Spatial Pattern Mining for Soil Erosion Characterization

2011 ◽  
Vol 2 (2) ◽  
pp. 73-92 ◽  
Author(s):  
Nazha Selmaoui-Folcher ◽  
Frédéric Flouvat ◽  
Dominique Gay ◽  
Isabelle Rouet
Keyword(s):  
Soil Erosion ◽  
Pattern Mining ◽  
New Caledonia ◽  
Regional Scale ◽  
Strong Impact ◽  
Interestingness Measure ◽  
Knowledge Based ◽  
Spatial Features ◽  
Spatial Approach ◽  
Complexity Assessment

The protection and the maintenance of the exceptional environment of New Caledonia are major goals for this territory. Among environmental problems, erosion has a strong impact on terrestrial and coastal ecosystems. However, due to the volume of data and its complexity, assessment of hazard at a regional scale is time-consuming, costly and rarely updated. Therefore, understanding and predicting environmental phenomenons need advanced techniques of analysis and modelization. In order to improve the understanding of the erosion phenomenon, this paper proposes a spatial approach based on co-location mining and GIS. Considering a set of Boolean spatial features, the goal of co-location mining is to find subsets of features often located together. This system provides useful and interpretable knowledge based on a new interestingness measure for co-locations and a new visualization of the discovered knowledge. The interestingness measure better reflects the importance of a co-location for the experts, and is completely integrated in the mining process. The visualization approach is a simple, concise and intuitive representation of the co-locations that takes into consideration the spatial nature of the underlying objects and the experts practice.

Spatial Pattern Mining for Soil Erosion Characterization

2012 ◽  
pp. 190-210
Author(s):  
Nazha Selmaoui-Folcher ◽  
Frédéric Flouvat ◽  
Dominique Gay ◽  
Isabelle Rouet
Keyword(s):  
Soil Erosion ◽  
Pattern Mining ◽  
New Caledonia ◽  
Regional Scale ◽  
Strong Impact ◽  
Interestingness Measure ◽  
Knowledge Based ◽  
Spatial Features ◽  
Spatial Approach ◽  
Complexity Assessment

The protection and the maintenance of the exceptional environment of New Caledonia are major goals for this territory. Among environmental problems, erosion has a strong impact on terrestrial and coastal ecosystems. However, due to the volume of data and its complexity, assessment of hazard at a regional scale is time-consuming, costly and rarely updated. Therefore, understanding and predicting environmental phenomenons need advanced techniques of analysis and modelization. In order to improve the understanding of the erosion phenomenon, this paper proposes a spatial approach based on co-location mining and GIS. Considering a set of Boolean spatial features, the goal of co-location mining is to find subsets of features often located together. This system provides useful and interpretable knowledge based on a new interestingness measure for co-locations and a new visualization of the discovered knowledge. The interestingness measure better reflects the importance of a co-location for the experts, and is completely integrated in the mining process. The visualization approach is a simple, concise and intuitive representation of the co-locations that takes into consideration the spatial nature of the underlying objects and the experts practice.

Spatial characteristics of the human factors of soil erosion at the boundary of political divisions: A spatial approach

CATENA ◽  
2021 ◽  
Vol 201 ◽  
pp. 105278
Author(s):  
Xiao Meng ◽  
Jiannong Cao ◽  
Xiaofeng Wang ◽  
Chong Zhang ◽  
Jinsheng Lv
Keyword(s):  
Soil Erosion ◽  
Human Factors ◽  
Spatial Characteristics ◽  
Spatial Approach

scholarly journals Overview of the Mount Tai Experiment (MTX2006) in central East China in June 2006: studies of significant regional air pollution

2013 ◽  
Vol 13 (16) ◽  
pp. 8265-8283 ◽  
Author(s):  
Y. Kanaya ◽  
H. Akimoto ◽  
Z.-F. Wang ◽  
P. Pochanart ◽  
K. Kawamura ◽  
...  
Keyword(s):  
Air Pollution ◽  
Regional Climate ◽  
Regional Scale ◽  
Photochemical Activity ◽  
East China ◽  
Strong Impact ◽  
Source Attribution ◽  
Annual Variations ◽  
Photochemical Aging ◽  
Regional Air Pollution

Abstract. We conducted an intensive field campaign at the summit of Mt. Tai (36.26° N, 117.11° E, 1534 m above sea level), Shandong Province, located at the center of central East China, during the period 28 May to 30 June 2006, to study seasonal maxima of regional air pollution with respect to ozone (O3) and aerosols. The specific objectives, campaign design, and major findings are summarized. High concentrations of O3 and its precursors, and aerosols, were detected and studied in the context of annual variations. Most importantly, we identified that emissions from regional-scale open crop residue burning after the harvesting of winter wheat, together with photochemical aging, strongly increased the concentrations of O3, aerosols, and primary pollutants in this month of year. Studies of in situ photochemical activity, regional source attribution of O3, O3–aerosol interactions, validation of satellite observations of tropospheric NO2, behaviors of volatile organic compounds and organic/inorganic aerosol species, loss rates of black carbon (BC), and instrument inter-comparisons are also summarized. The observed BC levels must have a strong impact on the regional climate.

scholarly journals Remote sensing of <i>Trichodesmium</i> spp. mats in the western tropical South Pacific

2018 ◽  
Vol 15 (16) ◽  
pp. 5203-5219 ◽  
Author(s):  
Guillaume Rousset ◽  
Florian De Boissieu ◽  
Christophe E. Menkes ◽  
Jérôme Lefèvre ◽  
Robert Frouin ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Large Scale ◽  
New Caledonia ◽  
Hot Spot ◽  
Regional Scale ◽  
Atmospheric Correction ◽  
South Pacific ◽  
Aggregation Processes ◽  
Modis Imagery ◽  
Generate Surface

Abstract. Trichodesmium is the major nitrogen-fixing species in the western tropical South Pacific (WTSP) region, a hot spot of diazotrophy. Due to the paucity of in situ observations, remote-sensing methods for detecting Trichodesmium presence on a large scale have been investigated to assess the regional-to-global impact of this organism on primary production and carbon cycling. A number of algorithms have been developed to identify Trichodesmium surface blooms from space, but determining with confidence their accuracy has been difficult, chiefly because of the scarcity of sea-truth information at the time of satellite overpass. Here, we use a series of new cruises as well as airborne surveys over the WTSP to evaluate their ability to detect Trichodesmium surface blooms in the satellite imagery. The evaluation, performed on MODIS data at 250 m and 1 km resolution acquired over the region, shows limitations due to spatial resolution, clouds, and atmospheric correction. A new satellite-based algorithm is designed to alleviate some of these limitations, by exploiting optimally spectral features in the atmospherically corrected reflectance at 531, 645, 678, 748, and 869 nm. This algorithm outperforms former ones near clouds, limiting false positive detection and allowing regional-scale automation. Compared with observations, 80 % of the detected mats are within a 2 km range, demonstrating the good statistical skill of the new algorithm. Application to MODIS imagery acquired during the February-March 2015 OUTPACE campaign reveals the presence of surface blooms northwest and east of New Caledonia and near 20∘ S–172∘ W in qualitative agreement with measured nitrogen fixation rates. Improving Trichodesmium detection requires measuring ocean color at higher spectral and spatial (<250 m) resolution than MODIS, taking into account environment properties (e.g., wind, sea surface temperature), fluorescence, and spatial structure of filaments, and a better understanding of Trichodesmium dynamics, including aggregation processes to generate surface mats. Such sub-mesoscale aggregation processes for Trichodesmium are yet to be understood.

scholarly journals The Indo-Pacific Amalda (Neogastropoda, Olivoidea, Ancillariidae) revisited with molecular data, with special emphasis on New Caledonia

2020 ◽  
Author(s):  
Yuri I. Kantor ◽  
Magalie Castelin ◽  
Alexander Fedosov ◽  
Philippe Bouchet
Keyword(s):  
Gene Flow ◽  
Molecular Analysis ◽  
New Caledonia ◽  
Narrow Range ◽  
Regional Scale ◽  
Molecular Data ◽  
Shell Morphology ◽  
Species Limits ◽  
South West ◽  
Strait Of Malacca

In the ancillariid genus Amalda, the shell is character rich and 96 described species are currently treated as valid. Based on shell morphology, several subspecies have been recognized within Amalda hilgendorfi, with a combined range extending at depths of 150–750 m from Japan to the South-West Pacific. A molecular analysis of 78 specimens from throughout this range shows both a weak geographical structuring and evidence of gene flow at the regional scale. We conclude that recognition of subspecies (richeri Kilburn & Bouchet, 1988, herlaari van Pel, 1989, and vezzaroi Cossignani, 2015) within A. hilgendorfi is not justified. By contrast, hilgendorfi-like specimens from the Mozambique Channel and New Caledonia are molecularly segregated, and so are here described as new, as Amalda miriky sp. nov. and A. cacao sp. nov., respectively. The New Caledonia Amalda montrouzieri complex is shown to include at least three molecularly separable species, including A. allaryi and A. alabaster sp. nov. Molecular data also confirm the validity of the New Caledonia endemics Amalda aureomarginata, A. fuscolingua, A. bellonarum, and A. coriolis. The existence of narrow range endemics suggests that the species limits of Amalda with broad distributions, extending, e.g., from Japan to Taiwan (A. hinomotoensis) or even Indonesia, the Strait of Malacca, Vietnam and the China Sea (A. mamillata) should be taken with caution.

The effects of multiple factors on spring meltwater erosion on an alpine meadow slope

2021 ◽  
Author(s):  
Xiaonan Shi ◽  
Fan Zhang ◽  
Li Wang
Keyword(s):  
Soil Erosion ◽  
Sediment Yield ◽  
Alpine Meadow ◽  
Alluvial Soil ◽  
Strong Impact ◽  
The Tibetan Plateau ◽  
Slope Gradient ◽  
Multiple Factors ◽  
Total Runoff ◽  
The Impact

&lt;p&gt;Serious soil erosion is observed during the spring because soil thawing coincides with the period of snowmelt and low meadow coverage at this time. Studies relating to soil erosion caused by spring meltwater are limited and controversial. In this study, a field experimental study was conducted in an alpine meadow slope in the Binggou watershed on the northern edge of the Tibetan Plateau to assess the impact of multiple factors on spring meltwater erosion. The multiple factors included three flow rates, four slope gradients, and three underlying surface conditions (meadow, disturbed meadow, and alluvial soil). An equal volume of concentrated meltwater flow was used in all experiments. The results showed that rapid melting at a high flow rate could accelerate soil erosion. The influence of the slope gradient on the amount of runoff was positively linear and the influence was relatively low. However, the slope gradient had a strong impact on soil erosion. The meadow could effectively reduce soil erosion, although when the meadow was disturbed, the total runoff increased by 60% and the sediment yield by a factor of 1.5. The total runoff from the alluvial soil doubled in comparison to the meadow, while the sediment yield increased nearly 7-fold. The findings of this study could be helpful to understand the characteristics and impact of multiple controlling factors of spring meltwater erosion. It also aims to provide a scientific basis for an improved management of alpine meadows as well as water and soil conservation activities in high-altitude cold regions.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;

Personal Knowledge Management by the Knowledge Citizen

2010 ◽  
pp. 131-140
Author(s):  
América Martínez Sánchez
Keyword(s):  
Knowledge Management ◽  
Building Block ◽  
Research Work ◽  
Individual Performance ◽  
Individual Development ◽  
Personal Knowledge ◽  
Strong Impact ◽  
Personal Knowledge Management ◽  
Knowledge Based ◽  
The Individual

The discipline of Personal Knowledge Management (PKM) is depicted in this chapter as a dimension that has been implicitly present within the scope and evolution of the Knowledge Management (KM) movement. Moreover, it is recognized as the dimension that brought forth Knowledge-based Development (KBD) schemes at organizational and societal levels. Hence, this piece of research work aims to develop parallel paths between Knowledge Management moments and generations and the PKM movement. KM will be depicted as a reference framework for a state-of-the-art review of PKM. A number of PKM authors and models are identified and categorized within the KM key moments and generations according to their characteristics and core statements. Moreover, this chapter shows a glimpse of the knowledge citizen’s PKM as an aspect with strong impact on his/her competencies profile; which in turn drives his/her influence and value-adding capacity within knowledge-based schemes at organizational and societal levels. In this sense, the competencies profile of the knowledge citizen is of essence. Competencies are understood as the individual performance of the knowledge citizen interacting with others in a given value context. The chapter concludes with some considerations on the individual development that enables PKM to become a key element in the knowledge citizen’s profile, such as the building block or living cell that triggers Knowledge-based Development at organizational and societal levels.

scholarly journals Mapping rainfall erosivity at a regional scale: a comparison of interpolation methods in the Ebro Basin (NE Spain)

2009 ◽  
Vol 13 (10) ◽  
pp. 1907-1920 ◽  
Author(s):  
M. Angulo-Martínez ◽  
M. López-Vicente ◽  
S. M. Vicente-Serrano ◽  
S. Beguería
Keyword(s):  
Soil Erosion ◽  
Prediction Models ◽  
Regional Scale ◽  
Geostatistical Simulation ◽  
High Temporal Resolution ◽  
Rainfall Erosivity ◽  
Ebro Basin ◽  
Spatial Coverage ◽  
Interpolation Techniques ◽  
Ne Spain

Abstract. Rainfall erosivity is a major causal factor of soil erosion, and it is included in many prediction models. Maps of rainfall erosivity indices are required for assessing soil erosion at the regional scale. In this study a comparison is made between several techniques for mapping the rainfall erosivity indices: i) the RUSLE R factor and ii) the average EI30 index of the erosive events over the Ebro basin (NE Spain). A spatially dense precipitation data base with a high temporal resolution (15 min) was used. Global, local and geostatistical interpolation techniques were employed to produce maps of the rainfall erosivity indices, as well as mixed methods. To determine the reliability of the maps several goodness-of-fit and error statistics were computed, using a cross-validation scheme, as well as the uncertainty of the predictions, modeled by Gaussian geostatistical simulation. All methods were able to capture the general spatial pattern of both erosivity indices. The semivariogram analysis revealed that spatial autocorrelation only affected at distances of ~15 km around the observatories. Therefore, local interpolation techniques tended to be better overall considering the validation statistics. All models showed high uncertainty, caused by the high variability of rainfall erosivity indices both in time and space, what stresses the importance of having long data series with a dense spatial coverage.

Fire and Late Oligocene to Mid-Miocene peat mega-swamps of south-eastern Australia: a floristic and palaeoclimatic interpretation

2016 ◽  
Vol 64 (8) ◽  
pp. 609 ◽  
Author(s):  
Ian R. K. Sluiter ◽  
David T. Blackburn ◽  
Guy R. Holdgate
Keyword(s):  
New Caledonia ◽  
Regional Scale ◽  
Climatic Conditions ◽  
Mean Annual Precipitation ◽  
Late Oligocene ◽  
Structural Context ◽  
Open Canopy ◽  
Eastern Australia ◽  
Brown Coals ◽  
Gippsland Basin

The Late Oligocene to Mid-Miocene (25–13 million years ago) brown coals of the Gippsland Basin in southern Victoria, Australia, were deposited in peat mega-swamps, unlike any in the world at the present day. The swamps preserve a rich botanical suite of macro- and microfossils, many of which can be identified with plant genera and families present today in Australia, New Caledonia, New Zealand and New Guinea. The peat-forming environments also preserve evidence of past burning in the form of micro-charcoal as well as macro-charcoal, the latter being evident as regional lenses or layers of fusinite, generally in coals of the darkest colour termed dark lithotypes. The presence of micro-charcoal in dark and some other lighter lithotypes indicated that fires also burnt locally, although they may have been extinguished before regional-scale burning occurred. It is also feasible that some peat mega-swamp plant communities dominated by rainforest angiosperm plants may have been fire excluders and prevented widespread fires from developing. Pollen and macrofossil evidence is presented of a distinctive southern conifer and angiosperm flora with an open canopy, primarily associated with the darkest coals that formed in the wettest parts of the peat-forming environment. Elsewhere, swamp forests with a large rainforest component grew on swamps raised appreciably above the regional groundwater table in a structural context akin to the ombrogenous peats of tropical coastal Sumatra and Sarawak. These vegetation types were not fire prone, but may have occasionally burnt at a local scale or at forest margins. Evidence is presented for the existence of seasonal climatic conditions that would appear to have facilitated a drying-out of the peat swamps in the warmest months of the year. A mesothermal climate was invoked where mean annual precipitation was at least 1500 mm, and possibly as much as 2000 mm, and mean annual temperatures were ~19°C.

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