A. Remote sensing applications

35. Application of remote-sensing technology (China). In agriculture, LANDSAT MSS images have been utilised in agriculture to compile geological maps, and to investigate changes in the acreage of the Yellow River Delta, and migration of river channels, etc.

36. Use of remote-sensing technology in forestry (Thailand). The Royal Forest Department of Thailand has utilised LANDSAT imagery for surveying existing forest land for the whole country, surveying and assessing areas of shifting cultivation in Northern Thailand and for conducting a change detection study of forest conversion in the seven eastern provinces of the country. Other studies done by means of remote-sensing techniques in Thailand include the measurement of rubber plantations in the eastern and southern parts of the country.

The use of remote sensing techniques reduced the time and personnel required for forest surveys and made it possible to draw up policies and plans for forest conservation and protection.

In the future, remote sensing would be used to monitor the country’s forest resources on a routine basis, in view of the government policy to maintain 50 per cent of the country under forests.²⁸

37. Crop inventory applications of remote sensing (Bangladesh). In Bangladesh remote-sensing techniques were used to measure the extent of winter rice in some regions. When the results of remote sensing were compared with field estimates a high correlation was found to exist.²⁹

38. Soilmapping by remote sensing (Egypt). Remote sensing techniques were used for mapping soils of an area over 100,000 square kilometres in El Shazly in Egypt. The maps obtained were at a scale of 1:500,000 and analysis differentiated arable from non-arable land. The soils were classified further into seven grades. This basic soil classification enables priority areas for agricultural development to be identified.³⁰

39. Detection of areas of copper deposits (Pakistan). A rock classification map, derived from LANDSAT images over Pakistan, has been used to predict copper deposits in the country. Of the 19 sites chosen from the map, five were found to have evidence of surface mineralization indicating the possibility of an enriched copper zone below the surface.³¹

40. Identification of salt-affected soils (India). A study in India has succeeded in delineating salt-affected soils around the Ganges Plain area. Salt-affected soils were easily detected in the MSS bands four and five. This information is important in an attempt to reclaim soils for agriculture in areas where population pressures make this necessary.³²

41. IDRC remote sensing project (Sudan, Bolivia, Bangladesh, Mali and United Republic of Tanzania).³³ In the Sudan project, personnel was trained, a remote-sensing unit was set up and thematic maps of the surface water hydrology, soils and erosion, vegetation and soil use in parts of the Kordofan and White Nile provinces were obtained.

In Bolivia, a series of thematic maps on geology, soils and soil use was produced. This was compiled in the form of an atlas entitled “Area Desaguadero Procesamiento Digital de Datos Multispectrales”. In addition a training programme on remote-sensing techniques was undertaken.

The Bangladesh project also had a training component and involved production of thematic maps by computers. Coloured LANDSAT images were analysed to produce hydrological maps of the hydrology of the Ganges Basin.

In Mali, a large number of maps on geology, hydrography, soil use, forest cover and agricultural potential in the south western part of the country were produced.

The main purpose of the project in Tanzania was to assess the natural resources in the Rukwa region. Maps outlining the biophysical zones of the Sumbawanga and Mpanda districts, and the agricultural potential of the entire region (for crops such as rice, corn, tobacco and cotton) were produced. Details on the geology, accessibility and irrigation possibilities were also obtained.