=Paper=
{{Paper
|id=Vol-1152/paper54
|storemode=property
|title=The Gully Erosion Effect On the Environment
|pdfUrl=https://ceur-ws.org/Vol-1152/paper54.pdf
|volume=Vol-1152
|dblpUrl=https://dblp.org/rec/conf/haicta/NemesC11a
}}
==The Gully Erosion Effect On the Environment==
https://ceur-ws.org/Vol-1152/paper54.pdf
The Gully Er osion Effect on the Envir onment
!"!#$%&'()1,Constantinescu Laura1
1
Department CHIF, “Politehnica” University of *+"+#(&,&-$.("&/+&0$
e-mail: iacob.nemes@hidro.upt.ro; lauraconstantinescu_m@yahoo.com;
Abstr act. The paper contains data about the destructive effects of gully
erosion on the environment. It provides general information about the gully
erosion in several countries around the world including Romania and is
considered a case study for a river basin located in the Semenic Mountains
(Bârzava drainage area).
The case study is based on the following assumptions: the presence of
different types of soil, the constant rain intensity over the entire river sub-
basins, the land use is the same over all the sub-basins; there are no soil
erosion control works.
The model was applied to the each area of the bed (gully), by calculating the
quantity of the soil lost, depending on the soil type.
The data entered in the program are: the use of the land - forests, climate - the
average monthly temperature and precipitation, the soil characteristics, the sub-
basins areas, the characteristics of the river beds: the average width of the river
bed and the river bed type (channel river bed in the forest area).
Keywor ds: gully erosion, exogenous factors, water erosion, anthropogenic
factors, river basin, the calculation model
1 Intr oduction
In its evolution, the Earth has suffered and continues to suffer major changes due
to the action and interaction between endogenous and exogenous factors.
Crust movements, caused by endogenous factors, lead to the activation of
exogenous factors such as gully erosion.
In 1983, according to the estimates made by FAO in the world, an area of 5-7
million hectares of land were removed from the agricultural lands, due to the
degradation processes (erosion, toxic chemicals, soil salinization, urbanization, etc.)
the estimated losses at the end of year 2000, being of 100-140 million ha.
In Europe, an area of about 115 million hectares (about 12% of the Europe’s
surface) is affected by water erosion.
The most affected areas are the Mediterranean region and large areas in the central
and eastern parts of the continent due to natural contributing factors (relief, climate,
_______________________________
Copyright ©by the paper’s authors. Copying permitted only for private and academic purposes.
In: M. Salampasis, A. Matopoulos (eds.): Proceedings of the International Conference on Information
and Communication Technologies
for Sustainable Agri-production and Environment (HAICTA 2011), Skiathos, 8-11 September, 2011.
621
soil, etc.) and to anthropogenic factors (massive deforestation, improper practice of
agriculture, overgrazing on the same area).
In Romania, taking into account the specific indicator of the erosion intensity
(t/ha/year), counties in the bend area of the Carpathians Mountains (Buzau, Vrancea,
with values of approximately 40 and respectively, 35 t/ha/year) are clearly different
from the maximum allowable erosion of 4-6 t/ha/year. According to Motoc (1982),
Romania weighted average was of 16.28 t/ha/year. Gully erosion in the world has
various effects on the environment, namely:
- In Russia, land area is degraded by approximately 500 thousand ha/year.
Through water erosion, approximately 400 thousand gully erosion formations were
formed, covering over 500 thousand hectares (according to G. Gardner 1996).
- In Pakistan, 75% of the country is affected by water and wind erosion and gully
erosion affects 36% of the agricultural area of the country (according to G. Gardner
1996).
- Greece has about 40% of the total area of cultivated land affected by erosion, and
over 800 active torrents transport over 30 million m3 of solid material (Vousaros A.
quoted by 123(+4$V., 1986).
- China is affected by erosion - approximately 3.7 million km2 (about one third of
the country (Mircea S., 1999).
- In India, gully erosion affects 3.67 million hectares (Mircea S., 1999).
- In Lesotho, a country with an area of only 30,000 km2, about 20-30 large
thousand ravines occupy 4% of the arable area of the country (according to Wenner,
1989, quoted by Mircea S., 1999).
- In Romania, a network totaling over 25,000 km of gully erosion in formations
assets has been inventoried (Mircea S., 1999).
From an economic and environmental point of view, the development works of
the gully erosion formations are of particular importance. The development of these
formations causes damage primarily to agriculture, to socio-economic objectives, to
silting of storage lakes and to water courses. If a storage lake has a calculated dead
volume, which should be filled with silt in 80-100 years, there are cases when the
storage lakes were no longer usable due to sealing, in only a few years or decades.
The annual volume of sediments transported by rivers in Romania is over 44
million tons (C. Diaconu, 1971), to which gully erosion contributes by 31% (5(6('$
M. 1984).
2 Wor king Method
In order to estimate the losses of soil erosion on slopes, various computational
models have been developed (Laflen 2003 RUH-Ming 1973, Popovich 1991;
Carvaiho 1994, Di Silvio 1998, Trott and Singer 1983, Wischmeier and Smith 1960,
etc.).
In what follows, we treated soil losses through erosion and their impact on the
environment in the Bârzava river basin (Romania) by two methods.
The estimation of the soil erosion in the Bârzava river basin by the physical
modeling.
622
Universal soil loss equation developed by Wischmeier and Smith (1960) is based
on the experimental technique applied by the two researchers. Subsequently, soil
erosion assessment and prediction were improved by modeling techniques and by
the elaboration of computer programs that allow separate treatment of the
deployment processes of soil particles and fluid flow.
Thus, Trott and Singer (1983), using research with the rain simulator and
measuring leakage, developed an equation of sediment production based on
granulometric composition, for the forest soils in California:
SY= -9,391+25,298(P+A) – 0,2297(P+A)2 – 12,551(Kaolinite) + 31,420
(Smectite)
Where:
SY = sediment produced in g/m2;
P+A = dust percentage + clay percentage;
Kaolinite = kaolinite percentage present in the soil;
Smectit = smectite percentage present in the soil.
This equation was developed by Covaci, D. (2002) using the erosion tester and by
Rogobete Gh. and Grozav, A. (2006) using the plot with the rain simulator, which
gave the following equation:
SY= -9,391+ 25,298(P+A) – 0,2297(P+A)2 – 12,551(Kaolinite) + 31,420
(Smectite)-6,18(Humus).
Where:
Humus = percentage of humus on the soil surface
The estimation of the solid leakage by applying the WEPP model
The perimeter studied in her doctoral thesis by Grozav, A. (2011), is located in the
Semenic Mountains, near Gozna Peak (1444m), being the catchment basin of the
Eagles’ Bathroom’s source.
The studied area has a mountainous terrain with altimetry values between 600 and
1400m.
The case study is based on the following assumptions:
- the presence of different soil types (aluviosol, podzol, prepodzol, histosol,
districambosol)
- constant rain intensity over the entire river sub-basins;
- the land use is the same in all the sub-basins;
- there are no works to combat the soil erosion.
The model was applied to each area of the river bed sector (gully), by calculating
the quantity of the lost soil depending on the soil type.
The sub-basin was divided into sub-basins corresponding to the river bed sectors
taking into account the direction of the water flow. The sub-basins are noted with H
and the river beds with C (river beds sectors). (Figure 2)
The data entered in the program are:
- land use - forest;
- climate - the average monthly temperature and precipitation;
- soil characteristics;
- sub-basins areas;
- characteristics of the river beds: the average width of the river bed and the
river bed type (river bed channel in the forest area).
623
The scheme of the river sub-basin, resulting from the application of the WEPP
program is shown in Figure 1 and the river network diagram in Figure 2. In addition
to the quantities of soil loss, several graphs of variation of erosion and deposition
processes on each slope and the maximum rate of entrainment of soil particles on
each slope were also presented (Figures 3-7).
Fig. 1. The Bârzava river basin scheme using WEPP
Fig. 2. The hydrographic network scheme in WEEP with associated river sub-basins
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Graphs of variation of erosion and deposition processes
Fig. 3. The evolution of the erosion process on slope H2 (Aluviosol, maximum involvement
of soil particles at 484m - 57.1 kg/m2, the maximum deposit at 556m - 6.72 kg/m2)
Fig. 4. The evolution of the erosion process on slope H8 (Histosol, maximum involvement
of soil particles at 509m - 767kg/m2, without deposit)
625
Fig. 5 The evolution of the erosion process on slope H26 (Prepodzol, maximum
involvement of the soil particles at 264m - 7.79 kg/m2, without deposit)
Fig. 6. The evolution of the erosion process on slope H29 (Podzol, maximum involvement of
the soil particles at 648m - 74.2 kg/m2, the maximum deposit at 842m - 11.5 kg/m2)
626
Fig. 7. The evolution of the erosion process on slope H6 (Districambosol, maximum
involvement of the soil particles at 615m – 342kg/m2, the maximum deposit at 741m – 10,5
kg/m2)
Table 1. The results of the WEPP model on the whole river basin (Grozav, A. 2011)
Number of slopes Surface Leakage Lost Deposited Produced
Soil type volume Soil sediment sediment
Autocad WEPP ha (m3) (kg) (kg) (kg)
Dystric Cambisol 460,9 1346,7 0,0 1346,7
H1 Hill H8 10,663
Aluviosol 1214,0 10023,3 0,0 10023,2
H2 Hill H9 20,796
Dystric Cambisol 0,0 0,0 0,0 0,0
H3 Hill H7 44,586
Dystric Cambisol 373,6 5104,9 0,0 5104,7
H4 Hill H6 15,716
Dystric Cambisol 324,9 4965,9 0,0 4965,7
H5 Hill H4 10,295
Dystric Cambisol 740,1 14470,4 20,4 14450,0
H6 Hill H5 24,991
Dystric Cambisol 422,5 3581,7 0,0 3581,7
H7 Hill H2 6,587
Histosol 656,9 2552,1 0,0 2552,1
H8 Hill H3 26,551
Dystric Cambisol 556,3 1249,9 0,0 1247,9
H9 Hill H1 12,277
Dystric Cambisol 300,6 3673,2 0,0 3673,2
H10 Hill H10 10,909
627
Dystric Cambisol 700,1 4944,1 0,0 4944,1
H11 Hill H11 7,331
Dystric Cambisol 253,7 2371,9 0,0 2371,8
H12 Hill H13 2,725
Dystric Cambisol 94,9 1180,5 0,0 1180,5
H13 Hill H14 2,810
Dystric Cambisol 28,4 187,1 0,0 187,1
H14 Hill H12 0,516
Dystric Cambisol 783,5 10908,9 0,0 10908,7
H15 Hill H16 8,466
Dystric Cambisol 261,2 5080,5 0,0 5080,7
H16 Hill H15 12,837
Dystric Cambisol 287,3 2698,3 0,0 2698,4
H17 Hill H18 2,341
Dystric Cambisol 176,7 3282,3 0,0 3282,3
H18 Hill H19 5,306
Dystric Cambisol 13,2 27,1 0,0 27,1
H19 Hill H17 0,231
Dystric Cambisol 251,0 4444,0 0,0 4444,0
H20 Hill H20 12,922
Dystric Cambisol 602,4 12516,5 1,5 12514,9
H21 Hill H21 14,017
Dystric Cambisol 229,2 3803,5 0,0 3803,6
H22 Hill H22 8,302
Dystric Cambisol 469,0 9368,2 24,2 9344,0
H23 Hill H23 19,382
Prepodzol 202,5 1942,6 0,0 1942,6
H24 Hill H24 5,929
Prepodzol 743,1 11672,9 0,0 11673,0
H25 Hill H25 8,193
Prepodzol 0,0 0,0 0,0 0,0
H26 Hill H27 14,721
Prepodzol 0,0 0,0 0,0 0,0
H27 Hill H28 4,340
Prepodzol 0,0 0,0 0,0 0,0
H28 Hill H26 4,578
Podzol 0,0 0,0 0,0 0,0
H29 Hill H34 17,575
Dystric Cambisol 262,9 2734,7 0,0 2734,7
H30 Hill H35 8,356
Dystric Cambisol 645,3 10983,9 6,9 10977,1
H31 Hill H36 23,086
Dystric Cambisol 36,2 563,1 0,0 563,2
H32 Hill H37 2,269
Dystric Cambisol 284,5 3656,5 0,0 3656,5
H33 Hill H38 4,683
Dystric Cambisol 117,9 1060,0 0,0 1060,0
H34 Hill H39 4,050
Dystric Cambisol 1017,1 15284,1 4,2 15280,2
H35 Hill H32 43,287
Dystric Cambisol 455,8 5305,6 0,0 5305,6
H36 Hill H33 23,277
Dystric Cambisol 782,0 5840,6 0,0 5840,6
H37 Hill H30 25,003
Dystric Cambisol 335,7 1706,7 0,0 1706,7
H38 Hill H31 14,270
Dystric Cambisol 0,0 0,0 0,0 0,0
H39 Hill 29 58,027
TOTAL
542,203
628
Fig. 8. Comparative values of different soil types in the Bârzava river basin
(Grozav, A. 2011)
3 Conclusions
- The emergence and development of the torrential gullies in the studied river
basin evolved over time;
- The erosion values in this basin exceed the maximum allowable erosion;
- The muddy leakage produced on this river basin area also affects the
downstream lake;
- The massive deforestation in the area, without reforestation in that area and
without other works to combat the erosion of this river basin, leads to the
environmental degradation with serious long-term consequences.
- Because are not allocated money (in present) for erosion control works
cannot be a reason for the serious effects from the future.
Refer ences
1. Gardner, G. (1996) (Jane A. Peterson, editor) Shrinking fields: Cropland loss in a
World of Eight Billion, Wordwatch Paper 131, Washington.
2. Grozav, A. (2011), Soil and water pollution phenomena - a section of the Bârzava
river basin study, PhD thesis; “Politehnica” University of *+"+#(&,& , Romania
3. Mircea, S. (1999) Evolution study of gully erosion formations in terms of
arrangement and not arrangement in the Buzau area, PhD thesis, USAMV
Bucharest, Romania.
4. Mo6('-$ 5., 72824-$ A. (1992) Indicators of soil erosion, Environmental Review,
vol III, No. 3 Bucharest Romania.
5. Wischmeier, WH., Smith, D.D. (1960) A universal soil-loss equation to guide
conservation farm planning, Proc. Of. Seventh International Congress of. Soil
Science, 418-425.
629