scholarly journals Reconstructing long-term gully dynamics in Mediterranean agricultural areas

2016 ◽  
Author(s):  
Antonio Hayas ◽  
Tom Vanwalleghem ◽  
Ana Laguna ◽  
Adolfo Peña ◽  
Juan V. Giráldez
Keyword(s):  
Land Use ◽  
Temporal Resolution ◽  
Land Use Changes ◽  
Mediterranean Area ◽  
Drainage Density ◽  
Gully Erosion ◽  
Aerial Photographs ◽  
High Temporal Resolution ◽  
Erosion Rates ◽  
Erosion Processes

Abstract. Gully erosion is an important erosive process, especially in Mediterranean basins. However, the longterm dynamics of gully networks and the variation of sediment production in gullies is not well known. Available studies are often done over a few years only, while many gully networks form, grow, and change in response to environmental and land use or management changes over a long period. In order to clarify the effect of these changes, it is important to analyze the evolution of the gully network with a high temporal resolution. This study aims at analyzing gully morphodynamics over a long time scale (1956–2013) in a large Mediterranean area in order to quantify gully erosion processes and its contribution to overall sediment dynamics. A gully network of 20 km2 located in SW Spain, has been analyzed using a sequence of 10 aerial photographs in the period 1956–2013. The extension of the gully network both increased and decreased in the study period. Gully drainage density varied between 1.93 km km−2 in 1956, with a minimum of 1.37 km km−2 in 1980 and a maximum of 5.40 km km−2 in 2013. The main controlling factor of gully activity appeared to be rainfall, while land use changes were found to have only an indirect effect. A new Monte Carlo-based approach was proposed to reconstruct gully erosion rates from orthophotos. Gully erosion rates were found to be relatively stable between 1956–2009, with a mean value of 11.2 ton ha−1 yr−1, while in the period 2009–2011, characterized by extreme winter rainfalls, this value increased significantly, to 591 ton ha−1 yr−1. These results show that gully erosion rates are highly variable and that a simple interpolation between the start and end date would highly underestimate gully contribution during certain years, such as for example between 2009–2011. This illustrates the importance of the applied methodology using a high temporal resolution of orthophotos.

scholarly journals Reconstructing long-term gully dynamics in Mediterranean agricultural areas

2017 ◽  
Vol 21 (1) ◽  
pp. 235-249 ◽  
Author(s):  
Antonio Hayas ◽  
Tom Vanwalleghem ◽  
Ana Laguna ◽  
Adolfo Peña ◽  
Juan V. Giráldez
Keyword(s):  
Land Use ◽  
Temporal Resolution ◽  
Land Use Changes ◽  
Mediterranean Area ◽  
Gully Erosion ◽  
Aerial Photographs ◽  
High Temporal Resolution ◽  
Erosion Rates ◽  
Erosion Processes

Abstract. Gully erosion is an important erosive process in Mediterranean basins. However, the long-term dynamics of gully networks and the variations in sediment production in gullies are not well known. Available studies are often conducted only over a few years, while many gully networks form, grow, and change in response to environmental and land use or management changes over a long period. In order to clarify the effect of these changes, it is important to analyse the evolution of the gully network with a high temporal resolution. This study aims at analysing gully morphodynamics over a long timescale (1956–2013) in a large Mediterranean area in order to quantify gully erosion processes and their contribution to overall sediment dynamics. A gully network of 20 km2 located in southwestern Spain has been analysed using a sequence of 10 aerial photographs in the period 1956–2013. The extension of the gully network both increased and decreased in the study period. Gully drainage density varied between 1.93 km km−2 in 1956, a minimum of 1.37 km km−2 in 1980, and a maximum of 5.40 km km−2 in 2013. The main controlling factor of gully activity appeared to be rainfall. Land use changes were found to have only a secondary effect. A new Monte Carlo-based approach was proposed to reconstruct gully erosion rates from orthophotos. Gully erosion rates were found to be relatively stable between 1956 and 2009, with a mean value of 11.2 t ha−1 yr−1. In the period 2009–2011, characterized by severe winter rainfalls, this value increased significantly to 591 t ha−1 yr−1. These results show that gully erosion rates are highly variable and that a simple interpolation between the starting and ending dates greatly underestimates gully contribution during certain years, such as, for example, between 2009 and 2011. This illustrates the importance of the methodology applied using a high temporal resolution of orthophotos.

scholarly journals The Importance of Environmental Factors for the Development of Water Erosion of Soil in Agricultural Land: The Southern Part of Hronská Pahorkatina Hill Land, Slovakia

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1234
Author(s):  
Viera Petlušová ◽  
Peter Petluš ◽  
Michal Ševčík ◽  
Juraj Hreško
Keyword(s):  
Land Use ◽  
Environmental Factors ◽  
Geographical Information Systems ◽  
Agricultural Land ◽  
Land Use Changes ◽  
Water Erosion ◽  
Geographical Information ◽  
Aerial Photographs ◽  
Slope Length ◽  
Erosion Processes

The water erosion research was carried out in the lowland type of hilly landscape. The aim was to monitor and evaluate the importance of environmental factors (steepness of slope, relief shapes, aspect, slope length, combination slope length (L) and slope (S)—LS factor, types of land use changes) for the development of water erosion. We focused on the identification of areas threatened by erosion by interpreting aerial photographs from several time periods. This was followed by verification of erosion using soil probes. We identified 408.44 ha of areas affected by erosion, and measured the depth of soil and “A” horizons thickness. The environmental factors were modeled in geographical information systems by tools for spatially oriented data. Subsequently, the influence and significance of individual environmental factors were compared, and the probability of erosion was statistically estimated. The decisive factors in the formation of erosive surfaces are the LS factor and the slope. We also consider the factor of the relief shape to be important. The shape did not appear to be very significant as a separately evaluated factor, but all convex parts correlate with the identified erosion surfaces. The susceptibility of erosion related to the aspect of the slopes to the cardinal directions has not been confirmed. Types of land use changes with the most significant relation of erosion were confirmed in areas of strong intensification. We confirmed the importance of factors and land use for the development of erosion processes.

scholarly journals LAND USE AND LAND COVER MAPPING IN DETAILED SCALE: A CASE STUDY IN SANTA ROSA DE LIMA-SC

2018 ◽  
Vol 24 (2) ◽  
pp. 217-234 ◽  
Author(s):  
Rodrigo de Campos Macedo ◽  
Abdon Luiz Schmitt Schmitt Filho ◽  
Joshua C. Farley ◽  
Alfredo Celso Fantini ◽  
Ademir Antonio Cazella ◽  
...  
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Spatial Resolution ◽  
Temporal Resolution ◽  
Large Scale ◽  
Aerial Survey ◽  
Aerial Photographs ◽  
High Temporal Resolution ◽  
Land Cover Mapping

Abstract: It is challenging to reconcile large scale data with the dynamic characteristics present in land use. Such dynamism requires data with a high repetition of sampling. An alternative is the integration of data of high spatial resolution and low temporal resolution, with that of high temporal resolution and low spatial resolution. The aim addressed in this article is related to the integration of aerial photographs and temporal series for land use and land cover mapping in high detail scale. We conducted a case study in Santa Rosa de Lima-SC. The main data used was the aerial survey that overlaid the state of Santa Catarina, executed in 2010/2011. The interpretation key included typical elements of photointerpretation (color, texture, size, shape), aiming to classify the land use and land cover classes. The mapping evaluation resulted in 75.6% global accuracy, ranging from 54% (Grassland and Wetlands) to 96% (Water Bodies and Rocks). Such results are considered satisfactory. The integration of high-resolution images with high temporal resolution data has enabled the discrimination between classes that present great difficulties of separability. Such discrimination is essential in the territorial management processes of Encosta da Serra and the municipality of Santa Rosa de Lima.

scholarly journals Impacts of oak deforestation and rainfed cultivation on soil redistribution processes across hillslopes using 137Cs techniques

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Shamsollah Ayoubi ◽  
Nafiseh Sadeghi ◽  
Farideh Abbaszadeh Afshar ◽  
Mohammad Reza Abdi ◽  
Mojtaba Zeraatpisheh ◽  
...  
Keyword(s):  
Land Use ◽  
Magnetic Susceptibility ◽  
Soil Erosion ◽  
Erosion Rate ◽  
Land Use Changes ◽  
Soil Samples ◽  
Natural Forest ◽  
Oak Forests ◽  
Erosion Rates ◽  
Rainfed Farming

Abstract Background As one of the main components of land-use change, deforestation is considered the greatest threat to global environmental diversity with possible irreversible environmental consequences. Specifically, one example could be the impacts of land-use changes from oak forests into agricultural ecosystems, which may have detrimental impacts on soil mobilization across hillslopes. However, to date, scarce studies are assessing these impacts at different slope positions and soil depths, shedding light on key geomorphological processes. Methods In this research, the Caesium-137 (137Cs) technique was applied to evaluate soil redistribution and soil erosion rates due to the effects of these above-mentioned land-use changes. To achieve this goal, we select a representative area in the Lordegan district, central Iran. 137Cs depth distribution profiles were established in four different hillslope positions after converting natural oak forests to rainfed farming. In each hillslope, soil samples from three depths (0–10, 10–20, and 20–50 cm) and in four different slope positions (summit, shoulder, backslope, and footslope) were taken in three transects of about 20 m away from each other. The activity of 137Cs was determined in all the soil samples (72 soil samples) by a gamma spectrometer. In addition, some physicochemical properties and the magnetic susceptibility (MS) of soil samples were measured. Results Erosion rates reached 51.1 t·ha− 1·yr− 1 in rainfed farming, whereas in the natural forest, the erosion rate was 9.3 t·ha− 1·yr− 1. Magnetic susceptibility was considerably lower in the cultivated land (χhf = 43.5 × 10− 8 m3·kg− 1) than in the natural forest (χhf = 55.1 × 10− 8 m3·kg− 1). The lower soil erosion rate in the natural forest land indicated significantly higher MS in all landform positions except at the summit one, compared to that in the rainfed farming land. The shoulder and summit positions were the most erodible hillslope positions in the natural forest and rainfed farming, respectively. Conclusions We concluded that land-use change and hillslope positions played a key role in eroding the surface soils in this area. Moreover, land management can influence soil erosion intensity and may both mitigate and amplify soil loss.

Reconnaissance Mapping for Land-use Planning in the Natal Drakensberg, South Africa

1977 ◽  
Vol 4 (2) ◽  
pp. 103-108 ◽  
Author(s):  
Gerald G. Garland ◽  
J. Pelham Chisholm ◽  
Colin R. Christian
Keyword(s):  
Land Use ◽  
Land Use Planning ◽  
Land Use Changes ◽  
Mass Movement ◽  
Land Use Pattern ◽  
Erosion Rates ◽  
Reconnaissance Survey ◽  
Adequate Understanding ◽  
Geomorphological Processes ◽  
Detailed Work

Changes in land-use can have an important effect on rates of erosion and denudation. In order to avoid accelerating erosion rates, decision makers in land-use planning require adequate information on the contemporary geomorphological processes and hydrology of areas where modifications in the land-use pattern are envisaged. The first phase in the acquisition of the information is the reconnaissance survey, which shows where and how the erosional status of an area is likely to be affected, and also acts as a foundation on which to base more detailed work in the future.The Solitude area is an active erosional system, dominated by mass movement and fluvial processes. The rate of removal of material is likely to be increased by modifications in land-use which, from other points of view, would be considered entirely suitable for the area. Therefore, if accelerated denudation is to be avoided, projects involving land-use changes should be implemented only by those having an adequate understanding of the mechanism of geomorphological processes operating in the area.

scholarly journals Assessment of the soil loss caused by riverbank erosion in Serbia

2021 ◽  
Vol 101 (1) ◽  
pp. 31-47
Author(s):  
Marko Langovic ◽  
Slavoljub Dragicevic ◽  
Ivan Novkovic ◽  
Nenad Zivkovic ◽  
Radislav Tosic ◽  
...  
Keyword(s):  
Land Use ◽  
Soil Loss ◽  
Large Scale ◽  
Temporal Dynamics ◽  
Land Use Changes ◽  
Arable Land ◽  
Aerial Photographs ◽  
Lateral Migration ◽  
Channel Migration ◽  
Riverbank Erosion

Riverbank erosion and lateral channel migration are important geomorphological processes which cause various landscape, socio-economic, and environmental consequences. Although those processes are present on the territory of Serbia, there is no available data about the soil loss caused by riverbank erosion for the entire country. In this study, the spatial and temporal dynamics of the riverbank erosion for the largest internal rivers in Serbia (Velika Morava, Zapadna Morava, Juzna Morava, Pek, Mlava, Veliki Timok, Kolubara) was assessed using remote sensing and GIS. The aim of this paper is to determine the total and average soil loss over large-scale periods (1923-2020), comparing data from the available sources (aerial photographs, satellite images, and different scale paper maps). Results indicated that lateral migration caused significant problems through land loss (approximately 2,561 ha), especially arable land, and land use changes in river basins, but also economic loss due to the reduction of agricultural production. Total and average soil loss was calculated for five most representative meanders on all studied rivers, and on the basis of the obtained values, certain regularities about further development and dynamics of riverbank movement are presented. A better understanding of river channel migration in this area will be of a great importance for practical issues such as predicting channel migration rates for river engineering and planning purposes, soil and water management and land use changes, environment protection.

Influence of climate and land use changes on recent trends of soil erosion rates within the Russian Plain

2018 ◽  
Vol 29 (8) ◽  
pp. 2658-2667 ◽  
Author(s):  
Valentin Golosov ◽  
Oleg Yermolaev ◽  
Leonid Litvin ◽  
Nelli Chizhikova ◽  
Zoya Kiryukhina ◽  
...  
Keyword(s):  
Land Use ◽  
Soil Erosion ◽  
Land Use Changes ◽  
Russian Plain ◽  
Erosion Rates ◽  
Soil Erosion Rates ◽  
Recent Trends

Prediction Changes for Nonstationary Multi-Temporal Satellite Images using HMM

2017 ◽  
pp. 387-406
Author(s):  
Ali Ben Abbes ◽  
Imed Riadh Farah
Keyword(s):  
Land Use ◽  
Land Use Changes ◽  
Satellite Image ◽  
Remotely Sensed ◽  
High Temporal Resolution ◽  
Remotely Sensed Data ◽  
Vegetation Monitoring ◽  
Area Of Interest ◽  
Multi Temporal ◽  
The Difference

Due to the growing advances in their temporal, spatial, and spectral resolutions, remotely sensed data continues to provide tools for a wide variety of environmental applications. This chapter presents the benefits and difficulties of Multi-Temporal Satellite Image (MTSI) for land use. Predicting land use changes using remote sensing is an area of interest that has been attracting increasing attention. Land use analysis from high temporal resolution remotely sensed images is important to promote better decisions for sustainable management land cover. The purpose of this book chapter is to review the background of using Hidden Markov Model (HMM) in land use change prediction, to discuss the difference on modeling using stationary as well as non-stationary data and to provide examples of both case studies (e.g. vegetation monitoring, urban growth).

scholarly journals Runoff processes and land use changes in the upper reaches of the Krupá river catchment during the last 70 years

2008 ◽  
Vol 2 (No. 3) ◽  
pp. 77-84
Author(s):  
R. Pavelková Chmelová ◽  
B. Šarapatka ◽  
M. Dumbrovský ◽  
P. Pavka
Keyword(s):  
Land Use ◽  
River Basin ◽  
Hydrological Model ◽  
Land Use Changes ◽  
Aerial Photographs ◽  
Historical Maps ◽  
River Catchment ◽  
Cadastral Maps ◽  
Left Tributary ◽  
Morava River

In this paper, the authors summarise the land use changes in the upper reaches of the Krupá river catchment, which is a left tributary of the Morava River. During last 70 years, the catchment was exposed to many important historical events that have been inscribed in the physique of the landscape in a very interesting way. The land use changes, which occurred during the last eight decades in the subcatchment of the Krupá river basin, have been analysed using historical maps, cadastral maps, and both historical and recent aerial photographs of the area. The next step is to estimate, through the CN method and DesQ hydrological model, how the runoff processes in the Krupá River catchment could be influenced by the land use changes.

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