Erosion Control Efforts Research Articles

Investigating survival/growth ratio of scots pine (Pinus sylvestris L.) afforestation efforts and effects of BUROR terracing operations on some soil properties in the lands susceptive to soil erosion in Erzincan

Erzincan-Keklik kayası mevkiinde yürütülen bu çalışmada, 2012 yılında, BUROR mini-ekskavatörle teraslama sonrası uygulanan ağaçlandırma ve erozyon kontrol faaliyetlerinde dikilen sarıçam fidanlarının 2018 yılı vejetasyon dönemi sonundaki (6 yıllık) gelişim durumlarının değerlendirmesi yapılmıştır. Bu amaçla, dikimlerin yapıldığı alandan 20 m x 20 m büyüklüğünde (yaklaşık 400 m2) toplam 7 deneme parseli seçilmiş ve her bir parselde rasgele tespit edilen 30 (toplamda 210 adet) fidanın boyu, kök boğazı çapları ve dikimden bu yana geçen her bir vejetasyon dönemine ait yıllık boy artımları ölçülmüştür. Ayrıca, söz konusu bu ağaçlandırma ve erozyon kontrol faaliyetlerinin toprakta neden olduğu olası bazı fiziksel ve kimyasal değişimleri tespit etmek üzere de 42 tanesi dikim yapılan terasların içinden (fidan dibinden), 29 tanesi ise terasların aralarından (doğal/kontrol alan) olmak üzere toplamda 71 bozulmuş toprak örneği alınarak pH, organik madde (OM), elektriksel iletkenlik (Eİ), agregat stabilitesi ve tekstür değerleri için analize tabi tutulmuşlardır. Araştırma sonucunda, altı yıllık büyüme dönemi sonunda, dikilen sarıçam fidanlarında %88’lik bir başarı oranı yakalandığı, ortalama kök boğaz çaplarının ise 47.3 mm’ye ulaştığı belirlenmiştir. Bununla beraber, güney bakıdaki yamaçlarda dikilen sarıçam fidanlarının ulaştıkları ortalama 130.3 cm’lik boy ile kuzey bakıdakilerden (120.9 cm) istatiksel olarak daha uzun oldukları tespit edilmiştir. Toprak analiz verileri üzerindeki değerlendirmelerde ise mini ekskavatörle yapılan BUROR terasların bazı toprak özellikleri üzerinde negatif etkiler yarattığı ve kısmen bozulan bu özelliklerin doğal değerlerine ulaşmasının zaman alacağı sonucuna varılmıştır. Son olarak, bu araştırmanın önemli sonuçlarından birinin de 2013 ile 2018 büyüme dönemlerindeki sarıçam boy artımlarıyla hem bir önceki yıl yağan toplam yağış miktarları (R2 = 0.77) hem de vejetasyon dönemindeki yağış miktarları arasında (R2 = 0.85) yüksek bir ilişki olduğunun tespit edilmesi olmuştur.

Tracking geomorphic changes after suburban development with a high density of green stormwater infrastructure practices in Montgomery County, Maryland

Stream morphology is affected by changes on the surrounding landscape. Understanding the effects of urbanization on stream morphology is a critical factor for land managers to maintain and improve vulnerable stream corridors in urbanizing landscapes. Stormwater practices are used in urban landscapes to manage runoff volumes and peak flows, potentially mitigating alterations to the flow regime that drive changes in channel morphology. However, there remains a paucity of long-term studies assessing watershed-scale relationships between urbanization and effects on stream morphology where green stormwater infrastructure exists in high densities. This paper evaluates the geomorphic changes across four headwater catchments in the Chesapeake Bay Watershed over the course of >10 yr and relates these changes to urban development. Annual cross-sectional surveys conducted from 2002 to 2019 in one forested catchment, one agricultural catchment, and two treatment catchments were used to understand the relationship between urbanization and changes in stream morphology. Six cross-sectional geomorphic metrics were calculated and compared with development timelines and high flow events. A channel evolution model was then used to understand the status of morphologic stability at sites within the study. Results suggest downstream environments in developing areas are more impacted during early phases of suburban construction. Channel change during construction could be a result of sediment and erosion control efforts' limitations on preventing and controlling overland sediment mobilization or of increased discharge causing widening and thus bank-derived sediment to move to the streambed. Results demonstrate that geomorphic metrics are highly variable within a small area and are not always accurate representations of broader landscape changes but rather of the more localized environment at a specific stream segment. Despite a high density of stormwater management facilities in urban catchments, substantial alterations to cross sections were found at multiple locations in each catchment including the controls.

Impacts of Climate Change on Soil Erosion in the Great Lakes Region

Quantifying changes in potential soil erosion under projections of changing climate is important for the sustainable management of land resources, as soil loss estimates will be helpful in identifying areas susceptible to erosion, targeting future erosion control efforts, and/or conservation funding. Therefore, the macro-scale Variable Infiltration Capacity—Water Erosion Prediction Project (VIC-WEPP) soil erosion model was utilized to quantify soil losses under three climate change scenarios (A2, A1B, B1) using projections from three general circulation models (GFDL, PCM, HadCM3) for the Great Lakes region from 2000 to 2100. Soil loss was predicted to decrease throughout three future periods (2030s, 2060s, and 2090s) by 0.4–0.7 ton ha−1 year−1 (4.99–23.2%) relative to the historical period (2000s) with predicted air temperature increases of 0.68–4.34 °C and precipitation increases of 1.74–63.7 mm year−1 (0.23–8.6%). In the forested northern study domain erosion kept increasing by 0.01–0.18 ton ha−1 year−1 over three future periods due to increased precipitation of 9.7–68.3 mm year−1. The southern study domain covered by cropland and grassland had predicted soil loss decreases of 0.01–1.43 ton ha−1 year−1 due to air temperature increases of 1.75–4.79 °C and reduced precipitation in the summer. Fall and winter had greater risks of increased soil loss based on predictions for these two seasons under the A2 scenario, with the greatest cropland soil loss increase due to increased fall precipitation, and combined effects of increases in both precipitation and air temperature in the winter. Fall was identified with higher risks under the A1B scenario, while spring and summer were identified with the greatest risk of increased soil losses under the B1 scenario due to the increases in both precipitation and air temperature.

Watershed Sediment Losses to Lakes Accelerating Despite Agricultural Soil Conservation Efforts

Agricultural soil loss and deposition in aquatic ecosystems is a problem that impairs water quality worldwide and is costly to agriculture and food supplies. In the US, for example, billions of dollars have subsidized soil and water conservation practices in agricultural landscapes over the past decades. We used paleolimnological methods to reconstruct trends in sedimentation related to human-induced landscape change in 32 lakes in the intensively agricultural region of the Midwestern United States. Despite erosion control efforts, we found accelerating increases in sediment deposition from erosion; median erosion loss since 1800 has been 15.4 tons ha−1. Sediment deposition from erosion increased >6-fold, from 149 g m−2 yr−1 in 1850 to 986 g m−2 yr−1 by 2010. Average time to accumulate one mm of sediment decreased from 631 days before European settlement (ca. 1850) to 59 days mm−1 at present. Most of this sediment was deposited in the last 50 years and is related to agricultural intensification rather than land clearance or predominance of agricultural lands. In the face of these intensive agricultural practices, traditional soil conservation programs have not decelerated downstream losses. Despite large erosion control subsidies, erosion and declining water quality continue, thus new approaches are needed to mitigate erosion and water degradation.

Revegetation of steeplands in France and New Zealand: geomorphic and policy responses

Efforts to address erosion and land degradation in steeplands of many countries have largely relied on revegetation. The policy responses to this issue are many and varied as have been their successes. Revegetation efforts tend to occur when it is realised that deforestation, mountain land erosion, and flooding of rivers are linked. Using the Southern Prealps region in France and the East Coast North Island region of New Zealand as ‘study sites’, past and current revegetation efforts to address steepland degradation were compared. Both areas have similarities in geology, geomorphology and types of erosion processes (shallow landsliding and gullying). Landscape responses to large-scale erosion and subsequent reforestation have been similar between France and New Zealand though major reforestation occurred in France more than a century before that in New Zealand. Attempts to control sediment production in headwater regions reinforces the view that conditions controlling the evolution of channel response (through time and space) to a change in sediment supply are complex. While there is a consistent sequence of responses in channels and on hillslopes to reforestation efforts and the direction of changes may be anticipated, the magnitude and timing of those responses are not. The key lesson for future management and policy development arising from these studies is that erosion-control efforts that are aimed at producing basin-scale impacts will require targeting of areas where the proposed land use change or intervention will have the most beneficial influence on reducing sediment supply to river channels.

Water quality response to the Angora Fire, Lake Tahoe, California

The Angora Fire (summer of 2007) was the largest and most severe wildfire in recent history within the Lake Tahoe basin of the Sierra Nevada. To determine the watershed response and to assess the potential for downstream impacts of nutrient and sediment delivery to Lake Tahoe, we monitored the post-fire hydrology and stream water chemistry for 2 years at four locations along the length of Angora Creek, a perennial stream draining the burned watershed. When compared with unburned streams, the hydrology of Angora Creek indicated an earlier and faster melting of the spring snowpack. Peak stream water concentrations of total N (TN) and ammonium occurred within the burned area, whereas peak concentrations of nitrate (NO3 −), total P, soluble reactive P, total suspended solids, turbidity, electrical conductivity (EC), and dissolved organic C occurred below the burned area. In comparison to pre-fire data, TN, NO3 −, TP, total dissolved P, EC, and turbidity increased following the fire, particularly in the wetter second year. Yields for subwatershed areas suggest that the burned urban subwatershed was the largest source of nutrients and sediments, whereas the wet meadow subwatershed downstream of the burned area retained materials. Erosion control efforts, below-average annual precipitation and the timing of its arrival (absence of summer and fall rainstorms), and the existence of a wet meadow below the burned watershed likely reduced the negative impacts that would have been expected from such a severe wildfire.

Land use and land cover classification over a large area in Iran based on single date analysis of satellite imagery

Accelerated soil erosion, high sediment yields, floods and debris flow are serious problems in many areas of Iran, and in particular in the Golestan dam watershed, which is the area that was investigated in this study. Accurate land use and land cover (LULC) maps can be effective tools to help soil erosion control efforts. The principal objective of this research was to propose a new protocol for LULC classification for large areas based on readily available ancillary information and analysis of three single date Landsat ETM+ images, and to demonstrate that successful mapping depends on more than just analysis of reflectance values. In this research, it was found that incorporating climatic and topographic conditions helped delineate what was otherwise overlapping information. This study determined that a late summer Landsat ETM+ image yields the best results with an overall accuracy of 95%, while a spring image yields the poorest accuracy (82%). A summer image yields an intermediate accuracy of 92%. In future studies where funding is limited to obtaining one image, late summer images would be most suitable for LULC mapping. The analysis as presented in this paper could also be done with satellite images taken at different times of the season. It may be, particularly for other climatic zones, that there is a better time of season for image acquisition that would present more information.

The Monstering of Tamarisk: How Scientists made a Plant into a Problem

Dispersal of biota by humans is a hallmark of civilization, but the results are often unforeseen and sometimes costly. Like kudzu vine in the American South, some examples become the stuff of regional folklore. In recent decades, "invasion biology," conservation-motivated scientists and their allies have focused largely on the most negative outcomes and often promoted the perception that introduced species are monsters. However, cases of monstering by scientists preceded the rise of popular environmentalism. The story of tamarisk (Tamarix spp.), flowering trees and shrubs imported to New England sometime before 1818, provides an example of scientific "monstering" and shows how slaying the monster, rather than allaying its impacts, became a goal in itself. Tamarisks' drought and salt tolerance suggested usefulness for both coastal and inland erosion control, and politicians as well as academic and agency scientists promoted planting them in the southern Great Plains and Southwest. But when erosion control efforts in Arizona, New Mexico and Texas became entangled with water shortages, economic development during the Depression and copper mining for national defense during World War Two, federal hydrologists moved quickly to recast tamarisks as water-wasting foreign monsters. Demonstrating significant water salvage was difficult and became subsidiary to focusing on ways to eradicate the plants, and a federal interagency effort devoted specifically to the latter purpose was organized and continued until it, in turn, conflicted with regional environmental concerns in the late 1960s.

Accuracy and applicability of linear spectral unmixing in delineating potential erosion areas in tropical watersheds

This study was undertaken to assess the accuracy of linear spectral unmixing (LSU) in estimating fractional abundance of land cover components and to examine its applicability in delineating potential erosion areas in tropical watershed. Five image end‐members (mixed vegetation, grass, Acacia auriculiformis, bare soil and water/shadow) were selected and used in different combinations in unmixing Landsat Enhanced Thematic Mapper (ETM) into fraction images. The accuracy assessment was conducted by comparing the land cover abundance estimates derived from unmixing with the land cover abundance measured from field‐validated classified QuickBird imagery. Good agreement was obtained using a four‐end‐member combination in which shadow was eliminated. The results suggest that LSU could be implemented for soil erosion detection. In general, soil erosion increases when vegetation cover decreases; hence, we used the fraction images to derive a bare soil/vegetation cover ratio and used that as a simple indicator to map high potential erosion areas. Comparison with field assessment of actual erosion levels in the study area showed that the technique is effective in identifying areas on which erosion control efforts should be concentrated.

Soil Restoration and Erosion Control: Quantitative Assessment and Direction

There are few statistically rigorous field evaluations of the performance of revegetation or soil restoration type erosion control efforts applied to steeper slopes associated with vineyards, rangelands, and disturbed soils (e.g., burns, roadcuts, and ski runs) in foothill or sub-alpine environments. Moreover, aside from the goal of runoff and sediment reduction, the particular treatment goal and functional duration in these environments is practically unknown, or unspecified. Information is also lacking on the runoff and erosion characteristics of less-disturbed range and forest soils that may help develop target restoration parameters. Erosion modeling using either Universal Soil Loss Equation (USLE) type erosion assessments or in Water Erosion Prediction Program (WEPP) type process models relies on laboratory, plot, and some field studies of erosion from bare to vegetated soils on relatively mild slopes. It is not clear how bare soil sediment transport processes can be realistically expanded to include those sediment control or filtration processes resulting from soil restoration efforts. Available predictions of erosion rates from partially rehabilitated or treated soils (e.g., grass covers, tillage, compost/mulch incorporation) are poor, due in part to limited data and understanding of the controlling factors affecting infiltration/runoff rates associated with the treatment. Present erosion control efforts often lack direction towards determination of the soil processes to be treated, changed, or restored such that runoff and erosion rates are effectively reduced. A new erosion control paradigm may be directed at restoring soil ecologic functioning. Gaining such information is crucial towards water quality modeling/monitoring and nonpoint pollution assessment associated with setting watershed Total Maximum Daily Loads (TMDLs) and represents a significant applied research opportunity.

Some Native Plants for Erosion Control Efforts in Coruh River Valley, Artvin, Turkey

Some Native Plants for Erosion Control Efforts in Coruh River Valley, Artvin, Turkey

Measurement and prediction of sediment production from unpaved roads, St John, US Virgin Islands

AbstractExcess delivery of land‐based sediments is an important control on the overall condition of nearshore coral reef ecosystems. Unpaved roads have been identified as a dominant sediment source on St John in the US Virgin Islands. An improved understanding of road sediment production rates is needed to guide future development and erosion control efforts. The main objectives of this study were to: (1) measure sediment production rates at the road segment scale; (2) evaluate the importance of precipitation, slope, contributing area, traffic, and grading on road sediment production; (3) develop an empirical road erosion predictive model; and (4) compare our measured erosion rates to other published data. Sediment production from 21 road segments was monitored with sediment traps from July 1998 to November 2001. The selected road segments had varying slopes, contributing areas, and traffic loads. Precipitation was measured by four recording rain gauges.Sediment production was related to total precipitation and road segment slope. After normalizing by precipitation and slope, the mean sediment production rate for roads that had been graded within the last two years was 0·96 kg m−2 cm−1 m m−1 or approximately 11 kg m−2 a−1 for a typical road with a 10 per cent slope and an annual rainfall of 115 cm a−1. The mean erosion rate for ungraded roads was 42 per cent lower, or 0·56 kg m−2 cm−1 m m−1. The normalized mean sediment production rate for road segments that had been abandoned for over fifteen years was only about 10 per cent of the mean value for ungraded roads. Sediment production was not related to traffic loads. Multiple regression analysis led to the development of an empirical model based on precipitation, slope to the 1·5 power, and a categorical grading variable.The measured and predicted erosion rates indicate that roads are capable of increasing hillslope‐scale sediment production rates by up to four orders of magnitude relative to undisturbed conditions. The values from St John are at the high end of reported road erosion rates, a finding that is consistent with the high rainfall erosivities and steep slopes of many of the unpaved roads on St John. Other than paving, the most practical methods to reduce current erosion rates are to minimize the frequency of grading and improve road drainage. Copyright © 2005 John Wiley & Sons, Ltd.

Vanishing Earth: Soil Erosion in the Palouse, 1930-1945

Abstract This article examines the environment and agricultural activity in the Palouse, a fertile, hilly prairie in the inland Northwest, during the Great Depression and World War II. This area is home to some of the most productive wheatland in the nation, but because of constant farming activity on its steep slopes, soil erosion has been a problem since the turn of the twentieth century. Erosion threatened the long-term viability of farming in the Palouse and the economic health of greater eastern Washington. Local efforts at stemming the problem were nonexistent in the 1910s and 1920s, but after the depression began, New Deal erosion control programs attempted to improve the erosion situation in the Palouse and countless other areas in the United States. A great deal of time and money were devoted to the problem, including the construction of a USDA erosion experiment station in Pullman, Washington. However, federal erosion control efforts were only minimally successful, in part because programs to stop erosion were voluntary, not compulsory. Not enough farmers initiated or maintained soil conservation techniques, and Palouse farmers continued to endanger their most crucial natural resource.

Vanishing Earth: Soil Erosion in the Palouse, 1930-1945

This article examines the environment and agricultural activity in the Pa? louse, afertile, hilly prairie in the inland Northwest, during the Great Depres? sion and World War II. This area is home to some of the most productive wheatland in the nation, but because of constant farming activity on its steep slopes, soil erosion has been a problem since the turn ofthe twentieth century. Erosion threatened the long-term viability of farming in the Palouse and the economic health of greater eastern Washington. Local efforts at stemming the problem were nonexistent in the 1910s and 1920s, but after the depres? sion began, New Deal erosion control programs attempted to improve the erosion situation in the Palouse and countless other areas in the United States. A great deal oftime and money were devoted to the problem, includ? ing the construction of a USDA erosion experiment station in Pullman, Washington. However, federal erosion control efforts were only minimally successful, in part because programs to stop erosion were voluntary, not compulsory. Not enough farmers initiated or maintained soil conservation techniques, and Palouse farmers continued to endanger their most crucial natural resource.

Engineering geomorphology at the cutting edge of land disturbance: erosion and sediment control on construction sites

Construction site management, traditionally dominated by professional engineers, provides an important opportunity for engineers and geomorphologists to work together in minimizing the environmental impacts of land disturbance. Areas disturbed for construction activity have soil erosion rates from 2 to 40,000 times greater than pre-construction conditions, and are important components of nonpoint source (NPS) pollution that degrades surface water quality. Despite significant local-to-watershed-scale environmental and economic impacts, the lack of an individual economic incentive for land developers to control erosion has limited voluntary adoption of erosion and sediment control measures. However, increased regulatory requirements, combined with efforts to identify and publicize the benefits of erosion control, are increasing the number of construction sites on which erosion control efforts are being implemented. Geomorphologists have the opportunity to play an active role in erosion and sediment control by implementing knowledge of erosion and sedimentation processes and of the variables that effect these processes. Pre-project geomorphological site assessments allow project designers to work around areas with high erosion potential, and to stage and schedule land disturbing activities to minimize erosion potential. Combined engineering and geomorphological analyses can increase the likelihood that streams and drainage channels are stable under altered hydrologic conditions, both during and after land use change, and can be used to design a drainage plan that minimizes surface water flow through disturbed areas. A variety of temporary measures to reduce erosion and to trap sediment on site can be designed and implemented, such as temporary surface covers, silt fence, and sedimentation basins. However, design and implementation of these measures require an understanding of erosion and sedimentation processes, and in many cases incorrect installation and maintenance limit their effectiveness. Regular on-site inspections and training by geomorphologists specializing in erosion control can ensure that measures are being installed and maintained correctly, and allow the inspector to modify the erosion control plan to deal with changing conditions and unanticipated problems. In addition, geomorphologists and engineers can use their combined understanding of erosion processes and construction site realities to develop innovative and practical measures to improve erosion control. Construction site erosion control is a field that relatively few academic geomorphologists have shown an interest in, yet has great potential both in terms of job opportunities and research. It is an area in which morphologists and engineers can work together using their complementary knowledge, both for the development and implementation of erosion control plans; as the basis for developing innovative practices; and for undertaking research on the effectiveness of traditional and new approaches to erosion control.

Importance of rural roads as source areas for runoff in mountainous areas of northern Thailand

Unpaved road surfaces have extremely low infiltration rates compared with other watershed land surfaces and, therefore, are significant source areas for erosion-producing Horton overland flow. The hydrologic role of roads is an important issue in mountainous areas of the tropics where erosion control efforts are predominately focused on deforestation and agricultural practices. We report on an investigation of soil physical properties that control excess rainfall (rainfall intensity in excess of infiltration capacity) on rural roads and surrounding lands in a mountainous watershed in northern Thailand. The results of our disk permeameter measurements indicate that saturated hydraulic conductivity on unpaved roads is about one order of magnitude lower than on any other land-surface type. Median saturated hydraulic conductivities were not exceeded by measured rainfall intensity on any land use except road surfaces and roadside margins. By simulating excess rainfall, we found that in contrast with other areas of the watershed, the road surface tends to generate excess rainfall early in a rain event, and on nearly all of its area. Despite the relatively small areal extent of road-related surfaces (<0.5% of basin area), they contribute a large portion of basin-wide total excess rainfall during frequently occurring, small rainfall events. However, during larger events, agricultural, secondary vegetation, and forested areas assume greater importance because of their larger areal extent. ©1997 Elsevier Science B.V.