Geomorphological Forms Research Articles

Pedogenic influence on profile distribution of total and DTPA - extractable micronutrients in rice growing hydric soils of Majuli river island, Assam, India

The rice-growing river floodplain ecosystems of Majuli island, India, have been recognized as a biodiversity hotspot with a high degree of variability in geomorphological forms and geochemical conditions for trace metals in hydric soils. Ten hydric soil series in rice-growing soils of Majuli island were studied with the aim of understanding the pedogenic influence on distribution and content of total and diethylenetriamine penta acetic acid (DTPA) extractable micronutrient cations (Fe, Mn, Cu and Zn) and their enrichment levels. The correlation analysis showed that these cations were closely linked with soil texture, organic carbon, cation exchange capacity and pH levels. The multiple regressions and cluster analysis was employed to identify the effect of river fed deposits on distribution pattern and lithological enrichment of metals. The contamination status was assessed through quantitative indexes with reference material. The negative geo-accumulation index values were used to conclude that these soils had been practically unchanged by anthropogenic influences. They showed moderate Cu contamination but were otherwise unpolluted (Pollution load index < 1) with respect to total elements under study.

USING OF REMOTE SENSING FOR MONITORING GEOMORPHOLOGICAL TEOMPRAL CHANGES FOR TIGRIS RIVER IN BAGHDAD CITY

Tigris River was chosen as astudy area in Baghdad province to study the geomorphological temporal changes due to the effect of erosion and deposition by remote sensing .Normalized Difference Suspended Sediment Index (NDSSI) was calculated by data of Landsat 7 and 8 for +ETM and OLI ,respectively , between 1989 and 2014. Ten sites were selected within five regions represent all geomorphologic forms in the study area starting from Altajee to Alga’ara site located between the longitude 44° 19´ 50.512" E, 33° 23´ 24.754" N and 44° 32´ 07.762" E , 33° 09´ 21.432" N, with distance of 59945 m. The results indicated that there is a difference in the activity of geomorphologic processes associated with the movement of the Tigris River in Baghdad province, particularly sculpture and sedimentation processes. It was easy to find the existence of activity of sedimentation, especially in some curves that have helped to reduce the movement factor of the carrier sediments speed, and the results showed a significant contrast in the sedimentary material area between the selected sites during the study period in the year 2014 than it was in 1989. The results indicated there is an inverse relationship between the sediment guide values and deposits outstanding.

Morfogeneza slepe doline Brdanska dana

Slepa dolina Brdanska dana se nahaja na južnem robu Brkinov, kjer se ti stikajo s kraškim ravnikom Matarskega podolja. Na preučevanem območju se prepletajo značilnosti fluvialnega ter kraškega geomorfnega sistema, kar se kaže v veliki pestrosti reliefnih oblik in procesov. V okviru te raziskave je bila opravljena geomorfološka analiza preučevanega območja. Na podlagi morfografskih, morfometričnih in granulometričnih podatkov smo preučili glavne geomorfološke značilnosti, funkcijo in razvoj te slepe doline.

Geomorfološka regionalizacija srednjeg i južnog dijela otoka Paga

The paper represents an analysis of geological, climatic, geomorphologic and morphometric characteristics of the central and southern parts of Pag Island. It identifies 21 categories of relief thoroughly studied and explained by using the methods of remote sensing. The predominant geomorphological processes and forms are indicated within the chosen 243 spatial units. An acquired dataset has been used to implement a generalization which provided the land use evaluation criteria for determining the favourability of certain areas for construction.

Landscape metrics applied in geomorphology: hierarchy and morphometric classes of sand dunes in Inner Somogy, Hungary

Landscape metric is mostly used to quantify landscape patches. However, these patches could also be geomorphological forms, thus using traditional landscape metrics their shape and spatial distribution, or their dynamics could be analysed. The aim of the paper is to study the geomorphological applicability of different indices studying the aeolian forms of Inner Somogy (SW Hungary). In the present research 15 landscape metric indices were calculated with Patch Analyst 5.1 and vLATE 2.0. The negative aeolian forms (blowout depressions and holes) have high number but small size, whilst the positive forms (parabolic dunes and hummocks) have large number and complex spatial structure, thus the negative and positive forms can not be directly connected. The spatial distribution revealed by the applied indices refers to differences in moisture content, abundance of sand supply and relief on a regional scale. The negative forms appear in a considerable distance from each other, while the positive forms tend to cluster. Based on the spatial distribution of the forms the matrix could be described as an erosion-transportation zone, and in three accumulation zones the dune size and superimposition increases downwind.

Statistical and Spectral Features of Corrugated Seafloor Shaped by the Hans Glacier in Svalbard

High-resolution images of the seabed obtained with the use of hydroacoustic measurements allow a detailed identification of inaccessible seabed areas such as the Hans Glacier foreland in the Hornsund Fjord on Spitsbergen. Analyses presented in the paper were carried out on a Digital Elevation Model (DEM) of the bay’s seafloor exposed in the process of deglaciation, obtained from bathymetric data recorded by a multibeam echosounder. The main objective of this study was to show the relevance of the autocorrelation length parameter used to describe the roughness of the bottom surface based on the example of seafloor postglacial forms in the Hans Glacier foreland. The resulting parameter reflects the scale of the terrain roughness, which varies between geomorphologic forms. Maps of the autocorrelation length were derived from successive tiles of the data, overlapping by 90%. Based on this, the two-dimensional Fourier transform (2D FFT) was successively conducted, and the power spectral density and autocorrelation were calculated following the Wiener–Khinchin theorem. The thus obtained parameter describes the scale of the glacial bay seafloor roughness, which was assigned to the geomorphological features observed.

Hydrologiczne i geomorfologiczne skutki ekstremalnego opadu w maju 2014 roku w zlewni Rybnego Potoku (Masyw Babiej Góry)

<p>Mountain streams are subject to continuous modeling of river beds during floods. The greatest changes occur within them, however, during the catastrophic floods caused by sudden rainfall. The increase in the intensity of transformation occurs in forest areas, where the wooden logs carried by the swollen streams create a dumping ground, around which there is a greater accumulation of transported material and the formation of an increased mosaic of geomorphological forms.</p><p>The study was conducted in the Rybny Potok catchment area (Babia Góra National Park). The flooding occurred on 15–16 May 2014 due to the heavy rainfall, which on 15 May amounted to 138 mm. Whereas 216.5 mm of rainfall fell in the catchment area in three days. This resulted in a sudden and full spate streams, contributing to a significant transformation in the bottoms of their geomorphological valleys. There were created many new forms, while the pre-existing increased their size.</p>

Geomorphology of the Slovak Karst (Eastern Part)

ABSTRACTThe Slovak Karst region is an interesting European area that consists of karst plateaus at heights of 550–700 m, divided by deep gorges 300–400 m in depth. Gorges have classical fluviokarstic genesis with caves situated on the slopes indicating valley evolution during the Quaternary. During our geomorphological research, two plateaus were mapped – Jasov and Zádiel near the city of Košice. Due to the lack of typical karst forms, these plateaus are considered as less developed karst. According to our mapping, karst forms do in fact exist here, but the density and size of depressions are smaller than the western-situated plateaus. The dolines are not typical in that the shape and plateau relief is flat with east facing hills and valleys. The result of our field work is a geomorphological map at a scale of 1:10,000 involving the main geomorphological forms of diverse origin and age. Morphometric analyses of surface depressions were used to compare the Slovak Karst plateaus with other karst areas.

Geomorphometric analysis of cave ceiling channels mapped with 3-D terrestrial laser scanning

Abstract. The change of hydrological conditions during the evolution of caves in carbonate rocks often results in a complex subterranean geomorphology, which comprises specific landforms such as ceiling channels, anastomosing half tubes, or speleothems organized vertically in different levels. Studying such complex environments traditionally requires tedious mapping; however, this is being replaced with terrestrial laser scanning technology. Laser scanning overcomes the problem of reaching high ceilings, providing new options to map underground landscapes with unprecedented level of detail and accuracy. The acquired point cloud can be handled conveniently with dedicated software, but applying traditional geomorphometry to analyse the cave surface is limited. This is because geomorphometry has been focused on parameterization and analysis of surficial terrain. The theoretical and methodological concept has been based on two-dimensional (2-D) scalar fields, which are sufficient for most cases of the surficial terrain. The terrain surface is modelled with a bivariate function of altitude (elevation) and represented by a raster digital elevation model. However, the cave is a 3-D entity; therefore, a different approach is required for geomorphometric analysis. In this paper, we demonstrate the benefits of high-resolution cave mapping and 3-D modelling to better understand the palaeohydrography of the Domica cave in Slovakia. This methodological approach adopted traditional geomorphometric methods in a unique manner and also new methods used in 3-D computer graphics, which can be applied to study other 3-D geomorphological forms.

Ceiling erosion in caves: early studies and Zdeněk Roth as author of the concept

Ceiling channels belong to specific geomorphological forms occurring only in caves. Their origin has been commonly connected with the paragenesis. According to review articles, the terms of ceiling channel and paragenesis were defined by Philippe Renault (1958) for the first time. Nevertheless, Zdeněk Roth in his study of morphology and geomorphological evolution of the Domica Cave (southern Slovakia) published in 1937 (in Czech with long French summary) not only described ceiling channels, but he presented also their definition. Roth and other authors used the term later in describing features of several caves in Slovakia and Hungary. Based on original Roth observations, Josef Kunský defined the term generally in his textbook (1950 in Czech, 1956 in Polish and 1958 in French). The description of paragenetic ceiling channels by Renault (1958) can be considered as the first one only in Western European karstology literature.

A formal approach to the automated labeling of groups of features

A variety of recurring geographic entities form collections of point, line, or area features. Examples are groups of islands (Archipelago), relief features in deserts, periglacial lakes or geomorphological forms, such as drumlins and sinkholes. All these groups of features might be best identified with a single label. Surprisingly, the (automated) labeling of groups of features has received little attention so far. We propose a framework to determine formal measures that describe the geometric aspects of the cartographic design space for labeling feature groups. Our framework gives rise to a large variety of geometrically optimal labels. We list the optimal label positions and shapes for which labels can already be computed using existing algorithms. However, in many of the cases computing optimal label placements is still an open algorithmic question which can readily be investigated in future work. Once the necessary algorithms are developed, our framework provides an objective basis to investigate the geometric measures used by cartographers to label groups of features. We preliminarily explore the applicability of our framework using one of the geometric optimality choices.

Realizing the value of fluvial geomorphology

ABSTRACTFluvial geomorphological forms and processes exert a fundamental influence on riverine processes and functions. They thereby contribute significantly to beneficial services for humanity, yet remain largely undervalued. Major ecosystem service studies to date tend to overlook the contribution of geodiversity and geomorphological processes, particularly of fluvial geomorphology, to human well-being. Yet, management of the water environment which overlooks fundamental driving processes, such as those encompassed by fluvial geomorphology, is inherently unsustainable. Inferences from the literature highlight a broad range of contributions of fluvial processes and forms to the four ecosystem service categories of the Millennium Ecosystem Assessment, contributing to system functioning, resilience and human well-being. Fluvial geomorphologists can help society better address sustainability challenges by raising the profile of fluvial forms and processes to continuing human well-being and system resilience. To achieve this, we identify three challenges: (1) cross-disciplinary collaboration, addressing interrelations between biodiversity and geodiversity as well as broader scientific disciplines; (2) quantification to an appropriate level and, where possible, mapping of service generation and benefit realization; and (3) persuasive demonstration projects emphasizing how investment in this aspect of the natural environment can enhance service provision and net human benefits. We explore lessons learnt from case studies on river rehabilitation, floodplain management, and mapping ecosystem services. We contend that linking fluvial geomorphology to societal well-being outcomes via the language of ecosystem services provides a pathway towards social and economic recognition of relevance, influencing policy-makers about their importance and facilitating their ‘mainstreaming’ into decision-making processes. We also advance a prototype conceptual model, guiding fluvial geomorphologists better to articulate the contribution to a sustainable flow of services through better characterization of: (1) interactions between anthropogenic pressures and geomorphology; (2) how forms and processes contribute to ecosystem services; and (3) guidance on better management reflecting implications for service provision.

The Origin of Tar Al-Say’ed and Tar Al-Najaf, Karbala-Najaf Vicinity, Central Iraq

In central part of Iraq within the vicinity of Karbala-Najaf, two cliffs called Tar Al-Say'ed and Tar Al-Najaf form conspicuous geomorphological forms between the Mesopotamia Plain and the Western and Southern Deserts. The top surface between the two cliffs (tars) is covered by alluvial fan sediments, laid down by Al-Khir Valley when merging in a large depression due to the drop in the gradient of the valley. Consequently, the depression was divided into two parts, to the left is called Al-Razzazah Depression, whereas to the right is called Bahir Al-Najaf. This affected the course of the River Euphrates. The deposition stopped due to an uplift movement which caused the elevation of the two cliffs which are covered by alluvial fan sediments. The two cliffs had and are still suffering from retreating, due to lateral erosion by wave actions in Al-Razzazah Depression. Springs located along a straight line, sag pond, deflected drainage, shutter ridges and pressure ridges can be noticed in the area. The age of both cliffs is estimated to be upper Late Pleistocene—early Holocene.

Size and Characteristics of the DOC Pool in Near-Surface Subarctic Mire Permafrost as a Potential Source for Nearby Freshwaters

Subarctic peatlands are rich sources of organic carbon for freshwater ecosystems. Where those peatlands are underlain by permafrost, permafrost thaw may cause an initial release of bioavailable dissolved organic carbon (DOC) to surrounding freshwaters. In this study, we measured icebound and potentially leachable (extracted) DOC quantities and indices of DOC quality in active layer and permafrost layers from two subarctic peat mires, Stordalen and Storflaket. Most of the permafrost layers did not contain more organic matter or exportable DOC (as g kg-1 dry soil) than the overlying active layer, and there was no difference in aromaticity, molecular weight, or the ratio between labile and recalcitrant DOC extracted from the permafrost and active layer. However, DOC held in segregated ice of the near-surface permafrost had relatively low aromaticity compared to extracted DOC from the same depth. Total icebound and potentially leachable DOC in the Stordalen mire permafrost that is predicted to experience active layer deepening during each of the next 50 years corresponded to about 0.1% of the current annual aquatic export of DOC from the mire. We conclude that the pool of potentially leachable DOC currently stored in permafrost layers is small. We also highlight differences in permafrost organic material between the two studied mire systems, which has an effect on the pool and properties of leachable DOC that is potentially available for export during thaw. Moreover, the geomorphological form of permafrost thaw will influence future hydrological connectedness and DOC production, in turn determining future DOC export from the mires.

Characterizing fluvial systems at basin scale by fuzzy signatures of hydromorphological drivers in data scarce environments

Despite the relevance of river hydromorphology (HYMO) for integrated water resource management, consistent geomorphic information at the scale of whole river basin is still scarce, especially in emerging economies. In this paper, we propose a new, scalable and globally applicable framework to analyze and classify fluvial systems in data-scarce environments. The framework is based on a data-driven analysis of a multivariate data set of 6 key hydro-morphologic drivers derived using freely available remote-sensing information and several in situ hydrological time series. Core of the framework is a fuzzy classifier that assigns a characteristic signature of HYMO drivers to individual river reaches. We demonstrate the framework on the Red River Basin, a large, trans-boundary river basin in Vietnam and China, where human-induced morphological change, concretely endangering local livelihoods, is contrasted by very limited HYMO information. The derived HYMO information covers spatial scales from the entire basin to individual reaches. It conveys relevant information on subbasin hydro-morphologic characteristic as well as on local geomorphologic forms and processes. The fuzzy classifier successfully distinguishes abrupt from continuous downstream change and spatially dissects the river system in segments with homogeneous hydro-morphologic forcings. Successful numerical modelling of morphologic forms and process rates based on the HYMO signatures indicates that the multivariate, basin-scale classification captures relevant morphological drivers, outperforms an analysis based on local drivers only, and can support river management from diverse, morphology related perspectives over a wide range of scales.

How was the Anatolian Side of Istanbul Formed? A Geomorphologic Assessment (NW Turkey)

This study investigates the Geomorphological evolution of Anatolian side of Istanbul. This area is one of the most problematic and most discussed areas in the Near East geography. There is no detailed contemporary geological study undertaken in the area although there are various publications regarding the study area in terms of geomorphology. Current study aims to explicated the geomorphologic features of the study area. In addition to examining the related literature in terms of subject and field, topography maps scaled 1/25.000 were utilized in the study as main materials. Geological characteristics were compiled from geological maps with various scales and reports generated by different researchers. Mapping phase of the study was undertaken with the help of Geographical Information Systems (GIS) software ArcGIS/ArcMAP 10 package program. Obtained data were checked in situ via field surveys and missing points were completed. It was observed that Anatolian side of Istanbul was a product of elements and processes that completely developed in the new tectonic period. The field was observed to be the product of various morphological transformations, different developments and different elements and processes with a topography which has various landforms and polycyclic features due to a lengthy and discontinuous process. Time concept which started with the first lithological storage in Lower Ordovician continued with the deformation related to the right lateral heave around the Marmara Sea and with the clockwise rotation of the study area in Middle-Upper Miocene. The distortion caused by relief inversion during the geomorphologic development caused the formation of embedded valleys in places as a result of drainage gaining a new energy. The study area has obtained its contemporary geomorphologic form.

Plants as river system engineers

ABSTRACTPlants growing within river corridors both affect and respond to fluvial processes. Their above‐ground biomass modifies the flow field and retains sediment, whereas their below‐ground biomass affects the hydraulic and mechanical properties of the substrate and consequently the moisture regime and erosion susceptibility of the land surface.This paper reviews research that dates back to the 1950s on the geomorphological influence of vegetation within fluvial systems. During the late twentieth century this research was largely pursued through field observations, but during the early years of the twenty‐first century, complementary field, flume and theoretical/modelling investigations have contributed to major advances in understanding the influence of plants on fluvial systems. Flume experiments have demonstrated the fundamental role of vegetation in determining river planform, particularly transitions from multi‐ to single‐thread forms, and have provided insights into flow–vegetation–sediment feedbacks and landform building, including processes such as channel blockage and avulsion. At the same time, modellers have incorporated factors such as moisture‐dependent plant growth, canopy and root architecture and their influence on flow resistance and sediment/bank reinforcement into morphodynamic models. Meanwhile, field investigations have revealed that vegetation has a far more important and complex influence on fluvial systems than previously realized.It is now apparent that the influence of plants on river systems is significant across space scales from individual plants to entire forested river corridors. Small plant‐scale phenomena structure patch‐scale geomorphological forms and processes, and interactions between patches are almost certainly crucial to larger‐scale and longer‐term geomorphological phenomena. The influence of plants also varies continuously through time as above‐ and below‐ground biomass change within the annual growth cycle, over longer‐term growth trajectories, and in response to external drivers of change such as climatic, hydrological and fluvial fluctuations and extremes. Copyright © 2013 John Wiley & Sons, Ltd.

Late Cenozoic geological evolution of the northern North Sea: development of a Miocene unconformity reshaped by large-scale Pleistocene sand intrusion

Despite hundreds of wells and extensive 3D seismic coverage, the late Cenozoic geological evolution is still not completely understood in the prolific northern North Sea hydrocarbon province. This is mainly due to post-depositional modification of sediment body geometries by injections of large volumes of sand. Using high-quality 3D seismic and well data above the Snorre and Visund Fields we propose a new late Cenozoic geological model that describes pre-injection geomorphological forms and sand injection events. The northern North Sea was exposed during mid- and late Miocene times (10 myr), simultaneously with the regional Miocene compression phase. Subaerial and coastal cliff erosion formed escarpments, up to 100 m high. Around the Miocene–Pliocene boundary the northern North Sea subsided below sea level and a layer of glauconitic sand was deposited. During the early Pleistocene glacial period, high fluid pressures fractured the regional Hordaland Group seal. Fluidized sand either vented to the sea floor or was deposited in irregular sand bodies up to 150 m thick. Above them, the injected sand lifted the overburden and formed irregular mounds that reshaped the top Hordaland Group unconformity regionally. During the glacial period the area was tilted regionally by 0.3° towards the NNE.

Análise estratégica do relevo e planejamento territorial urbano: compartimentos ambientais estruturantes na macrometrópole de São Paulo

The great urban spreading occurred in metropolitan areas worldwide, still in intense movement of urban expansion on old rural areas, evidenced that the environmental problems, which most affect the territories nowadays, are the result of intensive urbanization processes. In this sense, the decision about where and how to occupy a territorial area must pass through a different analysis on the topography, not anymore as just as static and passive element, which conforms to the several urban uses requested for a strategic approach linked to the urban territorial and environmental planning. By highlighting the main lines and environmental structuring compartments of a landscape under the topographic aspect and the processes of its geomorphologic form, it is possible to better glimpse the relationships urban processes and imposed infrastructures establish with these strategic landscape portions, which allow to define ways of use and land occupancy more suitable to urban and natural processes, aiming the selection of the main topographic sectors designated to environmental services for preservation of spaces of natural processes occurrence.

A geometria fractal da rede de drenagem da bacia hidrográfica do Caeté, Alfredo Wagner-SC

Os objetivos deste trabalho foram estimar e avaliar a dimensão fractal da rede de drenagem da bacia hidrográfica do Caeté, em Alfredo Wagner, SC, a partir de diferentes métodos, com o propósito de caracterizar as formas geomorfológicas irregulares. A rede de drenagem apresenta propriedades multifractais. As dimensões fractais para os segmentos individuais (df) e para a rede de drenagem inteira (Df) foram determinadas por métodos que se fundamentaram nas razões de Horton e pelo método da contagem de caixas (Box-Counting). A rede de drenagem tem característica de autoafinidade. A dimensão fractal proveniente da relação de parâmetros obtidos pelas Leis de Horton apresentou resultados dentro dos limiares da teoria da geometria fractal.