The Role of Frost Processes in the Retreat of River Banks

The rate of bank retreat was measured using erosion pins on the alluvial banks of the rivers in the Podhale region (the boundary zone between Central and Outer Carpathians) during the hydrological year 2013/2014. During the winter half-year (November–April), the bank retreat was mainly caused by processes related to the freezing and thawing of the ground (swelling, creep, downfall). During the summer half-year (May–October), fluvial processes and mass movements such as lateral erosion, washing out, and sliding predominated. The share of fluvial processes in the total annual amount of bank retreat (71 cm on average) was 4 times greater than that of the frost phenomena. Erosion on bank surfaces by frost phenomena during the cold half-year was greatest (up to 38 cm) on the upper parts of banks composed of fine-grained alluvium, while fluvial erosion during the summer half-year (exceeding 80 cm) mostly affected the lower parts of the banks, composed of gravel. The precise calculation of the relative role of frost phenomena in the annual balance of bank erosion was precluded at some stations by the loss of erosion pins in the summer flood.

Measurement of Riverbank Erosion Rates of Pusu River Using Erosion Pins Method

Riverbank erosion is a major concern in all parts of the world due to its extensive impacts geomorphologically and economically. This study aims to quantify the rates of riverbank erosion of Pusu River using erosion pins method. Two sections of the river were selected namely site A and site B where site A is a straight section while site B is situated on the outside bend. 21 pins were installed at each site in a grid pattern. Measurement of erosion pins exposure were taken from February 2019 to April 2019. Field observation were made to identify the possible factors influencing the bank erosion. The average rates of bank erosion ranged between 0.05 cm/day to 0.21 cm/day at site A and 0.09 cm/day to 0.51 cm/day at site B. Bank failure occurred at site B towards the end of measurement period due to high flow after heavy rainfall event. Field observations suggest that rates of riverbank erosion were influenced by several factors such as the flow velocity and vegetative cover of the bank.

Short-term impacts of conservation and traditional agriculture on natural resources and corn yield

Crops production on the Peru’s highland is carried out under the traditional agriculture’s practices of, degrading natural resources. Contrary, conservation agriculture’s practices are less tedious and conservationist to natural resources. A field experiment with corn crop was set up to compare the two agricultural systems, evaluating bulk density, volumetric humidity, earthworm population, soil erosion, corn ear yield, and economic utility. An LSD test was designed to assess bulk density, volumetric humidity, earthworm population, and corn yield, with 20 replications each one. Additionally, a completely randomized design was established to assess erosion, with three replications of 50 erosion pins. In conservation agriculture’ssoil erosion was significantly reduced; volumetric humidity, earthworm population, and yield were significantly higher in conservation agriculture. The results showed that conservation agriculture’s practices are more profitable and friendly to natural resources than traditional agriculture’s practices. Keywords: bulk density, corn yield, erosion, earthworm population, volumetric humidity

Sediment production in flysch badlands: A case study from Slovenian Istria

This article deals with the results of seven years of measurements of sediment release from the flysch badlands in the Rokava River headwaters. Measurements of sediment production were carried out in erosion plots, and measurements of cliff (or rockwall) retreat using erosion pins. Selected meteorological time series from the Portorož Airport meteorological station were included in the analysis. The calculation showed that from 2008 to 2015 (149 measurements) sediment production was 36 kg/m² per year and the flysch cliff retreated by 146 mm or 21 mm per year. The amount of sediment produced is moderately positively correlated with the number of days between successive measurements (r = 0.51), with a recorded daily transition of air temperature over/below 0 °C (r = 0.56) and slightly more weakly correlated with the precipitation amount (r = 0.45). On the other hand, the amount of sediment produced has a low negative correlation with average air temperature (r = −0.29) and average minimum air temperature (r = −0.30). However, no statistically significant correlation was calculated between the amount of sediment produced and average wind speed.

Agronomic Practices for Reducing Soil Erosion in Hillside Vineyards under Atlantic Climatic Conditions (Galicia, Spain)

Water erosion is a severe threat to soil resources, especially on cultivated lands, such as vineyards, which are extremely susceptible to soil losses. In this context, management practices aiming at reducing erosion risks must be favored. This current study aimed at estimating soil losses in two vineyards under Atlantic climatic conditions (Galicia, North West Spain). The capacity of two management practices for reducing soil erosion was tested and compared with tilled soil in the inter-rows: (i) application of mulching, and (ii) maintaining native vegetation. Soil losses were assessed using erosion pins and micro-plots. In addition, the improved stock unearthing method (ISUM) was employed in one of the vineyards to estimate soil remobilization since plantation. Soil loss rates in one of the vineyards were lower when soil was managed under mulching (0.36 Mg ha−1) and native vegetation (0.42 Mg ha−1), compared to tilled soil (0.84 Mg ha−1). Sediment losses measured in the second vineyard ranged between 0.21 and 0.69 Mg ha−1, depending on the treatment, but no clear conclusions could be drawn. Long-term soil loss, as estimated by ISUM, was of the same order of magnitude than that obtained by erosion pins and micro-plots. In both vineyards, soil loss rates were lower than those registered in Mediterranean vineyards, and were below the limit for sustainable erosion in Europe. Nevertheless, soil management practices alternative to tillage in the inter-row might reduce erosion risks under Atlantic climate conditions.

Freeze-Thaw Induced Gully Erosion: A Long-Term High-Resolution Analysis

Gullies are significant contributors of sediment to streams in the southeastern USA. This study investigated gully erosion in the clay-rich soils of east Tennessee under a humid subtropical climate. The aims of this study were to (1) estimate long-term erosion rates for different gully geomorphic settings, (2) compare patterns of erosion for the different settings, and (3) model the response of gully erosion to freeze-thaw events. Erosion was measured weekly from June 2012 to August 2018 using 105 erosion pins distributed in gully channels, interfluves, and sidewalls. Erosion rates were estimated from average slopes of lines of best fit of pin lengths versus time. Maximum and minimum temperature was calculated daily using an on-site weather station and freeze-thaw events were identified. Gully erosion was modeled using antecedent freeze-thaw activity for the three geomorphic settings. Long-term erosion rates in channels, interfluves, and sidewalls were 2.5 mm/year, 20 mm/year, and 21 mm/year, respectively; however, week-by-week erosion was statistically different between the three settings, indicating different erosive drivers. Models of erosion with lagged freeze-thaw variables explained up to 34.8% of the variability in erosion variables; sidewall erosion was most highly related to freeze-thaw activity. Freeze-thaw in prior weeks was an important variable in all erosion models.

Measuring Streambank Erosion: A Comparison of Erosion Pins, Total Station, and Terrestrial Laser Scanner

Streambank erosion is difficult to quantify; models and field methods are needed to assess this important sediment source to streams. Our objectives were to (1) evaluate and compare three techniques for quantifying streambank erosion: erosion pins, total station, and laser scanning, (2) spatially assess streambank erosion rates in the Indian Mill Creek watershed of Michigan, USA, and (3) relate results with modeling of nonpoint source pollution. We found large absolute and relative errors between the different measurement techniques. However, we were unable to determine any statistically significant differences between techniques and only observed a correlation between total station and laser scanner. This suggests that the three methods have limited comparability and differences between measurements were largely not systemic. Further, the application of each technique should be dependent on site conditions, project goals, desired resolution, and resources. The laser scanner collected high-resolution data on clear, barren streambanks, but the erosion pin and total station were more representative of complex vegetated banks. Streambank erosion rates varied throughout the watershed and were influenced by fluvial processes. We estimate that streambank erosion contributed 28.5% of the creek’s total sediment load. These findings are important to address sources of watershed impairments related to sedimentation, as choosing an applicable technique for individual purposes can help reduce the challenges and costs of a streambank erosion study.

Quantifying channel bank erosion of a small mountain river in Russian wet subtropics using erosion pins

Channel bank erosion was monitored using erosion pin arrays in a small mountain stream located in the Tsanyk River basin near the Caucasian Black sea coast. The study area is characterized by high precipitation, low mountainous topography, and flysch bedrock. Erosion pins arrays were installed at six key sections each with different bank lithology and morphology. Bank lithology (bedrock or alluvial deposits), morphology (vertical or concave) and orientation towards the local flow direction were the dominant factors controlling the rate of bank retreat and/or collapse. In contrast to alluvial banks, bedrock slopes are predominantly affected by chemical weathering processes in a wet subtropical climate. Results on sediment mobilization and volume removed are presented for different bank types. Variability in channel bank recessional dynamics is discussed in the context of hydrometeorological data (2016–2018) and an extreme flood.

SOIL PHYSICAL CHARACTERISTICS NEAR THE RESERVOIR OF THE LUIZ GONZAGA HYDROELECTRIC POWER PLANT - PE

The erosive processes generated at the reservoir banks affect the quantity and the water supply, causing serious environmental and economic consequences. The objective of this study was to define the erosive laminar process in the surroundings of the reservoir of the Hydroelectric Power Plant. To perform the evaluation in sixteen areas, Echanced Thematic Mapper Plus images were used from Ladsat 7 satellite, RGB color composition and 543 bands, with nine classes of use and occupation of the areas, as well as the methodology with erosion pins. The pedological survey revealed a variation in the taxonomic classes, such as: Eutrophic Regolithic Neosol (area 1); Eutrophic Littoral Neosol (areas 2, 3, 4, 12 and 13); Optical Quartzene Neosol (areas 4, 6, 7, 8, 9, 10, 11 and 16); Luvissolo Crômico Órtico (area 5); And Eutrophic Haphol Plantain (area 15); The physical characterization of the soils and the soil loss of the marginal debulking (ranging from the very low to severe level) studied were susceptible to erosive processes. Soil loss in the studied areas varied from 85.00 to 205.20 kg ha-1ano-1.