endobj If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. 0 0 0 556 556 500 556 556 278 556 556 222 222 500 222 833 The result reveals that the soil loss ranges from 0 ton/ha/year in flat slope to 38.09 ton/ha/year from steep slopes. 1.1 and to Lorenzo Orioli for the information and photos of the Sanetti Plain. 6, annual R value ranges between 376 and 465 MJmm/ha/year. Acrisols having plinthite within 125 cm of the surface, Other Acrisols showing hydromorphic properties within 50 cm of the surface, Other Acrisols having an umbric A horizon or a high organic matter content in the B horizon, or both. Soil erosion is a serious problem in Ethiopia. From the gross soil erosion, 43,762 ton/year sediment yields have been estimated at watershed outlet. Missing rainfall data for all stations have been filled using nearest neighborhood interpolation technique. M.Sc. /StemV 78 CNR Italy, Firenze, Natali C, Beccaluva L, Bianchini G, Siena F (2013) The Axum-Adwa basalttrachyte complex: a late magmatic activity at the periphery of the Afar plume. 0000003302 00000 n It measures the combined effect of all the interrelated cover and management variables on soil erosion (Wischmeier and Smith 1978). In: Edwards S, Demissie A, Bekele T, Haase G (eds) Forest genetic resources conservation: principles, strategies and actions. 3). Soil OC was analyzed by wet digestion method (Walkley and Black 1934), and total N was determined by a modified micro- The finding shows that the estimated model result was by far lower than the previous model result, which could be due to positive effect of watershed management intervention at watershed scale and plot level in particular. (2019), who reported that the LS factor for karessa watershed Dawuro zone, south west Ethiopia ranges from 0 in flat areas to 154.6 steeper and longer slope area of the watershed. Volcanoes in the ecoregion are also intermittently active. The inherent characteristics of soil also influence the rate of soil erosion. trailer ( 2013) classified the land mass of Ethiopia into 60 soil types with an area coverage ranging from 1.4 to 208,882 km 2. where SDR denotes the sediment delivery ratio and area of the watershed. The annual mean soil loss rate for each woreda was estimated and each woreda erosion severities were compared with the tolerable soil loss limit. Because of moisture deficiency and coarse texture, they lack potential for rain-fed agriculture. All four species are found in the Western and Eastern highlands in numbers ranging from a few hundred for the walia ibex to a few thousand for the others. The dramatic views are due to this volcanic activity. The major part of the Simien Mountains consists of remnants of a Hawaiian-type shield volcano. Water Resour Manag. 6). 9). 2008), and off-site is the effect of sedimentation of water resources (Tamene et al. endobj /LastChar 116 /FontBBox [-665 -325 2000 1006] GLEYSOLS (G)Other soils showing hydromorphic properties within 50 cm of the surface; having no diagnostic horizons other than (unless buried by 50 cm or more new material) an A horizon, an H horizon, a cambic B horizon, a calcic or a gypsic horizon. Eight factors/parameters such as soil type, soil depth, soil texture, soil drainage, slope, distance from a water supply, and land cover were used to evaluate the suitability of the area for surface irrigation. Mangroves occur along the coast, in muddy wadi mouths and inlets. 5, Table4). 0000004317 00000 n The result also reveals that most of the watershed erosion severity evaluated under very low and low soil erosion severity classes covering 97.3% of the watershed areas which is due to the effect of mixed plantation of various tree and terraces. occurrence in South America In South America: Soils slopes are often steep, and lithosols (shallow soils consisting of imperfectly weathered rock fragments) abound, accounting for another 10 percent of the continent's surface. The only purely endemic mammal is a gerbil, Gerbillus acticola. /FontName /Arial-ItalicMT 8). They are par-ticularly common in mountain regions. 1 3} \right)^{0. 2018. FLUVISOLS (J)Other soils developed from recent alluvial deposits, having no diagnostic horizons other than (unless buried by 50 cm or more new material) an ochric or an umbric A horizon, an H horizon, or a sulfuric horizon. Bagegnehu Bekele. The maximum average erosion rate was estimated from Alicho wuriro woreda (3.6 ton/ha/year) and the minimum (1 ton/ha/year) from Sankura woreda (Table8). The climate fluctuates between Mediterranean subtropical and Mediterranean temperate, with annual average temperatures of between 13 C and 17 C, and average annual rainfall of between 400 mm and 800 mm. The clay loam, Debele (1985) reported that of the 25 FAO/Unesco soil orders, 17 exist in Ethiopia. 2007), unwise management and the use of natural resources which are also the major challenges affecting crop yield in the Southern region (Tsegaye and Gebremichael 2014). It is also one of the biggest threats in Ethiopian highland which threatens agricultural productivity. 22 sub-watershed classes (A, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, T, U, V, W, Y) falls under low erosion severity classes (15 ton/ha/year). Discussed further in Frederick J. Simoons, "Snow in Ethiopia: A Review of the Evidence", Learn how and when to remove this template message, "Welcome to the official website of Simien Mountains National Park", "Historical Notes on Books: An Early Ethiopian Map", https://en.wikipedia.org/w/index.php?title=Simien_Mountains&oldid=1131529902, This page was last edited on 4 January 2023, at 15:09. 0000025719 00000 n 0000000836 00000 n Finally, the aggregated effects of However, integrating the model with Geographical Information System (GIS) could solve this limitation (Fistikogli and Harmancioglu 2002). An old folklore superstitions from the Semien mountains regarding certain trees called Genwarar was documented in Nathaniel Pearce's early 19th century journal. There are three seasons in Ethiopia. This study has been conducted at Dijo watersheds in the Rift valley Basins of Ethiopia to estimate soil erosion rate and identify erosion hotspot areas for proper planning using Geographic Information System and Universal Soil Loss Equation adapted to Ethiopian condition. 0000001480 00000 n /FontDescriptor 5 0 R The soil erosion contributing factors were estimated through different Approaches. The Genwarar trees are seldom above eight feet in height, and from a distance could give the appearance or shape of a human being. form of soil erosion is a serious and continuous environmental problem in Jabi 61(23):122130. [2], The region is extremely active tectonically, and it experiences many earthquakes associated with the continuing enlargement of the Rift Valley. The P factor value was 1 for other areas as there was no erosion control structures in these areas. Human population density is typically less than ten persons per square kilometer (km2). The conservation status of this ecoregion is not good, with few protected areas and lack of enforcement in existing ones. A Feasibility Study on theUseof Remote Sensing and GIS-analysis for Planning Purposes in Developing Countries. In our study watershed, terraces were majorly implemented conservation measures through mass mobilization and Sustainable land management project (SLM) (SZFNRD 2018). From the result, 58.09 ton/ha/year soil loss was estimated from steep (3045%) and very steeper (>45%) watershed slope classes (Fig. Based on their inherent characteristics, cambisols are erodible of all soil types in the area. Masters Thesis. Other soils having an argillic B horizon; having a base saturation which is less than 50 percent (by NH4OAc) in at least some part of the B horizon within 125 cm of the surface. Moderate soil loss was estimated from pellic vertisols followed by Lithosols. Lithosols, Andosols and Luvisols (Mitiku. Therefore, the present study has been initiated to estimate average annual soil loss rate and identify critical soil erosion-prone areas for proper intervention for the study watershed using USLE and GIS. overgrazing and exploitation of biomass for firewood, construction and other Therefore, the overall Senegalia mellifera and Rhigozum somalense grow as shrubs or small trees on basaltic lava fields. Tigray livelihood papers no. endobj 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 There are also fault-induced depressions, such as the Danakil Depression and Lac Assal, lying as much as 160 m below sea level. examining different topographic and anthropogenic factors for the planning and 0000003988 00000 n 0 0 0 667 0 722 722 667 611 778 0 278 0 667 556 833 C. General, Mathematical and Regional Geography, No. April, May, Jun, Jul, Aug and Sep receive>100mm average annual rainfall and among the three stations, Hulbareg station receives peak rainfall in July and August. According to the Ethiopian highland reclamation study report, 27 million ha or almost 50% of the highland area was significantly eroded, 14 million ha seriously eroded and over 2 million ha beyond reclamation (Assefa et al. Socio-economic and environmental issues. Lack of moisture and shallow profile preclude cultivation of these soils. /MissingWidth 278 https://doi.org/10.1016/j.catena.2005.03.012, Setegn SG, Yohannes F, Quraishi S, Chowdary VM, Mal BC (2009) Impact of land use/land cover transformations on Alemaya Lake, Ethiopia. Total annual precipitation varies from 20 to 40 inches (500 to 1,000 mm). [2] Climate[edit] Its index is defined as mean annual soil loss per unit of erosivity for a standard condition of bare soil, no conservation practice, 5o slope of 22m length. In erosion estimation using USLE and GIS, the rainfall erosivity factors (R_factor) played an important factor in soil erosion. Uniquely Ethiopian and among the most endangered species are the walia ibex of the Simien Mountains, the mountain nyala (a kind of antelope), and the Simien jackal. RANKERS (U)Other soils having an umbric A horizon which is not more than 25 cm thick; having no other diagnostic horizons (unless buried by 50 cm or more of new material). The moderate and low soil erosion severity areas should be managed through terracing, inter-cropping, contour farming, strip cropping, conservation tillage, mulching and biological stabilizers based on their slope range, soil type and land use type. 0000005191 00000 n Free grazing and cultivation of steep slope(Northern parts) contributed for moderate soil erosion in the watershed should be managed by cutcarry system, limiting the number of cattle units to be grazed in the specific plot of land and leaving the marginal steep slope areas with no ground covers for natural regeneration. Global Journal of Science Frontier Research: D Agriculture and Veterinary (Article under press), Bekele B, Muluneh A, Wondrade N (2019) Geographic Information System (GIS) based soil loss estimation using Universal Soil Loss Equation Model (USLE) for soil conservation planning in Karesa Watershed, Dawuro Zone, and South West Ethiopia. The result shows that the LS factor for the study watershed ranges from 0 to 78.48. Whereas the rest low and moderate soil erosion risk classes account 24.7% and 5.07%, respectively (Table8). << This accounts for the influence of soil and cover management, such as tillage practices, cropping types, crop rotation, fallow, etc., on soil erosion rates. The average annual soil loss rate was estimated to be 2.2 ton/ha/year. Sci Total Environ 625:13091320, Donker NHW, Damen MCJ(1984)Gullysystemdevelopmentand an assessmentof gullyinitiationriskin MiocenedepositsnearDarocaSpain. Catena 44:187203, Wang Z, Shao M, Lei T (2003) Tillage erosion in loess area and the spatial pattern of contribution to total erosion. The mean annual soil loss rate was analyzed based on the sub-watersheds, soil types, land uses, slopes and woreda basis. Rainfall is very low and yearly averages range from 100 to 200 millimeters (mm), with less rain falling closer to the coast. Landscapes and Landforms of Ethiopia pp 332Cite as, Part of the World Geomorphological Landscapes book series (WGLC). Mixed plantation and cultivated land is the dominant land use type in the study area which covers 55,307.4 (44.8%) and 49,864.2 (40.4) of the total study area, respectively; while other land use covers 14.8% (Table1). [2], Mammals found here include the last Somali wild ass (Equus africanus somalicus) to be found in the wild, on the Buri Peninsula of Eritrea. 0000005613 00000 n 15). Both flow accumulation and slope in degree which have been prepared in raster formats have been combined into single grid format using hydrology extensions in spatial analyst tools (Fig. This study tried to quantify and map soil erosion in Dijo watershed. 1). Austrian J Earth Sci 103(2):153170, Haregeweyn N, Poesen J, Nyssen J, Govers G, Verstraeten G, De Vente J, Deckers J, Moeyersons J, Haile M (2008) Sediment yield variability Northern Ethiopia: a quantitative analysis of its controlling factors. Notable animals in the mountains include the walia ibex, gelada, and caracal. Therefore, the soil erosion could be reduced if the current land use land cover scenario is considered. PHAEOZEMS (H)Other soils having a mollic A horizon. Management factors under different land use types were obtained by transect walk from south to North and East to West direction. 0 0 0 0 0 0 0 0 0 0 0 556]>> Slider with three articles shown per slide. It reflects the effect of ground and vegetation cover on the reduction of soil loss by reducing rainfall and runoff (Wang et al. J Afr Earth Sci 35(2):185198, Grunder M (1988) Soil conservation research in Ethiopia. Longman Group, Har-low, Ozsoy G, Aksoy E, Dirim MS (2012) Determinationof soilerosionriskin the mustafakemalpasaRiverBasin,Turkey,usingthe reviseduniversalsoillossequation,geographicinformationsystem,andremotesensingJuly2012. 64 years mean annual rainfall data for estimating . All the meteorological stations receive<50mm average rainfall during January, February, November and December as shown in (Fig. Institute of Land Administration, Bahir Dar University, Bahir Dar, Ethiopia, Creative Commons Attribution 4.0 International License. There are very few permanent watercourses. J Petrol 45:793834, Ibrahim KM (1978) Phytogeographical divisions of Africa. 2015 Springer Science+Business Media Dordrecht, Billi, P. (2015). Based on the classification, two sub watersheds fell under very low erosion severity classes (01 ton/ha/yr), 22 sub-watersheds fell under low erosion severity classes (15 ton/ha/yr). Ethiopia has had a rich variety of wildlife that in some cases has been reduced to a few endangered remnants. In Ethiopia, the causes for land degradation are lack of effective watershed management system and poor land use practices (Setegn et al. 0000017283 00000 n slopes are often steep, and lithosols (shallow soils consisting of imperfectly weathered rock fragments) abound, accounting for another 10 percent of the continents surface. << Soil erosion risk and sediment yield assessment with universal soil loss equation and GIS: in Dijo watershed, Rift valley Basin of Ethiopia. Elevation generally increases westward towards the Ethiopian and Eritrean highlands. The characteristics of soil, watershed topography (gently sloping and sloping), lack of vegetation cover, cultivation of steep slope without engineering measures, free grazing and sand extraction contributed for moderate soil erosion. Especially of note is the 2,000m high escarpment extending in a southwest to northeast axis. Part of Springer Nature. The watershed covers 123,395 Ha. Rain falls year-round in the southern portions of the Western Highlands, where annual precipitation may reach 80 inches (2,000 mm). Fluvisols having a sulfuric horizon or sulfidic material, or both, at less than 125 cm from the surface, Other Fluvisols which are calcareous, at least between 20 and 50 cm from the surface, Other Fluvisols having a base saturation (by NH4OAc) of less than 50 percent, at least in some part of the soil between 20 and 50 cm from the surface, SOLONCHAKS (Z)Other soils having high salinity and having no diagnostic horizons other than (unless buried by 50 cm or more new material) an A horizon, an H horizon, a cambic B horizon, a calcic or a gypsic horizon, Solonchack showing hydromorphic properties within 50 cm of the surface, Other Solonchack showing takyric features, Other Solonchack having a mollic A horizon. household uses due to increasing population ultimately lead to severe soil - 159.203.63.113. After analyzing all model parameters, areas in steeper /FontDescriptor 7 0 R 278 0 0 556 0 0 0 0 0 0 556 0 0 0 0 0 Quiz. Birds include the endemic Archer's lark (Heteromirafra archeri).[2]. Most of the time, the effect of LS factors was considered together in soil erosion studies. Policy aim at keeping land productivity will need to focus to reduce low and moderate soil erosion through terracing, inter-cropping, contour farming, strip cropping, conservation tillage, mulching and biological stabilizers based on their slope range, soil type and land use type. 0 0 0 222 222 0 0 0 556 0 0 0 0 0 0 0 The average soil loss rate is 2.2 tons per hectare per year and has been classified into three erosion severity classes as very low, low and moderate. Ethiopia can be divided into four rainfall regimes. 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 /Descent -212 /Encoding /WinAnsiEncoding This indicates there is a need to quantify the rate of soil erosion for the study watershed. These soils are formed from volcanic material and, with proper management, have medium to high potential for rain-fed agriculture. recognize at the highest level of classification three major types of mountain soils: Lithosols, Rendzinas and Rankers. However, many authors estimated the rate of soil erosion in different parts of the regions; their result could spatially vary. Because Ethiopia is located in the tropical latitudes, its areas of lower elevation experience climatic conditions typical of tropical savanna or desert. 2023 Springer Nature Switzerland AG. Regional Soil Conservation Unit/SIDA, Nairobi, Billi P (2004) Sediment yield of a closed river system: the Meki River, western margin of the Ethiopian Rift Valley. /Type /FontDescriptor Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Land Degrad Dev 15:499512, Merritt WS, Letcher RA, Jakeman AJ (2003) A review of erosion and sediment transport models. Earth Syst. Google Scholar, Amsalu T, Mengaw A (2014) GIS based soil loss estimation using RUSLE model: the case of Jabi Tehinan Woreda, ANRS, and Ethiopia. However, they are unable to analyze the dynamics of sediment erosion and deposition in the watershed as it contains fewer amounts of input data. Let us know if you have suggestions to improve this article (requires login). 0 0 0 0 0 0 278]>> After analyzing all model parameters, areas in steeper slope with Lithosols, Eutric Nitosols, Orthic Luvisols, croplands, bare lands and river banks have been identified as the most erosion vulnerable areas. 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 The authors declare no conflicts of interest. a mangrove forest, reeds or sedges). Catena 37:309318, Article Renato Gerdol is greatly acknowledged for reviewing the section on vegetation. Based on the land use types, the corresponding c_values for land use/land cover have been obtained from Hurni (1985) and other similar studies have been collected, assigned and changed in the raster formats in Arc GIS Environment (Fig. SOLONETZ (S)Other soils having a natric B horizon. Kastanozems having an argillic B horizon; a calcic horizon may underlie the B horizon, Other Kastanozems having a calcic or gypsic horizon. Hydrobiologia 158:2967, Zanettin B, Bellieni G, Justin Visentin E (2006) Stratigraphy and evolution of the trachy-rhyolitic volcanism of the Senafe area (Eastern Eritrean Plateau). Molic Andosols covers (37.2%), Pellic vertisols (19.6%), Chromic luvisols (17.2%), Haplic phaeozems (17.1%), Eutric cambisols (7.6%) and Lithosols (1.3%). These outliers are part of the Day Forest and Mabla Mountains above 1,100 m in Djibouti. The current soil erosion level was compared with the tolerable soil loss limit to Ethiopian condition. This erosion has been observed at northern parts of the watersheds (Alicho wuriro. Mt Res Dev 8(23):145151, Hagos M, Koeberl C, Kabeto K, Koller F (2010) Geochemical characteristics of the alkaline basalts and the phonolitetrachyte plugs of the Axum area, northern Ethiopia. (2019) from Karesa watershed reported the gross erosion as 42,413.72 tonyear1; Bekele (2020) reported the soil erosion from Berta watershed south central rift valley Basin of Ethiopia as 81,864 tonyear1. 556 556 556 556 333 500 278 556 500 722 500 500 500 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Paolo Billi . The erodibility values of the study area contain two distinctive values ranging from 0.14 which is Chromic luvisols soil to 0.35 which is Eutric cambisols (Table7 and Fig. The prevailing soil types are described and soil erosion data are reported and analyzed. The finding was also consistent with the finding of Belayneh et al. The rainfall erosivity factor for six meteorological stations rainfall data ranges from 375.06 to 486.96 for the rainfall of distribution of 912.40mm1220.44mm, respectively, as shown in (Table6 and Fig. Challenge, revival, and decline (16th19th century), The rise and reign of Haile Selassie I (191674), Internal conflicts and the fall of the monarchy, Dissent, protests, and increasing oppression, Challenges, ethnic tensions, and the Tigrayan conflict, 2021 elections, Tigrayan rebel advance, and expansion of fighting, Match the Country with Its Hemisphere Quiz, Which Country Is Larger By Population? 12, Dijo watershed was classified into four severity classes. [2], This ecoregion extends inland from the Red Sea and the Gulf of Aden, including the Dahlak Archipelago and other islands, stretching from the Sudanese-Eritrean border, south through Ethiopia to Djibouti and eastwards into Somaliland. It shows wide . The required data collected for analysis are included in the manuscript. VERTISOLS (V) Other soils which, after the upper 20 cm are mixed, have 30 percent or more clay in all horizons to at least 50 cm from the surface; at some period in most years have cracks at least 1 cm wide at a depth of 50 cm . A total of 456,415.60 ton of soil has been lost annually (Fig. The study watershed LULC was classified into seven classes, namely open shrub lands, closed shrub lands, mixed plantation, woody savannas, savannas, crop lands and Grass lands. Phaeozems, having an argillic B horizon, showing hydromorphic properties within 50 cm of the surface, Other Phaeozems having an argillic B horizon, Other Phaeozems being calcareous at least between 20 and 50 cm from the surface. Lithosols, Cambisols, Nitosols, Vertisols, Xerosols, Solonchaks, Fluvisols and Luvisols cover more than 80% of the 537; U.S. Department of Agriculture: Washington, DC, USA. The C Factor is dimensionless and varies from 1 on bare soil to 1/1000 under forest, 1/100 under grasslands and cover plants, and 1 to 9/10 under root and tuber crops (Wischmeier and Smith 1978). The shallow soil depth coupled with the sandy clay soil texture characteristics of Lithosols leads to low water-holding capacity soil which contributed for comparable soil loss with pellic vertisols. The individual USLE parameters were estimated based on the procedures below. FERRALSOLS (F)Other soils having an oxic B horizon. Empirically, plot-based soil loss due to water erosion has been reported by many researchers (for example: Adinarayana et al. Nitosols having a base saturation of less than 50 percent (by NH4OAc) in at least a part of the B horizon within 125 cm of the surface; having an umbric A horizon or a high organic matter content in the B horizon, or both, Other Nitosols having a base saturation of less than 50 percent (by NH4OAc) in at least a part of the B horizon within 125 cm of the surface. [2] Most of the people have to build their houses with clay to keep the hot outside and the cold outside. Using the empirical equations, the sediment yield at the watershed outlet was calculated as follows. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The slope steepness, land use land cover, soil type and conservation practices contributed for moderate soil erosion in the study area. Other grazing animals include beira, dorcas gazelle, Soemmerring's Gazelle, gerenuk and the beisa oryx (Oryx beisa). /LastChar 233 The watershed annual rainfall of the study area ranges from 912.4mm to 1160.8mm. Nat Hazards 75. doi:10.1007/s11069-014-1554-0, Bojo J, Cassells D (1994) Land degradation and rehabilitation in Ethiopia: a reassessment. Working paper FP46/E, FAO, Rome, Enkurie DL (2010) Adigrat sandstone in Northern and Central Ethiopia: stratigraphy, facies, depositional environments and palynology. https://doi.org/10.1007/978-94-017-8026-1_1, Shipping restrictions may apply, check to see if you are impacted, Tax calculation will be finalised during checkout. 4} *\left( {{\text{Sin slope}}/0.0 8 9 6} \right)^{ 1. 121142). Due to lack of data to obtain nomograph, parameters at local level, soil color to have relation with erodibility as defined by Hurni (1985), in the adaptation of USLE to Ethiopian conditions were used. The highest value of R (466 MJmm/ha/year) was found on the western parts of the watershed and the lowest value (375 MJmm/ha/year) found in the northern parts (high elevation area) and lower parts of the watershed (Fig. 0 0 0 667 667 722 722 667 611 778 722 278 500 667 556 833 /FirstChar 32 Ultisols are classified by D'Hoore as Ferruginous Tropical Soils, Ferrisols, and Humic Ferrisols. Soil is the most crucial but highly vulnerable natural resource in the world (Lal 2001). Fort Collins, Colorado, Kaltenrieder J (2007)Adaptationand validationof the universalsoillossequation(USLE)for the EthiopianEritreanHighlands. 5). The mean annual soil losses of Dijo watershed range from 0 in the flat slope to 38.09 ton/ha/year from steep slope areas with the annual average soil loss rate of 2.2 ton/ha/year. https://doi.org/10.1007/s40808-020-01017-z, DOI: https://doi.org/10.1007/s40808-020-01017-z. Botany 2000: East and Central Africa NAPRECA monograph series no. 16:447467, Food and Agriculture Organization (FAO) (2012) A national soil model of Ethiopia a geo statistical approach to create a national soil map of Ethiopia on the basis of an SRTM 90 DEM and SOTWIS soil data. Part of Springer Nature. 8 0 obj /FontName /ArialMT The moderate soil erosion in Litho sols should be managed by applying the practices of increasing water-holding capacity through inter-cropping, mulching. 0000001820 00000 n 0000017099 00000 n The mean annual soil erosion rate in the area has been classified into four erosion severity classes. /FirstChar 32 The lowest soil erosion on Molic Andosols could be due to their good aggregate stability and high permeability to water which make these soils resistanttowater erosion. The IUCN Red List of Threatened Species 2018: e.T30402A95306943. EC was measured by conductivity meter in soil to water ratio of 1:2.5 (Van Reeuwijk, 2006). 137 27 Similarly, flooding as the result of intensive rainfall affected agricultural land and displaced many farmers from their resilience (SZFNRD 2007; Survey 2007). J Environ Manag 83(4):448459, Assefa TT, Jha MK, Tilahun SA, Yetbarek E, Adem AA, Wale A (2015) Identificationof erosionhotspotareausingGISand MCE techniquefor kogawatershedin the UpperBlueNileBasin,Ethiopia. U.S.Departmentof AgricultureHandbookNo. Other soils which, after the upper 20 cm are mixed, have 30 percent or more clay in all horizons to at least 50 cm from the surface; at some period in most years have cracks at least 1 cm wide at a depth of 50 cm, unless irrigated, and have one or more of the following characteristics: gilgai microrelief, intersecting slickensides or wedge-shaped or parallelepiped structural aggregates at some depth between 25 and 100 cm from the surface. The Eastern Lowlands get rain twice a year, in AprilMay and OctoberNovember, with two dry periods in between. /Length 3452 a Soil loss with respect to land use b soil loss with respect to soil types. Soilsdeveloped over the lava deposits are mainly lithosols, while regosols are predominant on the Quaternary and pre-Cretaceous basinal deposits. Lithosols are shallow soils consisting of imperfectly weathered rock fragments having sandy clay soil texture classes. /FontBBox [-517 -325 1359 998] Cambisols having permafrost within 200 cm of the surface, Other Cambisols showing hydromorphic properties within 100 cm of the surface, Other Cambisols showing vertic properties, Other Cambisols showing one or more of the following: a calcic horizon or a gypsic horizon or concentrations of soft powdery lime within 125 cm of the surface when the weighted average textural class is coarse, within 90 cm for medium textures, within 75 cm for fine textures; calcareous at least between 20 and 50 cm from the surface, Other Cambisols having an umbric A horizon which is thicker than 25 cm when a cambic B horizon is lacking, Other Cambisols having a cambic B horizon with ferralic properties, Other Cambisols having a base saturation of less than 50 percent (by NH4OAc) at least in some part of the B horizon, Other Cambisols which have a strong brown to red B horizon (rubbed soil has a hue of 7.5YR and a chroma of more than 4, or a hue redder than 7.5YR), Regional Office for Europe and Central Asia, Regional Office for Latin America and the Caribbean, Regional Office for the Near East and North Africa.

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