A SIMPLE FORM OF CATENARY APPARATUS FOR MINOR CONTROL TRAVERSES IN ROUGH COUNTRY     

《测量评论》2013,45(70):344-351

Abstract

In 1945 I was sent down to Yambio in the southern Sudan to carry out a detailed large scale survey of an area scheduled for the headquarters of an extensive development programme known as the Zande Scheme. The area is not far from the Nile-Congo watershed and the ground is very uneven, covered by ant-hills, and clothed in tall grass and thick bush which includes trees nearly a hundred feet high. Surveys of this kind had not been executed, in the southern Sudan previously except in towns. Nearly all the available experience of cadastral survey work in the Sudan,was therefore based on the very open and flat conditions of the north, where chaining along the ground is the natural and best way of measuring distances within the accuracy required. Except for the geodetic base measurement gear there was therefore nothing in the way of catenary apparatus available, though it was obvious that this would probably be the best equipment for the conditions to be expected in the south. However I had been engaged for most of my survey career up to this time on surveys of a more exploratory nature on much smaller scales such as 1/250,000, and I was unwilling to start experimenting until I had gained some experience in large scale work.  相似文献   

A STELLAR PROGRAMME FOR TIME OBSERVATIONS     

《测量评论》2013,45(20):343-346

Abstract

A GOOD deal of astronomical work was called for during the operations of the British Somaliland–Ethiopia Boundary Commission. The method employed by the British Section for the determination of local time being that of star altitudes in the prime vertical, after the first few stations had been occupied the suggestion was made that the observer could be saved considerable strain by the preparation of a programme for time observations, much on the same lines as for latitudes. The proposal was tried, proved eminently successful, and became a standard part of the British Section's procedure. An example of such a programme is given below. I t is a little laborious, but simple.  相似文献   

RECOLLECTIONS OF A SURVEY OFFICER IN INDIA     

《测量评论》2013,45(55):2-10

Abstract

Crabs! Thousands of bright red crabs on a white foreshore; clinging black mud in tidal creeks with an overhanging tangle of tropical forest. These dominate one's memories of the Irrawaddy Delta in 1924. The Forest Department of Burma is the custodian of some 1,000 square miles of valuable forest reserves in the delta of this great river. The survey and production of “Forest” maps of this area was long overdue, postponed by reason of the immense expense and difficulty of a ground survey. Air survey, developed during the First World War, was ideally suited to this type of country but was still in its infancy, so that prolonged negotiations were necessary to persuade the Government of Burma to risk £25,000 on what appeared to them a doubtful proposition, as this was one of the first of the peace-time air surveys to be undertaken. Eventually, in July 1923 the contract was signed. Ronald Kemp, the first Chief Inspector of Civil Aircraft in India, gave up that post and formed an air survey company to carry out the photography as the first of his many survey contracts in India and Burma; I was in charge of the ground work and subsequent mapping.  相似文献   

USE OF SURVEY SECTIONS IN OPERATIONS     

《测量评论》2013,45(50):162-164

Abstract

When I took over the command of a West Africa Brigade Group in 1939, I found that one of the units in the brigade was a survey section, and, in the course of training this brigade, I was rather concerned as to how this survey unit would or should be used. It was a small unit consisting of three officers (Europeans) and approximately 50 African other ranks, all belonging to the local Government Survey Department. I knew that it could map any particular piece of country, or could lay outbuilding sites, ranges, etc., but, beyond this, and normal military training, I am afraid that I could think of no other ways of using it. I knew also that, when the brigade was trained, we were to move to another part of Africa and that operations were likely to take place over country which was mostly unmapped. This, then, would be the opportunity for the survey section. At the same time, the size of the country we were likely to operate in was so enormous that my little survey unit would be swamped and quite unable to produce operational maps in time for me to use them. In due course we arrived on the scene of operations. My survey section was taken away from me and merged with other sections in a survey company. This company commenced to map parts of the country in which it was considered likely fighting might take place. This was exactly what I had anticipated, although I still considered that even this bigger unit was much too small for the huge job it had to do.  相似文献   

CADASTRAL AIR SURVEY     

《测量评论》2013,45(28):334-338

Abstract

I Hope Dr Wolff's interesting article will stimulate to action some of those who have not given sufficient attention to air survey as a method of mapping or planning those areas which lend themselves to that method. At the same time, whether so many of us are as conservative as the author appears to think is a matter for doubt, and moreover we do not all look upon air survey as an “innovation”. As Dr Wolff writes from Palestine he might be interested to know that as the second British Officer to take up field survey work in the War in 1915—Major (now Brigadier) Winterbotham being the first—I was one of the earliest in my profession to study, and to assist in the development of, air survey. In 1915 our unit in the 3rd Army was the first to make use of air photographs for the production of a regular series of trench maps. There are consequently few surveyors more interested in the method. I have watched the progress of the science and the work of the Air Survey Committee with continued interest and have used air methods whenever these have been possible or suitable. On my last visit to Paris I tried my hand at plotting with a new instrument at the Service Géographique and was much impressed by the work that was being done.  相似文献   

THE SIERRA LEONE TOPOGRAPHICAL SURVEY     

《测量评论》2013,45(9):163-166

Abstract

The survey of Sierra Leone was fortunate enough to be completed just in time before the economic blizzard (if I may be permitted a well-worn journalistic cliché) descended on West Africa in common with the rest of the world and largely curtailed such activities. I do not propose to deal here with its technical side to any great extent. An excellent account of bush surveying is to be found in the “Handbook of the Southern Nigerian Survey”, which account always filled me with the greatest awe and respect for the men working there, their output being vastly greater than anything we were able to achieve in Sierra Leone. Truly “there were giants … in those days”.  相似文献   

Controlling CO2 emissions for each area in a region: the case of Japan     

Tamaki  Tetsuya  Nozawa  Wataru  Managi  Shunsuke 《Carbon balance and management》2019,14(1):1-10

Background

Unlike in the developed countries, Ethiopia does not have carbon inventories and databank to monitor and enhance carbon sequestration potential of different forests. Only small efforts have been made so far to assess the biomass and soil carbon sequestration at micro-level. This study was carried out to obtain sufficient information about the carbon stock potential of Gerba-Dima forest in south-western Ethiopia. A total of 90 sample plots were laid by employing stratified random sampling. Nested plots were used to collect data of the four carbon pools. For trees with a diameter range of 5 cm < diameter < 20 cm, the carbon stock was assessed from a plot size of 49 m² (7 m * 7 m). For trees with a diameter range of 20 cm < diameter < 50 cm, the carbon stock was assessed from a plot size of 625 m² (25 m * 25 m). For trees > 50 cm diameter, an additional larger sample of 35 * 35 m² was used. Litter, herb and soil data were collected from 1 m² subplot established at the center of each nested plot. To compute the above ground biomass carbon stock of trees and shrubs with DBH > 5 cm, their DBH and height were measured. The biomass carbon assessment of woody species having DBH < 5 cm, litter and herb were conducted by measuring their fresh weight in the field and dry weight in the laboratory.

Results

The mean total carbon stock density of Gerba-Dima forest was found to be 508.9 tons carbon ha⁻¹, out of which 243.8, 45.97, 0.03 and 219.1 tons carbon ha⁻¹ were stored in the above ground biomass, below ground biomass, litter biomass and soil organic carbon, respectively.

Conclusions

The existence of high carbon stock in the study forest shows the potential of the area for climate change mitigation. Thus, all stakeholders at the local and national level should work together to implement effective conservation measures and get benefit from the biocarbon fund.

  相似文献   

A FIFTY-YEARS RETROSPECT     

《测量评论》2013,45(8):66-73

Abstract

Early in 1902 I accepted with some misgivings the post of Instructor in Surveying at the School of Military Engineering, Chatham, in succession to Major A. C. MacDonnell. I had hardly joined at Chatham when Sir Thomas Holdich offered me the post of second in command of the Chile-Argentina Boundary Commission. However, my new chief, the Commandant, would not let me go, so I settled down to a few years of very pleasant work at Chatham. The first thing to do was to introduce a correct method of computing the geographical coordinates of the trigonometrical stations of a topographical survey, a matter over which my predecessor had suffered a rebuff. Now, however, the War Office personnel had changed; no opposition arose, and the thing was done.  相似文献   

DIRECT USE OF AIR PHOTOGRAPHS FOR CADASTRAL PURPOSES IN ZANZIBAR     

《测量评论》2013,45(63):2-14

Abstract

At the end of 1934 I visited Zanzibar at the invitation of the Government to advise on methods of cadastral survey and land registration suited to local conditions. Here I am only concerned with the former aspect of this problem. Although stated in general terms, it was in the tenure of the clove and, to a lesser extent, the coconut holdings that the need for these associated records had primarily appeared. My inquiry led to the submission of proposals for the direct use of vertical air photographs for a dual purpose cadastral survey of the Protectorate, which would not only satisfy the requirements of a Land Register, but also systematically furnish information of value to clove cultivation following earlier recommendations made by Professor R. S. Troup. Space does not permit of consideration of this associated objective here, but the possibilities which the method offers of providing concurrently an agricultural as well as a cadastral record is one of its claims to consideration.  相似文献   

LAND TENURE IN CANA     

《测量评论》2013,45(51):200-209

Abstract

The Dominion of Canada has an area of 3,695,189 sq. miles, nearly as large as the whole of Europe. It includes nine provinces, in six of which the cadastre (legal survey) has been laid down under different systems of survey, and only the remaining three under the comprehensive Dominion Lands System of Survey.  相似文献   

The effects of land cover change on carbon stock dynamics in a dry Afromontane forest in northern Ethiopia     

Negasi Solomon  Opoku Pabi  Ted Annang  Isaac K. Asante  Emiru Birhane 《Carbon balance and management》2018,13(1):14

  相似文献   

TRAINING AFRICAN SURVEYORS IN UGANDA     

《测量评论》2013,45(80):79-83

Abstract

Under the Buganda Agreement, which was made in 1900 between the British Government and the Kabaka (King) of Buganda, approximately 9,000 square miles of the kingdom of Buganda were divided into numerous estates, which were allocated to the various reigning chiefs and people of importance at that time. The British Government agreed to survey these estates, most of which were one square mile in area; thus, the term “Mailo” as applied to the land owned by the Baganda, came into use. Since the original Mailo survey, which was completed in 1935, many of the estates have been subdivided. The land has been sold piecemeal, gifted and bequeathed, so that plots now exist which are even less than one acre in area and some in and near large townships are as small as half an acre. The task of the Survey Department is a gargantuan one and, in 1949, it was estimated that there were some 150,000 outstanding surveys.  相似文献   

ROAD LOCATION IN ROUGH COUNTRY     

《测量评论》2013,45(43):284-286

Abstract

As a survey cadet I suppose one accepted the “tricks of the trade” without question. To turn out of the tent at crack of dawn, cook breakfast, and later devote a few idle moments to light pipes, pull on half-dried boots, pack the tucker bag and billy, then set off to work through wet fern and scrub; to boil the billy in the rain-soaked bush, then trek back again at dusk, with more food to cook for supper by the light of a flickering candle,—all added to the day's work, seldom arousing much enthusiasm in the youngest member of the party. Looking back one realizes how much knowledge was gained unintentionally.  相似文献   

Shorter Notices     

none 《The Cartographic journal》2013,50(2):181-182

Abstract

No statement appears to have been made at the time of why the national survey was put in hand in 1791. How far the Ordnance launched it in furtherance of its own responsibilities for the defence of the realm, and was therefore right to confer on the ordnance survey the prestige of its name, is a question which this article considers.

The Board of Ordnance was a department of state which was already by then two and a half centuries old. Furnishing the ordnance survey with scientific and administrative skills and Ordnance also lumbered it with the political difficulties which led to its own demise.  相似文献   

HEIGHT CONTROL IN AIR-PHOTO SURVEY     

《测量评论》2013,45(41):148-151

Abstract

1. An air-photo survey of part of Southern Palestine was carried out in 1938, both field-work and plotting being executed by the same surveyor, a comparative newcomer to this type of work, who therefore equipped himself with Lieut Salt's valuable book (Professional Papers of the Air Survey Committee, no. 8, 1933) for guidance. The area covered was very broken barren country and the contours became the principal features of the map, so that a great many spot-heights were necessary and certain deviations in detail from the routine laid down in the Paper suggested themselves.  相似文献   

A bevy of area-preserving transforms for map projection designers     

Daniel “daan” Strebe 《制图学和地理信息科学》2013,40(3):260-276

ABSTRACT

Sometimes map projection designers need to create equal-area projections to best fill the projections’ purposes. However, unlike for conformal projections, few transformations have been described that can be applied to equal-area projections to develop new equal-area projections. Here, I survey area-preserving transformations, giving examples of their applications and proposing an efficient way of deploying an equal-area system for raster-based Web mapping. Together, these transformations provide a toolbox for the map projection designer working in the area-preserving domain.  相似文献   

MODERN INFLUENCES ON THE UNIVERSITY ASPECT OF PROFESSIONAL TRAINING IN SURVEYING     

《测量评论》2013,45(69):282-295

Abstract

Surveying in, the sense in which I propose to consider it this evening, is the technical term given to the science of admeasuring and delineating the physical features of the earth and of works executed or proposed upon its surface. I am in some difficulty over a precise definition which will satisfy everyone since, although “surveying” is generally understood in the English language to have the above meaning, there is a growing tendency to use the somewhat restricted term” land survey"; restricted since it implies omission of hydrographic, hydrological and other forms of measurement of natural features and of setting out. This is, of course, not so.  相似文献   

LIDAR Validation Using GIS: A Case Study Comparison between Two LIDAR Collection Methods     

Tim L. Webster 《国际地球制图》2013,28(4):11-19

Abstract

In the summer of 2000, the Annapolis Valley of Nova Scotia, Canada was selected for a high‐resolution elevation survey utilizing LIDAR (Light Detection And Ranging). Two different LIDAR systems were used to acquire data for the area. The vertical accuracy specification for the survey called for heights to be within an average of 15 cm of measured GPS heights and 95% of the data to be within 30 cm. Prior to the application of these data to geoscientific problems, extensive validation procedures were employed. High precision GPS and traditional surveys were conducted to collect height validation checkpoints. Two validation methods were developed in a GIS environment that involved comparing the checkpoints to the original LIDAR points and to an interpolated “bald earth” DEM. A systematic height error between flight lines for one of the LIDAR methods was detected that related to the calibration procedures used in the survey. This study highlights the differences between laser systems, calibration and deployment methodologies and emphasizes the necessity for independent validation data.  相似文献   

THE STATE OF THE SURVEYS OF BRITISH AFRICA IN 1905-06     

《测量评论》2013,45(76):255-260

Abstract

Whilst turning over some old papers the other day I came across a copy of the first Annual Report of the Colonial Survey Committee, and the recent, much regretted death of Sir Herbert Read reminded me of his services in the development of the surveys and explorations of British possessions in Africa, especially his suggestion, which was approved by the Secretary of State for the Colonies, of the formation of the Colonial Survey Committee, an Advisory Committee which was set up in August, 1905. This Committee advised the Secretary of State “in matters affecting the survey and exploration of British Colonies and Protectorates, more especially those in Tropical Africa”.  相似文献   

Geographic information system for semi‐detailed mapping of soils in a semi‐arid region     

Arnon Karnieli  Irina Verchovsky  John K. Hall  Enav Oren 《国际地球制图》2013,28(3):29-42

Abstract

The paper presents a GIS model for mapping soils in the semi arid region of Israel. The model is based on a priori knowledge of the soil generating factors in the study area, namely (1) the parent‐material (lithology) which determines the origin of the soil; and (2) the relief (including the drainage patents) which is responsible for erosion, deposition, and leaching processes along the catena. A special attempt was made to represent soil belts in small subwatersheds with different parent‐material. The width of these belts can be varied as a function of the local relief.

We believe that GIS techniques, in contrast to conventional survey and mapping methods, have the potential to overcome the manpower and fiscal restrictions which limit monitoring of large areas and areas which are for different reasons difficult to access. However, systematically generalizing a spatial model for a large area may introduce some errors, either due to local variations which were not taken into account, or regional variations.  相似文献