Zambezia (1988), XV (ii).AERIAL PHOTOGRAPHY IN ZIMBABWE, 1935-1986R. WHITLOWDepartment of Geography, University of ZimbabweONE OF THE earliest references to the potential of aerial photography in surveyingin this country is attributed to C. F. Webb who, in 1912, noted that by means ofaeroplanes 'huge tracts of country could be surveyed and rivers accuratelymapped in one tenth of the time and not half the expense involved at present'.1The first aerial survey in South Central Africa was in July 1925, when areconnaissance study was carried out on the Okavango Delta.2 During 1926 theBritish-based Aircraft Operating Company (AOC) undertook a contract forextensive aerial surveys in the then Northern Rhodesia3 and, to assist in its 'AfricaExpedition', it built a base at Bulawayo in 1928 but this only operated until1931.4 In that year it seems that test aerial surveys were done over Bulawayo andGwelo by a Captain R. E. Castigan, but no formalized mapping resulted fromthese experimental flights.It was not until 1934 thatthe Government of Southern Rhodesia decided to allocate annually a sum of £3 000 toallow for aerial survey of an equivalent number of square miles of terrain, and from 1935until the outbreak of war in 1939 a contract was put out to tender. While anothercompany capable of undertaking small air surveys existed in South Africa, it was almost aforegone conclusion that AOC. with its extensive experience in Northern Rhodesia andelsewhere, would be awarded the contract.5Thus in May-June 1935 the Lomagundi area was flown at a scale 1:20 000 andin 1936 two further blocks were flown in the Belingwe and Gwanda areas (seeFig. 1). Initially, the aerial films were processed in Johannesburg but in 1936 aphotographic laboratory was built at the Bulawayo field base of AOC. In thefollowing year a similar facility was established in Salisbury to assist in an aerialsurvey of the Umvukwes area. Subsequently, extensive aerial photography at avariety of scales was carried out throughout the country by AOC, othercommercial survey companies and the national air force.The aerial photography that has been carried out in Zimbabwe since 1935constitutes a valuable and unique record of the country's landscape. Whilst a1 J. McAdam, 'The Flying Mapmakers Š Some Notes on the Early Development of Air Surveyin Central and Southern Africa' (no details, MSS in Library of National Archives of Zimbabwe), 1.2 Ibid.3 R. A. Pullan. 'The history and use of aerial photography in Zambia', Zambia GeographicalJournal (1976), XXXI, 33-52.4 McAdam, 'The Flying Mapmakers'.5 Ibid., 29.137138AERIAL PHOTOGRAPHY IN ZIMBABWEFigure 1: AERIAL PHOTOGRAPHY PRE-19500 kilometres ISONŁ S SalisburyŁB ButawayoŁU UfntaliŁFV Fort VictoriaŁOw GwctoŁ0 Qu« OutŁ 3 Qatooma@primary motive in doing this photography was systematic topographical mappingby the Surveyor-General's Department and, at a later stage, land-use planning,sequential aerial photographs are of immense value to environmental and,perhaps to a lesser extent, social scientists concerned with changing patterns in thelandscape. For example, changes in settlement and cropland in ZimunyaCommunal Land have been evaluated on the basis of photography taken in 1949,1955, 1963 and 1981,6 whilst detailed analysis of the growth of gullies near StMichael's Mission in Ngezi Communal Land has been done using five differentsets of photography dating from 1956.7 It appears that the potential of aerial6 R. Whitlow and L. Zinyama, 'Up hill and down vale: Farming and settlement patterns inZimunya Communal Land', Zimbabwe Agricultural Journal (in press).7 R. Whitlow and C. Firth, 'Gnlly distribution and development on Karoo sediments in centralZimbabwe: A preliminary survey', Zambezia (in press).R. WHITLOW 139photographs in such research is not realized by many scientists. This is partlybecause training in the use of aerial photography is restricted to only a fewacademic disciplines, but more so it is because many scientists are simply unawareof the existence of this data source.Moreover, there are numerous logistic problems related to the use of certainaerial photography, especially that done prior to 1963. These include thedifficulties of identifying and procuring photographs for specified areas and, inthe general absence of proper indexes, locating the particular photographs thatare of value in a given study. In addition, in my experience over the last twelveyears of using older photography in this country, cases may arise where thenegatives of photographs cannot be located or have been damaged throughimproper handling, poor storage or extensive cracking and tearing of filmemulsions. It is hardly surprising, therefore, that limited use is made of olderaerial photography!The primary aim of this article is to document the coverage of aerialphotography in Zimbabwe over the period 1935 to 1986 for the benefit of thosewho, hitherto, have made little or no use of photographs as a tool in the study oflandscapes. The review is concerned mainly with 1:20 000 and 1:25 000 aerialphotography, but scales within the range 1:10 000 to 1:50 000 are mentioned inseveral places. The article is divided into three main sections. Firstly, an overviewof the earliest dates and frequency of aerial photography on a national level isgiven. Secondly, the extent of aerial photography prior to 1963 is described.Thirdly, the photography since 1963 is outlined. In the last two sections, whereverappropriate, the circumstances related to the execution and applications of aerialphotography are discussed. This is done to provide a complete picture on thenature of the aerial photography which may be of assistance in the contemporaryuse of this material in research.The article was compiled using information given in the annual reports of theDepartment of the Surveyor-General since 1925, the annual reports of theDepartment of Federal Surveys (1956-63), records in the present offices of theDepartment of the Surveyor-General and two master indexes at 1:1 000 000 ofpre-1963 photographs held by the Chief Topographer in that Department. Whilstevery effort has been made to check the existence of the aerial photography citedin this review, incomplete records on the nature and fate of the pre-1963photography make it impossible to verify that all this material is still accessibleand in a usable condition. Regrettably, given the limited uses currently made ofthe older photography, there is little to motivate the responsible authorities toimprove the status of this unique record of the Zimbabwean landscape. Asecondary aim of this article, therefore, is to stimulate greater use of this olderaerial photography in pure and applied research so that a stronger case can bemade for upgrading the status of this reference material.140AERIAL PHOTOGRAPHY IN ZIMBABWEFigure 2: AERIAL PHOTOGRAPHIC COVERAGE OF ZIMBABWE:EARLIEST DATES OF PHOTOGRAPHS0 kilomctras 150EARLIEST DATES AND FREQUENCY OF AERIAL PHOTOGRAPHYTwo interpretive maps showing the earliest dates (Fig. 2) and frequency ofdifferent dates (Fig. 3) of photography for a given area were compiled using thetwo 1:1 000 000 master indexes for the pre-1963 photos and records of the'blanket photography' since 1963.8 Given the fragmentary, patchworkcharacter of the older aerial photography a spatial framework of grid squares,equivalent to one quarter divisions of a standard 1:50 000 map sheet, was usedto extract and combine data on the aerial photographic coverage. During theexamination of annual reports of the Surveyor-General it became apparent thatthe master 1:1 000 000 indexes used in this compilation exercise were by nomeans complete. For example, many of the Reserves in the 1950s were8 Chief Topographer, personal communication.R. WHITLOW141Figure 3: NUMBERS OF DIFFERENT DATES OF PHOTOGRAPHYNUMBERS OF OFFEREKT DATES OFamphotographed as part of the land reform programme initiated in these areas at thattime; few of these are indicated on the master indexes. Similarly, the three earliestblocks of photography, notably Lomagundi (1935), Belingwe (1936) andGwanda (1936), do not appear on the indexes. Overall, however, the interpretivemaps do include the greater part of the photographic coverage carried out since1937. They are intended as guides on the progressive extension of large-scaleaerial photography as a basis for identifying the status of coverage for any givenpart of the country.By the beginning of the Second World War some 7,7 per cent of the countryhad been surveyed, mainly around Salisbury, Gwelo and Bulawayo (Fig. 2). Thepersonnel and equipment of AOC were incorporated into the air force during the1940-5 period, but normal photography resumed in 1946. By the end of the1940s nearly one quarter of the country had been flown, primarily in the142 AERIAL PHOTOGRAPHY IN ZIMBABWEnorth-central and eastern regions. Between 1950 and 1954 photography wasextended over a further 28,1 per cent of the country, including a large portion ofthe Zambezi Valley and blocks in the Eastern Highlands. A major phase of aerialphotography took place in 1955 during which well over one quarter of thecountry was flown, especially in the southern regions but also in the extremesouth-west and north-east (Fig. 2). The motivation behind this volume of aerialphotography in 1955 relates, in part, to the implementation of the Native LandHusbandry Act, some aspects of which are outlined later. During the remainderof the 1950s small blocks of photographs were done throughout the country suchthat by 1963, with one exception, virtually all areas had been covered by aerialsurveys. The exception is a small area in the extreme north of Zimbabwe whichwas not photographed until 1973 (Fig. 2).Figure 2, therefore, provides an indication of the earliest dates of photographyavailable for given areas. Details on the actual blocks of photography arediscussed later. It is also of value to know how many different dates ofphotography are available as a basis for monitoring changes in the landscape. Thishas been attempted in Figure 3 but, in view of the omissions of certain phases ofphotography mentioned earlier, the frequency of coverage is likely to be betterthan that portrayed in this map. For descriptive purposes five categories of aerialphotography have been defined as follows:under 5 dates: poor (9,5%)5 dates: fair (24,7%)6 dates: good (37,5%)7 dates: very good (23,0%)over 7 dates: excellent (5,3%)The percentage values relate to the proportion of the country within a designatedcategory. Prior to 1963 aerial photography was done on an ad hoc basis but in1963 a more systematic scheme of what became known as 'blanket photography'was initiated. The inset map in Figure 3 shows the frequency of coverage of thisphotography over the period 1963-86. Comparison of this inset with the mainmap shows that for most parts of Zimbabwe it is possible to have at least one andsometimes two or three dates of photography prior to 1963.Areas with poor coverage are located mainly in the Zambezi Valley borderingand downstream of Lake Kariba, in the extreme south in the Gwanda andChiredzi districts, and in the south-west, including parts of Hwange National Park(Fig. 3). About one quarter of the country has fair coverage (5 dates of photos),mainly in the north-east, south-east and south-west border regions. Over onethird of Zimbabwe was rated as having 6 different dates of photography, that isR. WHITLOW 143'good' coverage in Figure 3. Large parts of Masvingo, Matabeleland North andMatabeleland South provinces are within this category. Areas with very goodcoverage (7 dates) are of more limited extent and scattered widely, but do includelarge blocks in the central and eastern parts of Zimbabwe. The areas of excellentcoverage, with up to 10 different dates of photography, are centred on present-day Gweru and in the eastern districts, including parts of Save Valley (Fig. 3).Additional photography is available for restricted areas, particularly theurban centres, and details on some of this material is outlined later. Overall,therefore, Zimbabwe is fortunate in having extensive aerial photography,although coverage is better in some parts of the country than others. This isunusual in Africa where relatively few areas have sequential photography datingfrom the 1940s and 1950s, whilst some parts of the continent have never beensubject to aerial surveys. There are some exceptions to this, notably Zambia,where extensive photography has been carried out.9AERIAL PHOTOGRAPHY PRE-1963The pre-1963 aerial photography comprises a patchwork of sometimes irregular-shaped blocks at various scales. The locations of these blocks are indicated inFigures 1 and 4-6 compiled from the two 1:1 000 000 master indexes notedearlier. The pre-1963 period, mainly for cartographic convenience in depictingthe locations of blocks of photography, has been divided into four phases asfollows:pre-1950: 25 blocks of photos (Fig. 1)1950-1954: 19 blocks of photos (Fig. 4)1955-1959: 34 blocks of photos (Fig. 5)1960-1962: 25 blocks of photos (Fig. 6)Further details on this photography are summarized in Tables I, II, III, and IV.Requests for the consultation of this material should be routed through theSurveyor-General's Department but the film negatives and prints are kept by theNational Archives. In terms of the actual examination of this material it should benoted that under 40 per cent of the photography is recorded on indexes, mainly inthe form of linen base maps which are not easy to work with, and that in somecases, in the absence of contact prints, it is necessary to examine rolls of aerial film,which is also a difficult task for those unfamiliar with such material. Selectedaspects concerning the applications of aerial photography are given in thedescription which follows on the four phases of photography.' Pullan, 'The history and use of aerial photography in Zambia'.Table IPRE-1950 PHOTOGRAPHY ON INDEXLocationh Umvukwes (6)h Bulawayo (17)" Shabani (18)" Shabani (19)b Bulawayo (16)" Gwelo (14)Salisbury (7)b GaUKima/Hartley (9)b Galooma/Que Que (8)" Marandellas (10)' Ndanga Sabi (22)* Sabi (21)* Miami Block A (A)" Miami Block B (2)" Doma 13)' Sipolilo (4)Victor) (5iInvanga West (II)" Inva/uta (12)" Umiali South (13)" Nala Reserve (15)" Fon Victoria (20)Date193719381939193919401940194019461946/719471947/S19481948194819491949/50194919491949?194919491949 1Scale1:20 0001:20 0001:20 000: 20 000: 20 000: 20 000: 20 00020 00020 (KM)20 00020 00020 OIK):20 (KX):20 000: 20 000:20 000.20 000Area(sq. miles)_2 9753702 7916 300'.'2 8001 7854 7426006006003556003 3003 2004831 200A gency/CommentRoutine mapping?Surveyor-General - mappingAreas marked on master index but no full detailsavailable in annual reports of the Surveyor-GeneralPhotos probably at scale of 1:20 000Requested by Surveyor-General, flown by RRAF Š poorquality photosNo details available on purpose of this photographybut likely to be routine mappingSurveyor-General mappingSurveyor-General mappingSurveyor-General mappingSurveyor-General mappingRoutine mapping?Surveyor-General mappingSurveyor-Cieneral mappingSurveyor-General mappingDepartment of Native AgricultureSurveyor-General - mappingm3)Tooo>I^c2NCDm" Numbers in brackets relate to numbers of blocks in Photo Index, Figure I.'' o\d mik«cv avi.i\aMc upon request from the Chief Topographer, Ilepartment of the Surveyor-General.Table II1950-1954 PHOTOGRAPHY ON INDEXLocationDaleScaleArea (sq. miles)Agency/(. 'ommem° Glendale North (4)Inyanga (13): Gwelo (14): Melsetter (17)Lomagundi (2)1 Shamva (6)Sebungwe (8)b Salisbury (12)p Figtree (18)' Umvuma (15)c Gutu (16)1 Zaka (19)Zambezi Valley (1)' Sinoia West Block 1 (3)b Bindura (5)Zambezi (7)' Mafungabuzi (9)' Sinoia West Block 2 (10)c Norton (11)19501950195019501951195119511951195119521953195319541954195419541954195419541:20 0001:20 0001:20 0001:20 0001:20 0001:20 0001:20 0001:12 000 and1:20 0001:20 0001:20 0001:20 0001:20 0001:44 0001:20 0001:20 0001:12 000 and1:25 0001:20 0001:20 0001:20 0003601 2003 3601 5802 3802 50010 6206602 5002 4003 1901 4504 4353 225 (includesBlock 2)575see Zambezi Valley650see Block 11 150Surveyor-General mappingSurveyor-General mappingSurveyor-General mappingSurveyor-General - mappingSelect Committee on Assignment ofUnassigned Lands33X<-oKariba Hydroelectric ProjectKariba Hydroelectric Project" Numbers in brackets relate to numbers of blocks in Photo Index, Figure 4.b Index available in Air Photo Sales, Department of the Surveyor-General.c Old indexes available upon request from the Chief Topographer, Department of the Surveyor-General.Table III1955-1959 PHOTOGRAPHY ON INDEXLocation 'Date Scale195519551955195519551955195519551955195519561956195619561956195719571956/7:20 000:20 000:20 000:20 000:20 000:20 000:20 000:20 000:20 000:20 000:20 000:20 000:20 000:20 000:20 000:20 000:20 000:20 000Area (sq. miles)__---4306 988_13 058_3 8003 670-3 4802 2805 6407 300Agency/CommentMount Darwin (4)Mtoko (6)Gokwe (10)Gwaai (20)Lower (24)" Plumtree (24)b Shashi River (29)Belingwe (30)Limpopo (32)Shangani (as marked)c Mtepatepa (3)Nyagadsi (7)Nyamaropa (8)" Wankie (14)Charter (19)g Banket (5)c Gatooma (11)Sabi Catchment (12)Department of Native AffairsDepartment of Native AffairsDepartment of Native AffairsDepartment of Native AffairsDepartment of Native AffairsIntensive Conservation Area Committeem5Iooa>TJI2N03>00mWankie (15)Nata Reserve (as marked)Matetsi (13)Dett/Gwaai (1)Essexvale/Filabusi/Matopo South (25)Bikita (27)Inyati (21)Sipolilo North (1)Doma (2)Sebungwe (9)Wankie Game Reserve (16)Gwelo River (18)Gwelo (23)Fort Victoria (26)Chipinga (28)Ndanga (31)1957195719581958195819581958/91959195919591959195919591959195919591:20 0001:20 0001:20 0001:20 0001:20 0001:20 0001:20 0001:40 0001:40 0001:40 0001:40 0001:40 0001:40 0001:40 0001:40 0001:40 000194-3 0354 120--2 1501 89214 7004 0791 0622 2368688301 659Native Affairs and ResettlementDepartment of Conservation and ExtensionNative Affairs and ResettlementNational ParksDepartment of Conservation and ExtensionDepartment of Conservation and ExtensionDepartment of Conservation and ExtensionDepartment of Conservation and ExtensionDepartment of Conservation and Extension* Numbers in brackets relate to number of blocks in Photo Index, Figure 5.b Old indexes available upon request from the Chief Topographer, Department of the Surveyor-General.° Index available in Air Photo Sales, Department of the Surveyor-General.O148 AERIAL PHOTOGRAPHY IN ZIMBABWETable IV1960-1962 PHOTOGRAPHY ON INDEXLocation 'Mzarabani (2)Karoi (3)Wedza/Mutcma (9)Weya Reserve (10)Rowa (12)Musikavanhu (17)Gwanda (19)Shashi River (21)Umzingwane River (22)Maranda (23)Matibi (24)Limpopo River (25)Chewore (1)Bindura (4)Mount Darwin (5)Gwaai (6)Nkosikasi (7)Silobela (8)Tsonzo (11)Plumtree/Figtree (13)Ramaquabane (14)Mzinyatini (15)Jenya (16)Gwanda/Shashi (18)Shobi (20)Date1960196019601960196019601960196019601960196019601961196119611961196119611961196119611961196119611961%cale:20 000:40 000:20 000:20 000:20 000:29 000:20 000: 10 000: 10 000:29 000:40 000: 10 000:40 000:40 000:40 000:40 000:40 000:40 000:40 000:40 000:40 000:40 000:40 000:40 000:40 000a Numbers in brackets relate to numbers of blocks in Photo Index, Figure 6.b Index available in Air Photo Sales, Department of the Surveyor-General.Pre-1950 photographyThe Lomagundi aerial survey (Fig. 1) carried out in 1935 was primarily to assistin topographical mapping and, in the following year, surveys were done in theBelingwe and Gwanda areas (Fig. 1). The annual report of the Surveyor-Generalin 1937 comments that 'areas to be mapped are selected according to theireconomic importance, and due regard is paid to the requirements of theGeological Survey Department which must of necessity be supplied withtopographical maps on which to show geological information'.10 It is also notedthat aerial surveys assist in reducing time spent in the field on ground survey.10 'Abstract of the Report of the Surveyor-General', in Southern Rhodesia, Report of theSecretary, Department of Agriculture and Lands for the Year 7«7(C.S.R. 13, 1938), 40.R. WHITLOW 149Certainly, a major reason for the subsequent extension of aerial photography inthis country relates to the use of this material in the compilation and updating oftopographical maps.Prior to the outbreak of war in Europe in 1939 four further blocks ofphotography were flown Š Umvukwes in 1937, Bulawayo in 1938 and twoareas in the Shabani district in 1939 (Fig. 1; Table I). This aerial photographyproved to be of great interest and value in fields apart from topographicalmapping. For example, in 1938 public sales of photographs amounted to nearly900 prints, plans were made to establish a lending library of duplicate aerialphotos in the Surveyor-General's Department, and an inter-departmentalmeeting in government resolved to promote the use of aerial photographs."Other applications of aerial photographs before 1940 include the surveying offarm and road layouts in Purchase Areas by the Department of Lands and thedefinition of boundaries of the Matopo National Park by the Conservator ofForests.12 At the outbreak of war in 1939 the Rhodesian Air Training Group(RATG) was formed, incorporating the personnel and equipment of AOC asnoted earlier. Air bases were established at Salisbury, Gwelo and Bulawayo.Aerial surveys at 1:20 000 scale were carried out around these three centres (Fig. 1;Table I) to facilitate planning of the bases.The routine mapping programme of the Surveyor-General's Department wascurtailed because of the 1939-45 war, but in 1946 aerial surveys resumed in theGatooma-Hartley area where the RATG covered some 6 300 square miles with'indifferent photography'13 and only printed 1 350 out of the 5 000 photographsin the block. In 1946 the RATG was disbanded and Central African Airways(CAA) was formed. Most of the aerial surveys in the 1947-9 period were done byCAA on behalf of the Surveyor-General's Department. One factor promotingaerial surveys at this time was the increasing use of photomosaics and prints byEuropean farmers (Table V). Many of these were ex-servicemen who had 'gainedpractical experience of the value of photographs during the war'.14 To facilitatethe opening up of farms for ex-servicemen, aerial surveys were undertaken to thenorth-west of Salisbury including the Miami (1948), Doma (1949), Sipolilo(1949-50) and Victory (1949) blocks (Fig. 1; Table I).In 1948 some 13 000 square miles in the Zambezi Valley were surveyed by11 Southern Rhodesia, Report of the Surveyor-General for the Year 1938 (C.S.R. 10, 1939).12 'Report of the Surveyor-General for the Year 1939', and 'Report of the Surveyor-General forthe Year 1940', in Southern Rhodesia, Reports of the Surveyor-General for the Years 1939, 1940,1941, 1942, 1943, 1944 and 1945 (C.S.R. 2, 1947).13 Southern Rhodesia, Report of the Surveyor-General for the Year 1946 (C.S.R. 20, 1947).14 'Report of the Surveyor-General for the Year 1945', in Southern Rhodesia, Reports of theSurveyor-General for the Years 1939. 1940, 1941, 1942, 1943. 1944 and 1945, 41.150 AERIAL PHOTOGRAPHY IN ZIMBABWEthe Directorate of Colonial Surveys for a proposed dam site in the Kariba Gorgearea, but the Surveyor-General's report in that year does not indicate whether thisinvolved the use of aerial photography. Apart from topographical mapping, aerialphotography was employed for a variety of purposes during the late 1940s. Theseincluded surveys by a Sabi Development Commission, the Roads Department,the Irrigation Department (for dam sites) and the preparation of photomosaics ofWedza, Matobo, Shiota and Nata Reserves for the Department of Agriculture toassist in the demarcation of arable and grazing areas in accordance with the'centralization' process introduced by Alvord, the founder director of thatdepartment. Demand for farm mosaics continued to rise during this period andinto the early 1950s (Table V) as commercial farming operations extended andconservation works were developed.15 By 1949, some 24,8 per cent of the countryhad been covered by aerial surveys and in the period 1946-9 over 26 565 squaremiles of land were photographed at a scale of 1:20 000, mainly in the central andeastern districts (Fig. 1; Table I).Table VPURCHASE OF AERIAL PHOTOGRAPHY BY FARMERSAND INTENSIVE CONSERVATION AREA COMMITTEES, 1945-1955Year Mosaics Prints Year Mosaics Prints19451946194719481949195090253794260220195119521953195419551945-55978593512101 26266071584870214304 355Source: Compiled from annual reports of the Surveyor-General.1950-54 photographyDuring this period aerial surveys, mainly at 1:20 000 scale, were carried out inthe central and north-western districts (Fig. 4) and covered an estimated area of42 235 square miles (Table II). There were considerable overlaps between someof the aerial surveys and, in general, the early 1950s blocks were located adjacentto areas that had been photographed previously (compare Figs. 1 and 4), therebyextending photo coverage over a further 28,1 per cent of the country by the end of1954. This photography was used mainly to develop the 1:50 000 topographical15 R. Whitlow, "Soil conservation history in Zimbabwe: Part 1: Large-scale commercial farminoareas', Zimbabwe Agricultural Journal (in press). ^R. WHITLOW151Figure 4: AERIAL PHOTOGRAPHY 1950-19540 kilom«tr«s 150©®©©®r©NŁS SalisburyŁB BuMwayoŁU UmtaliŁFV Fort VictoriaŁ Gw GwcioŁO Out QuaŁG Gatooma®©mapping series which had been initiated in 1937.16 In turn, these 1:50 000 mapswere of use in development activities of various kinds. However, manygovernment departments (particularly Irrigation and Forestry) and fanners(Table V) preferred to use prints or photomosaics in their planning activities.Special photography was undertaken for different purposes during the 1950-4period. For example, a Select Committee on Assignment of Land commissionedan aerial survey of 13 000 square miles in the Sebungwe and Lomagundi districtsin 1951 (Fig. 4; Table II). In the following year the Surveyor-General's reportmentions a survey of 2 195 square miles in an area between the western boundaryof Gwaai Reserve and the Panda-ma-Tenka (1952 spelling) road for use by the16 R. S. Cole, 'Surveys and Mapping in Zimbabwe' (Harare, Department of the Surveyor-General, unpublished report, 1984).AERIAL PHOTOGRAPHY IN ZIMBABWEdepartment.17 However, specific details on the location of this photographyiHgiven and it did not appear on the 1:1 000 000 master index from whichwas compiled. Similarly, portions of Sabi, Selukwe, Que Que andReserves were subject to aerial surveys in this period (see Table VI) for'Wtment of Native Affairs during the early stages of the implementation of*'iie Land Husbandry Act of 1951. These areas are also omitted from the*'i«dex, and so do not appear in Figure 4. In 1954 an area of 4 435 square''lithe Zambezi Valley was flown at a scale of 1:44 000 to assist in theof the Kariba Hydroelectric Project (Fig. 4). The Department ofition and Extension (Conex), founded in 1950 to service the needs oflii farmers,18 provided further stimulus for aerial surveys through the*n of photographs in agricultural planning.iphotographyŁŁa period of widespread aerial surveys (Fig. 5), with nearly 80 per cent ofiiry being covered by 34 blocks of photography varying in size from 194'liiles in the Wankie area in 1957 to 13 058 square miles in the Limpopo!. The blocks are, in some cases, highly irregular in shape and there isIble overlap between adjacent blocks. This wasteful duplication of|phy was one of the reasons that led to the introduction of a systematicr1ane of aerial surveying in 1963. In July 1956 the Department of Federal^iWas created under the directorship of Brigadier M. O. Collins. With anmapping programme, Collins initiated the preparation of 1:50 000Łhiical maps using 1:40 000 aerial photography in 1958.19 This proved to*Tmore economical in terms of manpower inputs and aerial survey costs,20ii«esult, the aerial photography between 1959 and 1961 was done mainlyNtDO scale (Tables III and IV).::iompilation of topographical maps remained a major use of aerialtemhy during the late 1950s. However, considerable use was made offcm»hy by government departments and the public (notably farmers and"(ŁConservation Area Committees). For example, sales of contact printsCa»-enlargements increased from about 23 000 photos in 1955 to over»i«i«ern Rhodesia, Report of the Surveyor-General for the Year Ended 31st December 1952:iiniit953).ŁKennan, "The development of the extension service among the European farmers inaetoxfesia Agricultural Journal (1971), LXVIII, 116-20.saaition of Rhodesia and Nyasaland, Report of the Director, Federal Department of"~-;imcal and Topographical Surveys for the Year Ended 31st December 1959(C. Fed. 140).aauwcobs, 'The development of the survey of the Rhodesian 1:50,000 map series', Rhodesiawas (1969), III, 140-3.R. WHITLOW153Table VI'NATIVE RESERVES' PHOTOGRAPHED DURINGIMPLEMENTATION OF NATIVE LAND HUSBANDRY ACTDURING 1950s AND EARLY 1960sDate1954195519571958195919601961AreaChinyikaSelukweQue QueFungweChiwesheWeyaMasunzweMangeniGutuGokwe*Mtoko*MarankeLower Gwelo*ZimunyaBushuInyatiUmzingwaneNtabazindunaBikitaMutasa/JenyaMondoroNata*ChidukuSebungwe area withinGokwe (?)Sabi NorthSangwe/Ndanga EastBushuChiwamoraSosweMangeniWeya*NtabazindunaNumber ofphotos3513975126(1:25 000)1817444442681095245017636371513421295937953126123117215843225464477236(1:10 000)Total numberof photos3753 467531492330435236* Areas marked on indexes in Figures 5 and 6.Photography at 1:20 000 unless otherwise stated.Source: Compiled from index held by Chief Topographer in the Department of theSurveyor-General.154AERIAL PHOTOGRAPHY IN ZIMBABWEFigure 5: AERIAL PHOTOGRAPHY 1955-19590 kilomctr** 150ŁsŁ BŁ UŁ FVSalisburyBokwoyoUmtotiRwt VlctorioŁ OwGwcIOŁ 0Ł GOuc OutOatoomo40 000 by 1959.21 Two major users of this photography were Conex and theDepartment of Native Affairs. Conex, in 1956, introduced a system of farmplanning. This relied heavily on the use of aerial photography in the assessment ofland capability and the design of field layouts, access roads and conservationworks.22 Conex commissioned at least six major blocks of 1:40 000 photographycovering over 8 500 square miles during 1959 (Table III). The present-daysuccessor to this department, Agritex, remains a major user of aerial photographytoday, building on many years of experience in the field of aerial photointerpretation.2321 Southern Rhodesia,/te/wrt of the Surveyor-General for the Year Ended 31st December 1955(C.S.R. 16, 1956); Federation of Rhodesia and Nyasaland, Report of the Director FederalDepartment of Trigonometrical and Topographical Surveys for the Year Ended 31st December 1959a See, for example, P. Ivy, A Guide to Soil Coding and Land Capability for Land Use Planners(Salisbury, Department of Agricultural, Technical and Extension Services, 1981).23 See, for example, A. J. Carver, Air Photography for Land Use Planners (SalisburyDepartment of Conservation and Extension, 1981). J>R. WHITLOW 155In an attempt to improve agricultural output and conservation measures in theReserves, legislation was passed in 1951 in the form of the Native Land HusbandryAct. The implementation of this legislation involved detailed mapping of existingland use and settlement within the Reserves and the subsequent development ofalternative patterns of land use and holdings. Aerial photography was a vital part ofthis work. The Secretary for Native Affairs reports that it 'was further decided thatonly photographs after 1950 would be sufficiently up to date to be of use, and itwas found that photographs covering some 17 500 square miles of NativeReserves and Native Areas were immediately available. This left a total area of24 350 square miles still to be photographed'.24 In 1959 the Under-Secretary ofNative Agriculture commented that 'one of the outstanding features of the processof implementing the Land Husbandry Act has been the extensive and intensive useof aerial photographs and mosaics which has saved many laborious hours ofmap-making, surveying and field observations'.25 Photography commissioned forthis agrarian reform programme in 1955 includes Mount Darwin, Mtoko, Gokwe,Gwaai and Lower Gwelo (Table III). Between 1954 and 1961 at least thirty-twoReserves were surveyed in whole or part (Table VI), but most of this photographydoes not appear on the 1:1 000 000 master index held by the Surveyor-General,nor is it certain that this material still exists.1960-62 photographyApproximately 30 per cent of the country was surveyed during this period atscales varying from 1:10 000 to 1:40 000 (Table IV; Fig. 6). A tender for aerialphotography of 10 000 square miles was cancelled in 1962 owing to the highprices quoted by the air survey companies.26 Consequently, details on the 1960and 1961 photography only are provided here.The blocks of photography in 1960-1 occur mainly in the northern, easternand south-western border regions, but do include some areas in the central partsof the country (Fig. 6). Some 24 700 square miles were covered in thesesurveys.27 As in previous years most of the photography was intended fortopographical mapping. However, 1:20 000 photography in 1960 (Table IV)24 Southern Rhodesia, Report of the Secretary for Native Affairs, Chief Native Commissionerand Director of Native Development for the Year 1955 (Sess. Pap. C.S.R. 12, 1956), 15.25 Southern Rhodesia, Report of the Secretary for Native Affairs and Chief Native Commissionerfor the Year 1959 (Sess. Pap. C.S.R. 18, 1960), 22.26 Southern Rhodesia, Report of the Surveyor-General for the Year Ended 31st December 1962(C.S.R. 12, 1963).27 Federation of Rhodesia and Nyasaland, Report of the Director, Federal Department ofTrigonometrical and Topographical Surveys for the YearEnded31st December I960 (C. Fed. 170);Federation of Rhodesia and Nyasaland, Report of the Director, Federal Department of Trigono-metrical and Topographical Surveys for the Year Ended 31st December 1961 (C. Fed. 206).156AERIAL PHOTOGRAPHY IN ZIMBABWEFigure 6: AERIAL PHOTOGRAPHY 1960-1962®N»S SalisburyButawayoUmtoli»FV Fort Vic tonQw«ioŁO Quc OutŁ G Oatoomacovers areas of Reserves for the Department of Native Affairs. In addition,1:10 000 coverage of the Shashi, Umzingwane and Limpopo Rivers (Blocks21,22 and 25 in Fig. 6) appears to have been commissioned for definition ofboundaries along selected stretches of these rivers.With reference to the pre-1963 photography as a whole, the Surveyor-General's records indicate that there is additional aerial photography excludedfiom the indexes presented here. This includes large-scale photography, generallyat 1:10 000 or 1:12 500, of the major urban centres and some of the smaller onesdating from 1948 (Table VII). Salisbury, for example, was flown in whole or partat least six times since 1949 whilst Bulawayo has been covered at least five times.This photography was carried out for large-scale mapping in the 1:5 000 mapseries, for example, as well as to assist in planning of urban development bymunicipal authorities. In addition, there are records of 32 blocks of more generalR. WHITLOW157Table VIIPHOTOGRAPHY OF URBAN CENTRES PRIOR TO 1963DateCentreScale194819491950195119521953195419551959196019611962BinduraGlendaleQue QueBulawayoSalisburyBulawayoSalisburySalisburyQue QueGweloPenhalongaUmtaliMarandellas?InyangaGweloSinoiaBulawayoSalisburySalisburySelukweGweloRusapeShabaniPenhalongaUmtaliGwelo?Salisbury?Gatooma?KaribaBeitbridgeMashabaGwandaPlumtreeDettVictoria FallsGweloBulawayoKariba?Chipinga?UmtaliBulawayo?1:10 0001:10 0001:10 000 and 1:24 0001:10 0001:10 0001:10 0001:12 0001:12 0001:12 0001:12 0001:12 0001:12 000:25 0001:12 000 and 1:25 0001:12 000 and 1:24 0001:14 000 and 1:28 000: 12 500 and 1:10 0001:10 0001:25 000 and 1:10 0001:10 0001:10 0001:15 000 and 1:25 000:15 000 and 1:25 000: 15 000 and 1:25 000:15 000 and 1:25 0001:25 0001:25 000:25 000: 10 000: 10 000: 10 000:10000:10000: 10 000: 10 000: 10 000:15 000:25 000:25O0O:25 000:25 000? = Photography may cover urban area or general area near urban centre.Source: Compiled from index held by Chief Topographer in the Department of the Surveyor-General.158AERIAL PHOTOGRAPHY IN ZIMBABWEphotography at scales varying from 1:10 000 to 1:50 000 scattered throughoutthe country (Table VIII). Some of this coverage was commissioned to assist inagricultural development, notably irrigation schemes in cases such as the SabiRiver East Bank Pilot Scheme (1950) and Nyamaropa (1952), but littleinformation is available on the precise locations and purpose of this photography.Table VIIIGENERAL PHOTOGRAPHY PRIOR TO 1963Date194819491950195119521953*1958195919601961Area ScaleMelsetter '.Fort VictoriaSebakwe RiverSabi RiverSabi River East Bank Pilot SchemeWankie 1NortonHartleySabi Native DivisionTriangleGatoomaLundiStaplefordCashelTarka Martin and Border FarmsGwaaiHunyaniOdziGatoomaNyamaropaBuhera*Gwelo*SalisburyArcturusMatoposTuliUmvumaKaroiKaribaBingaLundi:20 000:20 000: 10 000:12 000:12 000:20 000:20 000:42 000:32 000:32 000:32 000:32 000:24 000:24 000:32 0OO:20 0001:40 0001:12 000:32 0001:24 0001:20 0001:20 0001:50 0001:40 0001:20 0001:12 0001:40 0001:40 0001:25 0001:25 0001:40 000* Possibly part of photography initiated to cover the Reserves in these areas.Source: Compiled from index held by Chief Topographer, Department of the Surveyor-General.R. WHITLOW 159AERIAL PHOTOGRAPHY SINCE 1963The year 1963 was a turning point as far as aerial surveys were concerned since itsaw the initiation of what is known locally as 'blanket photography'. In the 1963report of the Surveyor-General it is noted that previouslyaerial photography, mainly for interpretation purposes, has been undertaken for a numberof [government] departments, and this has proved to be expensive owing to the scatterednature of the areas to be photographed and the irregular shape of the areas. This year it wasdecided to embark on a plan of covering the whole of Southern Rhodesia with 1:25 000scale of photography within five years.28The rationale behind this was to avoid duplication of photography, facilitatemore economical flying in large rectangular blocks and to enable userdepartments to make plans around the pre-arranged 'blanket programme'. The1:25 000 scale chosen for this photography appears to have been a compromisebetween basic economics and user requirements. For example, the 1:40 000photography done by the Department of Federal Surveys was regarded as toosmall a scale by most users, yet the costs of blanket coverage at 1:20 000 wouldhave been excessive.In practice, six series of blanket photography have been carried out in thiscountry since 1963, the general details being as follows:First series: 1963-1968Second series: 1969-1970Third series: 1971-1975Fourth series: 1976-1980Fifth series: 1981-1983Sixth series: 1984-1986The second series was planned originally to cover the entire country between1969 and 1973, but difficulties arose during 1970 that resulted in the terminationof this programme. During the fourth series a decision was taken, afterconsultation with major users of photography, to reduce the extent of coveragesuch that the country would be completely covered in a ten-year cycle rather thana five-year cycle.29 Prior to the start of the fifth series the contract period of blanketphotography was reduced from five to three years at the request of the surveycompanies faced with unpredictable and escalating operating costs.The dates and locations of the blocks of blanket photography are shown in28 'Report of the Surveyor-General for the Year Ended 31st December 1963", in SouthernWaadem,AnnualReponoftheSecreuuyforLandsandNamralResourcesl963(CS.9.. 12,1964), 2.29 Chief Topographer, personal communication.160AERIAL PHOTOGRAPHY IN ZIMBABWEFigure 7: BLANKET AERIAL PHOTOGRAPHY 1963-19690 kilometres 1501965 18-21963 20 - 11963 20 - 340:19146i'Is40-341-1SfJ"340-240-441-241-4i1965 17 - 41965 18 - 51964 19 - 21963 20 - 21963 20-4Figures 7 to 10 covering the periods 1963-9,1970-4,1975-9 and 1980-6. Thisphotography is somewhat easier to use than that done prior to 1963 for severalreasons. Firstly, there are proper flight diagrams plotted on to 1:250 000 overlaysattached to the appropriate topographical map of the same scale; this makes itpossible to locate photography for areas of interest relatively easily. Secondly,with the exception of some of the first series, the photographic prints are availablefor examination in the Air Photo Sales section in the Surveyor-General'sDepartment in Harare; this obviates the time-consuming, bureaucratic proced-ures involved in the examination of prints of the pre-1963 photography housed inthe National Archives. Thirdly, with the exception of the 1963-5 photography,the film negatives are kept by the Surveyor-General's Department, thus reducingthe time required to organize prints for users; in contrast, there are sometimes longdelays involved in getting prints for the pre-1963 photography, assuming that onecan locate the film negatives and that these are in a usable state.R. WHITLOW161Figure 8: BLANKET AERIAL PHOTOGRAPHY 1970-1974The blanket aerial photography has been used extensively in the compilationand updating of topographical maps, especially the 1:50 000 series. In addition, ithas been employed in the fields of agriculture, forestry, wildlife management,rural and urban planning, as well as in a variety of road and civil engineeringprojects.30 The Surveyor-General in 1968, for example, noted that the blanketphotography had been of assistance in many fields of development and was 'theenvy of many other countries'.31 Some indication of the economic significance ofthe first series of blanket photography can be gauged from sales of aerialphotography during the 1963-8 period (Table IX). Over 275 000 contact printswere sold during this period, sufficient to cover the country five times over! In30 See, for example, A. Holden, 'Development in the use of aerial photography in the Ministry ofRoads and Road Traffic in Rhodesia', The Rhodesian Engineer (1971), IX, 943-8; J. C. M. Molyn,'Airphoto interpretation in civil engineering', Rhodesia Science News (1973), VII, 66-7.31 'Report of the Surveyor-General for the Year Ended 31st December 1968', in Rhodesia,Report of the Secretary for Lands for 1968 (C.S.R. 20, 1969), Appendix B, 2.162AERIAL PHOTOGRAPHY IN ZIMBABWEFigure 9: BLANKET AERIAL PHOTOGRAPHY 1975-19790 kilometre* M\B 1977IV/"Š1A1978197619797i1975 /addition, a substantial number of enlarged photographs and diapositives weresupplied. Peak sales of contact prints were reached in 1969 when 64 429photographs were supplied to government departments and the public. Since thensales have declined and, in recent years, between 30 000 to 35 000 contact printsand enlargements are done annually.All the blanket photography is in panchromatic form, more commonlyknown as 'black and white' photos. The question arises, therefore, as to thepossibilities of using colour rather than panchromatic film in the blanketprogramme. In fact, towards the end of the first blanket series and followingconsultation with Conex, Geological Survey and the Roads Department, theSurveyor-General's Department commissioned two blocks of colour photo-graphy to be flown in 1969. One area, the Eldorado block, was 'covered by fourrunsofphotographsatascaleof 1:25 000, [was] approximately 160 km in lengthand [extended] from the Urungwe Reserve in the west to a line north of GlendaleR. WHITLOWFigure 10: BLANKET AERIAL PHOTOGRAPHY 1980-1986163in the east'.32 The other area, the Diti block, was located to the north of Beitbridgeand was flown at a scale of 1:12 500. Both areas were approximately 3 550square kilometres in extent. The utility of this colour photography was debated ina symposium in 1970, and the opinions of users varied from a highly favourableresponse through to generally unenthusiastic, depending on the specific featuresof interest and how easily such features could be identified on colour as opposedto panchromatic prints.33 In practice, the major argument against colourphotography is cost! With current prices of materials, assuming these can beimported, colour photography is in the order of fifteen times the price of the moreconventional panchromatic photography.One further project that is worth noting in relation to the blanket series is the32 J. G. Stagman and I. M. Kirkpatrick, 'The use of aerial colour photography in regionalgeological mapping', Rhodesia Science News (1971), V, 247-8.33 Rhodesia Science News (1971), V, viii.164 AERIAL PHOTOGRAPHY IN ZIMBABWETable IXSALES OF AERIAL PHOTOGRAPHY 1963-1968Year Contact prints Enlargements Diapositives*19631964196519661967196833 07569 18551 39727 83034 69758 9651 0858031 9861 9041 6153 239717147608703766570Totals 275 149 10 632 3 511* Used for detailed surveying.Sources: Annual reports of the Surveyor-General.Canadian-assisted Zimbabwe Aerial Survey Project. The aim of this project is toproduce 1:25 000 ortho-photo maps of the country, these being in the form ofrectified photomosaics with a 10 m contour interval and basic cadastral details.Photography for the production of these ortho-photo maps was carried out in1982 with areas to the east of the Bulawayo-Harare axis being flown at1:65 000 scale and areas to the west of the axis being flown at 1:80 000. Longdelays have been experienced in making this photography readily available tousers in Zimbabwe and, to date, only a limited portion of the country in thenorthern and eastern districts has been completed in the ortho-photo series. Since1982, the 1:25 000 blanket photography has covered over 65 per cent of thecountry and, being more recent and readily available, has been of greater interestand value to users than the photography carried out in the Zimbabwe AerialSurvey Project.CONCLUSIONZimbabwe is fortunate in having extensive large-scale aerial photographydating back to the mid-1930s in some parts of the country. It is impossible toquantify the contribution of this photography to the economic development ofthe country, partly because of the wide range of applications of aerialphotography. The high standards and good coverage of topographical mapsproduced by the Surveyor-General's Department are one major benefit of aerialphotography. Similarly, agricultural development and conservation extensionhave been assisted considerably, in both the commercial and peasant farmingsectors, by the application of aerial photography. Other important uses ofphotography include road route planning and location of road-building materials,R. WHITLOW 165identification and development of dam sites and in urban planning. There are,therefore, strong arguments to maintain the blanket photography programme asan important component in economic planning and development in Zimbabwe.As noted in the introduction, the primary aim of this review of aerial photocoverage in Zimbabwe was to inform present and potential users about the natureof aerial photography. It is hoped that the information contained in this reviewwill stimulate greater use of aerial photography in pure and applied research, aswell as being of interest to those who already make use of aerial surveys in theirvarious professions.AcknowledgementsI would like to thank the following for their assistance in preparing this review:staff in the Surveyor-General's Department, especially Mr Fussel, Mr Cook andMr Nyabindi; technical staff in the Department of Geography, especially MrWheeler, Mr Maruziva and Mr Burton for preparation of the figures.I would appreciate comments on the usefulness of this review, especially fromthose who have made little use of aerial photography in the past owing to lack ofinformation on the nature and availability of this material.