Though knowledge about the distribution and properties of soils is a key issue to support sustainable land management, existing knowledge of the soils in Tigray (Northern Ethiopian Highlands) is ...limited to either maps with a small scale or with a small scope. The goal of this study is to establish a model that explains the spatial soil variability found in the May-Leiba catchment, and to open the scope for extrapolating this information to the surrounding basalt-dominated uplands. A semi-detailed (scale: 1/40
000) soil survey was conducted in the catchment. Profile pits were described and subjected to physico-chemical analysis, and augerings were conducted. This information was combined with information from aerial photographs and geological and geomorphologic observations. The main driving factors that define the variability in soil types found were: 1) geology, through soil parent material and the occurrence of harder layers, often acting as aquitards or aquicludes; 2) different types of mass movements that occupy large areas of the catchment; and 3) severe human-induced soil erosion and deposition. These factors lead to “red-black” Skeletic Cambisol–Pellic Vertisol catenas on basalt and Calcaric Regosol–Colluvic Calcaric Cambisols–Calcaric Vertisol catenas on limestone. The driving factors can be derived from aerial photographs. This creates the possibility to extrapolate information and predict the soil distribution in nearby regions with a comparable geology. A model was elaborated, which enables the user to predict soil types, using topography, geomorphology, geology and soil colours, all of which can be derived from aerial photographs. This derived model was later applied to other catchments and validated in the field.
Istraživanje tala u geografiji Vovk Korže, Ana
Acta Geographica Croatica,
12/2010, Letnik:
37., Številka:
1.
Journal Article
Recenzirano
Odprti dostop
U članku se navode metode terenskog rada u području istraživanja tala, u geografiji vrlo važna za razumijevanje krajolika. Ovim metodama se u posljednje vrijeme posvećuje veća pozornost geografskoj ...edukaciji. Naglasak je na spoznavanje strukture tala, uz pomoć pedoloških profila. Fizička i kemijska svojstva tla, mjerena na terenu i u laboratoriju, imaju važnu ulogu u procjeni mogućnosti načina korištenja zemljišta.
In 2005 and 2006 intensive measurements were made of various erosion-denudation processes in the Dragonja River basin. The measurements included geomorphic processes in the badlands: the rockwall ...retreat of steep bare flysch slopes, movements of flysch debris along erosion gullies, and geomorphic processes on talus slopes. At the same time, measurements of soil erosion were made in three different land use areas: bare soil in an olive grove, an overgrown meadow, and a forest. The results are presented in two parts. Part One presents the measurements of soil erosion, and Part Two in the next issue of the journal (No. 49-2) will present geomorphic processes in the badlands. The measurements of soil erosion made on one-meter-square closed erosion plots south of the village of Marezige revealed that the greater part of the annual erosion was caused by only a few major erosion events. Between May 2005 and April 2006, interrill erosion amounted to 9,013 g/m2 (90 t/ha) on bare soil in an olive grove with an inclination of 5.5º and an average weekly proportion of specific runoff of 23%, 168 g/m2 (1.68 t/ha) on an overgrown meadow with an inclination of 9.4º and an average weekly proportion of specific runoff of 8%, and 391 g/m2 (3.91 t/ha) in a forest with an inclination of 7.8º and 415 g/m2 (4.15 t/ha) in a forest with an inclination of 21.4º with an average weekly proportion of specific runoff of 6% regardless of the inclination. The amount of precipitation during the reference year was slightly below the long-term average.
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