Search Results

You are looking at 1 - 3 of 3 items for

  • Author: Ioniță Ion x
Clear All Modify Search
Open access

Ionela Popa and Ion Ioniţă

Abstract

The Bahluieţ catchment, located in the Moldavian Plateau, at the contact between the Jijia Rolling Plain, the Suceava Plateau and the Central Moldavian Plateau, has 54,866 hectares in size. The sculptural landforms are prevailing, described by elongated rolling hills, and are underlain by the Bessarabian layers laid in marine brackish facies. In turn, the typical plateau relief (Coasta Iasilor and the eastern border of the Suceava Plateau) is developed in coastal facies also Bessarabian in age.

This paper focuses on the spatial distribution and intensity of land degradation processes and associated controlling factors within the Bahluieţ catchment. The most characteristic geomorphological processes, playing an essential role in the morphogenesis of the landforms are soil erosion and landslides, while gully erosion and sedimentation have a reduced intensity.

Soil erosion is ubiquitous, being the process with the highest extension. Therefore, the soils on the arable land, affected by moderate-excessive erosion, hold a weight of 38%. The slopes subjected to landslides are stretching on 19,040 ha, representing 35% of the studied area. Nowadays, most landslides show high degree of stability, due to the drier period of time since 1982. The gully erosion has a reduced incidence resulting from the prevailing Bessarabian clayey-sandy facies. The average rate of sedimentation in reservoirs, after the year 1986, is around 2 cm yr-1.

Land degradation within the Bahluieţ catchment occurs on steeper slopes, mainly in the shape of cuesta fronts, usually northern and western facing, but also on some degraded cuesta back slopes.

Open access

Suzana Mirela Puflea and Ion Ioniţă

Abstract

Located in the Central Moldavian Plateau, the Stavnic catchment is associated to a left tributary of the upper Barlad River, and extends on 21,341 ha of which 39% is under forest.

The typical hilly landforms, the alternation of permeable and impermeable rocks (clays, sands, loess-like deposits), the unrolling of wetted and dry periods, the sequence of freeze and thaw cycles, and the influence of the anthropogenic factor triggered the acceleration of land degradation processes. The present day geomorphic processes such as soil erosion, gullying, mass movements and silting of reservoirs represent a major threat to the local environment.

Soil erosion on the agricultural land covers mainly the land with slopes of over 5%, and it highlights through different stages of intensity. By data processing, gained from the soil surveys undertaken by O.J.S.P.A. Iasi and Vaslui, it is obviously that moderate-excessive soil erosion extends on 52% of the surveyed area.

The gully erosion apparently plays secondary role in the Stavnic catchment. However, there has been identified a total number of 330 gullies, most of them being included into discontinuous gullies class, often located on the hillslopes.

Landslides are the most representative geomorphologic processes and they extend on 12,006 ha, which represents 56% of the Stavnic catchment. One mention must be made, that in the context of climate aridisation occurred during the last three decades, the landslides are almost all stabilized. The majority of the few active landslides have frequently formed through the reactivation of the old landslide diluvia.

By using the Cesium-137 technique in dating the recent sediments from the Cazanesti accumulation, within the lower Stavnic catchment, the mean siltation rate of 4.5 cm yr-1 after the Chernobyl nuclear accident was estimated.

Open access

Samoilă Grigoraș Claudia, Ioniță Ion, Niacșu Lilian, Grigoraș Georgel and Blebea-Apostu Ana Maria

Abstract

Land degradation has been recognized as an important environmental threat in the Moldavian Plateau of eastern Romania. This study was designed to estimate the magnitude of land degradation and to review land management in a small catchment in the Central Moldavian Plateau. Several methods were deployed to estimate soil erosion losses, gully distribution, landslide inventory and reservoir sedimentation rates. Results obtained in the study area of 7,766 ha, of which 31% is arable and 32% native forest, show that the mean value of soil losses by water erosion on agricultural land is 19.0 t ha−1y−1. By adding the woodland contribution, this value significantly decreases to 12.8 t ha−1y−1. Then, a large proportion of land (58%) is covered by landslides. Most of them are shallow and dormant (stable), and the active ones form only ~2% of the total landslide area. Siltation rates determined using 137Cs reflect the impact of land management on deposition patterns in reservoirs. Proper conservation measures were applied over a 20-year time-span from 1970-1990. Since 1991 the contour farming system collapsed and returned to the traditional ‘up-and-down slope’ farming system on very small plots.