6.0 USE OF THE SOIL MAP AND DATA

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6.1 Planning the Use and Management of Soil

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The soil survey is an analysis and evaluation of the most basic resource of the survey area - the soil. It may be used to fit the use of the land to the limitations and potentials of the natural resources and the environment, and help to avoid soil-related errors in uses of the land. However, it must be remembered at all times that no interpretation of a soil survey is complete without due consideration of interactions among all components of an ecosystem. In this regard, it is very important for the soil surveyor to consult and work with other professionals when developing interpretations. This will help ensure that the most appropriate techniques and data are used to make the interpretations and that the soil maps and data are of widespread use.

During a soil survey extensive notes are kept, not only about the nature of the soils but also about unique aspects of behaviour of these soils in the field. These notes include observations of erosion, damage to plants, flooding, soil failures, wildlife habitat, and other factors relating to the kinds of soil and their productivity, potentials and limitations under various uses and management. In this way, field experience incorporated with measured data on soil properties and performance can be used as a basis for predicting soil behaviour. Information from these field notes should be incorporated into the soil survey report where applicable.

Information from the soil survey can be used in applying basic facts about the soils to plans and decisions for use and management of the soils for many farm and non-farm uses (e.g.highways, sanitary facilities, parks, wildlife habitat, etc.). From the data provided by the soil survey, the potential of each soil for specified land uses may be determined, soil limitations to those land uses may be identified and costly failures avoided. A site can be selected where the soil properties are favourable, or a practice can be planned that will overcome the soil limitations. Planners and others using the soil survey can evaluate the impact of specific land uses on the environment. Plans can be made to maintain or create a land use pattern in harmony with the natural soil.

6.2 The Kinds of Interpretations

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In B.C., to-date, the most extensive interpretation of soil survey information have been by the Canada Land Inventory (CLI) and B.C. Land Inventory (BCLI) programs. These programs provided a series of maps outlining capability classes for agriculture and forestry and these applications should continue in the future. In addition to these, several soil survey map areas have provided interpretations for a variety of other uses to which soil and other natural resource information (e.g. climate) have been applied. Table 6.1 provides an example of these interpretations for forestry, agriculture and grazing. Table 6.2 provides an example for engineering and related land uses.

Methods for undertaking these interpretations are outlined in several publications. These publications are listed in Appendix C and while the list of interpretation references is not exhaustive, it is important to note that whatever interpretive methodology is chosen, it must be applied in a consistent manner throughout the project or survey area.

Table 6.1 Example of Agriculture and Forestry Interpretations from a Soil Survey
(From Biophysical Resources of the East Kootenay Area: Soils, Lacelle, 1990)

	Agriculture		Forestry
Soil Association Component	Climate Capability for Agriculture	Soil Capability for Agriculture	Land Capability for Forestry	Natural Forest Regeneration Potential	Windthrow Hazard	Relative Susceptibility of Soils to Damage by Disturbance
AS1,3,9,10	3G	5IP	2S	high	low	low
AS11,12	3G	6WI	6WI	low	moderate	low
AZ1-3	3GF	4X	2S	high	moderate	high
AZ7	3GF	6ED	3ED	high	moderate	high
BB1-6	6G	7TR	6ER	moderate	high	high
BB7,8	6G	7ER	7ER	low	high	high
BC1-6; B01-6; BP1-6; RF1-6; RG1-6; RT1-6	6GH	7TR	5HR	moderate	high	moderate
BC7; BO7; BP7; RF7	6GH	7ER	6ER	moderate	high	moderate
BC8; BO8; BP8; RF8; RG8; RT8	6GH	7ER	7ER	low	high	moderate
BF1-6; RC1-6; RP1-6; RS1-6	5G	7TR	5MR	moderate	high	moderate
BH1-6; BK1-6; RS8	6G	7TR	5HR	moderate	high	moderate
BH7; BK7	6G	7ER	6ER	low	high	moderate
BH8; BK8	6G	7ER	7ER	low	high	moderate
BK - see BH
BN1-6	5G	7TR	5R	moderate	high	moderate
BN7	5G	7ER	6ER	low	high	moderate
BN8	5G	7ER	7ER	low	high	moderate
BO - see BC
BP - see BP
BS1-6; RH1-6	6G	7TR	5R	moderate	high	moderate
BS7; RH7	6G	7ER	6ER	low	high	moderate
BS8; RH8	6G	7ER	7ER	low	high	moderate
CA1-4	3GF	3C	1	high	high	high
CA7	3GF	5TE	2ED	moderate	high	high
CAI1-4; CE1-4	5G	6T	4M	high	low	low
CAI7; CE7	5G	6TE	4ME	moderate	low	low
CB1-4; CW1-4	6G	6T	4M	high	low	low
CB7; CW7	6G	6TE	5ME	moderate	low	low
CB8; CW8	6G	6TE	7E	low	low	low
CC1-4	5G	6T	2S	high	high	high
CC7	5G	6TE	3ED	moderate	high	high
CD1-4	3G	4TDs	2S	high	high	high
CD%	3G	5TR	3RD	high	high	high
CD7	3G	5TE	3ED	moderate	high	high
CE - see CAI
CE8	5G	6TE	7E	low	low	low

Table 6.2 Example of Geological Hazards and Terrain Capability for Residential Settlement Interpretations from a Soil Survey

		Constraints Affecting Use For*
Soil Parent Material Groups	Soil Associateion Components	Septic Tank Disposal Fields	Foundations for Low Rise Dwellings	Road and Street Subgrade	Ease of Excavation	Sites for Sanitary Landfill	Source of Topsoil	Source of Sand and Gravel	Geological Hazards**
Floodplain deposits (Regosolic soils)	AS1,9-11; CN1,3; FA1,3; FD1,2; FE1,2; FF1,3; FJ1,2; FK1,2; FM1,3,9; FQ1,2; FR10; FS1,3; FT10; FU1,3; FV1,2; FZ1,3; GN10; KO10; L10; NW1,2; S1,2	severe	severe	severe	moderate	severe	moderate	moderate	inundation; shifting channels; bank erosion
Floodplain deposits (Gleysolic soils)	AS3,11,12; CN10,11; FA10,11; FD10,11; FE10,11; FF10,11; FJ10,11; FK10,11; FM10,11; FQ10,11; FS10,11; FU10,11; FV10,11; FZ10,11; KO11; L11; MA10; NW3,11; S3,10,11	severe	severe	severe	severe	severe	severe	severe	inundation; shifting channels; bank erosion
Fluvial fans (relatively fine texture)	CA1-4; F01-4,9; FP1-4; GE1-4; GZ1-4; MA1-3	moderate	moderate	moderate	slight	moderate	slight	moderate	inundation; shifting channels; bank erosion; debris, mud or earth flows
Fluvial fans (relatively coarse texture)	FR1-4; FT1-3	moderate	slight	slight	slight	slight	moderate	slight	inundation; shifting channels; bank erosion; debris, mud or earth flows
Fluvial terraces and fluvioglacial terraces, plains and fans (coarse texture)	FX1,2,9; GB1-4; GC1-4; GL1-4; GN1-4; GR1-4; GT1-4; GY1-4; KA1-4; KG1-4; KR1-4	severe	slight	slight	slight	moderate	moderate	slight	--
Fluvial, fluvioglacial and eolian deposits (sandy surface texture)	E1,2,4,9; F1,2,9; GD1-4; H1,3; KE1-4; KO1-4; L1-3; MY1-4; SA1,3,9,10	severe	slight	slight	slight	moderate	slight	slight	wind erosion

6.3 Quality Control and Correlation

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The need to maintain quality throughout the process of preparing interpretive maps and information is as equally important as quality control is during the conduct of the soil survey itself. With the increased use of computers and sophisticated software for preparing interpretive maps and summary tables, it is of vital importance to undertake checking and other quality control procedures prior to the release of the information. Methods used for the interpretation must be fully documented for the user and limitations inherent in the results must be explained.

Perhaps the most useful way to provide quality control is to have periodic reviews of the interpretive information conducted by the Soil Correlator. In this manner, the soil scientist is provided with a peer review of his work and inconsistencies and errors can be detected and corrected.

6.4 The Use of Other Data

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It is unlikely that all interpretations can be undertaken solely with the data provided by the soil survey. A soil survey provides information about soils and should not be considered as the only data source required for land use planning and management. Other than derivations from the map and laboratory data (e.g. drainage, depth to bedrock, pH) it is often necessary to include information from other disciplinary studies for the interpretation to be complete and of most value to the user. For example, the preparation of an Agriculture Capability Map cannot be completed without climatic information such as freeze - free period and growing degree - days. Equally, it is not feasible to prepare interpretations regarding wildlife habitat without information on plant ecology and the specific requirements of the wildlife being considered. Where computers are used to prepare interpretations from the soil map and related data, augmented by other data sets (e.g. climate, terrain), it is important for the individual who is responsible for the interpretations to be aware of any inconsistencies among the data sets (e.g. accuracy of the information) prior to performing the interpretations.

The need for additional studies to support the objectives of the soil survey must be identified and planned for during the initial organization of the soil survey. It is not satisfactory to discover at the end of the survey that a vital piece of information is missing. Scheduling and budgeting for these studies must be considered an essential part of the soil survey workplan.

The use of data from other sources must be fully acknowledged by the soil surveyor. Those individuals who have contributed their time and effort in providing information and professional opinion should be referenced in the soil survey report.

6.5 Distribution and Format of Interpretive Information

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The largest number and greatest geographical coverage by interpretive maps based on soil survey are those produced by the Canada Land Inventory and B.C. Land Inventory (e.g. Agriculture Capability). In addition, many recent soil surveys have not actually produced interpretive maps, but have provided "interpretive tables" in the soil survey report that the users can apply in the construction of their own interpretive map.

With the increased application of digital files for both the map polygon as well as attribute data regarding the properties of the map unit, it is possible to prepare interpretive maps very quickly and efficiently upon request. Consequently, it is not usually necessary to prepare a multitude of interpretive maps waiting for the user to request them, but rather to respond to the request when it is made. Regardless of the method used, it is important that the soil surveyor, or his colleagues, who were responsible for the survey, to undertake and perform quality control checks on the interpretive maps and data.

For all future systematic soil surveys, it is assumed that they will be supported by computer-based cartographic and data handling tools. In one form or another, these will be Geographic Information Systems that will be linked to other geographic data bases such as TRIM. By providing soil survey maps and data in this manner to the user, it is redundant to prepare a series of interpretive maps since they can be provided on demand to the user or the user himself can undertake the work. Regardless of this, it is recommended that specific, well documented methods be utilized for the interpretations and that the results of the interpretations be checked by the soil surveyor. The most important aspect is for the soil surveyor and his support agency to maintain an organized, up-to-date, and easily accessible data base for user groups to utilize.

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