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The aim of the study performed in years 2007-2009 in the Suwałki Lakeland was assessed the intensity of soil erosion and runoff on a sandy slope under different cultivation. The study also focused on analysis of selected factors affecting the erosion (intensity of rainfalls, erosion susceptibility of soil, vegetation cover). Measurements were performed on the standard USLE plots inclined 8°. The mean annual erosion amounted to 0,2 t ha⁻¹ under cereals (rye and oat), 2,1 t ha⁻¹ under potatoes planted in rows parallel to the slope gradient, and 2,75 t ha⁻¹ on the black fallow. Experimentally determined index of erosion susceptibility K was 0,0041. The mean annual value of the canopy factor C was 0,064 for cereals and 0,8 for potatoes. Short rainfall events of 20-30mm and erosivity 100-200 MJ mm ha⁻¹h⁻¹ are characteristic for the study area. The results obtained for the sandy slope support previous findings that such short-term events play a significant role in soil erosion. Effectivity of such events strongly depends on the vegetation cover as they are responsible for 25-30% of soil loss under potatoes and 45-50% under cereals.
The aim of this thesis was to present the characteristic of precipitation conditions in Suwałki Lake District. Analysis was made on the base of daily sum of precipitation of six meteorological stations during 1971–2000 period. Frequency of months and seasons with defi cit or excess of precipitation according to Kaczorowska’s criterion, frequency of non-precipitation day sequences >10, >15 and 20 days in the periods April–May, June– July, August–September and April–September were taken into consideration. Numbers of days with-precipitation ≥ 0.1 mm, ≥ 1.0 mm, ≥ 10.0 mm, ≥ 20.0 mm and ≥ 30.0 mm was analyzed also. All examined weather stations indicate that precipitation shortages are characteristic for the 90”s. Not only total precipitation amount indicate that, but also their classifi cation presented according to Kaczorowska as well as precipitation – free periods.
Research on soil erosion undertaken on selected slopes of the Suwałki Lakeland (NE Poland) in years 1986–1989, 1998–1999 and in 2007 allowed to determine features of deposits transported and deposited within the slopes. Sedimentological analyses were used and following granulometric indices calculated: mean grain size diameter, sorting and skewness. Organic matter content was also determined by loss on ignition. Size of mineral grains (Mz and d-5%) were analysed in relation to rainfall erosivity. Analyses of sediments originated from soil erosion supports previous fi ndings regarding their structural and textural features. Granulometric composition of deluvial deposits is determined by the source material – soil cover. Analysed slope deposits were medium and weakly sorted and their skewness was positive which shows similarity to the slope soil cover. Deposits originated from rill erosion had skewness varying from slightly positive to slightly negative. Rainfall erosivity weakly correlates with the size of mineral grains transported and deposited. This is explained by the fact that transported material included not only separate grains but also grain aggregates and because the material partially originated from rainsplash. Following juxtaposition of sedimentological indices: Mz-σ1, Mz-Sk1, Sk1-σ1 and also Mz with loss on ignition proved helpful in determining conditions of the erosion-transportdeposition process. Multimodal frequency curves with a low amplitude of the modes are characteristic and typical for deluvial sediment. It is found that the minimum transport distance needed for registration of the process in sedimentological properties of the deposits is 30 m. Moreover, only rainfall of a high intensity was able to modify sedimentological proporties of the deposits.
The aim of studies was the recognition of the contemporary denudation considering tillage translocation and water soil erosion. This study was performed in the typical last glacial relief. The Cs-137 inventory was analysed along two hillslope profiles and at their footslopes. The value of soil erosion and sedimentation was calculated using the proportional model and the simplified mass balance model. Studies showed that eroded soil from upper and middle segments of the slopes was re-deposited on concave segments of the slopes. The erosion rate was 0.5-1.6 mm on the top of hills and 0.8-3.2 mm on their slopes. The deposition occurs on the concave slope at rate of 3.8-6.6 mm per year on average. Erosion-deposition balance indicate that the small part of eroded soil was exported to the valley bottom and bottom of depression. The share of the water rill and interrill erosion in the total of topsoil erosion is range from 1 to 10% depending on used model. Tillage translocation is the main process shaped a small hills in the last glacial ares.
Segetal communities of the Suwałki Lakeland (Pojezierze Suwalskie). Fragmenta Floristica et Geobotanica Polonica 7: 167–208. Kraków. PL ISSN 1640–629X. ABSTRACT: The paper presents the results of research on plant communities in arable fields in the Suwałki Lakeland (Pojezierze Suwalskie), i.e. the northeastern most region of Poland, where the climate is the coolest and most continental. This young glacial area has a hilly relief and numerous lakes. Farming intensity is relatively low. I have described 9 types of segetal communities of this area: 7 in cereal fields and only 2 in root crops fields. Among the recognized communities I have identified 3 cereal associations and 1 of root crop association. Two of these associations – Papaveretum argemones and Vicietum tetraspermae occur in very poor forms since they are at the north eastern limit of their geographical range. The Papaveretum argemones does not develop the spring aspect here, whereas the Vicietum tetraspermae developes solely in the acidophilous subassociation of sperguletosum. The root crop field association – Fumarietum officinalis occurs in the Suwałki Lakeland beyond its hitherto recognized western limit of its geographical range. I have distinguished one new association – Medicagini falcatae Consolidetum regalis with three character species: Consolida regalis, Medicago falcata and Anthemis tinctoria. It develops on hill slopes and peak areas covered with stony gravel soils. The association is divided into two subassociations – typical and papaveretosum dubii. It is the most common community in the Suwałki Lakeland.
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