Lucr ări Știin țifice vol. 58 (1) 2015, seria Agronomie [615882]

Lucr ări Știin țifice – vol. 58 (1) 2015, seria Agronomie

147

TRACKING DOWN THE MODIFICATIONS OF THE RIGHT BANK
OF THE PRUT RIVER IN THE TERRITORIAL ADMINISTRATIVE UNIT
OF PRISACANI COMMUNE – IASI COUNTY

Daniel George BUTNARIU 1, Ersilia Valeria ONIGA 1, Florian ST ĂTESCU 1

e-mail: [anonimizat]

Abstract

This article presents the change while following th e right bank of the Prut River from territorial adm inistrative unit of
the Prisacani commune – Iasi County in the period 1 985 – 2015, caused by erosion / deposition of sediments, highlighted
by comparing the ground surface modification of Pri sacani Territorial Administrative Unit (TAU) in the observ ed
period of time. The reference terrain of Prisacani TAU was considered the one defined by the territori al-administrative
boundary during the last cada stral demarcation and the cadastral right bank of t he Prut river digitized on topographic
maps at 1:25000 scale edited in 1985. The reference terrain of Prisacani TAU used to conduct the comparative study
was determined on the basis of administrative terri torial limits and the right bank of the Prut river, digitized based on
the LANDSAT TM and ETM + satellite records dated 17 August 2000, 13 August 2010 and 4 March 2015. The surface
comparison method allows not only to highlight and to measure separately th e erosion and the sediment deposition for
the entire study area, but also to view, to draft t hematic maps and to analyze these phenomena.

Key words : change in time, river bank, surfaces, digitizing, satellite image.

1 ”Gh Asachi” Technical University of Iasi As of 1948, Romania’s state border with the
Union of Soviet Socialists Republics and, later on,
with Ukraine and the Republic of Moldova, was
established on the Prut river, starting from the
place where this river enters into Romania in the
Oroftiana locality to its confluence with the
Danube river.
Since the Prut river is considered a border
river, access of individuals and carrying out of
activities in the border area have a special juridi cal
regime. The Treaty between the People's Republic
of Romania and the Government of the Union of
Soviet Socialist Republics on the Romanian –
Soviet state border, cooperation and mutual
assistance on border related issues (still enforced
today in the absence of a treaty on the Romanian –
Moldovan state border, cooperation and mutual
assistance on border related issues between
Romania and the Republic of Moldova) lays down
strict rules on conducting the measures of the stat e
border demarcation. This latter activity is
performed only during Joint Border Commissions
(the latest check of the state border line was
conducted between 1972 – 1974). The above-
mentioned enforced Treaty also lays down strict
rules regarding the activities that the neighbourin g
countries are conducting on the banks of the Prut
river. These rules were the reasons for which the study of the progress of side riverbank erosion and
evolution tendencies of its route was sufficiently
conducted in the past 30 years.
This article presents the change while
pursuing the right bank of the Prut river from the
administrative territorial unit of the Prisacani
commune – Iasi County in the period 1985 – 2015,
due to erosion / deposition of sediments,
highlighted by comparing the ground surface
modification of TAU Prisacani in the analyzed
period of time, using the ArcGis software.

MATERIAL AND METHOD

By georeferencing topographic maps at
1:25000 scale, planimetric rectangular Gauss
coordinates of trapezoids corners and intersection
points of the kilometric grid, have been transforme d
into planimetric rectangular Stereo -70 coordinates
using the Matlab programming language. Given the
fact that, in order to georeference one raster imag e,
between 84 – 104 points have been used, third
degree polynomial transformation method was used
to optimize local accuracy (Imbroane A.M.,2012).
Satellite images dated 17th of August 2000,
13th of August 2010 and 4th of March 2015 released
by the manufacturer, are referenced in UTM
projection system with WGS84 datum.
(www.earthexplorer.usgs.gov) They were transformed
in Stereo – 70 projection system with „Dealul Pisculu i

Universitatea de Știin țe Agricole și Medicin ă Veterinar ă Ia și

148 1970” datum by using the ArcGIS software (Imbroane
AM, 2012).
The reference terrain surface of Prisacani
TAU, was considered the one defined by the
territorial-administrative boundary during the last
cadastral demarcation and the cadastral right bank of
the Prut river digitized on topographic maps at
1:25000 scale edited in 1985.
In order to highlight the right bank of the Prut
river, maps of the normalized difference water index
were created, based on the LANDSAT TM and ETM+
satellite records dated 17th of August 2000, 13th o f
August 2010 and 4th of March 2015 and using Raster
Calculator tool from ArcGIS software.
The terrain surfaces of the Prisacani TAU used
to conduct the comparative study, were determined
on the basis of administrative territorial limits a nd the
right bank of the Prut river, digitized based on ma ps
of the normalized difference water index (NDWI)
dated 17 August 2000, 13 August 2010 and 4 March
2015.
Surfaces thus created, were compared with
the reference surface using Symmetrical Difference
analysis function of the ArcGIS software.

RESULTS AND DISCUSSIONS

1. Creating the maps of the normalized
difference water index (NWDI) based on the
LANDSAT TM and ETM+ satellite records dated 17th of August 2000, 13th of August 2010
and 4th of March 2015.
In order to highlight the Prut river and,
implicitly, its right bank from the study area, the
normalized difference water index was calculated
using the following formula:
NDWI=(NIR-G)/(NIR+G)=(B4-B2)/(B4+B2) (1)
This index is also useful for mapping bodies
of water, for visualisation of turbidity difference s
and vegetal content of water, alluvial soils or for
differentiation of water content from vegetation. I t
also using green and near-infrared spectral bands.
Dark gray levels (close to -1) expresses the water
surface, bright gray levels (close to one), dry lan d
and intermediate gray levels (close to 0), land
containing intermediate moisture (Herbei M.,
2013).
Based on the satellite image LANDSAT
ETM dated 17th of August 2000, the NDWI was
calculated using the ArcGIS software. The result
was a raster with pixel values between -1 and 1
(NDWI_2000) (figure 1).
In a similar way, normalized difference
water indexes have been calculated for the satellit e
images LANDSAT ETM dated 13th of August
2010 and 4th of March 2015.

Figure 1 NDWI_2000 map of the study area

2. The digitization process of land
surfaces for the TAU of Prisacani for 1985,
2000, 2010 years and comparing these surfaces
Given the evolution in time of the right bank
of the Prut river during the analyzed period of
time, marked both by erosion and the sediment
deposition, it was analyzed the evolution in time o f the ground surfaces belonging to the Prisacani
territorial administrative unit.
The reference terrain surface of Prisacani
TAU, was considered the one defined by the
territorial-administrative boundary during the last
cadastral demarcation and the cadastral right bank
of the Prut river digitized on topographic maps at
1:25000 scale edited in 1985 ( figure 2 ).

Lucr ări Știin țifice – vol. 58 (1) 2015, seria Agronomie

149

Figure 2 Digitization result of the Prisacani TAU from 1985 year

By using the ArcGis software, there were
created reports regarding surfaces resulting from
digitization. Surface areas are presented in table 1 :

Table 1
Terrain surface of the Prisacani TAU in the
analyzed period of time
No. Year Surface area of TAU Pris ăcani
(m 2)
1 1985 59,070,800.00
2 2000 59,271,200.00
3 2010 59,183,100.00
4 2015 59,044,500.00

In order to highlight erosion / sediment
deposition, Symmetrical Difference tool from
ArcMap was used, in order to calculate the
difference between two polygon type vector layers.
One by one, differences have been
calculated between vector data on
UAT_PRISACANI_1985 layer and the ones from
UAT_PRISACANI_2000,
UAT_PRISACANI_2010 and UAT_PRISACANI_
2015 layers. The software created a new layer for
each difference using the result of the respective
tool, polygon type vector data, each one divided
into two categories: extra surfaces as a result of
sediment deposition phenomenon and missing surfaces as a result of erosion phenomenon. For
each of these differences reports have been created
which emphasise the evolution in each time stage
of the right river bank of Prut river in the
territorial-administrative unit of Prisacani
commune, highlighting and quantifying in the
same time the eroded surfaces and the ones newly
created (table 2).

Table 2
Surface areas as a result of erosion
phenomenon / sediment deposition
phenomenon in the Prisacani TAU for the
analysed period of time
No. Time frame Surface area (m 2)
Erosion Sediment
deposition
1 1985 – 2000 69,266.00 269,655.00
2 1985 – 2010 139,165.00 251,493.00
3 1985 – 2015 266,936.00 240,972.00

For an expressive representation of the
modification process in time of the right bank of
Prut river, three thematic maps have been created
using the ArcMap module in order to compare the
situation from 2000, 2010 and 2015 years, using as
reference the 1985 year. Figure 3 presents the
thematic map regarding the evolution of the right

Universitatea de Știin țe Agricole și Medicin ă Veterinar ă Ia și

150 river bank of Prut river between 1985 and 2015 in t he Prisacani TAU.

Figure 3 Thematic map representing the evolution of the rig ht river bank of Prut river
between 1985 and 2015 years

CONCLUSIONS

Regarding the satellite data, as a part of the
cartographic base, the LANDSAT TM and ETM+
images offer just an approximate estimate of the
modifications of the right river bank of Prut river .
The relatively low resolution of 30 meters, does
not allow us to conduct precision measurements. In
order to conduct high precision studies on
extended areas, like the minor riverbed of Prut
river, SPOT 5 data, IKONOS data, QuickBird data
or aerial images may be used.
While analysing the erosion phenomenon for
the whole period between 1985 and 2015 years we
reached the conclusion that a surface of 266,936.00
m2 has been lost while a new surface of 240,672.00
m2 has been created. We find out that the erosion
phenomenon is more pronounced between 2010
and 2015 when 127,771.00 m2 have been lost from
the national territory. This lost surface from the
Prisacani TAU is almost double when compared to
the one lost between 1985 and 2015 years.
These things happened due to climatic
changes manifested through dry years followed by very rainy or normal years from a hydrological
point of view, but also due to the lack of
improvement measures applied to the riverbed of
Prut river in order to control the soil erosion in the
study area.
REFERENCES

Herbei M., 2013, Sisteme informatice geografice,
aplica /uni021Bii, Editura Universitas, ISBN 978-973-741-
143-3, Petro șani.
Imbroane A. M., 2012, Sisteme informatice geografice ,
Volumul I, Structuri de date , Presa Universitar ă
Clujean ă, ISBN 978-973-595-417-8, Cluj-Napoca.
*** – TREATY between the People's Republic of
Romania and the Government of the Union of
Soviet Socialist Republics on the Romanian –
Soviet state border, cooperation and mutual
assistance on border related issues , signed in
Bucharest on 27th of February 1961 and ratiffied
on 20th of June 1961
*** – CONVENTION between the Socialist Republic of
Romania and the Government of the Union of
Soviet Socialist Republics on cooperation in
border water management , signed in Moscow on
9th of April 1986 and ratified on 14th of October
1986.
*** – www.earthexplorer. usgs.gov
*** – www.esri.com