Rogers, C.D.F., 1995. Types and distribution of collapsible soils. In: Derbyshire, E., T. Dijkstra and I.J. Smalley (eds), Genesis and Properties of Collapsible Soils. NATO ASI Series C, vol 468. Springer. Accessed 14 October 2020.
" }, "editorialNote": { "en": [ "source:UNDRR HIPS" ] }, "scopeNote": { "en": [ "Volume change when a soil is subject to load, results from changes in pore volume, initially as a result of the loss of air and water from the voids and then as a consequence of more ordered grain packing. Organic matter in the soil may be highly compressible; peat soils being particularly susceptible to consolidation. Consolidation is the gradual reduction in soil volume resulting from an increase in compressive stress. The resulting increase in density is compaction (USDA, 1990). Consolidation is the gradual reduction in soil volume resulting from an increase in compressive stress. It consists of initial consolidation, which is a comparatively sudden reduction in volume resulting from the expulsion and compression of gas; primary consolidation, which results principally from a squeezing out of water and is accompanied by a transfer of load from the soil water to the soil solids; and secondary consolidation, resulting principally from the adjustment of the internal structure of the soil mass after initial consolidation. Settlement is the displacement of a structure due to the compression and deformation of the underlying soil. Compaction is the densification of a soil by means of mechanical manipulation (USDA, 1990). Collapsible soils differ from compressible soils in that they are low density soils with a structure that collapses upon wetting. They may have considerable strength when dry or moist. They lose strength and undergo sudden compression when they are saturated. Some will collapse under their own weight when saturated; others, only when loaded (USDA, 1990). Compaction reduces the volume of void available for water, potentially affecting water infiltration into soil, crop root moisture uptake and penetration, and consequential crop yield. Soil compaction can lead to surface ponding of water and water logging, leading to chemical deterioration in soil quality. The potential for increased surface water run-off can lead to soil erosion (USDA, 1990). The Food and Agriculture Organization of the United Nations (FAO) and Intergovernmental Technical Panel on Soils estimate that 33% of land is moderately to highly degraded due to the erosion, salinisation, compaction, acidification and chemical pollution of soils (FAO and ITPS, 2015). They noted that compaction-related soil degradation is increasing in Asia, Latin America and the Near East and North Africa; it is variable in Europe and Eurasia, the SW Pacific and North America (FAO and ITPS, 2015)." ] }, "broader": { "id": "http://connectivity-hub.com/terms/17bb4e8f-1a97-4343-95a9-d506b8a7c832", "prefLabel": { "en": "Environmental degradation" } }, "inScheme": [ { "id": "http://connectivity-hub.com/terms/", "title": { "en": "Climate Connectivity Taxonomy" } } ], "inSchemeAll": [ { "id": "http://connectivity-hub.com/terms/" } ], "@context": { "@version": 1.1, "id": "@id", "type": "@type", "@vocab": "http://www.w3.org/2004/02/skos/core#", "xsd": "http://www.w3.org/2001/XMLSchema#", "dct": "http://purl.org/dc/terms/", "dc": "http://purl.org/dc/elements/1.1/", "schema": "https://schema.org/", "vann": "http://purl.org/vocab/vann/", "ldp": "http://www.w3.org/ns/ldp#", "owl": "http://www.w3.org/2002/07/owl#", "title": { "@id": "dct:title", "@container": "@language" }, "dc:title": { "@id": "dc:title", "@container": "@language" }, "dc:description": { "@id": "dc:description", "@container": "@language" }, "description": { "@id": "dct:description", "@container": "@language" }, "license": { "@id": "dct:license", "@container": "@language" }, "issued": { "@id": "dct:issued", "@type": "xsd:date" }, "created": { "@id": "dct:created", "@type": "xsd:date" }, "modified": { "@id": "dct:modified", "@type": "xsd:date" }, "creator": "dct:creator", "publisher": "dct:publisher", "preferredNamespacePrefix": "vann:preferredNamespacePrefix", "preferredNamespaceUri": "vann:preferredNamespaceUri", "isBasedOn": "schema:isBasedOn", "source": "dct:source", "prefLabel": { "@container": "@language" }, "altLabel": { "@container": [ "@language", "@set" ] }, "hiddenLabel": { "@container": [ "@language", "@set" ] }, "definition": { "@container": "@language" }, "note": { "@container": [ "@language", "@set" ] }, "changeNote": { "@container": [ "@language", "@set" ] }, "editorialNote": { "@container": [ "@language", "@set" ] }, "historyNote": { "@container": [ "@language", "@set" ] }, "scopeNote": { "@container": [ "@language", "@set" ] }, "notation": { "@container": "@set" }, "example": { "@container": "@language" }, "narrower": { "@container": "@set" }, "related": { "@container": "@set" }, "relatedMatch": { "@container": "@set" }, "narrowerTransitive": { "@container": "@set" }, "broaderTransitive": { "@container": "@set" }, "broadMatch": { "@container": "@set" }, "narrowMatch": { "@container": "@set" }, "closeMatch": { "@container": "@set" }, "exactMatch": { "@container": "@set" }, "hasTopConcept": { "@container": "@set" }, "inScheme": { "@container": "@set" }, "topConceptOf": { "@container": "@set" }, "deprecated": { "@id": "owl:deprecated", "@type": "xsd:boolean" }, "isReplacedBy": { "@id": "dct:isReplacedBy", "@container": "@set" } } }