Search results for " DEGRADATION"

The need for harmonizing methodologies for assessing soil threats in Europe

2010

Central to the EU thematic strategy for soil protection is that areas affected by soil degradation through erosion, soil organic matter (SOM) decline, compaction, salinization and landslides should be identified in a clear and consistent way. However, the current methodologies to achieve this often differ and this can result in different perceptions of risks amongst EU Member States. The aims of this paper are to: (i) assess the current status of assessment methodologies in Europe (EU27) associated with erosion, SOM decline, compaction, salinization and landslides and (ii) discuss the issues associated with harmonization of these methodologies throughout the EU27. The need for harmonization…

2019

Gully erosion is considered to be one of the main causes of land degradation in arid and semi-arid territories around the world. In this research, gully erosion susceptibility mapping was carried out in Semnan province (Iran) as a case study in which we tested the efficiency of the index of entropy (IoE), the Vlse Kriterijumska Optimizacija I Kompromisno Resenje (VIKOR) method, and their combination. Remote sensing and geographic information system (GIS) were used to reduce the time and costs needed for rapid assessment of gully erosion. Firstly, a gully erosion inventory map (GEIM) with 206 gully locations was obtained from various sources and randomly divided into two groups: A training d…

Soil erosion after land abandonment in a semiarid environment of southeastern Spain

1997

Different soil units were selected in southeastern Spain to investigate the effects of land abandonment on soil erosion under semiarid conditions. The study sites selected were a cultivated field (bare), a 3‐yr‐abandoned field (herbs), a 10‐yr‐abandoned field (Artemisia herba‐alba Asso.), and two soil units covered with semi‐native (Stipa tena‐cissima L) and native (Pinus halepensis Miller) vegetation. Simulated rainfall measurements showed that the erosion and runoff increased after the land abandonment, but later erosion decreased owing to the influence of increasing vegetation. Runoff discharge (35%) and the erosion rates (334 g m2 h‐1) were high in the 3‐yr‐abandoned land in comparison …

Using Static and Dynamic Indicators to Evaluate Soil Physical Quality in a Sicilian Area

2013

Both capacitive indicators derived from the water retention curve and dynamic measurements of the flow-weighted mean pore radius, R0, were used to assess the soil physical quality of two agricultural areas (cropland and olive orchard) and two natural areas (grassland and managed woodlot plantation) potentially subject to soil degradation. The overall idea of the study was to investigate whether a dynamic indicator quantitatively derived from hydraulic conductivity measurements could be used to supplement the traditionally applied capacitive indicators retrieved from water retention measurements. According to the available criteria, only the surface layer of the cropland site showed optimal …

The Impact of Climatic Change and Land Use on the Hydrological Response of Mediterranean Soils; a Study along a Climatological Gradient in Crete (Gre…

1995

Abstract To help understand the impact of Climatic Change on the soils of the Mediterranean area, measurements of physical soil properties were carried out in a mountain zone in Crete (Greece), following a climatological gradient. Four experimental slopes were chosen, south facing and situated on limestone lithology. Soil hydrological properties including infiltration, runoff and sediment concentration, were measured and the percentage of waterstable microaggregation in the soil was calculated and used as an indicator of soil degradation. It was found that as well as climate, soil properties were highly affected by the extensive land use of the area, intensive grazing by goats and small sca…

Moving Ahead from Assessments to Actions by Using Harmonized Risk Assessment Methodologies for Soil Degradation

2010

Almost all developed countries use risk assessment methodologies (RAMs) for the evaluation of risks related to soil degradation, viz. soil organic matter decline, erosion, landslides, salinization and/or compaction. However and for various reasons, seldom the use of such RAMs seldom results in actual measures to combat soil degradation in practice. In this study the current status of RAMs in EU-27 was evaluated and factors hampering the implementation of action plans were explored. To do so we used a so-called risk assessment chain, which describes the five successive steps of any risk assessment for soil threats viz., (1) notion of the threat, (2) data collection, (3) data processing, (4) …

THE IMPACT OF FIRE ON REDISTRIBUTION OF SOIL ORGANIC MATTER ON A MEDITERRANEAN HILLSLOPE UNDER MAQUIA VEGETATION TYPE

2010

Soil organic matter (SOM) changes affect the CO2 atmospheric levels and is a key factor on soil fertility and soil erodibility. Fire affects ecosystems and the soil properties due to heating and post-fire soil erosion and degradation processes. In order to understand fire effects on soil organic carbon (SOC) balance research was undertaken on a fire-prone ecosystem: the Mediterranean maquia. The spatial distribution of SOC was measured in a Burnt site 6 months after a wildfire and in a Control site. Samples were collected at two different depths (0–3 and 3–10 cm) and SOC was determined. The results show that 41·8 per cent of the SOC stock was lost. This is due to the removal of the burnt ma…

The role of vegetation on gully erosion stabilization at a severely degraded landscape: A case study from Calhoun Experimental Critical Zone Observat…

2018

Abstract Gully erosion was evidence of land degradation in the southern Piedmont, site of the Calhoun Critical Zone Observatory (CCZO), during the cotton farming era. Understanding of the underlying gully erosion processes is essential to develop gully erosion models that could be useful in assessing the effectiveness of remedial and soil erosion control measures such as gully backfilling, revegetation, and terracing. Development and validation of process-based gully erosion models is difficult because observations of the formation and progression of gullies are limited. In this study, analytic formulations of the two dominant gullying processes, namely, plunge pool erosion and slab failure…

Vulnerability of Mediterranean ecosystems to Climatic Change, study of soil degradation under different climatological conditions in an altitudinal t…

1995

Abstract To investigate the potential response of soils to climatic change, measurements of soil physical and chemical properties were carried out during a year in a mountain zone in Alicante (Spain), along an altitudinal and climatological gradient. Hydrological properties (infiltration runoff and sediment concentration) were measured under winter and summer conditions. Chemical and physical soil properties were analyzed for reference soil profiles along the transect. The erosional response of the soils as well as soil properties like organic matter and CEC are found to be under the direct influence of the climate, and as a result they have to be considered as important factors in the dese…

Validating the use of caesium-137 measurements to estimate soil erosion rates in a small drainage basin in Calabria, Southern Italy

2001

Recent concern for problems of soil degradation and the offsite impacts of accelerated erosion has highlighted the need for improved methods of estimating rates and patterns of soil erosion by water. The use of environmental radionuclides, particularly caesium-137 (137Cs), as a means of estimating rates of soil erosion and deposition is attracting increasing attention and the approach has now been recognised as possessing several important advantages. However, one important uncertainty associated with the use of 137Cs measurements to estimate soil erosion rates is the need to employ a calibration relationship to convert the measured 137Cs inventory to an estimate of the erosion rate. Existi…