scholarly journals Analysis of the Level of Erosion Hazard By Using Remote Sensing and Geographic Information System in the Sub-Watershed of Rindu Hati

2020 ◽  
Vol 3 (2) ◽  
pp. 32-38
Author(s):  
Prayogi Dhuha Brahmanto ◽  
Bambang Sulistyo ◽  
M. Faiz Barchia

Rindu Hati sub-watershed is located in District of Central Bengkulu, Bengkulu Province, that has flat until montainous topography with various slope and annual rainfall up to 4,032 mm year-1 which possible causes erosion. This research was aimed to analyze soil erosion at Rindu Hati sub-watershed based on the Universal Soil Loss Equation formula, using remote sensing imagery data and by applying GIS technique. USLE method were uses five parameters, those were length and slope factor, rainfall erosivity factor, crop management factor and land conservation , and soil erodibility factor. An overlay analysis has been conducted to obtain the erosion. Then, the result is overlaid with soil depth map to get the level of erosion hazard, which is classified into: very light, light, moderate, heavily, and very heavily. The results showed that the total erosion was 12,410,650.59 tons ha-1 year-1, while its level of erosion hazard were very light (15 tons ha-1 year-1) covering an area of 2,983 ha spreading over community agricultural areas and forest areas, the rate of light erosion (> 15-60 tons ha-1 year-1) has the largest area of covering an area of 10,410.05 ha which scattered in plantation areas having flat topography, moderate erosion rates (> 60-180 tons ha-1 year-1) of 1,317.33 ha spread over land areas with shrub land use and relatively flat topography, heavily erosion rates (> 180- 480 tons ha-1 year-1) covering 1,735.48 ha spread over land with shrub land use but has a hilly topography and very heavily erosion rates (> 480 tons ha-1 year-1) covering 2,700.42 ha located in the mining area. Erosion potential rate mapping will be very helpful in determining good and appropirate land management and conservation in the study area. 

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Veera Narayana Balabathina ◽  
R. P. Raju ◽  
Wuletaw Mulualem ◽  
Gedefaw Tadele

Abstract Background Soil erosion is one of the major environmental challenges and has a significant impact on potential land productivity and food security in many highland regions of Ethiopia. Quantifying and identifying the spatial patterns of soil erosion is important for management. The present study aims to estimate soil erosion by water in the Northern catchment of Lake Tana basin in the NW highlands of Ethiopia. The estimations are based on available data through the application of the Universal Soil Loss Equation integrated with Geographic Information System and remote sensing technologies. The study further explored the effects of land use and land cover, topography, soil erodibility, and drainage density on soil erosion rate in the catchment. Results The total estimated soil loss in the catchment was 1,705,370 tons per year and the mean erosion rate was 37.89 t ha−1 year−1, with a standard deviation of 59.2 t ha−1 year−1. The average annual soil erosion rare for the sub-catchments Derma, Megech, Gumara, Garno, and Gabi Kura were estimated at 46.8, 40.9, 30.9, 30.0, and 29.7 t ha−1 year−1, respectively. Based on estimated erosion rates in the catchment, the grid cells were divided into five different erosion severity classes: very low, low, moderate, high and extreme. The soil erosion severity map showed about 58.9% of the area was in very low erosion potential (0–1 t ha−1 year−1) that contributes only 1.1% of the total soil loss, while 12.4% of the areas (36,617 ha) were in high and extreme erosion potential with erosion rates of 10 t ha−1 year−1 or more that contributed about 82.1% of the total soil loss in the catchment which should be a high priority. Areas with high to extreme erosion severity classes were mostly found in Megech, Gumero and Garno sub-catchments. Results of Multiple linear regression analysis showed a relationship between soil erosion rate (A) and USLE factors that soil erosion rate was most sensitive to the topographic factor (LS) followed by the support practice (P), soil erodibility (K), crop management (C) and rainfall erosivity factor (R). Barenland showed the most severe erosion, followed by croplands and plantation forests in the catchment. Conclusions Use of the erosion severity classes coupled with various individual factors can help to understand the primary processes affecting erosion and spatial patterns in the catchment. This could be used for the site-specific implementation of effective soil conservation practices and land use plans targeted in erosion-prone locations to control soil erosion.


2005 ◽  
Vol 17 (2) ◽  
pp. 163-180 ◽  
Author(s):  
C. O.A. Coelho ◽  
A. J.D. Ferreira ◽  
A. Laouina ◽  
A.-K. Boulet ◽  
M. Chaker ◽  
...  

The ongoing intensification of grazing as well as the replacement of traditional land management systems in the Maghreb has brought to the forefront the fundamental role of land-use in determining soil erosion hazard. This paper reports on erosion rates and soil hydrological characteristics of a variety of land uses in Morocco and Tunisia. The results were obtained through rainfall simulation experiments carried out in the field using a portable simulator, following the design of CERDÀ et al. (1997). Traditional land management systems - typically involving a combination of agriculture, animal husbandry and forestry - produced the least amounts of overland flow and the lowest soil erosion rates. Over-exploitation of these systems apparently has only minor hydrological and erosional impacts. Heavily grazed, degraded "maquis" shrublands, on the other hand, produced considerable amounts of overland flow. At the plot scale of the rainfall simulation experiments (0.24 m2), the corresponding sediment loads are rather insignificant. Nevertheless, slopes where "maquis" shrublands (which generally have very compacted soils) occur upslope from more erodible soils may present a major erosion hazard.


Jurnal Solum ◽  
2009 ◽  
Vol 6 (2) ◽  
pp. 54
Author(s):  
Yulnafatmawita Yulnafatmawita ◽  
Asmar Asmar ◽  
Mimien Harianti ◽  
Suci Betrianingrum

A research about soil organic matter (SOM) classification based on the density was conducted for soil in Bukik Pinang-Pinang region.  The objective of this research was to identify whether the SOM in Pinang-Pinang area, having very high annual rainfall, was mostly particulate or had been associated with mineral particles.  Soils were sampled at three different land use, forest, bush, and mixed wood land on 0-10, 10-20, and 20-30 cm soil depth.  Soil organic matter was classified into 2 classes, < 1.0 g cm-3 and ≥ 1.0 g cm-3 by using pure aquadest.  Total and fractionated SOM samples were analyzed by using Walkley and Black method in soil laboratory, Agriclculture College, Andalas University.  The result showed that, among the three land use surveyed, mixed wood land use gave the highest SOM, then followed by bush land.  Soil OM content in forest ecosystem was much lower than the other two land use for the whole depth.  Based on the density, SOM particulate was higher on the soil surface and decrease by depth in each land use.  Among the ecosystem, SOM under forest was less associated with soil particles than that under bush and mixed wood land. Key Words:  SOM-light fraction, SOM-heavy fraction, land use


2020 ◽  
Author(s):  
Jamie Glass ◽  
Alexandru Codilean ◽  
Reka Fülöp ◽  
Klaus Wilcken ◽  
Tim Cohen ◽  
...  

&lt;p&gt;The eastern seaboard of Australia is characterized by a passive margin and a continental divide that separates the inland-draining rivers from those that drain to the Coral and Tasman seas. Seaward of this divide lies the Great Escarpment (GE) of Australia that separates a moderate relief coastal plain from a low relief, high elevation plateau. Quantifying the spatial variation of erosion rates from temperate New England (NE), NSW and tropical Bellenden Ker (BK), Queensland, two regions with distinctly different climates and escarpment embayment, could help constrain erosional controls that contribute to escarpment form. In this study, we compared forty detrital 10Be samples collected from sediments in the main trunk and tributaries of five major rivers: the Macleay, Bellinger, and Clarence in NE and the Russel-Mulgrave and North Johnstone in BK. We then traced the escarpment position in ARCGIS and calculated a sinuosity ratio to better compare the degree of embayment in each region. Across both datasets we found that for NE, which has deep gorges cutting into the plateau, the degree of embayment was twice that of BK, where the escarpment position is significantly less embayed and erosion rates significantly more variable (ratio of .18 vs .38). Erosion rates in low slope areas, such as on the plateau, were universally low with no other significant controlling factors. There was no correlation between erosion rates and catchment area, and that our data echo previous studies that find that once mean rainfall passes an approximate threshold (around 2000mm/yr) basin characteristics that are known to control erosion rates, such as slope and lithology, are subdued.&lt;/p&gt;&lt;p&gt;&amp;#160;In temperate NE, where rainfall ranges from approximately 800-1200mm/yr, there was a moderate linear correlation with mean catchment rainfall and erosion rates (R&lt;sup&gt;2&lt;/sup&gt; .50), which is likely due to a strong orographic effect due to the escarpment. Erosion rates from tributaries below the plateau were highly variable and ranged from 5m/Ma up to 60m/Ma and correlated strongly with mean catchment slope (R&lt;sup&gt;2&lt;/sup&gt; .86). In addition, there were moderate inverse linear correlations between erosion rate and the catchment total percent granite and sedimentary rock (R&lt;sup&gt;2&lt;/sup&gt; .53 and .63 respectively) and a moderate correlation between erosion rate and catchment total percent metamorphic rock (R&lt;sup&gt;2&lt;/sup&gt; .57). Similar to previous studies, these data suggest that in temperate climates with moderate amounts of annual rainfall, individual basin characteristics play a significant role in controlling basin wide erosion rates.&lt;/p&gt;&lt;p&gt;In contrast, data from tropical BK, where mean rainfall amounts are in excess of 2000mm/yr, erosion rates from tributaries below the plateau were significantly less variable than NE. Rates had a mean of 37m/Ma &amp;#177; 9 (standard deviation 5m/Ma, N=10) and were not significantly correlated with mean catchment slope nor catchment lithology. The mean erosion rate of BK is similar to that of other studies in the region, though with slightly less variability, and possibly reinforces the hypothesis from other researchers that in tropical climates with significant mean rainfall, soil depth effectively armors hillslopes and prevents bedrock erosion from occurring.&lt;/p&gt;


2021 ◽  
Vol 13 (11) ◽  
pp. 2223
Author(s):  
Mahboobeh Tayebi ◽  
Jorge Tadeu Fim Rosas ◽  
Wanderson de Sousa Mendes ◽  
Raul Roberto Poppiel ◽  
Yaser Ostovari ◽  
...  

Soil organic carbon (SOC) stocks are a remarkable property for soil and environmental monitoring. The understanding of their dynamics in crop soils must go forward. The objective of this study was to determine the impact of temporal environmental controlling factors obtained by satellite images over the SOC stocks along soil depth, using machine learning algorithms. The work was carried out in São Paulo state (Brazil) in an area of 2577 km2. We obtained a dataset of boreholes with soil analyses from topsoil to subsoil (0–100 cm). Additionally, remote sensing covariates (30 years of land use history, vegetation indexes), soil properties (i.e., clay, sand, mineralogy), soil types (classification), geology, climate and relief information were used. All covariates were confronted with SOC stocks contents, to identify their impact. Afterwards, the abilities of the predictive models were tested by splitting soil samples into two random groups (70 for training and 30% for model testing). We observed that the mean values of SOC stocks decreased by increasing the depth in all land use and land cover (LULC) historical classes. The results indicated that the random forest with recursive features elimination (RFE) was an accurate technique for predicting SOC stocks and finding controlling factors. We also found that the soil properties (especially clay and CEC), terrain attributes, geology, bioclimatic parameters and land use history were the most critical factors in controlling the SOC stocks in all LULC history and soil depths. We concluded that random forest coupled with RFE could be a functional approach to detect, map and monitor SOC stocks using environmental and remote sensing data.


Author(s):  
Indarto Indarto

Erosion processes are still the dominant factor affecting land degradation. The rapid calculation of erosion loss is urgently required for conservation planning and management at the watershed level. This paper is reporting the use of USLE method and GIS at Brantas Watershed. The digital layer data of rainfall from 2005 to 2014, soil types, land use, and DEM (from ASTER GDEM2) were used as the main input. The research procedures consist of (1) data inventory dan preparation, (2) calculation of the erosion factors (R, K, LS, CP), and (3) calculation and classification of the erosion hazard. The erosivity factor (R) is calculated from the analysis of annual rainfall data. The erodibility factor (K) is obtained using analysis of soil type map. The length and slope factor (LS) is calculated from the DEM and Soil layer data. The crop cover and conservation activities (CP) is interpreted from RBI maps year 2014. The results showed that the erosion hazard in Brantas Watershed dominated by very low with predominantly the erosion yield of 0,96 ton/ha/year. Thus required conservation and watershed management activities to prevent an increase erosion hazard in the Brantas Watershed.Keywords: erosion yield, USLE, GIS, Brantas, Watershed


2021 ◽  
Vol 9 ◽  
Author(s):  
Nejc Bezak ◽  
Sašo Petan ◽  
Matjaž Mikoš

Rainfall erosivity is one of the most important parameters that influence soil erosion rates. It is characterized by a large spatial and temporal variability. For example, in Slovenia, which covers around 20,000 km2, the annual rainfall erosivity ranges from less than 1,000 MJ mm ha−1 h−1 to more than 10,000 MJ mm ha−1 h−1. Drop size distribution (DSD) data are needed to investigate rainfall erosivity characteristics. More than 2 years of DSD measurements using optical disdrometers located at six stations in Slovenia were used to investigate the spatial and temporal variability in rainfall erosivity in Slovenia. Experimental results have indicated that elevation is a poor predictor of rainfall erosivity and that erosivity is more strongly correlated to the mean annual precipitation. Approximately 90% of the total kinetic energy (KE) was accounted for in about 35% of 1 min disdrometer data. The highest 1 min intensities (I) and consequently also KE values were measured in summer followed by autumn and spring. The local KE-I equation yielded an acceptable fit to the measured data in case of all six stations. The relatively large percentage of 1 min rainfall intensities above 5 mm/h can at least partially explain some very high annual rainfall erosivity values (i.e., near or above 10,000 MJ mm ha−1 h−1). Convective and large-scale precipitation events also result in various rainfall erosivity characteristics. The station microlocation and wind impacts in case of some stations yielded relatively large differences between the data measured using the optical disdrometer and the pluviograph. Preliminary conclusions have been gathered, but further measurements are needed to get even better insight into spatial and temporal variability in rainfall erosivity under Alpine climate in Slovenia.


1997 ◽  
Vol 54 (spe) ◽  
pp. 130-135 ◽  
Author(s):  
G. Sparovek ◽  
M.M. Weill ◽  
S.B.L. Ranieiri ◽  
E. Schnug ◽  
E.F. Silva

By definition, erosion tolerance should consider the conservation of the soil as a natural resource essential for crop production. Erosion rates greater than soil renewal will cause soil depth loss. A minimum soil depth was defined as the depth in which the inputs (fertilizers, crop residues) and management technology (irrigation, improved genetic crop quality) were insufficient to prevent economic productivity loss. Thus, erosion rates greater than soil formation are acceptable only during the time in which the soil does not reach the minimum depth. We have defined this time period as life-time. The life-time concept was applied to the Ceveiro watershed (1,945 ha) located in a sugarcane growing region in the Southeast of Brazil Erosion rates were estimated with the Universal Soil Loss Equation and soil depths were measured by field surveys. Depth change and life-time calculations, considering a soil formation rate of 0.2 mm y-1, and assuming the present scenario of land use and a minimum soil depth of 1.0 m were made using the Geographic Information System. Land use represented 1,319 ha (68%) of sugarcane, 346 ha (18%) of forests and 278 ha (14%) of pasture. The area in which soil erosion was less than soil formation (not associated to long term impacts) represented 475 ha (24%), which included the total forest areas and 48% of pastures. The total sugarcane area had erosion rates greater than soil formation. The area with erosion rates greater than soil formation rates and soil depth less than 1.0 m, which resulted in a life-time equal to zero (soil erosion impacts are presently irreversible) was 832 ha (42%). This area was composed of 702 ha of sugarcane and 130 ha of pastures. The remaining area (erosion greater than formation and soil depth > 1.0 m) represented 638 ha (32%), which was composed of 620 ha of sugarcane and 18 ha of pasture. The half-lifetime for the watershed was estimated as 350 yr. The life-time concept was effective to evaluate the extreme soil degradation risk of the Ceveiro watershed in an integral and reliable form.


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