Modelling patternedground distribution in Finnish Lapland : an integration of topographical, ground and remote sensing information
Cold area ; Digital elevation model ; Finland ; Geographical information system ; Lapland ; Patternedground ; Periglacial features ; Plant canopy ; Remote sensing ; Slope gradient ; Topography
The AA. present a new modelling approach that integrates topographical, ground and remote sensing information in predictive geomorphological mapping using generalized additive modeling (GAM). The results indicate that non-sorted patternedground
is more common at lower altitudes where the ground moisture and vegetation abundance is relatively high, whereas sorted patternedground is dominant at higher altitudes with relatively high slope angle and sparse vegetation cover. This paper confirms
the potential utility of remote sensing information for modelling patternedground distribution in subarctic landscapes.
Formation of sorted patterned-grounds - a literature review
Classification ; Patternedground ; Pedogenesis ; Periglacial features ; Soil ; Theory
The article presents and compares current views on the development of sorted patterned-grounds in the periglacial zone. The theories can be divided into 8 groups, which assume : 1) convection and/or circulation of the ground en masse ; 2
) circulation of only fine particles of the ground ; 3) convection of pore water ; 4) heave-settlement pulsation and lateral expansion on the fine domains ; 5) cracking of the ground followed by heave-settlement pulsation and lateral expansion of the centres
Relict sorted patternedground in Rostu, northernmost Sweden
C 14 dating ; Cold area ; Deglaciation ; Patternedground ; Periglacial features ; Quaternary ; Spatial variation ; Stratigraphy ; Sweden
The objective of this study is to determine the age of active periods in relict sorted patternedground on Rostu by studies of internal structures, spatial analysis and radiometric datings.
Controls on sorted patterned-ground geometry in the Swiss Alps
Alps (The) ; Freeze-thaw cycle ; Lithology ; Mountain ; Patternedground ; Periglacial features ; Spatial distribution ; Switzerland
This paper represents results of field investigations on the distribution, morphology and structure of patternedground formed on alpine slopes in the Swiss Alps, focusing on factors affecting the spacing of patternedground. The study area lies
The article discusses the regular system of polygons and stripes which are observed in patternedground and which strongly suggests the occurence of one or another kind of free convection during the genesis of the pattern. It is argued
Relict sorted patternedground is described from an upland interfluve on the Lesotho-South Africa border at an elevation of 3280 m a.s.l. The site comprises 2-4° slope angles. Frost penetration through the regolith is inferred to have been to 1 m
depth during pattern formation. Sorting is thought to have resulted from deep seasonal freezing during the depressed temperatures of the Late-Pleistocene Last Glacial Maximum. No direct evidence for permafrost is documented.
Observations of sorted patternedground features, High Valley/Tangle Lakes region, Central Alaska, U.S.A. in Periglacial processes and landforms.
These features have been studied since 1981, and since 1982 sorted circles at six patternedground sites in High Valley have been monitored to determine their degree of activity.
Forms of unusual patternedground: examples from the Falkland Islands, South Atlantic
Aeolian features ; Atlantic Ocean ; Earth surface processes ; Island ; Lacustrine sediment ; Patternedground ; Peat ; Sand ; Sediment transport ; South Atlantic Ocean
This paper descibes the characteristics of, and outlines the most likely origins for, three forms of unusual patternedground observed in the Falkland Islands, South Atlantic. The features here described are not products of frost-related processes
Annually re-forming miniature sorted patternedground in the high Drakensberg, Southern Africa
Freeze-thaw cycle ; Freezing ; High mountain ; Microrelief ; Mountain ; Patternedground ; South Africa
An analysis of miniature sorted circles and polygons provides the first detailed assessment of sorted patternedground from a southern African alpine region. Pattern dimensions and particle sorting were determined from 2 sites in the high
Drakensberg. Although the sorted patterns in the high Drakensberg are somewhat polygenetic in developmental origin, they are primarily frost-induced. The development of miniature sorted patterns within 5 to 6 weeks demonstrates the effect of regular freeze
A novel spatial sampling strategy focusing only on fields with potential patternedground occurrence was used. The data were examined using factor analyses (multiple correspondence analysis and hierarchical ascendant classification) blended
with a complementary bivariate method to associate patternedground occurrence with 8 environmental variables. The absence of active patternedground is associated with low elevation, glacier absence, no slopewash, a low height-distance ratio and talus fans. Zones
where active patternedground features are present are divided into 3 homogeneous subzones and are mostly associated with glacier influence, a large height-distance ratio and an absence of vegetation. Their location is controlled by the presence of till
from different glacial sequences so that the former and current presence of glaciers favours the development of patternedground features at the landscape scale.
Non-sorted patternedground in the High Drakensberg, Southern Africa : some new data
Africa ; Cryopedology ; Freeze-thaw cycle ; Humid environment ; Micromorphology ; Patternedground ; Periglacial features ; Seasonal variability ; Southern Africa
This paper presents empirical data on non-sorted patternedground in the high Drakensberg. Some morphological and sedimentary characteristics for thufur and non-sorted steps are provided. The study also examines process data on ground heave activity
at a thufur site. Contemporary cryogenic activity at the non-sorted steps is indicative that the patterns are at least seasonally active. Soil heave measurements at the Mashai Valley thufur site support the contention that some thufur are active in the high
Generalized linear modelling in periglacial studies : terrain parameters and patternedground
Cold area ; Finland ; Geographical information system ; Model ; Patternedground ; Periglacial features ; Regression analysis ; Soil moisture ; Topography
Generalized linear models (GLM) are mathematical extensions of linear models. This paper demonstrates GLM model-building procedures step-by-step for the distribution and abundance of active patternedground in northern Finland. Both the distribution
and abundance models clearly indicate an increasing activity of patternedground with increasing soil moisture and proportion of concave topography. Activity decreases with increasing altitude. The AA. conclude that GLM techniques combined with a geographic
Temporal and spatial variability of soil pH in patterned-ground chronosequences : Jotunheimen, Norway
Cold area ; Geochemistry ; Glacier ; Little ice age ; Moraine ; Norway ; Patternedground ; Periglacial features ; Spatial variation
Glacier foregrounds of Jotunheimen are characterized by the occurrence of Little Ice Age end moraines, dating to approximately the mid 18th century. Patterned-ground features occurring within chronologically established time units were studied
. Sorted circles and sorted nets showed significant changes in soil pH across the chronosequences. All glacier forelands showed a higher soil pH with depth in patternedground features. The importance of microsite variability and associated disturbance
Development of miniature sorted patternedground following soil erosion in East Falkland, South Atlantic
and indicate that in cool oceanic climates the distribution of frost-sorted patterns is controlled by the presence of bare ground on suitable regolith rather than by altitude.
The features have developed in the L'Antioja valley, East Falkland, following recent erosion and display many of the characteristics associated with the operation of frost-related processes in regolith materials. The patterns are currently active
Ground water : a parameter in determining land use pattern in Siwana region, Western Rajasthan
This paper aims to identify ground water potential zones and remote sensing methods to demarcate various future land use units, through geo-electrical investigation conducted in a close grid pattern around Siwana region. Secondary data are used
to visualise changes in the present land use pattern in future. - (PLK)
Post-Little Ice Age patternedground development on two Pyrenean proglacial areas : from deglaciation to periglaciation
Deglaciation ; France ; Glacier retreat ; Moisture ; Mountain ; Patternedground ; Periglacial features ; Pyrénées ; Space time
This study aims to observe post-Little Ice Age glacier retreat and the constitutive patternedground development at 2 French Pyrenean glacier forelands (Taillon Glacier and Pays Baché Glacier). Periglacial feature observations are associated
with periods of deglaciation using aerial photos and archive files. It is highlighted that patternedground can develop very rapidly, sometimes only 10 years after deglaciation, but patternedground size does not systematically increase as a function
of the time elapsed since deglaciation. All the forms, even those developing near the Little Ice Age moraines, are active. The AA. propose that the location, activity and size of patternedground are more probably linked to drift characteristics and local
Changes and spatial patterns of the differences between ground and air temperature over the Qinghai-Xizang Plateau
The difference between ground soil and air temperature was studied by using the data of ground and air temperature of 99 stations over the Qinghai-Xizang (Tibet) Plateau from 1960 to 2000, and its spatial distribution and time changing tendency have
Arctic Region ; Canada ; Cold area ; Groundwater ; Humid environment ; Patternedground ; Periglacial features ; Permafrost
Preferential suprapermafrost groundwater flow was observed in deepened channels lying between raised frost mounds. In this study, the AA. examine how a type of patternedground (sorted net) influences saturated hydraulic conductivity (k
). Then, they assess the areal implications of this type of patternedground on estimates of saturated hydraulic conductivity (k) and daily and seasonal estimates of groundwater flow (Qs) across a transitional zone (gravelly area grading into a wetland).