Wyniki wyszukiwania - BazTech

1

Comparison of the Methods for LS Factor Calculation when Evaluating the Erosion Risk in a Small Agricultural Area Using the USLE Tool

Karásek Petr, Pochop Michal, Konečná Jana, Podhrázská Jana

Journal of Ecological Engineering

|

2022

|

Vol. 23, nr 1

100--109

EN

In the projects of anti-erosion protection in the Czech Republic, USLE was used as a standard tool for evaluating the risk of water erosion. The precision of the resulting USLE values is defined by the quality of input data and algorithms used. Two methods for LS factor calculation are recommended for use in the planning practice in the Czech Republic: the computing method based on the USLE 2D software and the other computing methods. Various methods can assess the LS factor; however, their results differ. On the example of the Starovice – Hustopeče study area (Czech Republic), strongly threatened by erosion, this report aimed to show the differences brought using these differing methods of LS factor assessment, all in two variants before and after application of antierosion measures (retention grass belts, grassed thalweg). Changes in the calculation of the LS factor were directly reflected in the calculation of the long-term average soil loss by water erosion.

2

Coupling of Space Remote Sensing and GIS for Detection of Areas at Risk of Degradation (Sidi Mohammed Ben Abdellah Dam Case – Morocco)

Abdelhadi Ouakil, Badr Benhichou, Kaoutar Elbelrhiti, Taha Amimi, Jamal Chao, Hicham Elbelrhiti

Ecological Engineering & Environmental Technology

|

2022

|

Vol. 23, iss. 6

161--172

EN

Sidi Mohamed Ben Abdellah dam watershed is one of the most vulnerable areas of the risk of soil degradation due to its wide exposure, lithological heterogeneity and varying climatic factors. In this sense, the qualitative study of the spatial-temporal evaluation of ground-level occupancy from satellite visualisation data (acquired by the Landsat TM 5 and Landsat TM 8) device derives a land-use map that shows the areas at risk of degradation after the integration of a combination of multiple factors into a GIS geographic information system (climate, terrain, pedology, vegetation cover and human intervention (anti-erosive practice); The results require adaptive vision to better control the phenomenon, to reduce its severity in areas at high risk of soil degradation.

3

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

Sabzevari T., Talebi A.

Acta Geophysica

|

2019

|

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.

4

Określenie erozji wodnej gleb w zlewni i ilości transportowanej zawiesiny w wodach potoku Ścieklec

Kowalczyk A., Smoroń S.

Woda-Środowisko-Obszary Wiejskie

|

2016

|

T. 16, z. 4

43--55

PL

W zlewni potoku Ścieklec, będącego lewostronnym dopływem rzeki Szreniawy, określano zawartość materiału glebowego erodowanego w formie zawiesiny ogólnej. Scharakteryzowano rodzaj pokrywy glebowej, sposób użytkowania ziemi, spadki terenu, intensywność opadów atmosferycznych oraz obliczono wartość erozji wodnej. W tym celu w okresie 2013–2015 mierzono zawartości zawiesiny ogólnej, a także (w latach 2014–2015) przepływów w wodzie potoku Ścieklec. Przedstawiono związek pomiędzy przepływem a wartością miesięcznych ładunków zawiesiny ogólnej. W okresie wegetacji 2014 r. suma ładunku zawiesiny ogólnej wynosiła 10,26 Mg·km-2, natomiast w 2015 r. była o ponad połowę mniejsza i wynosiła 6,15 Mg·km-2. W wodzie rozpatrywanego potoku podczas większych przepływów notowano wyraźne zwiększenie zawartości zawiesiny ogólnej. W pracy obliczono również masę erodowanego materiału glebowego metodą USLE wg Wischmeiera i Smitha. Zgodnie z uzyskanym wynikiem badań teren zlewni Ścieklca jest zagrożony erozją stopnia II – erozja słaba, a niektóre rejony z uprawą kukurydzy erozją stopnia III – erozja umiarkowana (wg klasyfikacji Zachara).

EN

The research aimed to determine the content of eroded soil material in form of suspended solids in water samples obtained within Ścieklec Stream which is the left tributary of Szreniawa River (Małopolska Voivodeship). The research was undertaken in order to determine the size of water erosion. During the analysis the following were registered: soil cover, type of land use, terrain configuration and intensity of precipitation. The results are based on analysis of samples taken through the years 2013–2015 as well as monitoring the water flow of the Ścieklec Stream for the years 2014– 2015. The results showed correlation between monthly flow rate of water and the load of suspended solids. The total load in the water was 10.26 Mg•km-2 in 2014 during growing season and 6.15 Mg•km-2 in 2015. The portion of the sediment was found to be increased significantly during more intense flows of the Ścieklec Stream. Analysis of water samples also included the mass of transported loose soil material using Wischmeier and Smith's USLE model. According to Zachar’s classification, the obtained results classify the area of the Ścieklec Stream basin to the second degree erosion (weak) which means a very slight reduction in soil depth due to a down slope transport of soil particles. Some regions with corn cultivation are classified to the moderate (the third) erosion degree.

5

Analysis of erosion vulnerability of agricultural land in the catchment of Luh stream using the GIS tools

Mašíček T., Kozlovsky Dufková J., Stejskal B.

Infrastruktura i Ekologia Terenów Wiejskich

|

2016

|

nr IV/4

1789--1810

EN

Utilization of geographic information systems (GIS) for the erosion vulnerability analysis of agricultural land is shown on the example of Luh stream catchment, Czech Republic, district of Vysočina. Evaluation of soil erosion conditions according to the Universal soil loss equation (USLE) was done in ArcGIS 10 Desktop, software product of ArcInfo using a set of integrated software applications ArcMap, ArcCatalog and ArcToolbox user interface with LS-converter and USLE2D programs. The project of erosion control measures and evaluation of their effect on the erosion were parts of the analyses. Erosion control crop rotations with soil protective technologies, that change the value of cover-management factor, were used as erosion control measures.

6

Wskaźnik średniej rocznej erozyjności deszczu i spływu powierzchniowego (R) na przykładzie stacji meteorologicznej w Łazach k. Bochni (region klimatu Pogórza Karpackiego)

Święchowicz J.

Landform Analysis

|

2013

|

Vol. 24

85--95

PL

Wskaźnik rocznej erozyjności deszczu i spływu powierzchniowego (R) jest jednym z parametrów empirycznego równania USLE (Uniwersalnego Równania Strat Glebowych) oraz innych modeli (np. RUSLE – Revised Universal Soil Loss Equation, USPED – Unit Stream Power based Erosion/Deposition). Jak dotąd nie dokonano szczegółowej charakterystyki erozyjności deszczów w Polsce, a wartości wskaźnika R zgodnie z procedurą opracowaną przez Wischmeiera i Smitha (1965, 1978) obliczono jedynie dla 13 stacji meteorologicznych. Celem pracy jest określenie wskaźnika erozyjności deszczu i spływu powierzchniowego (R) dla regionu klimatu Pogórza Karpackiego na podstawie pomiarów opadów atmosferycznych w wieloleciu 1987–2008 pochodzących ze stacji meteorologicznej w Łazach k. Bochni (Pogórze Wiśnickie). Średnia roczna z wielolecia 1987–2008 wartość wskaźnika R wynosi w Łazach 106,6 MJ cm ha–1 h–1. Jest ona większa od wartości podawanych dla Polski zachodniej (Wrocław-Swojec), północnej (Elbląg), północno-wschodniej (Suwałki), centralnej (Otwock, Sandomierz, Puczniew), zbliżona do wartości podawanych dla Karpat (Lesko, Limanowa, Szymbark). Roczne wartości wskaźnika R zmieniały się w Łazach w bardzo szerokim zakresie od 27,7 do 455,9 MJ cm ha–1 h–1. Maksymalne miesięczne wartości wskaźnika Rr w roku zmieniały się od 6,1 w lipcu (1993) do 428,7 MJ cm ha–1 h–1 w czerwcu (2006). Największa potencjalna erozja wodna gleby uzależniona od erozyjności deszczu możliwa była w czerwcu, lipcu, maju i sierpniu.

EN

Rainfall and runoff erosivity factor (R) is a key input parameter to the USLE (Universal Soil Loss Equation) and many other models (RUSLE – Revised Universal Soil Loss Equation, USPED – Unit Stream Power based Erosion/Deposition). There is still no precise characteristic of rainfall erosivity in Poland. Local R factor values, according to Wischmeier and Smith procedure (1965, 1978) were calculated only for 13 meteorological stations. The main aim of the paper is to estimate rainfall and runoff erosivity factor (R) for the Carpathian Foothills climatic region on the basis of 1987–2008 rainfall data for Łazy near Bochnia meteorological station (Wiśnicz Foothills). The average rainfall and runoff factor (R) for Łazy calculated for the years 1987–2008 equalled 106.6 MJ cm ha–1 h–1. This value was bigger in comparison with the values for other locations in western (Wrocław-Swojec), northern (Elbląg) northeastern (Suwałki) or central Poland (Otwock, Sandomierz, Puczniew) and similar to the values for the Carpathians (Lesko, Limanowa, Szymbark). The annual values of R factor for Łazy ranged between 27.7 in 1993 and 455.9 MJ cm ha–1 h–1 in 2006. Maximum monthly values of rainfall factor Rr in a year varied from 6.1 in July (1993) to 428.7 MJ cm ha–1 h–1 in June (2006). The most intensive potential soil erosion by water due to erosivity of rains is likely to happen in June, July, May and August.