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MORPHOMETRIC ANALYSYS, IN THE CARPATHIAN AND SUBCARPATHIAN VÂLSAN RIVER

Marius-Florin MARCU

University of Bucharest, Faculty of Geography Universitatea din Bucureşti, Facultatea de Geografie

Abstract

The Vâlsan river basin, is located in the central-southern territory of Romania, overlaps three distinct morpho-structural units: mountains, hills, and plateau. The river is formed from springs located below the top of the glacial cirque Scărişoara Peak (2489 m). Morphometric analysis was performed for the mountain and hills. The hydrographic network is the five size, dense, with a high degree of branchhing wich differ from one sector to another, depending on a local phisical-geographical conditions. The density value is over than 8 km/km2, and relief energy with maximum values of 600 m, are directly influenced by lito-structural, crystalline rocks in to the mountain, settling in to the foothills, ordered monoclini general north-south direction. Keywords: Vâlsan river, Cândeşti gravels, hydrographic bazin, Poieni depression, Dobroneagu river.

1. INTRODUCTION

Located in the central-southern part of the territory of România, Vâlsan river basin,

overlapping morphostructural three distinct units (fig.1):

- Făgăraş Mountains (southern flank);

- Argeş Subcarpathians (Argeş Muscelele);

- Getic Plateau (Gruiurile Argeşului).

From a mathematical perspective, the analysis falls within the following geographical

coordinates:

- northern limit corresponding secondary crest of Făgăraş Mountains is given by 45˚34'52"

parallel north, most point is given by the intersection of the 24˚43'59" meridian east longitude;

- in the south, is 45˚6'23 " parallel north latitude (the alignment Cândeşti gravels), the

southern most point is difficult to determine, pursue geological limit to the intersection 24˚17'14"

meridian east longitude;

- the western limit is on the meridian alignment 24˚40'47" east longitude, the extreme point

is located at the intersection with the 45˚29'1" parallel north;

- to the east, it is bounded by 24˚48'52" meridian east longitude, with most point in the

Subcarpathian at the intersection with 45˚10'25" north latitude.

Thus we see that in terms of latitude, Vâlsan river basin in the Carpathian and

Subcarpathian, takes place 28'29 " and has an ongoing longitudinal to 8'5".

©Department of Geography. Valahia University of Targoviste Annals of Valahia University of Targoviste. Geographical Series

Tome 13/2013 Issues 2: 99-106

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Fig. 1. Vâlsan river position

Vâlsan river basin is part of the river, located in the southern group of tributaries of the

Danube, is the 10 th largest tributary of the river basin with a total area of 358 km2 and flows for a

distance of 83 km from north to south. Vâlsan river basin is long and narrow with a straight length

of 68 km and 2177 m difference in level between the peak (Scărişoara Mare 2489 m) and the point

of confluence with Argeş river (Merişani town 312 m alt.).

In the analysis, mountains and Subcarpathian, occupies an area of 235,855 km2 and travel

in a straight line a distance of 50 km to the town Stroieşti to contact Getic Plateau (Cândeşti

gravels). Crossing the morphostructural units distinct geomorphological processes results in a

natural setting and biopedoclimatic components (Ielenicz, Pătru, Ghincea, 2003).

1.1. Research Methods For morphometric analysis of Vâlsan basin elements, we used the following methods:

- field observations and analysis;

- geomorphological mapping using topographic maps at scale 1: 25,000 (Grigore, 1979);

- digital mapping of the area by digitizing topographical and geological maps (1: 25 000, 1, 50 000,

1: 200 000) using Arc GIS 9.3 software;

- Horton-Strahler morphometric method for achieving network hierarchy basins, drainage density

and relief energy.

2. MORPHOMETRIC ANALYSIS 2.1. General morphometric characteristics Vâlsan river basin area of the Carpathian and Subcarpathian is 235,855 km2 resulting value

from the calculations and measurements performed using Arc GIS 9.3 program, after topographic

maps in scale 1: 25 000 (Military Topographic Directorate, 1978, 1981, 1982). The perimeter basin

river watershed Vâlsan in the analysis is 131,995 km.

The straight length is 50 km, while the effective length of the river measured 63,33 km,

resulting in an index of sinuosity Is = 1,27, a value which indicates that Vâlsan river is a river

Carpathian and Subcarpathian the route tortuous.

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The total energy of the analyzed basin relief is calculated from the highest point,

Scărişoara Mare (2489 m) and alignment Stroieşti village (400 m), with a value of 2089 m.

The basin shape, can be expressed using several mathematical expressions according to the

parameters taken into account and the purpose for which it applies.

According to Horton, shape index is the ratio of drainage area (S) and the square of basin

length (L2). The index form of Vâlsan river basin: If = S/L2, If = 0.059

2.2. Valleys The hydrographic network was classified in Horton-Strahler system consisting of five

orders of magnitude (Grecu, Comănescu, 1998). Morphographical and morphometric characteristics

of the Vâlsan river basin, differ from one sector to another, depending on the local physical

geography. Relief units have crossed the Vâlsan river not homogeneous geological and

geomorphological, this causing a variation in the degree of branching network of valleys. The basin

is elongated and narrow shape throughout the river, a situation which does not allow immediate

formation of higher order rates. Both the unit and the unit Carpathian mountain, Vâlsan river basin

is well developed, with many lower order tributaries leading high drainage density values (> 8

km/km2). Total segments and sub-Carpathian mountain river basin is 1270, of which: V order = 1,

IV order = 9, III order = 51, II order = 224, and I order = 985.

The most common are the valleys of order I (985), being the most recent rains bodies

located in both developed into the mountains, in the alpine (glacial cirques) and into the Carpathian-

looking ravines and torrents, deepened warehouses gravels, sands and clays, with steep banks and

affected by runoff and landslides, with lengths ranging from 0,044 to 2 km, with an average of 0,5

to 1 km and steep slopes (> 35˚). Longest to order I, is given by Staurul (> 2 km), located

downstream of valley mountain unit Zănoguţa with spring in Dobroneagu glade. Higher values for

length segments of order I is recorded Ţepilor Valley (the alpine), Ţarinei Valley (Poieni

depression) and Dobroneagu basin (Vâlsan main tributary). Into the Carpathian, segments order I to

great lengths to meet Lungă Valley (> 2 km) Muşăteşti depression, Stejarul brook (> 1,3 km) in

Galeşu – Slămneşti area and torrential basins across the Părului Valley (Muscelul Nuculeţ )

Hotarelor Valley, the Ogoarelor Valley (downstream from Vâlsăneşti).

The II (224) order valley measured lengths between 0,045 to 4,3 km, with large slopes. In

the glacial thalweg has rapids and waterfalls, the slopes have gradients exceeding 35 - 400. Second

order form even cirque (2200 m alt.), The first order segments, large values of the length of the

river segments are calculated into the mountain (Făgăraş Mountains) for a river segment

Dobroneagu (> 2,3 km ), Boilor brook (> 2 km) Largă valley (> 1,3 km), Râpei Valley, Ursului

Valley (> 1 km) and Zoruleasa brook (> 3,7 km) in the Ghiţu massif. Into the Carpathian recorded

the highest value for the second order, Mlăcii Valley (> 4,3 km).

The III (51) order valleys have lengths ranging from 0,4 to 2,6 km, is formed in the glacial

valley (1980 m alt.) of II order segments. The largest lengths for this order were measured Zănoaga

Valley (> 2,6 km), Cheii Valley (> 1,2 km) into the mountain and Satului Valley, Burdimanu

Valley (> 1 km), the unit Carpathian. In this sector, Vâlsan river receives tributaries inferior,

developing superior orders are subject to narrow the width of the basin (approx. 7 km) and lithology

(crystal rock).

The IV (9) order valleys is formed from 1495 meters altitude and is the main course of the

river Vâlsan a distance of 1,96 kilometers, to the point of confluence with Dobroneagu river (third

order) to get into depression Făgărăşan corridor (Poieni depression), where higher order switch. The

IV order length segments measures range from 1,5 to 6,25 km, the longest being Dobroneagu. Into

the Carpathian, representative segments IV orders are Părului Valley and Maş Valley .

The V order valley is the maximum value for Vâlsan river basin and Subcarpathian

mountain. Is formed by the confluence of Dobroneagu (898 m alt.) Vâlsan meadows depression

pervades space, cut a key sector (10 km) in metamorphic and conglomerates rocks of Ghiţu massif

and enter in the Subcarpathian (Muscele) of Brădet to Stroieşti locality, the alignment that was set

by all authors, contact Cetic Plateau (Cândeşti gravels). Throughout the period, receiving inferior

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tributaries, with steady: Galeşu, Robaia, Prosia, Satului Valley, Faurului Valley, and tributaries

shortest temporary and torrential rain raised to high.

2.3. Drainage density

Drainage density is consistent with the

general development of the river system, the

structural and lithological differences, being

influenced by the human factor: deforestation,

construction of adductions (Valea cu Peşti) and the

dam. In drainage density mapping was vectorised

and elementary thalweg (fig. 2). Spatial

drainage density distribution indicates differences in

the evolution of the river, the valley system (length,

branching), depending on the structure, lithology

and characteristics biopedoclimatics.

Drainage density values for the

Subcarpathian, Carpathian basin and the river varies

between 0-8 km/km2 Vâlsan, maximum values

being calculated into the Carpathian basin rainfall

Muscelelor sector where lithologic substrate (clay,

marl, gravel, sand) enables deployment in

accelerated slope processes (runoff, gullying,

torrent), developing rain pools on large areas with

high fragmentation. To drive mountain peaks range

from 6.1 to 8 km/km2 are specific catchments of

tributaries and especially to their confluence with

the Vâlsan river (tab. 1).

The lowest values of drainage density, 0-2

km/km2, occupies an 74,34 km2 (31.52% of the

pool) area, located on interfluves and leveling

surfaces of old drive and Carpathian mountains.

Into the mountain you can see a small

amount of drainage density on interfluves:

Scărişoara, Picuiata, Jepii de Sus, Piatra Tăiată,

Ţuica, Largă Valley, bounding the river basin

Vâlsan from Argeş and Doamnei river, and the

mountain heights of Jepii de Jos, Dobroneagu,

inside of the basin and Ghiţu massive.

Tab.1. River basin drainage density values

Into the Carpathian, small values of drainage density (0-2 km/km2) meet on Muscelelor

Heights High (Chiciura, Masa de Piatră, Poiana de Sus, Poiana cu Ghicitori, Poiana cu Tăieturi)

Deleanu Hills, Prosiei and southern corridor interhill depression (depression Muşăteşti), Râpa

Zmeului hills, ridge Muscelului.

Nr.

Crt.

Value fragmentation (km/km2) The area ocupied (km2) Pool area (%)

1 >8 0,165099 0,07

2 6,01-8 6,580355 2,79

3 4,01-6 54,105137 22,94

4 2,01-4 100,63932 42,67

5 < 2 74,341496 31,52

TOTAL POOL 235,855 100,00

Fig. 2. Drainage density map of Vâlsan river basin

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2.4. Energy relief The relief, are the result of erosion on lithologic substrate, calculated for a standard unit.

Energy map relief program was performed using Arc GIS 9.3, based on topographic maps 1: 25 000

(fig. 3), were obtained following ranges of values: <100 m, 101-200 m, 201-300 m, 301 - 400 m,

401-500 m, 501-600 m, 601-700 m. The largest share has range 101-200 m and 601-700 m lowest.

Range with values <400 m, has a share of

10,91%, which represents an area of 25,73 km2

and is found only in the Subcarpathian on

restricted areas in Brădet depression and south of

Muscelele Înalte in Muşăteşti depression the

central corridor of the Vâlsan valley, Vâlsăneşti-

Costeşti sector.

The 101-200 m interval, has a minimal

presence into the mountains, the valleys of

tributaries Dobroneagu, Dimia and Poieni

depression. Into the Carpathian is most

widespread, encompassing the entire basin, except

Muscelele Înalte, whose substrate lithological

harder (sandstones, burdigalien conglomerates),

developed with higher energies relief. The lower

energy landscape in Carpathian unit is due to

lithology, loose rocks (clay, marl, gravel, sand)

promote accelerated manifestation slope processes,

causing instability and deepening valleys while

decreasing the height of the slopes.

The 201-300 m interval, occupies an area

of 54,88 km2, accounting for 23,27% of the total

basin. Occupy large areas into the mountains,

where hardness rocks (crystalline schists,

amphibolites), determines the stability of slopes

and deep valleys development. Carpathian unit

values of this range are characteristic Muscelele

Înalte.

The 301- 400 m interval, and 401-500 m,

occupies the 42,55 km2 (18.04%) and 22,1 km2

(9,37%) and are typical mountain drive, Vâlsan

valley and major tributaries valleys : Dimia,

Zănoaga, Dobroneagu and isolated, the Ghiţu

massif restricted areas, tributary valleys

perpendicular to the Vâlsan river (tab. 2).

The 501- 600 m interval, and 601-700 m,

occupies small areas of 6,98 km2 (2,95%) and 1,98

km2 (0,84%) in the glacial valleys tributary originating in secundary circuses summits Scărişoara

and Picuiata located in Făgăraş mountains gorges of.

In Ghiţu massif, 501-600 m values are recorded in the key on a small area.

Tab. 2. Energy values relief and river basin areas occupied

Nr.

Crt.

Energy value (m/km2) The area ocupied (km2) Pool area(%)

1 601-700 1,981182 0,84

2 501-600 6,9577225 2,95

3 401-500 22,099613 9,37

Fig. 3. Energy map Vâlsan river basin relief

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Nr.

Crt.

Energy value (m/km2) The area ocupied (km2) Pool area(%)

4 301-400 42,548242 18,04

5 201-300 54,883458 23,27

6 101-200 81,653001 34,62

7 < 100 25,73178 10,91

TOTAL POOL 235,855 100,00

2.5. Hypsometric Vâlsan river basin in the Carpathian and Subcarpathian morphometric characteristics are

those of Făgăraş massif, Ghiţu massif and specific Getic Subcarpathians (Muscele). The specific

Vâlsan valley are high relief energy, lithologic and intensive mosaic landscape erosion (glacial,

fluvial and anthropogenic).

The analyzed area is 235,855 km2 and runs from the mountain, on the south side of Făgăraş

massif and to limit the Getic plateau.

Looking at the map, we see that steps like an amphitheater hypsometric down from the

north, from Vâlsan springs up out of the mountains, is carried out in terms of steps into the

Carpathian mountains.

I used to hypsometric mapping maps comprising Vâlsan basin and Carpathian mountains

establishments 1:25 000 scale (fig. 4).

Were differentiated, nine hypsometric levels at intervals of 250 m from the table compiled

based on hypsometric values obtained, it is observed that the highest weight relative to the total area

of the basin (235,855 km2), is the hypsometric level between 501 - 750 m, the lower the level of

2251-2489 m, being the highest (tab. 3).

Hypsometric level between 2251-2489 m, covers an area of 3,2 km2, representing 1,36% of

the total basin is located into the mountains, in the alpine gipfelflur corresponding higher level,

represented by pyramidal peaks, remnants of penetrating post-mezocretacic (Sârcu, 1971) and

surface erosion Borăscu I level (Scărişoara Peak, Piatra Tăiată, Picuiata, Jepii Lower) located a

secondary top of Făgăraş mountains.

2001-2250 hypsometric level, occupies 3,74 km2, representing 8,82% of the total analyzed

basin area. It ordered a side of the glacial cirque valley located here is the glacial circus Vâlsan and

secundary circuses. The altitude, corresponds to Borăscu II level erosion and extends south on the

left and right valley to the peaks Gruişoru and Jepii the Top.

Tab. 3. Hypsometric steps values and areas

Nr.

Crt.

Hipsometric step (m) The area occupied (km2) Pool area (%)

1 2251-2489 3,207628 1,36

2 2001-2250 8,820977 3,74

3 1751-2000 15,236233 6,46

4 1501-1750 20,660898 8,76

5 1251-1500 25,519511 10,82

6 1001-1250 29,859243 12,66

7 751-1000 40,732158 17,27

8 501-750 70,331961 29,82

9 < 500 21,48639 9,11

TOTAL POOL 235,855 100,00

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The 1751-2000 m hypsometric level, has a

footprint of 15,24 km2, which represents 6,46% of

the total basin area. Fully occupy glacial valley

floor framed by a side of Scărişoara and Picuiata

ridges, extending southward framing glacial

valley, Jepii and Ţuica (right valley) peaks and a

narrow strip that runs until Lespezi and

Dobroneagu southern mountains. In Dobroneagu

glade be found parts of smoothing surface Râu-Şes

I.

The 1501-1750 m hypsometric level,

covers an area of 20,66 km2, representing 8,76%

of the total, is underway in the north (upper limit

of the forest), to Scroafa Peak (west) and Clabucet

Nucşoarei (east). For the most part, the

hypsometric is included in this range the forest,

except fragments leveled surface Râu-Şes II

(Zănoguţa glade).

The 1251-1500 m hypsometric level,

covers an area of 25,52 km2, accounting for

10,82% of the basin. Down from north to south,

following the shape of an amphitheater, holding

the first in the central valley, branching is a south

side of the valley to Mount Arefu (right) and

Domneşti ridge (left), until Poieni depression and

Ghiţu massif (Răchitei Peak, Scăldătoarei Peak).

The 1001-1250 m hypsometric level from

north to south down the valley and tributary

Vâlsan main mountain unit (Dobroneagu) with a

large development space Poieni depression and

Ghiţu massif (Ulmului Peak, Brăcinarului Peak),

extending up into the Carpathian, the interfluve of

right, D. Chiciura (1218 m).

The 751-1000 m hypsometric level, has a

share of 17,27% of the total, occupying an area of

40,73 km2. Takes place in space intra depression

(Poieni depression), the key (Ghiţu massif), Brădet depression contact with a broad right way

valley, Muscelele Înalte (D. Chiciura, D. Burdimanu). On the left appears as patches valley, the

Aluniş, Seciuri and Toaca hills.

The 501-750 m hypsometric level, is the highest way, occupying an area of 70,33 km2,

accounting for 29,82% of the total basin area.

Muscelele valley corridor occupies high to get into Muşăteşti depression where the heights

flanking the Vâlsan valley Muscelele Mijlocii to contact plateau (Stroieşti town).

Hypsometric level values up to 500 m, covers a small area of only 21,49 km2, representing

9,11% of the total area of the basin. Is the lowest (the meadow) with well defined terraces, which

are planted orchards.

3. CONCLUSIONS

- Vâlsan basin falls into the torrential river category type, with a high probability of

passing the order 6, hydrographic network hierarchy in Horthon-Strahler system;

Fig. 4. Hypsometric map of Vâlsan river basin

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- Due basin extending the geographical units with different geological characteristics were

different sectors with different characteristics;

- In the Carpathians are recorded the highest values hypsometric, energy relief and

drainage density average values;

- In the Subcarpathian identify hypsometric intervals between 400-1200 m and energy

values relief contained predominantly between 100 - 200 m;

- Torrents is more pronounced due constitution Carpathian lithological unit (clay, marl,

Sands), which favored the expansion and development of primary thalweg.

REFERENCES

Grecu Florina, Comănescu Laura, (1998), Studiul reliefului, Ed.Universităţii din Bucureşti;

Grigore, M.,(1979),Reprezentarea grafică şi cartografică a formelor de relief, Editura Academiei

R.S. România, Bucureşti;

Ielenicz M., Pătru Ileana-Georgeta, Ghincea Mioara, (2003), Subcarpaţii României, Editura

Universitară, Bucureşti;

Sârcu I. (1971), Geografia fizică a României, Editura Didactică şi Pedagogică, Bucureşti.

Topographic maps 1: 25.000, Direcţia Topografică Militară, Bucureşti, 1981.

Geological maps 1: 200 000, foaia Piteşti, scara 1: 50 000, foaia Cumpăna.