Adjustments in channel morphology due to land‐use changes and check dam installation in mountain torrents of Calabria (southern Italy)

A detailed knowledge of soil water repellency (SWR) and water infiltration capacity of soils under different land uses is of fundamental importance in Mediterranean areas, since these areas are prone to soil degradation risks (e.g., erosion, runoff of polluting compounds) as a response to different hydrological processes. The present study evaluates the effects of land uses on SWR and soil hydraulic conductivity (SHC) by direct measurements at the plot scale in three areas representing (1) intensive agricultural use, (2) abandoned farmland, and (3) a forest ecosystem in Southern Spain under Mediterranean climatic conditions. The physico-chemical properties and water content of the experimental soils were also measured. Significant SWR and SHC differences were found among the analyzed land uses. Forest soils showed high SWR and low SHC, while the reverse effects (that is, low SWR and high SHC) were detected in soils subjected to intensive agriculture. Organic matter and bulk density were important soil properties influencing SWR and SHC. The study, demonstrating how land uses can have important effects on the hydrological characteristics of soils, give land managers insights into the choice of the most suitable land use planning strategies in view of facing the high runoff and erosion rates typical of the Mediterranean areas.

Section: Introductionmentioning

confidence: 99%

Effects of Different Land Uses (Abandoned Farmland, Intensive Agriculture and Forest) on Soil Hydrological Properties in Southern Spain

Lucas‐Borja

Zema

Plaza‐Álvarez

et al. 2019

“…Findings from this study indicate broad convergence of the channel adjustments in the Basento River with those in other Italian rivers [41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60] over the last 150 years. Nevertheless, there are some significant differences.…”

Section: Discussionmentioning

confidence: 99%

“…To date, numerous studies have evaluated the morphological variations in river in central and northern Italy [43][44][45][46][47][48][49][50][51], while much fewer studies have focused on southern Italy [52][53][54][55][56][57]. This difference is perhaps related to the reduced interest and importance of rivers in southern Italy in terms of the size, length, and water discharge, and above all, the frequency of flood events and intensity of the effects, even though there have been several cases of great impacts.…”

Section: Introductionmentioning

confidence: 99%

Channel Changes and Controlling Factors over the Past 150 Years in the Basento River (Southern Italy)

Musso

Capolongo

Caldara

et al. 2020

Channel changes are receiving growing interest in relation to the relevant implications for river management and restoration. In this kind of analysis, purely qualitative approaches have been gradually replaced by quantitative approaches aimed at reconstructing the temporal variations in parameters (e.g., channel width and depth) to investigate not only the evolutionary trend of the river but also the possible cause-effect connections. This paper investigates the channel dynamics in the Basento River (Basilicata Region, Italy) over the past 150 years, when the river was heavily affected by human activities (e.g., hydraulic interventions and gravel mining) and climate changes. Channel adjustments were analysed with historical maps, aerial photos, and geomorphological surveys. The results show that the channel underwent a strong narrowing during the twentieth century, similar to many rivers in Italy, with the most intense phase from the 1950s to the 1990s (with the width varying from −30% to −80%). The morphology pattern remained almost completely unchanged, apart from a few reaches located in the hilly area that were affected by intense modifications before the 1940s. The causes of channel adjustments were identified as human disturbances (land use variations, channel interventions at the reach scale, sediment mining) from the end of the 1800s to present, as well as natural factors (changes in frequency, duration, and intensity of flood events), whose effects have intensified since the late 1990s.

“…Reduced infiltration increases the hydrological risk in particular on less permeable soils. The decrease of water infiltration capacity of soils is of fundamental importance in Mediterranean areas, where the infiltration-excess mechanism dominates runoff generation [43,44]; in such an environmental and climatic context, the intense storm events may increase overland flow [45,46]. Given that, retention of vegetal residues to insure mulching of the topsoil even under wet conditions may be advisable to reduce surface runoff generation rates.…”

Section: Discussionmentioning

confidence: 99%

Water Infiltration and Surface Runoff in Steep Clayey Soils of Olive Groves under Different Management Practices

Bombino

Denisi

Gómez

et al. 2019

Self Cite

When olive groves are cultivated on clayey soils with steep gradients, as in many Mediterranean areas, reducing the runoff and soil erosion rates by adopting proper soil management practices is imperative. A soil cover by pruning residues may represent an alternative to the commonly adopted mechanical tillage. This study evaluates the water infiltration rates and surface runoff volumes in a steep and clayey olive grove of Southern Italy. These hydrological variables are measured at the plot scale under four soil management practices (mechanical tillage, total artificial protection of soil and soil cover with two different rates of vegetal residues). The measurements have been carried out using a rainfall simulator under dry (undisturbed) and wet (that is, on soils disturbed by intense rainfall) conditions. The mechanical tillage leads to lower water infiltration rates and higher runoff production. The retention of a soil cover by vegetal residues (in the range 3.5–17.5 tons/ha of dry matter) reduces the runoff rate on average by 30%, mainly because of the increased soil infiltration rates (over 100%, compared to mechanical tillage). After soil disturbance due to antecedent rainfall, the runoff generation capacity of a soil disturbed by a heavy precipitation significantly increased compared to undisturbed soils because of the decrease in soil infiltration rates. Overall, the retention of vegetal residues over the soil may be advisable to reduce surface runoff generation rates, particularly for saturated soils.