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1

Impact of rainfall intensity on soil erosion based on experimental research

Majewski Mikołaj, Czuchaj Aleksandra, Marciniak Marek

Landform Analysis

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2023

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Vol. 42

25--36

EN

Soil erosion by water is influenced by a major morphogenetic factor – precipitation. Surface runoff, initiated by rainfall, plays a key role in this process. This article addresses the effects of rainfall intensity and soil moisture on soil erosion through a series of rainfall simulations of different intensity and duration. The implementation of measurements at a research station located in the Różany Stream catchment in Poznań made it possible to study the entire water balance within the slope, including precipitation, evaporation, surface runoff and infiltration. The study included various rainfall intensities, with a focus on extreme events reflecting ongoing climate change and increasing anthropopressure. Rainfall simulations were conducted on both dry and wet ground. The results showed that increasing rainfall intensity led to greater surface runoff and soil loss. Moreover, soil moisture was identified as a critical factor affecting soil erosion, with wetter conditions reducing soil loss while increasing surface runoff.

2

Soil erosion rate and hazard level at the Sianjo-anjo Reservoir watershed in Indonesia

Gusma Felia, Azmeri Azmeri, Jemi Faris Z., Rahmatan Hafnati

Journal of Water and Land Development

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2023

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no. 57

181--187

EN

The Sianjo-anjo reservoir is used to meet the need for downstream clean water. Land activity at the Sianjo-anjo reservoir watershed can potentially increase the rate of erosion and the silting of rivers and reservoirs due to sedimentation. Reservoir siltation is a crucial challenge for reservoir management because it can reduce its function and affect its service life. However, sediment yield is often overlooked in reservoir planning and environmental assessment. This study aims to predict the rate of land erosion and sediment yield, and create an erosion hazard map of the Sianjo-anjo reservoir watershed. The study used a Geographic Information System, GIS-based Universal Soil Loss Equation (USLE) method and discovered that the erosion rate of the Sianjo-anjo reservoir watershed was between 35.23 Mg∙ha-1∙y-1 until 455.08 Mg∙ha-1∙y-1, with 95.85% classified as the low level, 0.03% as moderate, and 4.12% as high. Meanwhile, the sediment yield from the Sianjo-anjo reservoir watershed was 218,812.802 Mg∙y-1. USLE is vital to identify areas susceptible to erosion and crucial for reservoir sustainability. Furthermore, it is necessary to plan good sediment management. Long-term land conservation is required to maintain storage capacity and ensure effective operation of the reservoir.

3

A multicriteria approach to different land use scenarios in the Western Carpathians with the SWAT model

Kowalczyk Agnieszka W., Grabowska-Polanowska Beata, Garbowski Tomasz, Kopacz Marek, Lach Stanisław, Mazur Robert

Journal of Water and Land Development

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2023

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no. 57

130--139

EN

Water erosion in mountainous areas is a major problem, especially on steep slopes exposed to intense precipitation. This paper presents the analysis of the topsoil loss using the SWAT (Soil and Water Assessment Tool) model. The SWAT model is a deterministic catchment model with a daily time step. It was designed to anticipate changes taking place in the catchment area, such as climate change and changes in land use and development, including the quantity and quality of water resources, soil erosion and agricultural production. In addition to hydrological and environmental aspects, the SWAT model is used to address socio-economic and demographic issues, such as water supply and food production. This program is integrated with QGIS software. The results were evaluated using the following statistical coefficients: determination (R2), Nash-Sutcliff model efficiency (NS), and percentage deviation index (PBIAS). An assessment of modelling results was made in terms of their variation according to different land cover scenarios. In the case of the scenario with no change in use, the average annual loss of topsoil (average upland sediment yield) was found to be 14.3 Mg∙ha-1. The maximum upland sediment yield was 94.6 Mg∙ha-1. On the other hand, there is an accumulation of soil material in the lower part of the catchment (in-stream sediment change), on average 13.27 Mg∙ha-1 per year.

4

Climate Change Effect on Soil Erosion in Vjosa River Basin

Marko Oltion, Gjoka Konalsi, Shkodrani Neritan, Gjipalaj Joana

Journal of Ecological Engineering

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2023

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Vol. 24, nr 2

92--100

EN

Soil erosion is closely related to climate changes, because changes to temperature and precipitation regimes may alter the erosivity of rainfall. The present study aimed to project future soil erosion phenomena in the Vjosa River Basin (VRB) using climate projections under the Representative Concentrations Pathway (RCP) 4.5 and 8.5 scenarios. SimCLIM model was used to perform the climate projection for the years 2035 and 2050, based on historical temperature and precipitation data (2000–2015). This investigation was carried out by using Erosion Potential Method EPM to estimate the effects of climate change on soil erosion in Vjosa River Basin, Albania. Results show an increase in average min and max annual temperature for both scenarios RCP4.5 and 8.5 by the end of 2050. The evaluation of the monthly precipitations for all RCPs reveals a likely decrease in summer precipitation, and a slight positive trend of winter precipitation for all time periods up to 2050. An increase in terms of eroded material and specific eroded material was estimated from the results of RCP4.5 and RCP8.5 scenarios. Thus, it can be stated that the study area has and will have a moderate erosion risk under these climate conditions.

5

Soil Erosion Estimation Using an Empirical Model, Hypsometric Integral and Geo-Information Science – A Case Study

Maliqi Edon, Kumar Nirmal, Latifi Loresa, Singh Sudhir Kumar

Ecological Engineering & Environmental Technology

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2023

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Vol. 24, iss. 4

62--72

EN

An approach that integrates the Revised Universal Soil Loss Equation (RUSLE) model and Geographic Information System (GIS) techniques was used to determine the soil erosion vulnerability of a forested mountainous watershed. The spatial pattern of annual soil loss rate was obtained by integrating geo-environmental variables in a raster data format based geoinformatics methods and tools. Thematic layers including rainfall erosivity (R), soil erodability (K), slope length and steepness (LS), cover management (C), and conservation practice (P) factors were computed to determine their effects on average annual soil loss in the Mitrovica city. The serial thematic map of annual soil erosion shows a maximum soil loss of 112.61 ton·ha-1·y-1 with a close relation to grass land areas, degraded forests and deciduous forests on the steep side-slopes (with high LS). The geographic age of the region shown by the hypsometric analysis was mature to old stage. The serial erosion maps compiled with the RUSLE model and GIS can serve as effective inputs in deriving strategies for land planning and management in terms of environment concerns.

6

Evaluation of the Impact of No-Till on Soil Erosion Using Soil Aggregate Stability and Fallout Radionuclides in Northern Morocco

Iaaich Hamza, Moussadek Rachid, Mrabet Rachid, Douaik Ahmed, Baghdad Bouamar, Benmansour Moncef, Zouagui Anis, Asserar Nezha, Bouabdli Abdelhak

Ecological Engineering & Environmental Technology

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2023

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Vol. 24, iss. 3

241--248

EN

The aim of this work is to assess the impact of no-till based cropping system on soil erosion using two indicators. The experiment plot was under no-tillage (NT) for four years, adjacent to a plot under conventional tillage (CT) with same other management practices. The two used indicators are Le Bissonnais soil aggregates’ stability test and the activities of the fallout radionuclides (FRN) 7Be and 137Cs. For each radionuclide, the reference sites were identified and sampled using grid sampling approach and the study sites (the two plots) were sampled by applying a one-dimensional point transect sampling. Five samples were collected from each study site with 10m increment. The results showed that the mean weighted diameter (MWD) was of 2.2 for the NT plot and 2.0 for the CT plot, this indicates a lower soil detachability under the no-till system. For the FRN results, the 7Be activity showed that the NT plot retained 79% of the reference site activity and the CT plot retained 54%. The 137Cs activity tests showed also that the NT plot retained more of reference site activity. The mass balance conversion models application to the FRN results showed that the no-till system generated 10% less soil erosion rate than the conventional tillage. The results showed that in spite of needing more than 4 years implementation for statistical significance, no-till helps reducing water erosion in the hilly agricultural lands of Northern Morocco.

7

Surface erosion hazard and sediment yield for Keuliling Reservoir in Indonesia

Azmeri Azmeri, Nurbaiti Nurbaiti, Mawaddah Nurul, Yunita Halida, Jemi Faris Zahran, Sundary Devi

Journal of Water and Land Development

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2022

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no. 52

108--118

EN

The construction of the Keuliling Reservoir aims to accommodate and utilise water for agricultural purposes. In this research, soil erosion modelling using the USLE method showed that the level of erosion hazard for each Keuliling Reservoir sub-watershed was classified into low-moderate. Land erosion occurred in the area around the reservoir inundation is the most significant contribution to the magnitude of erosion (38.62Mg∙ha-1y-1. Based on the point of sediment sampling in the Keuliling reservoir, the sediment volume was 1.43 Mg∙m-3. So, the volumetric sediment input from the Keuliling reservoir watershed is 20.918,32 m3∙y-1. The degradation of reservoir function due to sedimentation can affect reservoir services. The ability to estimate the rate of watershed surface erosion and sediment deposition in the reservoir is vital for reservoir sustainability. Besides the land erosion in the Keuliling Reservoir, there are also other potential sources of erosion that can reduce the capacity of the reservoir, i.e. the rate of sedimentation from a reservoir cliff landslide. The USLE estimation results show that the soil erosion analysis provides important and systematic information about nature, intensity and spatial distribution in the watershed and sediment volume in the Keuliling Reservoir. This finding allows the identification of the most vulnerable areas and the type of erosion dominant for long-term land management.

8

Soil erosion prediction and risk assessment using RUSLE model and GIS techniques in the Nangka watershed

Saadi Yusron, Mardiana Sus, Pradjoko Eko

Journal of Water and Land Development

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2022

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no. 55

185--191

EN

Soil erosion in the Nangka watershed has always been a matter of concern. Over the last decade, soil erosion has led to continuous environmental problems. A thorough examination of the extent of the problem was required to identify an appropriate soil conservation strategy within the watershed. This study was conducted to observe erosion rates and map out the erosion hazard level. Erosion predictions were analysed by using the Revised Universal Soil Loss Equation (RUSLE) model with the help of ArcGIS software. RUSLE was selected because of its quantitative ability to estimate average annual soil erosion and its compatibility with the GIS interface. The potential hazard of soil erosion was classified and ranked into five class categories as set by the national authority. The results reveal that the Nangka watershed is prone to soil erosion with the annual average values ranging from 1.33 Mg·ha-1·y-1 to 2472.29 Mg·ha-1·y-1. High soil erosion rates of 9.8% are in severe (class IV) and very severe (class V) conditions, primarily in the upper course of the watershed. The low annual average of soil erosion (class I and class II), which accounted for 75.95% of the total erosion, mostly took place in the steepness below 35%. The remaining area of 14.25% within the watershed is in moderate condition (class III). It is expected that the results of this study will help the authority in the implementation of soil conservation measures.

9

Non-prismatic channels for reducing shear stress

Haddad Samir

Journal of Water and Land Development

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2022

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no. 52

87--94

EN

To reduce the sediment transport capacity, shear stress needs to be reduced as well. The article describes work that has been done to find a way to make these reductions possible. The theoretical study and the approach proposed allowed us to obtain a general equation that determines conditions and calculates the most important parameters which support the reduction of shear stress. This describes the mechanism that erodes soils by free surface water flow. In a similar vein, we have shown that adding a short non-prismatic channel to the entrance of a prismatic channel, which has the same geometric shape, is a very powerful way to reduce shear stress. With the idea of reducing shear stress, we have shown that the water-surface profile type plays a key role and must therefore be included in future reflections on reducing the importance of shear stress. Additionally, the notion of efficiency was introduced that allows to evaluate the expected gain after the reduction of shear stress and adding a short non-prismatic channel. The laws of similarity applied to free surface flows allowed us to obtain an equation with several equivalence scales and compare different geometric shapes in terms of their efficiency in the reduction of shear stress.

10

Assessment of soil erosion using the GIS-based erosion potential method in the Kebir Rhumel Watershed, Northeast Algeria

Zeghmar Amer, Marouf Nadir, Mokhtari Elhadj

Journal of Water and Land Development

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2022

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no. 52

133--144

EN

Soil erosion is an important factor that should be considered when planning renewable natural resource projects, effects of which can be measured by modelling techniques. Therefore, disintegration models determine soil loss intensity and support soil conservation practices. This study estimates soil loss rates by water erosion using the Erosion Potential Method (EPM) in the Kebir Rhumel Watershed located in Northeast Algeria. The area is north to south sub-humid to semi-arid, receives irregular rainfall, and has steep slopes and low vegetation cover which makes it very vulnerable to erosion. The main factors in the EPM (soil erodibility, soil protection, slope, temperature, and rainfall) were evaluated using the Geographical Information System (GIS) and data provided by remote sensing technologies. The erosion intensity coefficient Z was 0.60, which indicates medium erosion intensity. While the results showed the average annual soil erosion of 17.92 Mg∙ha-1∙y -1, maximum and minimum losses are 190.50 Mg∙ha-1∙y-1 and 0.21 Mg∙ha-1∙y-1, respectively. The EPM model shows satisfactory results compared to some studies done in the basin, where the obtained results can be used for more appropriate management of land and water resources, sustainable planning, and environmental protection.

11

Application of the Erosion Potential Method in Vithkuqi Watersheds (Southeastern Albania)

Marko Oltion, Gjipalaj Joana, Shkodrani Neritan

Journal of Ecological Engineering

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2022

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Vol. 23, nr 4

17--24

EN

Soil erosion is one of the most important phenomena affecting land composition and settlement. Among all natural causes of soil erosion such as rainfall intensity, temperature and wind, the human activity; massive deforestation and intensive agriculture, including the latest climate changes are considered as very important factors, especially nowadays. Thus, calculating the soil erosion coefficient appears very important in order to prevent the phenomena. Many methods are used to calculate such coefficient but in the presented research, the Erosion Potential Method was chosen. In this study, eight watersheds in southeastern Albania were evaluated. Results show that erosion is present in all considered watersheds. In one case (Panariti watershed) the erosion coefficient was very high; excessive, while in others it varies from heavy to very slight erosion. In conclusion, it can be stated that the Erosion Potential Method can be applied in the Albanian contest, same as in other neighbor countries. The results from Panariti, Roshani and Gianci should be further investigated due to the high quantity of soil eroded.

12

Elemental Metals in Agricultural Soils Along Two Tributaries of Chaohu Lake: Implication on Soil Erosion Caused Enrichment in Sediments

Xie Fa-Zhi, Zhang Dao-De, Wang Ji-Zhong

Ecological Engineering & Environmental Technology

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2022

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Vol. 23, iss. 1

241-253

EN

Agricultural soil as a potential source of input of heavy metals into the lacustrine sediments of Chaohu Lake via soil erosion and weathering has not been well documented. In the present study, rice soil samples along two main tributaries of Chaohu Lake were collected to determine 30 metal elements which were compared with the data on the elements in surface sediments of Chaohu Lake to explore the impacts of soil erosion on the accumulation in the sediments. The results showed that the concentrations of most elements were less than their soil background values of Anhui Province, but Se, Sb, Sn, As, and Ba were greater than the corresponding background values. Furthermore, these elements except for Sc in the soils appeared a low variability in spatial distribution. Enrichment factor (EF) also suggested that most elements were minimally enriched, but Se, Th and As were found with moderate enrichment in the study areas. More than 90% of agricultural soils were not expected with significant contamination by the residual elements based upon the consideration of pollution level index (PLI) combining probabilistic density function. Compared with the residual elements in the surface sediments of Chaohu Lake, most elements (Ti, Mn, Zr, Sr, Zn, Ga, Hf, U, Se, Sn, Nb, Th, V, Cd) appeared depletion in agricultural soils but enrichment in sediments. Specially for Cd, it was not detectable in all soils samples, but it existed at an extreme average content in the lacustrine sediments. These results possibly implied that elements in agricultural soils in Chaohu Lake were depleted because of soil erosion and weathering during long-term agricultural practice, resulting in enrichment in sediments of the lake. The depletion of elements in soils was predominately due to the fact that these metals existed in the soil with a large mobile fraction. While As, Th and Se moderately accumulated in the soils due to their insusceptibility of transport potentials. Because Sr and U are easier to be leached from soils than Rb and Th, respectively, a greater ratio of Rb/Sr and a lower value of U/Th was found in soil samples than in sediments. Therefore, our study implied agricultural soils could play an important role in the input of heavy metals into sediments via soil erosion and weathering.

13

Assessment of soil erosion models for predicting soil loss in cracked vegetated compacted surface layer

Bora Manash Jyoti, Bordoloi Sanandam, Pekkat Sreeja, Garg Ankit, Sekharan Sreedeep, Rakesh Ravi Ranjan

Acta Geophysica

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2022

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Vol. 70, no 1

333--347

EN

Rainfall-induced progressive soil erosion of compacted surface layer (SL) impedes the functioning of cover system (CS) of landfills with high expected design life (≈ 100 years). The existing soil erosion models are not tested extensively for compacted soil with cracks and vegetation. This study evaluated the efficacy of three popular soil erosion models for estimating the soil loss of compacted SL of CS, which is useful for annual maintenance. The interactive effect of rainfall, vegetation and desiccation cracks on erosion of compacted surface layer was investigated under the influence of both natural and simulated rainfall events for one year. Among all, the Morgan, Morgan and Finney (MMF) model was found to be effective in predicting soil erosion of compacted SL. However, the MMF model overestimated soil erosion when the vegetation cover exceeded 60%. The soil loss estimated from Revised Universal Soil Loss Equation (RUSLE) and Water Erosion Prediction Project (WEPP) models was poor for high rainfall intensity (100 mm/h). The RUSLE and WEPP model overestimated the soil erosion for low vegetation cover (≤3%) and underestimated for vegetation area>3%. The mechanism of root reinforcement, strength due to root water uptake-induced soil suction and its effect on soil loss mitigation could not be adequately captured by the existing models for compacted SL. Further studies are needed to improve the existing erosion models for incorporating the effects of desiccation and vegetation on soil loss from the compacted SL.

14

Using RUSLE and GIS for the soil loss assessment in arid regions: The case of the Ain Sefra catchment in the Ksour Mountains, Algeria

Melalih Ahmed, Mazour Mohamed

Journal of Water and Land Development

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2021

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no. 48

205--214

EN

The loss of soil quality due to erosion is a global problem, particularly affecting natural resources and agricultural production in Algeria. In this study, the Revised Universal Soil Loss Equation (RUSLE) is applied to estimate the risk of water erosion in the Ain Sefra arid watershed (Algeria). The coupling of this equation with Geographic Information Systems (GIS) allows to assess and map the soil loss rates. The land erosion is influenced by many control variables, such as the topographic factor of the terrain and the length of slope (LS factor), rainfall erosivity (R factor), sensitivity of soil to erosion (K factor), presence of vegetation (C factor) and the antierosion cultivation techniques (P factor). To calculate the average annual soil loss, these five factors were considered and multiplied in the RUSLE Equation. The result shows that the average rate of soil loss is estimated at about 5.2 t·ha–1·y–1 over the whole watershed. This study is the first of its kind in the region and aims to assess the soil loss caused by water erosion processes in this arid zone. Consequently, it is essential to take real intervention measures in these upstream areas in order to combat this scourge, based on priorities ensuring the sustainable management of natural resources in the study area.

15

Multi-Site Calibration and Validation of SWAT Model for Hydrologic Modeling and Soil Erosion Estimation: A Case Study in El Grou Watershed, Morocco

Ait M'Barek Samir, Rochdi Aicha, Bouslihim Yassine, Miftah Abdelhalim

Ecological Engineering & Environmental Technology

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2021

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Vol. 22, iss. 6

45--52

EN

Water management is one of the critical challenges facing humanity due to increasing demand and limited resources resulting from the rapid growth of population, urban planning, agricultural and industrial sectors. Hydrological modeling is one of the key solutions used by researchers for estimating and monitoring the spatial and temporal variability of water resources in a watershed. This paper aims to evaluate the Soil & Water Assessment Tool (SWAT) performances and simulates the water cycle components of El Grou watershed (3504 km2 ), one of the main basins in the landscape hydrology of Morocco. It points to the need for developmrent of better model input data sets in Africa which are unlimted available when they are crucial for a detailed study of water resources. The model was built under ArcSWAT, and all other processes such as sensitivity analysis, calibration (10 years) and validation (4 years) were done with SWAT-CUP software using the SUFI-2 algorithm. The coefficient of determination (R2), the Nash–Sutcliffe efficiency (NSE) and the square error (RSR) were used to evaluate model performances. The results show that calibration and validation are considered very good, with R2 and NSE >0.81 and RSR <0.5. The hydrological regime of the El Grou watershed points out a predominance of evapotranspiration (75%). Moreover, soil erosion estimation for the period (2000–2015) indicates a low to medium potential of soil erosion with an average of 11.3 t/ha/year.

16

Soil and Eco-Economic Substantiation of the Need for Switching to the Adaptive-Landscape Systems of Agriculture in the Krasnodar Krai

Barsukova Galina Nikolayevna, Bershitskiy Yuriy Iosifovich, Vlasenko Valery Petrovich, Bagmut Alexey Alexandrovich, Rysmyatov Alexander Zakirovich

Journal of Ecological Engineering

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2020

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Vol. 21, nr 4

94--102

EN

The climatic, soil, ecological and economic features of the natural landscapes in the Krasnodar Krai were analyzed. The land structure of cultivated land in Western Ciscaucasia was given; the current state of soils in the Krasnodar Krai was analyzed. The changes in the content of humus in the arable layer over the century were considered. The qualitative state of agricultural lands, such as the susceptibility to erosion, the content of humus, and indicators of the nutrients balance in the soil was shown. A conclusion the existing zonal agriculture systems do not use the landscape diversity of the region was drawn. The need for switching to the adaptive landscape system of agriculture was substantiated. Using the GIS technologies, the boundaries of the natural landscapes in the Krasnodar Krai and the areas of agricultural land was determined by types and the degree of the manifestation of erosion processes. An eco-economic assessment of the field crop rotations adapted to the natural landscape by cultivated lands was made.

17

Effect of Unitary Soil Tillage Energy on Soil Aggregate Structure and Erosion Vulnerability

Wojciechowski Tomasz, Mazur Andrzej, Przybylak Andrzej, Piechowiak Jarosław

Journal of Ecological Engineering

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2020

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Vol. 21, nr 3

180--185

EN

The integrated soil tillage developed in the Institute of Biosystem Engineering is based on a single pass of basic tillage, secondary tillage and sowing or planting. The integrated soil tillage enables to achieve a relatively high mechanical strength of the soil. An important element of the technology is the use of tillage roller sets which significantly influence the obtained aggregate structure and its eolic resistance. The aim of the study was to determine the influence of roller speed under various soil moisture conditions on the aggregate structure of the arable soil layer. The research was carried out on the production field in Dziećmierowo, Wielkopolska Voivodeship, Poland, on medium soil with the mechanical composition of light clay. During the research, cultivation sets with two units of Campell + Croskill platelet and studded rollers were used. For two actual soil moisture levels and five speeds within the range of 3–7 km/h, the influence of unit tillage energy at three levels of the cultivating layer (0–5 cm, 5–10 cm and 10–15 cm) was analyzed on the aggregate structure of soil and the content of aggregates with the highest resistance to wind erosion. The results of the work lead to the conclusions that it is possible to use the working speed and overloading of rollers set in integrated soil tillage trailer to manipulate the process of forming an optimal, erosion-resistant soil layer. However, it should be pointed out that for even very similar types of roller sets, the process control under different soil moisture conditions may be different and require an individual test.

18

Estimation of annual average soil loss using the Revised Universal Soil Loss Equation (RUSLE) integrated in a Geographical Information System (GIS) of the Esil River basin (ERB), Kazakhstan

Mukanov Yerbolat, Chen Yaning, Baisholanov Saken, Chukwudi Amanambu Amobichukwu, Issanova Gulnura, Abenova Ainura, Fang Gonghuan, Abayev Nurlan

Acta Geophysica

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2019

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Vol. 67, no. 3

921--938

EN

The Revised Universal Soil Loss Equation (RUSLE) has enormous potential for integrating remote sensing and Geographical Information System (GIS) technologies for producing accurate and inexpensive assessments of soil erosion. In this study, the RUSLE method was applied to the Esil (Ishim) River basin (ERB), which is situated in Northern and Central Kazakhstan. The northern part of the ERB extends through the Tyumen and Omsk regions of the Russian Federation to the confluence of the Irtysh River. This article may be of interest to experts and specialists in the field of agriculture, as the findings can assist agricultural producers and government entities in making decisions that prevent soil degradation and promote optimal cropping systems for land and crop cultivation. The objective of this research is to detect, estimate and map areas of land plots most vulnerable to potential soil erosion within the ERB, using the RUSLE model under Arc GIS 10.2. The results reveal that average annual soil loss during the study period ranges from 0 to 32 (t y−1) and that 108,007.5 km2 (48%) of the ERB has no erosion. The remainder of the basin is prone to soil erosion ranging from 1 to 32 t ha−1 y−1, which comprises 117,216.9 km2 (52%), and total soil erosion is 565,368.7 (t y−1). Soil erosion in the ERB is relatively moderate due to low hill steepness and low annual precipitation (198–397 mm). Exceptions occur in plots which feature high slope length steepness, which are scattered throughout the region.

19

Effect of hillslope topography on soil erosion and sediment yield using USLE model

Sabzevari T., Talebi A.

Acta Geophysica

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2019

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Vol. 67, no. 6

1587--1597

EN

Catchment hillslopes in nature have a complex geometry. Complex hillslopes have different plans (convergent, parallel and divergent) and different curvature (straight, concave and convex). In this study, the erosion rates of the nine complex hillslopes were investigated using the universal soil loss (USLE) method. The topography factor (LS function) in the USLE was developed as a function of plan shape and profile curvature. The hillslopes studied were divided into sets of complex pixels and the erosion over the pixels was calculated. Total erosion was regarded as the sum of erosion of all pixels. Furthermore, to calculate the sediment delivery ratio of each pixel, a new travel time equation for complex hillslopes was employed. Results showed that the mean erosion of convex hillslopes was 1.43 times that of concave and 1.19 times that of straight slopes. The effect of curvature shape on erosion was much greater than plan shape effect. The highest erosion belonged to convex divergent slopes, and the least erosion was related to concave divergent slopes. The laboratory results intended for validation of the numerical model also show that in hillslopes with fixed plan, the erosion rate in the convex hillslopes exceeds that of concave and straight hillslopes. Also, in the hillslopes with fixed curvature profile, the erosion rate in the convergent hillslopes is more than in the divergent and parallel ones.

20

Straty chemicznych składników pokarmowych roślin oraz gleby w wyniku odpływu wody z zadarnionego stoku lessowego

Mazur A.

Przemysł Chemiczny

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2018

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T. 97, nr 12

2154--2157

PL

Celem badań było określnie odpływu powierzchniowego i śródglebowego wody oraz zawartych w niej składników chemicznych (azotu ogólnego, amonowego, azotanowego( V) i azotanowego(III) oraz fosforu i potasu), a także zawiesiny glebowej z zadarnionego stoku lessowego. Badania wykonano w latach 2008-2011. W wyniku przeprowadzonej analizy stwierdzono, że zawartości azotu ogólnego wynosiły 0,685-5,321 mg/dm³, azotu amonowego 0,311-2,765 mg/dm³, azotu azotanowego( V) 0,208-1,441 mg/dm³, azotu azotanowego( III) 0,122-0,862 mg/dm³, fosforu 0,086-0,862 mg/dm³, potasu 0,652-4,241 mg/dm³, a zawiesiny glebowej 0,112-1,021 g/dm³. Strata wyerodowanych składników materii była mała w porównaniu z gruntami ornymi. Na podstawie analizy korelacji liniowej Pearsona stwierdzono istotny wpływ opadu erozyjnego oraz odpływu wody na stężenie zawiesiny glebowej i straty badanych składników materii. Stwierdzono brak zależności korelacyjnej pomiędzy opadem atmosferycznym a stężeniem chemicznych wskaźników określających jakość wody.

EN

Losses of total N, ammonium N and nitrite N as well as of P, K and soil suspension with surface and subsurface water outflow were detd. in Southern Poland in 2008- 2011. They were 0.685-5.321 mg/L, 0.311-2.765 mg/L, 0.208-1.444 mg/L, 0.122-0.862 mg/L, 0.086-0.862 mg/L, 0.652-4.241 mg/L, and 0.112-1.021 g/L, resp. A significant erosive effect of pptn. and water outflow on the concn. of soil suspension and loss of the studied matter components was found. In addn., no correlation relationship between atm. pptn. and the concn. of chem. water quality-detg. indicators was obsd.