Land classification and soil survey

The Yemeni Ministry of Agriculture will implement the project. The project will provide for development of a land use map scaled 1: 250,000 and reflecting the basic level I classification system (i.e., showing urban and built-up land, agricultural land, rangeland, forestland, water, barren land, tundra, and perennial ice or snow). The study area lies west of 45 degrees, 30 minutes longitude and includes the major populated areas. Work will be primarily based on manually processed satellite imagery. Only limited field checking will be undertaken; ground-truth photographs and 1973 British aerial photographs will serve as ground-truth documentation. A map at a scale of 1:500,000 of the major soil types (based on the U.S. soil taxonomy) will be prepared using remotely sensed data and field correlation. Up to 1,500 soil samples will be analyzed by the FAO-assisted Central Agricultural Research Station Soils Laboratory in Taiz. These analyses will be for texture, cation exchange, capacity, conductivity, pH, and levels of exchangeable calcium, magnesium, phosphorus, sodium, nitrogen, and calcium carbonate. The base maps will be procured from the British. Time-lapse analysis of satellite imagery will be undertaken to measure recognizable changes in land use, cropping patterns, etc. in relation to imagery take in 1972. Lastly, in order to institutionalize a Yemeni soils mapping capability, one or two Yemeni soil scientists will be trained in the United States in manual interpretation of satellite imagery, soil classification procedures, soil taxonomy, correlating land use to geomorpohology, and remote sensing applications.