○○○○○○○○○○○○○○○○○○○○ COLUMN Grids & Datums THE REPUBLIC OF MOÇAMBIQUE The contents of this column reflect the views of veys were authorized by the Portu- values were subsequently published the author, who is responsible for the facts and accuracy of the data presented herein. The guese crown in 1857. Topographic in the middle 1960s, this has been contents do not necessarily reflect the official mapping for Moçambique was de- ignored. The Cape Datum theoreti- views or policies of the American Society for Photogrammetry and Remote Sensing and/or signed by the Portuguese “Junta das cally covers a substantial portion of the University of New Orleans. Investigações do Ultramar” (Board South East Africa, but has been sub- The first Portuguese explorer to of Overseas Research) in Lisbon, jected to several regional adjust- arrive in Moçambique was Pero de Portugal. The Junta coordinated the ments that effectively separate into Covilha who was dispatched in 1487 activities of the geographic mission a variety of individual local sys- to find a route to India, which he that established horizontal and ver- tems. The countries surrounding reached via Egypt and Aden. On his tical control for photogrammetric Moçambique that are on the Cape return trip in 1489, he visited sev- mapping accomplished by Serviços Datum include South Africa and eral places on the East Coast of Af- Geográficos e Cadastrais (SGC) in Swaziland. rica, including the ancient port of Maputo. Control surveys for system- The Arc Datum has the same ori- Sofala. The flourishing Arab port atic mapping was initiated in 1931 gin as the Cape Datum, but its initial city on the Island of Moçambique by the SGC with the assistance of the fieldwork started in Uganda and was visited by Vasco de Gama in Junta, and all 61 sheets at 1:250,000 Kenya. Individual country adjust- 1498, following the rounding of the scale were completed by 1955. ments of this meridional chain (or Cape of Good Hope the previous year The Dutch ceded South Africa to arc) of quadrilaterals have resulted by Bartolomeo Dias. Soon a Portu- the British in 1814. The last two de- in the countries surrounding Mo- guese trading port, the region re- cades of the 19th century saw exten- çambique that are on the Arc Datum mained under the control of Portugal sive African development by the Eu- to include Tanzania which is on the through a complicated series of ar- ropean powers. The geodetic survey Arc Datum of 1960. This particular rangements until its independence of the 30th Meridian West of Green- adjustment is carried further north in June of 1945. That port city re- wich became a symbol of the progress into the Sudan. Malawi, Zambia, mained the capital until 1907 when of documenting the British Empire and Zimbabwe are on the Arc Datum the capital was moved to the south- borders in Africa. This was the of 1950. Note that Zimbabwe was ern port of Lourenço Marques (now same rationale as had already been formerly Southern Rhodesia, Zambia Maputo). Moçambique has 10 prov- established by Everest 100 years was formerly Northern Rhodesia, inces, some of which are the name- prior in India. The goal was for Malawi was formerly Nyasaland, sakes of local datums: Cabo Delgado, “continuous British pink on the map and Tanzania was formerly Tangan- Gaza, Inhambane, Manica, Maputo, from the Cape to Cairo.” The classi- yika, which had been formerly Ger- Nampula, Niassa, Sofala, Tete, and cal triangulation of the 30th Merid- man East Africa. After World War I, Zambézia. ian arc has its roots both in South the British assumed colonial admin- Before the peace accord of Octo- Africa that extended northward from istration of Tanganyika. The conse- ber 1992, Moçambique had been dev- the Cape and also southward from quence of this was that Moçambique astated by civil war and was one of British Central Africa. was now surrounded by British colo- the poorest countries on the globe. The Cape Datum has its initial nies, and its borders were subse- Prospects have subsequently im- origin point in Port Elizabeth, South quently entirely surveyed by the proved, and with its solid economic Africa, at station Buffelsfontein British Royal Engineers. F performance in 1996-97, Moçambique where: o = 33° 59’ 32.000” South, The Moçambique – Tanzania L has begun to exploit its sizable agri- o = 25° 30’ 44.622” East of Green- boundary initially delimited German cultural, hydropower, and transpor- wich. The ellipsoid of reference is and Portuguese spheres of influence tation resources. The restoration of the Clarke 1880, where: a = in East Africa. In accordance with 1 electrical transmission lines to South 6,378,249.145 meters, /f = 293.465. the terms of a German-Portuguese Africa and the completion of a new The azimuth to station Zurrberg is: declaration signed at Lisbon in 1886, a transmission line to Zimbabwe (per- o = 004° 15’ 26.311”, and the geoi- a boundary was established between mitting the giant Cahora Bassa hy- dal height (Ho - ho) at the origin is the Indian Ocean and Lake Nyasa. dropower plant to export large defined by implication to be zero. Subsequent treaties delimited the amounts of electricity) will greatly The deflection of the vertical at boundary in additional detail, and a improve foreign exchange receipts. Buffelsfontein was initially assumed joint expedition in 1907 changed the Land surveying and boundary sur- to be zero, and although non-zero CONTINUED ON PAGE 1002 CLIFFORD J. MUGNIER, C.P., C.M.S. PHOTOGRAMMETRIC ENGINEERING & REMOTE SENSING September 1999 1001 ○○○○○○○○○○○○○○○○○○○○ Grids & Datums COLUMN CONTINUED FROM PAGE 1001 14th parallel in accordance with the -293m ±11m. boundary slightly in the west and agreement of June 11, 1891 between The Moçambique – South Africa demarcated the land segment by pil- the United Kingdom and the King- boundary, which is about 488 km lars. Following WWI, the former dom of Portugal. The tripoint was (305 miles) in length, consists of German territory of Tanganyika was determined to be located at two discontinuous parts. The longer made a British mandate, and during f = 14° 00’ 00”S, l = 33° 14’ 32”E by part extends southward from the 1936 and 1937 an exchange of notes a joint boundary commission in 1904. confluence of the Limpopo River and between Portugal and the United The commission was led by Captain the Luvuvhurivier River for 408 km Kingdom determined the sovereignty (later Admiral) Carlos Viegas Gago (255 miles) along straight line seg- of the island in the Rio Rovuma Coutinho of the Portuguese Navy ments to the northern tripoint with (Ruvuma River) which forms more and by Major O’Shee of the United Swaziland and the M’Pundweni Bea- than 90 percent of the total bound- Kingdom. The boundary proceeds to con. The remainder of the boundary ary. With a total length of 752 km the southwest along the Zambesi from the southern tripoint with Swa- (470 miles), streams comprise 712 River drainage divide until it meets ziland to the Indian Ocean follows km (445 miles) of the distance of the River Aroangwa or Luangwa. the Maputo River (Great Usutu) which the Rio Rovuma and its tribu- Thence, the boundary follows along downstream for about 17 miles and taries account for all but about 1½ that river until it meets the Zambesi then continues by straight-line seg- km (1 mile). The Rule of the Thal- River to tripoint (with Zimbabwe) ments for another 53 km (33 miles). weg (thread of the stream) is speci- Beacon Number 1 where: The parameters published by DMA/ fied for this riparian boundary. The f = 15° 37’ 27”S, l = 30° 25’ 20.3”E. NIMA for the South Africa Cape Da- parameters published by DMA/NIMA Note that Zambia is where the tum to WGS84 datum shift are not as for the Tanzania Arc 1960 Datum to Livingstone Memorial is located. accurate as those are according to WGS84 are: DX = -175m ± 6m, DY = (“Dr. Livingstone, I presume …?”) Rens & Merry. Professor Charles -23 m ± 9m, DZ = -303 m ±10m. The parameters published by DMA/ Merry of the University of Cape The Moçambique – Malawi boun- NIMA for the Zambia Arc 1950 Da- Town found a substantial improve- dary is approximately 1560 km (975 tum to WGS84 are: DX = -147m ± 21m, ment with a 4-Parameter transforma- miles) in length and was originally de- DY = -74 m ±21m, DZ = -283 m ±27m. tion such that: DX = -190.0m ± 7.7m, marcated in 1899-1900 with errors. It Coutinho and O’Shee later spent DY = -137.9m ±3.7m, DZ = -257.4m traverses Lake Nyasa for about 328 km 1904-1905 correcting and re-marking ±4.7m, scale = +11.0x10-6, and the (205 miles) including lines around the border north of the “14°S” aggregate positional rms = ±2.9m. Likoma Island and Chisumulu Island, Malawi tripoint. Note that the values quoted are the which are part of Malawi. Southward The Moçambique – Zimbabwe most reliable for points within from Lake Nyasa to the Malosa River, boundary is about 1224 km (765 Moçambique. the boundary extends along straight- miles) in length. It is demarcated The Moçambique – Swaziland line segments for 312 km (195 miles) throughout this distance by pillars boundary has two tripoints with passing through both Lake Chiuta and or rivers. The tripoint (with Zam- South Africa. Northward from the Lake Chilwa. It follows consecutively bia) Beacon Number 1 addressed in Maputo River it extends along the the thalwegs of the Malosa, Ruo, and “The Northern and Southern Rhode- summit of the Lebombo Mountains Shire rivers downstream for 240 km sia Order in Council 1963” indicated for approximately 106 km (66 miles) (150 miles).