Presupunand ca bolovanul ramane intr-o pozitie stabila si nu se rostogoleste sau nu se misca dupa depunere, acest bolov va oferi o estimare excelenta pentru varsta de expunere pentru moraina. Et l on s est aperçu, une fois de plus, que l extension urbaine dans bon nombre de nos villes n a pas toujours respecté les cours d eau.
Cuza, Iaşi Prof. Cuza, Iaşi Dr. Regina Elisabeta, nr.
- Datarea cu nuclide cosmogene - Bcr Club Antreprenori
- Metodele de datare sunt sigure și predicțiile lor se potrivesc unele cu altele.
- Metode de datare | O Privire Sceptică
- Dating felixstowe
Hazard Vulnerabilitate Risc, Edit. The map of vulnerability to hydrogeomorphological processes occurring in the plain landforms plain units is a synthetic map emphasizing the present state of topographic relief evolution, the trend of change of hydrogeomorphological systems and the evolution of man-environment relationships.
Being a synthetic cartographic representation, it relies on analytical maps, developed on the base of quantitative indexes. The paper aims to analyze the main factors that determine the vulnerability of the study area Mostistea catchement.
For the Romanian Plain, where quasi-horizontal interfluves and shallow channels are widespread, the assessment of vulnerability to hydrogeomorphological hazards relied both on common and on specific criteria for the two major landform units.
In order to assess some of the landscape features several morphometric indexes were computed with regard to the almost flat surfaces to the channels of the rivers capable of flooding the adjacent plains, and to the channel processes. Subsequently, analytical maps were prepared based on the obtained values.
Folosind nuclide cosmogene in geologia glaciara
By employing GIS techniques, we finally came up with two synthetic vulnerability maps, one for the interfluves and the other one for the river channels. Keywords: vulnerability, hydrogeomorphological hazard, rivers, flat interfluves, Romanian Plain. Introduction, objectives and study area The map of vulnerability to hydrogeomorphological processes of the floodplains emphasizes not only the present state of relief dynamics and the trend of change of hydrogeomorphological systems, but also the evolution of man-environment relationships.
Being this a synthetic cartographic representation, it relies on previously developed analytical maps. The first stage of the investigation consisted in a detailed assessment of the factors influencing relief dynamics, as well as in the analysis of morpho dynamic potential and geomorphological processes. This method was tested on selected areas in the Romanian Plain, a Quaternary physiographic division, formed within a former sedimentary basin, which long ago was lying inside the Carpathian- Balkanic arch Vîlsan, These territories are part of the Mostiştea Plain, which is situated in the eastern section of metode cuaternare de dating walker Romanian Plain, east of the Arges River Fig.
Here, the Upper Pleistocene deposits, which are metode cuaternare de dating walker for the formation and dynamics of micro-landforms, overlie the Mostiştea sands Grecu et.
In order to assess some of the landscape features several morphometric indexes were computed with regard to the quasi-horizontal surfaces vulnerable to compaction, piping, salting, salinization or waterloggingto the channels of the rivers capable of flooding the adjacent territories, and to the channel processes lateral erosion, meandering, caving-ins of the riverbanks and sedimentation within the channels Grecu et.
In the plain regions, the hazards affecting the interfluves and those affecting the channels have distinct genesis and dynamics, hence the necessity to make the respective vulnerability maps based on specific criteria. Revista d e geo morfologie vol. They served as a base map for the digitization of contours, elevations and perennial and ephemeral streams.
Meniu de navigare
Method There are several methods allowing the developing of vulnerability map, but each of them must necessarily take into account the geographical and geological features of the study area, which derive from the geographical location of the territory. The present study deals with a plain unit quite homogeneous from the geological and climatic points of view.
Unlike the classic method of analyzing land vulnerability based on the arithmetic mean of the features shown by the thematic maps taken into accountour approach was somehow different.
The values of the density of loess sinkholes were reclassified by assigning them points from 1 to 6, while the areas with different types of collapsible rocks were given values from 7 to 9 points.
In order 7 Vulnerability map to hydro-geomorphological processes Romanian Plain 7 to establish the intervals with different degrees of vulnerability we multiplied the reclassified values and we obtained six categories of vulnerability to field hydrogeomorphological processes especially sagging and pipingas follows: stable land less than 14 pointslow vulnerability pointsmedium vulnerabilityhigh vulnerability and very high vulnerability.
Metode de datare
The IV interfluvial vulnerability map has a scale of Table 1. In order to create the vulnerability map to hydrogeomorphological processes of the areas lying along the river courses the product obtained by multiplying the attributes of quantitative maps drainage density map and relative relief map Fig. A particular attention was paid to the position of settlements within the channels and to the distance separating metode cuaternare de dating walker from metode cuaternare de dating walker river.
Thus, the following five categories of vulnerability to the channel hydrogeomorphological processes were obtained: stable land less than 6 pointslow vulnerability 6. Index classification on categories of fluvial vulnerability After reclasification Local relief value m Ater reclasification density X local relief Vulnerability classes stable cources low medium high very high 4.
The vulnerability map 4. The vulnerability map to interfluvial processes Judging from the geomorphological processes specific for the flat interfluves of the Mostistea catchment the most important variables that might influence the occurrence and distribution of loess sinkholes are the following: land morphology and geomorphological processes, sinkhole morphometry density, circularity ratio, elongation ratio, shape factor and sinuosity index ; soil conditions soil type ; physical, mechanical and chemical properties of the loess formations; thickness of loess deposits; depth of water table Liteanu, ; digital elevation model; digital model of slope gradients, derived from the DEM; land use Corine Land Cover Drainage density X local relief Fig.
Slope X lateral cutting 9 Vulnerability map to hydro-geomorphological processes Romanian Plain 9 Land morphology and geomorphological processes. Sagging is more active in endorheic and semiendorheic areas e. The resulted landforms are represented especially by loess sinkholes.
Loess sinkholes have the highest density on the Ciornuleasa flatland and on the third terrace of the Danube, where the high thickness of loessoid deposits and the deep water table have encouraged the appearance of some small 10 m 2 to 3. In the northern part of the catchment and on the Ialomiţa Mostiştea interfluve, loess sinkholes metode cuaternare de dating walker a lower density, but their area is larger and sinuosity coefficient is high. In order to establish as precisely as possible the vulnerability to hydrogeomorphological processes, the metode cuaternare de dating walker areas identified on topographic maps and ortophotoplans were correlated with the distribution of typical phreatic-wet chernozems, levigated chernozems weakly eluviated affected by pseudogleyzation phenomena found in loess sinkholes and sagging areasphreatic-wet cambic chernozems and phreatic-wet, levigated vertic chernozems, affected by gleyzation.
In the Mostistea catchment, three areas with collapsible loess formations have been identified based on the values of an index that evaluates wet loess compaction under self-weight I mg according to asian dating community Normative regarding the foundation of constructions on collapsible grounds sensitive to damping, Technical University of Constructions, Bucharest, In order to assess supplementary sagging, other indexes were taken into account: granulometry, chemical-mineralogical composition, thickness of loessoid deposit, plasticity, shear resistance under natural and flooded conditions, sagging, volumetric weight, skeletal density and so on.
According to how these soils behave when become wet, they can be classified as follows: Group A: soils that experience a supplementary sagging I mg metode cuaternare de dating walker than 5 cm; A 1 with continuous spread in the Mostiştea Plain ; A 2 with discontinuous spread in the central section, and especially on the terraces of the Olt and the Danube ; Group B: soils that experience a supplementary sagging I mg equal with or higher than 5 cm.
Walker asked Piper to be his girlfriend *DATING*🔐❤️
Depending on the compaction rate under selfweight, values were assigned to each soil category so that to obtain results as reliable as possible in the aftermath of their multiplication by the values referring to the density of loess sinkholes.
In this way, five classes of values were established, from stable lands to highly vulnerable ones.
The vulnerability map of interfluvial areas lying within the Mostiştea catchment mirrors the existence of some sections with high and very high vulnerability to sagging and tunnel erosion Fig. The sagging areas have developed on loessoid deposits, cm thick, which when wet experience supplementary sagging under self-weight, with I mg values higher than 40 cm collapsible loesses B 1.
Here, the bad conditions for surface flow endorheic and semi-endorheic areas and the high depth of water table 30 m and even more have conditioned the appearance and development of underground erosion metode cuaternare de dating walker.
On metode cuaternare de dating walker territories, collapsible deposits with supplementary sagging values less than 5 cm collapse A 1 or less than 40 cm collapse B 1 prevail. Here, the typical loess is 10 to 15 cm thick and the water table lies between 5 and 10 m deep, which explains the low density of sagging areas Land vulnerability map to fluvial processes As far as the channels are concerned, their dynamics is strongly influenced by the relative altitude, the drainage density, the presence of stretches with steep banks, the banks gradients and the distance to the nearest settlement or built-up area.
Relative altitude ranges from 90 to 11 m. The drainage density the values were reclassified through raster multiplication density multiplied by energy resulting six classes of vulnerability from stable hong kong cupidon dating to highly vulnerable areas.
The presence of stretches with steep banks stretches of steep-sided valleys were identified and mapped in the field.
A S O C I AŢIA G E O M O R F O L O G I L O R D I N R O MÂ N I A REVISTA DE GEOMORFOLOGIE
Subsequently, they were multiplied by the gradients of the river thalwegs. By doing this, we identified the stretches with high and very high vulnerability lying along the middle Săruleşti and Valea Argovei and lower course Lake Mostiştea of the Mostiştea River.
The banks gradients several stretches with steep banks were identified and mapped. The distance to the nearest settlement or builtup area.
Cum putem sa intalnim roci?
The mapped valley stretches affected by erosion processes were correlated with the nick dating specialist values and thus a vulnerability map to the valley processes came into existence. In order to highlight as accurately as possible the stretches vulnerable to the channel processes these two products were in their turn multiplied and the result was the vulnerability map to river processes Fig.
From the analysis of vulnerability map, we were able to conclude that stable lands and the areas with low and medium vulnerability are prevalent However, at Săruleşti, Gurbăneşti, Valea Argovei and around Lake Mostiştea, the risk induced by channel processes is high detachments, collapses and lateral erosion.
Consequently, the built-up areas settlements and the agricultural lands stretching along the river s middle and lower course are prone to degradation expressed through riverbank retreat.
Interfluvial vulnerability map Table 3.
Fluvial vulnerability map 5. Conclusions - The plain areas in general and the Romanian Plain in particular, are difficult to decipher from the geomorphological point of view. However, field investigations and the employment of proper study methods lead to pertinent conclusions regarding the lowlands hydrogeomorphological dynamics, which are very useful for human society.
Datarea cu nuclide cosmogene 27 Cum putem sa intalnim roci? Utilizarea nuclidelor cosmogene in geologia glaciara Strategii de esantionare datarea de nuclide cosmogene Dificultati in intalnirea cu nuclide cosmogene Calcularea unei varste de expunere Lectura ulterioara Referinte Comentarii Cum putem sa intalnim roci?
The development of the vulnerability map is based on quantitative analysis undertaken at different moments in time. Thus, the outcome is a qualitative map, which allows an easier comparison of metode cuaternare de dating walker areas exposed to different types of processes. Applications to hazard and risk diagnosis in areas of Romanian Plain" Director, Prof.
Grecu Florina. The analysis of vulnerability to hydrogeomorphological processes is important for the proper management of the associated risks.
Metode de evaluare în geomorfologie, Edit.