Variabilidad espacial de los cambios de cauce en una rambla mediterránea en las seis últimas décadas (1946-2006)

Ibor, Carles Sanchís; Beltrán, Francisca S. Segura

doi:10.18172/cig.2530

Cited by 8 publications

(7 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In a review of the hydrological and geomorphological consequences of farmland abandonment in Europe, García-Ruiz and Lana-Renault (2011) cited many reports of incision and riverbank erosion processes in Mediterranean and Alpine catchments, associated with a decline of sediment supply from hillslopes (e.g., Liébault and Piégay, 2002;Piégay et al, 2004;Keesstra et al, 2009;Sanchis-Ibor and Segura-Beltrán, 2014). Stroosnijder (2005) suggested that the "large sediment load in a stream may primarily be due to bank erosion".…”

Section: Complex Hydrological and Geomorphological Response And Intermentioning

confidence: 99%

A meta-analysis of soil erosion rates across the world

et al. 2015

View full text Add to dashboard Cite

Over the last century extraordinary efforts have been devoted to determining soil erosion rates (in units of mass per area and time) under a large range of climatic conditions and land uses, and involving various measurement methods. We undertook a meta-analysis of published data from more than 4000 sites worldwide. The results show that there is extraordinarily high variability in erosion rates, with almost any rate apparently possible irrespective of slope, climate, scale, land use/land cover and other environmental characteristics. However, detailed analysis revealed a number of general features including positive relationships of erosion rate with slope and annual precipitation, and a significant effect of land use, with agricultural lands yielding the highest erosion rates, and forest and shrublands yielding the lowest. Despite these general trends, there is much variability that is not explained by this combination of factors, but is related, at least partially, to the experimental conditions. Our analysis revealed a negative relationship between erosion rate and the size of the study area involved; significant differences associated with differing measurement methods, with direct sediment measurement yielding the lowest erosion rates, and bathymetric, radioisotope and modeling methods yielding the highest rates; and a very important effect of the duration of the experiment. Our results highlight that, when interpreting erosion rates, the experimental conditions involved must be taken into account. Even so, the data suggest that only order of magnitude approximations of erosion rates are possible, and these retain a very large degree of uncertainty. Consequently, for practical purposes such as calculation of global sediment budgets, empirical equations are not a substitute for direct measurements. Our results also show that a large proportion of the experiments have been short-term (less than 3 years), which reduces dramatically the reliability of the estimated erosion rates, given the highly non-normal behavior of soil erosion (time-dependency). Despite the efforts already made, more long-term measurement experiments need to be performed, especially in regions of the world that are under-represented in global datasets. In addition, protocols need to be established for standardizing the measurement methods and reporting the results, to enable data to be compared among diverse sites.

show abstract

Section: Complex Hydrological and Geomorphological Response And Intermentioning

confidence: 99%

A meta-analysis of soil erosion rates across the world

et al. 2015

View full text Add to dashboard Cite

show abstract

“…The latter has also been incised to 3-4 m below the terrace level. Scouring is a process common to many rivers in the Mediterranean Ibisate et al, 2013;Segura-Beltrán & Sanchis-Ibor, 2013;Sanchís-Ibor & Segura-Beltrán, 2014) and alpine regions, and is a consequence of a decreased sediment supply following farmland abandonment and forest recolonization (Kondolf et al, 2002;Marston et al, 2003;Liébault et al, 2005;Beguería et al, 2006;Boix-Fayos et al, 2007;Keesstra, 2007;Surian & Cisotto, 2007). Natural vegetation rehabilitation is also responsible for a substantial decline in sediment yields and general landscape changes in the Loess Plateau, China (Zhao et al, 2013).…”

Section: Discussionmentioning

confidence: 99%

Linking Land Cover Changes in the Sub‐Alpine and Montane Belts to Changes in a Torrential River

et al. 2014

View full text Add to dashboard Cite

Channel changes are the consequence of changes in sediment yield from the slopes and in the connectivity between slopes and channels because of distinct land use and climate impacts. In this study, we investigated the characteristics and evolution of a short reach in the headwater of the Ijnez River, central-southern Pyrenees. Assessment of a series of sedimentary and geomorphic structures confirmed major changes to the valley bottom, mainly related to changes in the intensity of human activity. The oldest sedimentary structure is a terrace level located 3 to 4 m above the current alluvia] plain. General deforestation, overgrazing and recurring fires in the montane belt (1100-1600 m a.s.1.) have led to increased soil erosion and connectivity, and to the triggering of debris flows that have been deposited on the fluvial terrace. Woody fragments from within the debris flows were dated using accelerator mass spectrometry "C radiocarbon techniques (AMS), yielding ages between 100 and 115cal years BP, which coincides with the period of maximum deforestation and human density in the Pyrenees. Depopulation and farmland abandonment since the beginning of the 20th century has resulted in generalized natural and artificial reforestation, a shrinkage of the eroded areas and a decline in connectivity between slopes and the channel. The most important consequence has been channel incision and narrowing, and the development of a sediment armour layer. Active sediment transport is continuing, although there has been a decrease in sediment yield from the slopes.

show abstract

“…For instance, the Ijuez River in the Spanish Pyrenees has been affected by a 3‐m incision since the 1960s, as a consequence of land abandonment and general reforestation (Gómez‐Villar et al, ; Sanjuán et al, ) (Figure ). This is also the case for many mountain areas worldwide (García‐Ruiz & Lana‐Renault, ), in particular in the Mediterranean and Alpine basins (Liébault & Piégay, ; Piègay et al, ; Keesstra et al, ; Sanchis‐Ibor & Segura‐Beltrán, ; Lallias‐Tacon et al, ; Picco et al, ), and also in North America (Church & Slaymaker, ; Trimble, ).…”

Section: New Questions For An Old Problemmentioning

confidence: 81%

“…For instance, the Ijuez River in the Spanish Pyrenees has been affected by a 3-m incision since the 1960s, as a consequence of land abandonment and general reforestation (Gómez-Villar et al, 2014;Sanjuán et al, (Figure 9). This is also the case for many mountain areas worldwide , in particular in the Mediterranean and Alpine basins (Liébault & Piégay, 2002;Piègay et al, 2004;Keesstra et al, 2009;Sanchis-Ibor & Segura-Beltrán, 2014;Lallias-Tacon et al, 2016;Picco et al, 2016), and also in North America (Church & Slaymaker, 1989;Trimble, 2010). In semi-arid and sub-humid landscapes the main limiting resources for plant cover establishment and spatial organization are water and nutrients, these latter making more efficient use of water (Lasanta et al, 2000).…”

Section: The Spatial Organization Of Plant Cover In Reducing Sedimentmentioning

confidence: 89%

Ongoing and Emerging Questions in Water Erosion Studies

et al. 2016

View full text Add to dashboard Cite

Soil erosion is a threat to food security, especially in regions where the area of arable land is shrinking dramatically because of soil degradation. Research on soil erosion expanded progressively throughout the 20th centu\ry, although a number of unresolved problems persist despite this issue being crucial for the environment and the welfare of society. Some basic unresolved issues, including the absence of a universally accepted definition of soil erosion and disagreement about how to measure it have contributed to a degree of scientific stagnation. Accurate prediction of the response of soils to disturbance is hampered by the dependence of the erosion process on the spatial scale involved, the time lag between the disturbance and the erosion response and the short periods for which data are typically available. We argue that devoting increased attention to the following environmental, demographic, political and societal issues will reinvigorate progress in the field. (i) The relationships between on‐site and off‐site consequences of soil erosion need to be elucidated if the economic and environmental costs are to be adequately assessed. (ii) Effective measures for soil conservation need to focus on spatial patterns of plant cover that reduce sediment connectivity, and most importantly on the relationships between hillslopes and sediment transfer in eroded channels. (iii) The scientific community must be able to identify early warning signs of critical transitions, if irreversible soil degradation is to be prevented. (iv) Consensus needs to be reached concerning the contribution of soil erosion to the carbon cycle. (v) The consequences of climate change on erosion and sediment transport should be investigated in depth. (vi) The general society needs to perceive soil erosion as a critical matter requiring an urgent response. Copyright © 2016 John Wiley & Sons, Ltd.

show abstract

Variabilidad espacial de los cambios de cauce en una rambla mediterránea en las seis últimas décadas (1946-2006)

Cited by 8 publications

References 39 publications

A meta-analysis of soil erosion rates across the world

A meta-analysis of soil erosion rates across the world

Linking Land Cover Changes in the Sub‐Alpine and Montane Belts to Changes in a Torrential River

Ongoing and Emerging Questions in Water Erosion Studies

Contact Info

Product

Resources

About