scholarly journals Mapping Spatio-Temporal Soil Erosion Patterns in the Candelaro River Basin, Italy, Using the G2 Model with Sentinel2 Imagery

Geosciences ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 89 ◽  
Author(s):  
Christos Karydas ◽  
Ouiza Bouarour ◽  
Pandi Zdruli
Keyword(s):  
Soil Erosion ◽  
River Basin ◽  
Arable Land ◽  
European Space Agency ◽  
Retention Factor ◽  
Mitigation Measures ◽  
Erosion Rates ◽  
Apulia Region ◽  
Space Agency ◽  
Spatio Temporal

This study aims at mapping soil erosion caused by water in the Candelaro river basin, Apulia region, Italy, using the G2 erosion model. The G2 model can provide erosion maps and statistical figures at month-time intervals, by applying non data-demanding alternatives for the estimation of all the erosion factors. In the current research, G2 is taking a step further with the introduction of Sentinel2 satellite images for mapping vegetation retention factor on a fine scale; Sentinel2 is a ready-to-use, image product of high quality, freely available by the European Space Agency. Although only three recent cloud-free Sentinel2 images covering Candelaro were found in the archive, new solutions were elaborated to overcome time-gaps. The study in Candelaro resulted in a mean annual erosion rate of 0.87 t ha−1 y−1, while the autumn months were indicated to be the most erosive ones, with average erosion rates reaching a maximum of 0.12 t ha−1 in September. The mixed agricultural-natural patterns revealed to be the riskiest surfaces for most months of the year, while arable land was the most extensive erosive land cover category. The erosion maps will allow competent authorities to support relevant mitigation measures. Furthermore, the study in Candelaro can play the role of a pilot study for the whole Apulia region, where erosion studies are rather limited.

A Spatial and Temporal Continuum Remotely Sensed Soil Moisture Dataset of the Tibet Plateau From 2002 to 2015

2020 ◽  
Author(s):  
Yaokui Cui ◽  
Chao Zeng ◽  
Jie Zhou ◽  
Xi Chen
Keyword(s):  
Soil Moisture ◽  
Tibetan Plateau ◽  
Land Surface ◽  
European Space Agency ◽  
Remotely Sensed ◽  
General Regression Neural Network ◽  
Tibet Plateau ◽  
The Tibetan Plateau ◽  
Space Agency ◽  
Spatio Temporal

<p><strong>Abstract</strong>:</p><p>Surface soil moisture plays an important role in the exchange of water and energy between the land surface and the atmosphere, and critical to climate change study. The Tibetan Plateau (TP), known as “The third pole of the world” and “Asia’s water towers”, exerts huge influences on and sensitive to global climates. Long time series of and spatio-temporal continuum soil moisture is helpful to understand the role of TP in this situation. In this study, a dataset of 14-year (2002–2015) Spatio-temporal continuum remotely sensed soil moisture of the TP at 0.25° resolution is obtained, combining MODIS optical products and ESA (European Space Agency) ECV (Essential Climate Variable) combined soil moisture products based on General Regression Neural Network (GRNN). The validation of the dataset shows that the soil moisture is well reconstructed with R<sup>2</sup> larger than 0.65, and RMSE less than 0.08 cm<sup>3</sup> cm<sup>-3</sup> and Bias less than 0.07 cm<sup>3</sup> cm<sup>-3 </sup>at 0.25° and 1° spatial scale, compared with the in-situ measurements in the central of TP. And then, spatial and temporal characteristics and trend of SM over TP were analyzed based on this dataset.</p><p><strong>Keywords: </strong>Soil moisture; Remote Sensing; Dataset; GRNN; ECV; Tibetan Plateau</p>

scholarly journals Spatiotemporal Analysis of Potential Impact of Soil Erosion on Maize and Groundnuts Yield in Northern Ghana

2021 ◽  
Vol 5 (2) ◽  
pp. 486-493
Author(s):  
Wilson Agyei Agyare ◽  
Eliasu Salifu
Keyword(s):  
Soil Erosion ◽  
Water Conservation ◽  
Arable Land ◽  
Current Trend ◽  
Spatiotemporal Analysis ◽  
Crop Productivity ◽  
Potential Effect ◽  
Northern Ghana ◽  
Erosion Rates ◽  
North East

Abstract Soil erosion is a threat to the viability of arable land, which has a relationship with crop productivity. This study was carried out in the Northern, North-East and Savannah Regions of Ghana, which have a high agricultural potential. The study examined erosion-yield relationship by comparing estimated erosion rates with maize and groundnut yields in a GIS environment. The study also projected soil erosion and determined its potential effect on the yield of maize and groundnuts. The soil erosion rates were found to be 4.2 t ha-1y-1, 5.1 t ha-1y-1 and 7.1 t ha-1y-1 for the Northern, North-East and Savannah Regions respectively. Projections for the next 10 years showed that, soil erosion will averagely increase by about 12 %, which could reduce the yield of maize and groundnut by 21 % and 16 % respectively by the year 2031, should the current trend continue. The study also found out that crop (maize and groundnut) yield per land area is relatively lower in areas severely affected by soil erosion. Farmers in the study area and areas of similar ecology must be encouraged to adopt Soil and Water Conservation (SWC) strategies to enhance and sustain productivity.

scholarly journals Land Use Activities and Their Effects on Soil Erosion on the Slopes of Kajulu Hills, Kisumu County, Kenya

2019 ◽  
Vol 11 (2) ◽  
pp. 68
Author(s):  
Otieno, J. ◽  
Otieno, A. C. ◽  
Tonui, K. W
Keyword(s):  
Land Use ◽  
Soil Erosion ◽  
Human Activities ◽  
World Wide ◽  
Arable Land ◽  
Mitigation Measures ◽  
Natural Phenomenon ◽  
Mountainous Regions ◽  
The World ◽  
The Hill

Soil erosion is a natural phenomenon, but human activities accelerate it between ten to forty times the natural occurrences. It therefore calls for mitigating measure to curb the effects of erosion since soils form at a slower rate than they are destroyed. A study on land use activities and their effects on soil erosion was conducted in the upland ecosystem in Kenya, Kajulu hills. The study assessed the effectiveness of the mitigation measures adopted by the residents to ease the effects erosion on the hill slopes. A sample size of 295 households out of 1600 households engaged in various mitigating practices was used. The study collected data on the magnitude of soil (kg) lost from the arable lands using collector ditch technique. The data were analyzed using frequency distribution tables and Man U-test. The result showed a double amount (1.198kg/m2) of soil lost on the arable land without mitigation measures as compared to plots under cut off ditches (0,615kg/m2) and vegetative strips (0.904kg/m2) with Man U=7. These findings were above the world wide estimation of soil erosion on arable mountainous regions which range between 1.3-40.kg/m2/year (13-40T/Ha/year) as it was based on one rainy season.

scholarly journals Spatial Variabilities of Runoff Erosion and Different Underlying Surfaces in the Xihe River Basin

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 352 ◽  
Author(s):  
Ning Wang ◽  
Zhihong Yao ◽  
Wanqing Liu ◽  
Xizhi Lv ◽  
Mengdie Ma
Keyword(s):  
Spatial Distribution ◽  
Soil Erosion ◽  
River Basin ◽  
Loess Plateau ◽  
Arable Land ◽  
Alluvial Soil ◽  
Underlying Surface ◽  
Spatial Gradient ◽  
Hydrological Process ◽  
The Loess Plateau

Runoff erosion capacity has significant effects on the spatial distribution of soil erosion and soil losses. But few studies have been conducted to evaluate these effects in the Loess Plateau. In this study, an adjusted SWAT model was used to simulate the hydrological process of the Xihe River basin from 1993 to 2012. The spatial variabilities between runoff erosion capacity and underlying surface factors were analyzed by combining spatial gradient analysis and GWR (Geographically Weighted Regression) analysis. The results show that the spatial distribution of runoff erosion capacity in the studying area has the following characteristics: strong in the north, weak in the south, strong in the west, and weak in the east. Topographic factors are the dominant factors of runoff erosion in the upper reaches of the basin. Runoff erosion capacity becomes stronger with the increase of altitude and gradient. In the middle reaches area, the land with low vegetation coverage, as well as arable land, show strong runoff erosion ability. In the downstream areas, the runoff erosion capacity is weak because of better underlying surface conditions. Compared with topographic and vegetation factors, soil factors have less impact on runoff erosion. The red clay and mountain soil in this region have stronger runoff erosion capacities compared with other types of soils, with average runoff modulus of 1.79 × 10−3 m3/s·km2 and 1.68 × 10−3 m3/s·km2, respectively, and runoff erosion power of 0.48 × 10−4 m4/s·km2 and 0.34 × 10−4 m4/s·km2, respectively. The runoff erosion capacity of the alluvial soil is weak, with an average runoff modulus of 0.96 × 10−3 m3/s·km2 and average erosion power of 0.198 × 10−4 m4/s·km2. This study illustrates the spatial distribution characteristics and influencing factors of hydraulic erosion in the Xihe River Basin from the perspective of energy. It contributes to the purposeful utilization of water and soil resources in the Xihe River Basin and provides a theoretical support for controlling the soil erosion in the Hilly-gully region of the Loess Plateau.

scholarly journals Estimation of Sediment Yield and Maximum Outflow Using the IntErO Model in the Sarada River Basin of Nepal

Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 952 ◽  
Author(s):  
Devraj Chalise ◽  
Lalit Kumar ◽  
Velibor Spalevic ◽  
Goran Skataric
Keyword(s):  
Soil Erosion ◽  
River Basin ◽  
Sediment Yield ◽  
Soil Loss ◽  
Surface Erosion ◽  
Good Opportunity ◽  
Erosion Rates ◽  
Erosion Processes ◽  
Erosion Coefficient ◽  
To Come

Soil erosion is a severe environmental problem worldwide as it washes away the fertile topsoil and reduces agricultural production. Nepal, being a hilly country, has significant erosion disputes as well. It is important to cognise the soil erosion processes occurring in a river basin to manage the erosion severity and plan for better soil conservation programs. This paper seeks to calculate the sediment yield and maximum outflow from the Sarada river basin located in the western hills of Nepal using the computer-graphic Intensity of Erosion and Outflow (IntErO) model. Asymmetry coefficient of 0.63 was calculated, which suggests a possibility of large floods to come in the river basin in the future whereas the maximum outflow from the river basin was 1918 m³ s−1. An erosion coefficient value of 0.40 was obtained, which indicates surface erosion of medium strength prevails in the river basin. Similarly, the gross soil loss rate of 10.74 Mg ha−1 year−1 was obtained with the IntErO modeling which compares well with the soil loss from the erosion plot measurements. The IntErO model was used for the very first time to calculate soil erosion rates in the Nepalese hills and has a very good opportunity to be applied in similar river basins.

scholarly journals A NOVEL INDEX FOR TEMPORAL STABILITY ANALYSIS IN SPACE AND TIME OF SAR-DERIVED SCENES

2020 ◽  
Vol XLIII-B3-2020 ◽  
pp. 1577-1583
Author(s):  
M. E. Molinari ◽  
A. Monti-Guarnieri ◽  
M. Manzoni
Keyword(s):  
United Arab Emirates ◽  
Risk Mitigation ◽  
European Space Agency ◽  
Temporal Stability ◽  
Stability Index ◽  
Mitigation Measures ◽  
Detection Analysis ◽  
Space Agency ◽  
Regular Time ◽  
Sar Imagery

Abstract. Detecting temporal changes is one of the most important applications of satellite sensors. In recent years, the increasing availability of regular time-series of SAR imagery, provided by the Sentinel-1 mission of the European Space Agency (ESA), has drawn increasing attention to these techniques, especially in earth environment monitoring and risk management. Within this paper, a coherent change detection analysis for evaluating the risk due to movements of dunes and sand sheets in desertic areas is proposed. To this purpose, we introduce a novel, coherence-based index, named Temporal Stability Index (TSI), that is suited for characterizing the percentage of stability of a target with time. TSI maps can be generated over areas as wide as hundreds of kilometers, in a short time, and mostly by exploiting available software tools (plus some simple coding). The information provided is complementary to the average of the short-term coherence, here shown. Results of analysis performed on two desertic regions (the United Arab Emirates and Egypt) document the usefulness of TSI for the identification of dune movements and areas subject to sand accumulation, supporting risk mitigation measures.

scholarly journals On sampling uncertainty of satellite ozone profile measurements

2014 ◽  
Vol 7 (3) ◽  
pp. 2381-2403
Author(s):  
V. F. Sofieva ◽  
N. Kalakoski ◽  
S.-M. Päivärinta ◽  
J. Tamminen ◽  
E. Kyrölä ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Transport Model ◽  
European Space Agency ◽  
Atmospheric Measurements ◽  
Sampling Uncertainty ◽  
Space Agency ◽  
Ozone Profile ◽  
Spatio Temporal ◽  
Continuous Fields ◽  
Satellite Instruments

Abstract. Satellite measurements sample continuous fields of atmospheric constituents at discrete locations and times. However, insufficient or inhomogeneous sampling, if not taken into account, can result in inaccurate average estimates and even induce spurious features. We propose to characterize the spatio-temporal inhomogeneity of atmospheric measurements by a measure, which is a linear combination of the asymmetry and entropy of a sampling distribution. It is shown that this measure is related to the so-called sampling uncertainty, which occurs due to non-uniform sampling patterns. We have estimated the sampling uncertainty of zonal mean ozone profiles for six limb-viewing satellite instruments participating in the European Space Agency Ozone Climate Change Initiative project using the high-resolution ozone field simulated with the FinROSE chemistry-transport model. It is shown that the sampling uncertainty for the instruments with coarse sampling is not negligible and can be as large as a few percent. It is found that the standard deviation of the sampling uncertainty in the monthly zonal mean data allows for a simple parameterization in terms of the product of the standard deviation of natural variations and the proposed inhomogeneity measure. The focus of this work is the vertical ozone distributions measured by limb-viewing satellite instruments, but the developed methods can also be applied to different satellite, ground-based and in-situ measurements.

scholarly journals Decision Making Methods to Optimize New Dam Site Selections on the Nitra River

Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 2042 ◽  
Author(s):  
Igor Gacko ◽  
Zlatica Muchová ◽  
Ľuboš Jurík ◽  
Karol Šinka ◽  
Ladislav Fabian ◽  
...  
Keyword(s):  
Decision Making ◽  
Soil Erosion ◽  
River Basin ◽  
Surface Runoff ◽  
Arable Land ◽  
River Basins ◽  
Divisive Hierarchical Clustering ◽  
New Locations ◽  
Dam Site ◽  
Special Case

Grouping both existing and newly planned reservoirs based on selected measurable characteristics allows to point out issues that are relevant to area management using experience obtained from the environment of other sites. Divisive hierarchical clustering has been deployed to find similarities between dam locations. The Nitra River Basin (located in Nitra District, Nitra Region in Slovakia) with its 54 reservoirs is the model area. Profiles for 11 potential new reservoirs have been developed. Partial river basins were identified for each of the existing and new reservoirs using a digital relief model. The area size, proportion of arable land, forestland and built-up area, degree of exposure to soil erosion and the volume of surface runoff have been used as parameters for comparisons. Six clusters have been identified containing similar existing as well as new locations, one of them being a special case.

Sign in / Sign up

Export Citation Format

Share Document