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University of Belgrade, Faculty of Forestry
Department for Ecological Engineering in Protection of Soil and Water Resources
SPATIAL AND TEMPORAL ANALYSIS OF THE
DEGRADATION OF NATURAL RESOURCES
IN RIVER LIKODRA WATERSHED
Vukašin MilčanovićSiniša Polovina Boris Radić Ratko Ristić
e mail: [email protected]
Soil Erosion Modelling JRC Ispra20-21-22 March 2017
In May 2014, the urban area and rural parts of the municipality Krupanj are afflicted catastrophic flash floods that resulted in the loss of human lives and enormous material damage.
The subject of this work is resource of soil, analyze of its degradation through review actual state (2012th year) and comparation with previous state of degradation (state from 1983th year) in watershed
of Likodra river.
Likodra river is locatedin the northwestern part ofthe Republic of Serbia(micro-regions Rađevina)on the right bank of theDrina.
Figure 1: The geographical position of the river Likodra watershed
Parameter Mark Unit Value
Drainage area А km2 140.38 Perimeter P km 78.75Peak point Pp m.a.s.l. 805 Confluence point Cp m.a.s.l. 160 The length of main stream L km 30.92 The shortest distance from confluence point to watershed centroid Lc km 16.13 Absolute slope of river bed Sa % 1.16 Weighted slope of main channel Sw % 2.09 Total length of the waterways ∑L km 377.4 Density of the hydrographic network G km/km2 2.68Module of the watershed development Е 1.86Local erosion base Be m 599Mean altitude Am m 495.68 Medium altitude difference Amd m 277.68 Mean slope of terrain Smt % 19.72
Table 1. Physical characteristics of the river Likodra watershed
In the analysis of the basic physical–geographical parameters of the watershed used topographic maps ofthe Military Geographical Institute in scale 1: 25000 and a digital elevation model DEM resolution 100m,which was formed on the basis of scanned topographic maps.
Analysis of relief was obtained based on DEM (Digital Elevation Model) resolution of 100 m.
Figure 2: The hydrographic of the river Likodra watershed Figure 3: DEM of the river Likodra watershed
Figure 4: Geological map of the river Likodra watershed
GEOLOGICAL DATA:
Basic Geological Map of Yugoslavia in 1970 scale 1: 100000
(issue of the Federal Geological Institute)
PEDOLOGICAL DATA:
Soil map of SR Serbia in 1966 scale 1: 50000
(edition of the Institute of Soil Science in Belgrade)
Figure 5: Pedological map of the river Likodra watershed
LAND USE:
Corine Land Cover database
Figure 6: Slope of the terrain in watershed of the river Figure 7: Land use in the watershed of the river Likodra
All the above databases are analyzed in GIS environment
Land degradation in the study area will be analyzed using the Erosion Potential Method(EPM) (Gavrilović):
Y –Coefficient of the soil resistance to erosionX · a – The land use coefficient,ϕ–Coefficient of the observed erosion process (takes visible erosion processes),Isr– Mean slope of terrainZ- Coefficient of erosion
Erosion category
Qualitative name of erosion category
Range of values ofcoefficient Z
Mean value ofcoefficient Z
IExcessive erosion- deep
erosion process1.1-1.5 1.25
IIHeavy erosion-milder from excessive erosion
0.71-1.0 0.85
III Medium erosion 0.41-0.70 0.55
IV Slight erosion 0.20-0.40 0.30
V Very slight erosion 0.01-0.19 0.01
LAND DEGRADATION:
Method Of Potential Erosion
Table 2. Classification category of erosion by erosion coefficient Z
Figure 8: The Intensity Erosion map of Likodra watershed Figure 9: The Erosion classes map (Z) of Likodra watershed
After digitalization of maps and assigning values to certain elements, a conversion was made into raster format, resolution of 100 m where the attribute values Y and Xa were a criteria for the conversion into raster baseRaster base becomes adequate for calculating erosion coefficient Z according to formula
Figure 10: The severity of erosion processes in the catchment area of the river, state in 1983 and current state
In the purpose of quantification of erosion intensity changes in Likorda river watershed, by using GIS, digitalization of research area was made with Map erosion from 1983 (Lazarević, 1983).
Erosion category
Qualitative name of erosion category1983 current state
km2 % km2 %I Excessive erosion- deep erosion process 0 0 0.12 0.09II Heavy erosion-milder from excessive erosion 2.73 1.95 0.86 0.61III Medium erosion 18.43 13.1 23.94 17.06IV Slight erosion 72.95 52.0 38.2 27.22V Very slight erosion 43.68 31.1 77.26 55.02VI Accumulation of sediment 2.56 1.8 0 0
Total 140.38 100 140.38 100
Mean value of coefficient Z Zsr=0.275 Zsr=0.204
Table 2: Erosion categories in the Likodra river watershed – 1983 and current state
Graph 1: Comparative review of erosion categories in two periods
Soil, as a natural resource, represents a dynamic system created in the process of thepedogenesis, and under the influence of atmospheric and biological factors is constantly changing.
With a view to assess the intensity of soil erosion and to propose measures for reducing thedegradation process, developed many methods for assessing erosion loss of land.
The (EPM) method is suitable for the definition of erosion processes on the surfaces of a widerange of sizes.
The advantage of using this method is that it does not require a large number of inputparameters and possible applications of GIS.
One of the many GIS task is to extract the relevant information from the complex relationsbetween the natural and geographical phenomena and processes.
Geographical information system enables all the relevant spatial data adequately systematized,analyzed and finally displayed.
CONCLUSIONS
