Spatial and Temporal Variation of Soil Erosion in Guangxi in Recent 20 Years

2013 ◽  
Vol 421 ◽  
pp. 787-791
Author(s):  
Yan Li Chen ◽  
Shi Quan Zhong ◽  
Jian Fei Mo ◽  
Yong Ming Luo
Keyword(s):  
Spatial Distribution ◽  
Soil Erosion ◽  
Temporal Variation ◽  
Digital Elevation Model ◽  
Spatial And Temporal Variation ◽  
Upward Trend ◽  
The Past ◽  
Digital Elevation ◽  
Elevation Model ◽  
Light Medium

TM/ETM data as the base information combined with a digital elevation model are used to analyze the spatial distribution and temporal variation of soil erosion in Guangxi. The results shows that light, medium and strong are the main three levels of soil erosion in Guangxi. The proportions of light and medium soil erosion are higher which are 6.18% and 4.76% respectively. The total area of soil erosion and its degrees exhibit an upward trend since the 1980s. The area of soil erosion in Guangxi increases 4% in the past 20 years. The five levels of soil erosion performance an upward trend mostly. Medium soil erosion is of the biggest change with an increase of 1.29% while acute soil erosion exhibits a smallest change with an increase of 0.49%.

Using GIS and a digital elevation model to assess the effectiveness of variable grade flow diversion terraces in reducing soil erosion in northwestern New Brunswick, Canada

2009 ◽  
Vol 23 (23) ◽  
pp. 3271-3280 ◽  
Author(s):  
Qi Yang ◽  
Zhengyong Zhao ◽  
Thien Lien Chow ◽  
Herb W. Rees ◽  
Charles P.-A. Bourque ◽  
...  
Keyword(s):  
Soil Erosion ◽  
New Brunswick ◽  
Digital Elevation Model ◽  
Flow Diversion ◽  
Digital Elevation ◽  
Elevation Model

scholarly journals Catchment properties in the Kruger National Park derived from the new TanDEM-X Intermediate Digital Elevation Model (IDEM)

2015 ◽  
Vol XL-7/W3 ◽  
pp. 293-300 ◽  
Author(s):  
J. Baade ◽  
C. Schmullius
Keyword(s):  
Digital Elevation Model ◽  
National Park ◽  
Kruger National Park ◽  
Data Sets ◽  
Earth Surface ◽  
The Past ◽  
Digital Elevation ◽  
Precision And Accuracy ◽  
Elevation Model ◽  
Reservoir Basin

Digital Elevation Models (DEM) represent fundamental data for a wide range of Earth surface process studies. Over the past years the German TanDEM-X mission acquired data for a new, truly global Digital Elevation Model with unpreceded geometric resolution, precision and accuracy. First processed data sets (i. e. IDEM) with a geometric resolution of 0.4 to 3 arcsec have been made available for scientific purposes. This includes four 1° x 1° tiles covering the Kruger National Park in South Africa. Here we document the results of a local scale IDEM validation exercise utilizing RTK-GNSS-based ground survey points from a dried out reservoir basin and its vicinity characterized by pristine open Savanna vegetation. Selected precursor data sets (SRTM1, SRTM90, ASTER-GDEM2) were included in the analysis and highlight the immense progress in satellite-based Earth surface surveying over the past two decades. Surprisingly, the high precision and accuracy of the IDEM data sets have only little impact on the delineation of watersheds and the calculation of catchment size. But, when it comes to the derivation of topographic catchment properties (e.g. mean slope, etc.) the high resolution of the IDEM04 is of crucial importance, if - from a geomorphologist’s view - it was not for the disturbing vegetation.

scholarly journals The Changes of Runoff with DEM Resolution Variations

2020 ◽  
Vol 8 (6) ◽  
pp. 2531-2538
Keyword(s):  
Land Use ◽  
Digital Elevation Model ◽  
Field Measurement ◽  
Surface Runoff ◽  
Satellite Images ◽  
Rational Method ◽  
The Past ◽  
Digital Elevation ◽  
Elevation Model ◽  
Upstream Catchment

Currently there has been a research gap in providing sufficient and reliable data for the estimation of surface runoff from ungauged catchment in Batang Kuranji watershed, City of Padang, West Sumatera, Indonesia. The need for such data arose from the fact that land cover changes occur rapidly in the past 20 years, and flash flood and river degradation have been experienced at an alarming scale. However, due to lack of discharge data from upstream catchment, modelling catchment response to the effect of land use changes is hampered. Field measurement is difficult due to accessibility to river tributaries in the upstream catchment. Therefore, the use of digital satellite images and digital elevation model is studied with various DEM (Digital Elevation Model) resolutions for the first time in this catchment. This catchment is situated from 95 to 1858 m above sea level with an annual rainfall of 3440 mm. This watershed is classified as steep with a watershed that has a slope of more than 40% reaching 37.01% of the entire Kuranji watershed area. This study used 30 m and 8 m DEM. Secondary data were gathered from satellite images such as MODIS (MODerate resolution Imaging Spectroradiometer) Land Use. Precipitation data were gathered from three rain gauging stations in or nearby the catchment. Stream geometry data were obtained from the Provincial Office for River Management. Annual discharge and 100-year discharge are calculated using rainfall data for the past 20 years. Runoff discharge was calculated using rational method and SCS (Soil Conservation Services) method. Overall, computed discharge decreases as DEM resolution decreases with percentage varies between 0.98% to 1.76%. The biggest difference between DEM of 30 m and 8 m was shown by the Rational method. However, the difference between years is inconsistent with methods used with no significant pattern. Using the rational method, the biggest difference was by 18.73 m3/s, making up 1.76%. With SCS-CN, however, the biggest difference was 14 m3/s or 1.32% and the smallest was 0.98%. Validation with field measurement suggests that the 8-m DEM varies only 0.16% with actual discharge. Therefore, in the Kuranji catchment, the SCS method coupled with 8-m DEM was found to be accurate for the estimation of surface runoff

scholarly journals Using EPM Model and GIS for Estimation of Soil Erosion in Souss Basin, Morocco

2019 ◽  
Vol 7 (8) ◽  
pp. 1228 ◽  
Author(s):  
Argaz Ahmed ◽  
Darkaoui Adil ◽  
Bikhtar Hasna ◽  
Ayouch Elbachir ◽  
Ramdan Lazaar
Keyword(s):  
Spatial Distribution ◽  
Soil Erosion ◽  
Potential Model ◽  
Soil Protection ◽  
Landsat 8 ◽  
Digital Elevation ◽  
Elevation Model ◽  
Data Layers ◽  
Gis Software ◽  
Basin Area

The study is aimed at predicting soil erosion and investigate its spatial distribution in Souss basin area used EPM (erosion potential model), also known as Gavrilovic method, incorporating into GIS (geographic information system) software. The spatial distribution of soil erosion shows three main zones in the studied area (very slight, slight to moderate). The main factors in the EPM (soil erodibility, soil protection, slope, temperature and rainfall) were evaluated using GIS software. Data layers used in this study were created from digital elevation model (DEM), lithology maps, landsat 8 oli digital images, the highest amount of erosion occurred in the northeast regions, Results showed that about 87.84% of the study area is classified in low and very low to destructive erosion intensify, 12.15% of the study area was moderate potential soil losses.

STUDY OF THE LANDSLIDE MORPHOLOGY BASED ON GNSS DATA AND AIRBORNE SOUNDING (ON THE EXAMPLE OF A SECTION OF THE PROTVA RIVER VALLEY)

2018 ◽  
Vol 12 (5-6) ◽  
pp. 50-57 ◽  
Author(s):  
I. S. Voskresensky ◽  
A. A. Suchilin ◽  
L. A. Ushakova ◽  
V. M. Shaforostov ◽  
A. L. Entin ◽  
...  
Keyword(s):  
Digital Elevation Model ◽  
Geodetic Network ◽  
Aerial Survey ◽  
River Valley ◽  
Ease Of Use ◽  
Digital Elevation ◽  
Loose Deposits ◽  
Positioning Method ◽  
Landslide Body ◽  
Elevation Model

To use unmanned aerial vehicles (UAVs) for obtaining digital elevation models (DEM) and digital terrain models (DTM) is currently actively practiced in scientific and practical purposes. This technology has many advantages: efficiency, ease of use, and the possibility of application on relatively small area. This allows us to perform qualitative and quantitative studies of the progress of dangerous relief-forming processes and to assess their consequences quickly. In this paper, we describe the process of obtaining a digital elevation model (DEM) of the relief of the slope located on the bank of the Protva River (Satino training site of the Faculty of Geography, Lomonosov Moscow State University). To obtain the digital elevation model, we created a temporary geodetic network. The coordinates of the points were measured by the satellite positioning method using a highprecision mobile complex. The aerial survey was carried out using an unmanned aerial vehicle from a low altitude (about 40–45 m). The processing of survey materials was performed via automatic photogrammetry (Structure-from-Motion method), and the digital elevation model of the landslide surface on the Protva River valley section was created. Remote sensing was supplemented by studying archival materials of aerial photography, as well as field survey conducted immediately after the landslide. The total amount of research results made it possible to establish the causes and character of the landslide process on the study site. According to the geomorphological conditions of formation, the landslide refers to a variety of landslideslides, which are formed when water is saturated with loose deposits. The landslide body was formed with the "collapse" of the blocks of turf and deluvial loams and their "destruction" as they shifted and accumulated at the foot of the slope.

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