts for visits due the whole trip from the highway, On the top of everything the access to its location in the Nevada nuclear country road, track, footpath, cross- to the sample points is challenged by test site, which is very restricted country to the point and back will tropical rain forests and intestine wars. U.S. government property. However, take. Unsuccessful visits are almost The density of visited confl uences nothing is impossible if there is always due to the fact that the real for a country however is hardly a strong will – so fi nally this last trip turns out to last much longer correlated to the population density land confl uence was documented. as estimated. Therefore it is useful (correlation coeffi cient +0.15), not to face tight deadlines such as but clearly correlated in the GDP I can clearly say that the challenge of darkness, bus schedules or promises (correlation +0.6) and the number of fi nding confl uences can be fascinating to spouses. A good rule of thumb internet users per 1000 inhabitants – if not addictive. From a rational is to estimate your time on getting (correlation +0.6). Figure 2 shows point of view, “confl uencing” seems there, and then double it. If you the locations of visited confl uence to be pointless, if not foolish. Why fi nish early, congratulate yourself. points – within large countries like should one shoulder so much effort China or Russia the density of visits just to get to a pointless place on The journey varies signifi cantly. Russia’s easy earth? Well, there are several reasons: accessible areas in the west and • Often takes you to places that Problems will always occur despite along the industrial belt are almost never sees tourists and has thorough planning. Facing and solving completed while the most of Siberia untouched wildlife. If the area is which is mostly covered by swamps, populated then friendly people uninhabited taiga and tundra is still are happy to see you coming untouched by confl uence hunters. because they rarely have visitors. • Provides a challenge in everyday life. Nowadays, modern societies Challenges in fi nding satisfy most needs causing confl uences a desire for further goals. Purposelessness is driven away by Navigating to confl uences can be the collective aim of the project. challenging – physically where a • Provides training skills in coarse road network demands long orientation, navigation, negotiation, Picture 1: 17°N 105°E, drying GPS hikes or climbs, such as the Tibetan climbing, hiking, problem receiver in southern Laos

Coordinates March 2006 9 Picture 2: 40°N 41°E, fi xing a Picture 4: 31°N 74°E, road control in Punjab fl at tyre in East Anatolia weather conditions, animals, or System 1980 (GRS80) ellipsoid, problems should be taken as part of the worried landowners keep the visits see Figure 3. As a consequence the play. When I tried to get to a remote short. The visit can be intense if the distance between degrees of longitude confl uence in Laos’ jungle at a rainy point is near a school in remote China varies considerably between 111.32 day and almost reached the confl uence, (#picture 5), a river in India (#picture km at the equator to 1.95 km at the the GPS receiver quit working. After 6) or a Cambodian town where 89° latitude circle. The distances of I had dried the instrument in the sun spiders are delicacy (#picture 7). latitude circles however do not vary for two days (picture #1) I started signifi cantly (between 110.57 km at again and made it a successful visit. Reporting the confl uence the equator to 111.69 km between I had a fl at tyre in Turkey (picture 89° latitude to the poles). Whatever #2), my car got stuck a remote part Submitting a report and pictures to coordinate system is used, it is not of Iran’s desert, and issues with the the website can be quite some effort, possible to equally distribute points police had to be solved in Yemen but is usually rewarded by feedback on the sphere except in a few special (picture #3) and Pakistan (picture #4). from the confl uence community. cases called the platonic solids like the Taking a local guide, being patient Tetrahedron or Dodecahedron. More with locals and communication with details see Womersley (2005). For people who know the area are key Equidistribution the confl uence project this problem is to success. We shouldn’t forget that on the sphere solved by excluding some points near some places we consider disagreeable the poles and calling them “secondary” are other people’s homes. Only when all degree confl uences have while all others are considered as been visited will a thorough view of “primary”. Further details can be found Standing at the confl uence our planet’s surface be possible. One on the website of confl uence.org. might argue now that all meridians It is the highlight of any confl uence meet at the poles and that pole areas trip, but usually time constraints, have a higher density of latitude- The future longitude intersections Will the project ever be completed? than the tropical Considering it took 10 years to visit regions. This 25% of the points, a linear prediction is due to the would give a positive answer, but defi nition of would also suggest a completion in the geographical year 2036, which means another 30 coordinates, years of hunting unvisited points. Well, which are some variables make this calculation referenced on unreliable. The last remaining unvisited the WGS84 point might be hard to conquer (e.g. datum and its imagine trying to visit a confl uence in underlying a military compound in North Korea) Geodetic or just unattractive to visit (as most of Picture 3: 14°N 44°E, required police escort in Yemen’s highlands Reference Antarctica seems to be with currently

10 March 2006 Coordinates Picture 5: 27°N 105°E, curious Picture 6: 24°N 77°E, women completed laundry at a nearby river. school kids in Guizhou years. While the number of total visits them being secondary): circle the only 5 out of 1718 primary points is still increasing, there is a downward South Pole at the 89° latitude circle visited). On the other hand, the project tendency for the number of fi rst visits on a snowmobile. If you take the has gained publicity and attracted a of confl uence points over the last fi ve required pictures of the confl uences rising number of active members. If years. If the downswing continues, a (being 1.95 km apart) on-the-fl y, the whole world population would completion in 30 years is doubtful. the 700km journey can be done participate, I guess that all points can on an average speed of 30km per be reached within in a couple of days. Here is my idea how one can hour. But I guess that realisation A realistic forecast can be made by break all records and visit 360 new face a lot of logistical challenges looking at the past. Figure 4 shows how confl uences in one day (350 of and also involve some costs. the project developed over the last 10 In conclusion I can say that it is currently an open question whether the project goal will be met one day or not. May this article contribute to the awareness of confl uences and help to answer this open question someday with: “project completed!”.

Womersley, R (2005), Distributing points on the sphere Homepage Figure 4: The blue line shows Articles School of Mathematics, the number of points that have UNSW, http://www.maths.unsw.edu. been visited for the fi rst time in au/school/articles/me100.html a year, the red line shows the Figure 3: Geographical Coordinates Grid number of all visits in that year. Rainer Mautz born 1969 in Wiesbaden (Germany) studied Surveying at the Technical University Darmstadt and holds a PhD degree in Geodesy from the Technical University Berlin. He spent two years in Columbus, Ohio (USA) and is currently a researcher in Positioning and Navigation at Imperial College London. [email protected] Picture 7: 12°N 105°E, fresh roasted spiders in Skon, Cambodia

Coordinates March 2006 11