Text. Soil Survey Texture Maps for Land Cadastre

The soil survey plays an extremely important role in land cadastre.

To put the classification and mapping of soils on a uni­form scientific basis is rather difficult, for no two places have soils identical in every respect. Soils have many pro­perties, some of which can be assessed in the field and others only in the laboratory.

Different users will not agree about the priority attached to these properties. To the specialist of fertilizers acidity or to the gas engineer liability to corrode pipes may be all im­portant. But the land use planner or ecologist concerns himself with a wider range of soil properties. Therefore to find a single classification suitable for everyone is impossible and impracticable.

The five alternatives listed below figure in most legends of soil survey texture maps for land cadastre.

1. The predominant size of the mineral particles is well correlated with other soil properties. In sandy soils particles between 0.06 and 2 mm diameter predominate. In silty soils those between 0.002 and 0.06 mm, and in clay soils those smaller than 0.002 mm. In loamy soils no one particle-size range is predominant. Sandy soils are also called "light" or coarse-textured, clay soils — "heavy" or fine-textured, and silty and loamy soils are sometimes grouped as medium-textured. Stoniness refers to the proportion of particles of a diameter larger than 2 mm. A more detailed scheme of tex­ture classes is outlined in soil survey manuals.

2. Natural drainage. The incidence of waterlogging is another important soil condition. It can be assessed directly or by interference from the presence or absence of grey or mottled colours, or by a peaty surface layer. The categories used are excessively well, moderately well, imperfectly, poorly and very poorly drained.

3. Major groups. Soils are formed by physical, chemical and biological processes. Classifications which emphasize properties indicating the nature and extent of these processes are called natural or genetic.

Soil-forming processes usually lead to the development of a distinct layering in the soil, more or less parallel to the surface of the ground. The sequence of layers (technically called soil horizons) down to unaltered geological material is called the soil profile. Most classifications define profile classes which group together similar soil profiles regardless of where they occur.

4. Parent material. Within a given neighbourhood, the nature of the geological material from which the soil has formed is often a useful indicator of its other properties, particularly when no soil map is available. Thus one may refer to "chalk soils", "boulder clay soils", etc. The land use planners should recognize that considerable variation occurs within these groups, caused by other soil-forming factors.

5. Soil series. Subgroups of the genetic classification are divided by texture and parent material into soil series. Soil series are named after localities where examples are known to occur. While thus defined as a profile class, soil series are commonly used as mapping units on detailed soil maps.

III. Определите без словаря значения следующих словосочетаний:

soil classification; soil scientists; important role; mapping of soils; large diameter; soil horizons; geological material; soil-forming factor; soil map; profile class

IV. Употребите глагол, стоящий в скобках, в нужном времени:

1. The dean was sure that the students of Land Use Planning faculty (to take part) in the meeting. 2. He knew that you (to be writing) the report for the conference on the problems of geodesy. 3. My friend told me he (to hear) the previous week that our chair (to be preparing) for the conference and that it (to be held) at the end of the next month. 4. Galileo proved that the Earth (to move) round the Sun. 5. The teacher said that the students of this group (to be) good at geodesy. 6. The student said that he (to become) a good specialist in soil science.

V. Закончите следующие предложения, используя текст:

1. Soil properties are well correlated with the... . 2. The sizes of particles in sandy soils are... . 3. Clay soils are called... . 4. Sandy soils are called... . 5. The categories of natural drainage are... . 6. Classifications emphasizing pro­perties indicating the nature and extent of physical, chemical and biological processing in soils are called... . 7. Soil-forming process usually leads to the development of... . 8. Soil series are named after... .

VI. Объяcните на английском языке значения следующих слов и cловосочетаний:

soil mapping; soil properties; ecologist; permanent physical properties; cultivation methods; "heavy" soils; "light" soils; soil horizons; parent material

VII. Поставьте вопросы к выделенным словам. Запишите вопросы в тетрадь:

1.Soil surveys show the distribution of soil classeson maps. 2. Soil classification and mapping play an important role in cadastral survey. 3.Most of us can make some sort of soil map of the familiar area. 4. The land use planner or ecologist concerns himselfwith a wide range of soil properties. 5. Soils are formedby physical, chemical and biological processes.6.Soil series are commonly used as mapping units on detailed soil maps. 7. Stoniness refers to the proportion of particles of a diameter larger than 2 mm.

VIII. Вставьте подходящие по смыслу слова.Переведите предложения на русский язык:

1. In ... soils the size of particles change from 0.06 to 2 mm in diameter. 2. What is the ... of particles in silty soils? 3. Sandy soils are ... "light" or coarse texture. 4. Soils may be excessively well, moderately well, imperfectly, poorly and very ... drained. 5. Soils are formed by physical, chemical and ... processes. 6. The sequence of soil layers is technically ... soil horizons. 7. The nature of the geological material from which the soil has formed is often a ... indicator of its properties. 8. Soil surveys ... necessary for land cadastre.

IХ. Переведите с русского языка на английский:

В техническом отношении метод В. В. Докучаева вклю­чал: 1) разработку естественной классификации почв; 2) оп­ределение геологических свойств почв; 3) установление химического состава; 4) определение физических свойств почв.

X. Определите, какими частями речи являются выделенные слова. Переведите предложения на русский язык:

1. What can you say about the properties of this soil? 2. Theysoil the animals all the year round. 3. Thissoilneeds theincrease of fertilizers. 4. This departmentincreasesits input forsoil surveys. 5. What is theobject of these labor­atory measurements? 6. The professorobjected to the method used in that investigation. 7. The formation ofsoil is the result of physical, chemical and biologicalprocesses. 8. They processed the data of the experiment for three hours. 9. Their workresulted in somesoil maps of high quality.