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The impact force of debris flow is the main cause of damage and destruction of check dam. In high altitude area, due to high mountains and deep valleys, serious physical weathering of surface materials, a wide range of source materials gradation, high frequency of debris flow occurence and high impact force, the damages induced by debris flow to the check dam are significant. To study the impact characteristics of the wide graded debris flow on check dam in high altitude area, the debris flow developed in Tibet is taking as a prototype. A physical test model of the impact check dam of wide graded debris flow is established. The unit weight of debris flow, the slope of flume and the maximum particle size of debris flow solid are selected as variable factors. 27 groups of flume tests were carried out to study the characteristics of impact force. The results show that: (1) Wide-graded debris flow mainly undergoes three contact evolution stages during the process of impact retaining dam, i.e. impact climbing-rolling return flow-accumulation and silting. The smaller of the debris flow volume weight could lead to a higher climbing distance, and more obvious stage performance of sourcing and sliting process. (2) The impact force in front of the dam decreases with the increase of the bulk weight of wide-graded debris flow. Under the same slope and gradation, a larger the bulk weight of debris flow materials lead to a lower velocity of the debris flow materials and less impact force, because it is more difficult to carry solid material sources. (3) The impact force in front of the dam increases with the increase of the groove gradient. The larger the groove gradient, the greater the flow velocity and flow depth of wide-graded debris flow, the greater the impact force of debris flow. The larger the particle size of solid phase of debris flow, the more significant the impact of slope on impact force. (4) The impact force in front of the sand bar increases with the increase of the maximum particle size of the solid phase of the wide graded debris flow, and the change trend is more significant than when the volume density of the debris flow and the slope conditions of the groove change. The maximum particle size has no obvious regular relationship with the velocity and depth of the debris flow. The research results will provide certain data reference for the prevention and research of wide graded debris flows.

As arid lands expand across the globe, scholars increasingly turn to the archaeological record for examples of sustainable farming in extreme environments. The arid north coast of Peru was the setting of early and intensive irrigation-based farming; it is also periodically impacted by sudden, heavy rainfall related to the El Niño Southern Oscillation (ENSO) phenomenon. While the sociopolitical effects, technologies, and engineering expertise of these irrigation systems have been thoroughly examined and theorized, little is known about how farmers managed periods of water stress. The aim of this study is to test whether arid zone farming was supported by hybrid, intermittent flood and perennial water source systems in the prehispanic past. An arroyo in the Chicama Valley was selected for preliminary data collection, and these data are presented here: (1) drone photography of the arroyo capturing the aftermath of a recent (2023) rain event; and (2) potassium (K) soil test kit results from samples collected near suspected prehispanic check dam features in the same area. The paper combines these data with comparative examples from the literature to suggest that the prehispanic features functioned as water-harvesting infrastructure. The paper concludes that sustainable, arid zone farming can be supported by hybrid, intermittent flood and perennial water source systems. [ABSTRACT FROM AUTHOR]

Copyright of Hydrogeology & Engineering Geology / Shuiwendizhi Gongchengdizhi is the property of Hydrogeology & Engineering Geology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Check‐dams are structures used extensively around the world for soil and water conservation. However, existing models for check‐dams are unable to simulate the Sediment Trap Efficiency (STE) at the catchment scale. A numerical model was developed to simulate the SEdiment Deposition upstream of Check‐Dams (SEDCD) and integrated into a distributed sediment yield model, the Digital Yellow River Model (DYRIM). Two versions of the SEDCD model were evaluated: the SV version which used the Saint–Venant equation to simulate the unsteady flow, and the BW version, which used a modified backwater equation (based on a quasi‐steady approximation) to improve computational efficiency. Sediment deposition and the associated bed profile adjustment were simulated with the sediment conservation equation and the non‐equilibrium suspended sediment transport equation. The SEDCD model was first validated in the laboratory using experimental data from a scale‐down check‐dam. The bed profiles predicted using both versions of the SEDCD model showed good agreement with the observations, with NSE values over 0.9 in most profiles. When integrated into the DYRIM and applied to the Xiaoli River Basin (818 km2) on the Loess Plateau, which has 183 active check‐dams, the SEDCD‐DYRIM combination predicted the STE for an extreme rainstorm event in 2017 with good accuracy and high computational efficiency. The SEDCD‐BW‐DYRIM simulated the hourly discharge and sediment concentration with high accuracy (NSE values of 0.79 and 0.71, respectively) and provided single‐event STEs (R2 value of 0.99) comparable to those of the SEDCD‐SV model, with an approximately 30 times faster runtime efficiency than the SEDCD‐SV model. The SEDCD‐BW model is a powerful and efficient tool to assess the effect of check dams on sediment dynamics at the catchment scale. [ABSTRACT FROM AUTHOR]

As arid lands expand across the globe, scholars increasingly turn to the archaeological record for examples of sustainable farming in extreme environments. The arid north coast of Peru was the setting of early and intensive irrigation-based farming; it is also periodically impacted by sudden, heavy rainfall related to the El Niño Southern Oscillation (ENSO) phenomenon. While the sociopolitical effects, technologies, and engineering expertise of these irrigation systems have been thoroughly examined and theorized, little is known about how farmers managed periods of water stress. The aim of this study is to test whether arid zone farming was supported by hybrid, intermittent flood and perennial water source systems in the prehispanic past. An arroyo in the Chicama Valley was selected for preliminary data collection, and these data are presented here: (1) drone photography of the arroyo capturing the aftermath of a recent (2023) rain event; and (2) potassium (K) soil test kit results from samples collected near suspected prehispanic check dam features in the same area. The paper combines these data with comparative examples from the literature to suggest that the prehispanic features functioned as water-harvesting infrastructure. The paper concludes that sustainable, arid zone farming can be supported by hybrid, intermittent flood and perennial water source systems.

The present study was conducted in the suburban forest of Thessaloniki city (Seich Sou), which constitutes one of the most significant suburban forests in Greece. In 1997, more than the half of the forest area was destroyed by a wildfire, after which soil erosion and flood control works (check-dams) were constructed in the burned areas. The aim of the study is to estimate the annual soil erosion rate for the last 30 years (pre- and post-fire periods) applying the WaTEM/SEDEM model, in order to investigate the impact of this wildfire on soil erosion, the effectiveness of the flood- and erosion-control works and the level of forest regeneration. It is the first time that WaTEM/SEDEM was calibrated and validated in Greece, taking into account soil erosion records from the 18 check-dams that were constructed in the study area in 2001. The mean annual erosion rate was 0.0419 t/ha/year, 0.998 t/ha/year and 0.08 t/ha/year for the pre-fire period, the first 3 years and 20 years after the fire, respectively. The results showed a very low erosion rate for the pre-fire period, an expected significant increase 3 years after the wildfire and a gradual decrease in the subsequent years until 2021. However, it seems that the post-fire regeneration of the forest has not been fully achieved, since the annual soil erosion rate at the long-term post-fire period is double compared with the pre-fire period. Concerning the check-dams' effectiveness, it was observed that after 20 years of operation, they were non-silted, and most of them retained a small amount of sediments. This fact could be attributed to multiple factors such as the very thin soil depth, fire severity and catchment geomorphology, though the main reason seems to be the time elapsed between fire occurrence and the check-dams' construction. The results of this study advance/strengthen the knowledge concerning the pre/post-fire soil erosion processes in already degraded ecosystems, while the calibrated model could serve as a useful tool able to be applied in other Mediterranean catchments of similar characteristics. [ABSTRACT FROM AUTHOR]

Forest fires and post‐fire practices influence sediment connectivity (SC). In this study, we use the 'aggregated index of connectivity' (AIC) to assess SC in five Mediterranean catchments (198–1090 ha) affected by a wildfire in 2012 in south‐eastern Spain. Two temporal scenarios were considered, immediately after the fire and before post‐fire management, and 2 years after the fire including all practices (hillslope barriers, check‐dams, afforestation, salvage logging and skid trails). One LiDAR (light detection and ranging)‐derived digital elevation model (DEM, 2 m × 2 m resolution) was generated, per scenario. The five catchment outlets were established as the computation target (AICOUT), and structural and functional SC were calculated. Index outputs were normalized to make the results of the non‐nested catchments comparable (AICN‐OUT). The output analysis includes the SC distribution along the catchments and at local scale (929 sub‐catchments, 677 in the burned area), the hillslope and channel measures' effect on SC, and a sedimentological analysis using observed area‐specific sediment yield (SSY) at 10 new (built after post‐fire practices) concrete check‐dams located in the catchments (SSY = 1.94 Mg ha−1 yr−1; σ = 1.22). The catchments with more circular shapes and steeper slopes were those with higher AICN‐OUT. The structural SC maps – removing the rainfall erosivity influence – allowed evaluating the actual role played by the post‐fire practices that reduced SC (x¯= − 1.19%; σ = 0.41); while functional SC was linked to the actual change of SC (x¯= + 5.32%; σ = 0.62). Hillslope treatments resulted in significant changes on AICN‐OUT at sub‐catchment scale with certain disconnectivity. A good and positive correlation was found between the SSY and the changes of AICN‐OUT. However, the coarse DEM resolution explained the lack of effect of the rock check‐dams – located on the secondary channels – on AICN‐OUT. AICN‐OUT proved to be a useful tool for decision making in post‐fire restoration, but an optimal input data is still necessary to refine calculations. [ABSTRACT FROM AUTHOR]

The present study was conducted in the suburban forest of Thessaloniki city (Seich Sou), which constitutes one of the most significant suburban forests in Greece. In 1997, more than the half of the forest area was destroyed by a wildfire, after which soil erosion and flood control works (check-dams) were constructed in the burned areas. The aim of the study is to estimate the annual soil erosion rate for the last 30 years (pre- and post-fire periods) applying the WaTEM/SEDEM model, in order to investigate the impact of this wildfire on soil erosion, the effectiveness of the flood- and erosion-control works and the level of forest regeneration. It is the first time that WaTEM/SEDEM was calibrated and validated in Greece, taking into account soil erosion records from the 18 check-dams that were constructed in the study area in 2001. The mean annual erosion rate was 0.0419 t/ha/year, 0.998 t/ha/year and 0.08 t/ha/year for the pre-fire period, the first 3 years and 20 years after the fire, respectively. The results showed a very low erosion rate for the pre-fire period, an expected significant increase 3 years after the wildfire and a gradual decrease in the subsequent years until 2021. However, it seems that the post-fire regeneration of the forest has not been fully achieved, since the annual soil erosion rate at the long-term post-fire period is double compared with the pre-fire period. Concerning the check-dams’ effectiveness, it was observed that after 20 years of operation, they were non-silted, and most of them retained a small amount of sediments. This fact could be attributed to multiple factors such as the very thin soil depth, fire severity and catchment geomorphology, though the main reason seems to be the time elapsed between fire occurrence and the check-dams’ construction. The results of this study advance/strengthen the knowledge concerning the pre/post-fire soil erosion processes in already degraded ecosystems, while the calibrated model could serve as a useful tool able to be applied in other Mediterranean catchments of similar characteristics.

With an area of 6,200 km2, the Gilbués badlands region in the Brazilian drylands is the largest desertification site in the Country. It is located upstream the Boa Esperança Hydroelectric Power Plant and is contiguous to an important Brazilian agricultural area. However, primary quantitative data on erosive processes are scarce or nonexistent. We analyzed on‐site data (2018–2019) concerning small‐scale (hillslope and micro basin) processes: inter‐rill gross erosion, vegetation coverage factor, sediment yield, and sediment delivery ratio. We measured gross erosion in four hillslopes using metal pins; rainfall erosivity using an automatic meteorological station; soil erodibility; and siltation of five check‐dams that control micro basins (101–103 m2) by means of an unmanned aerial vehicle. Gross erosion (102 Mg ha−1 yr−1; 7.5 mm yr−1) is up to 100‐fold the regional mean value and up to 45‐times the tolerable soil‐loss reference value (0.17 mm yr−1), showing that degradation still evolves. Sparse small vegetation directly exposes two thirds of the soil, with a high vegetation factor (0.90). The sediment delivery ratio of the micro basins is 0.88, compatible with low (12%) sediment‐deposition pattern at this scale. The Maner delivery‐ratio model mimicked field observation, which indicates that relief is the key element influencing sediment deposition there. The check‐dam effectiveness considerably decreased after the first decade of operation due to high siltation rates. Although the Gilbués badland occupies only 5% of the basin upstream of the power plant, it contributes 32% of the sediment load to reservoir and dam. This shows the relevance of the badland restoration for the regional sustainability of water and energy supply. [ABSTRACT FROM AUTHOR]

Puttaparthi is a birthplace of Bhagawan Sri Sathya Sai Baba and is a small town situated in the district of Anantapur, in Andhra Pradesh. Chitravathi River is the main water-body in Puttaparthi. The river remained dry for many years. Only in the recent years, rainfall events fed water to the river. Last year in 2019 a check-dam was also constructed in Puttaparthi due to which the river water has been stagnant. This review paper aims to assess the surface water quality of the Chitravati River in Puttaparthi after the establishment of the check-dam. In this regard, literature reviews were performed and the paragraphs in the literature reviews were arranged as per three major themes, which are: 1. check-dams, 2. water-quality assessment and monitoring, and 3. non-perennial river systems. By examining these three themes through the literature reviews, key inferences were made. For instance, it can be understood that the check-dam in Puttaparthi is an important water-storage structure, which is likely to have both positive and negative impacts upon the nearby region. Secondly, in order to examine water-bodies like the Chitravati River in Puttaparthi, we have to perform water quality assessment and monitoring. To perform water quality assessment and monitoring for the Chitravati River in Puttaparthi; we have to use important tools like the Water Quality Index (WQI), Water Pollution Index (WPI), and Water Poverty Index (WPI). Thirdly, non-perennial river systems such as intermittent rivers, ephemeral rivers and their key features have been stressed upon by several readings. These are river systems where a river ceases to flow for some months or for several years. The Chitravati River in Puttaparthi can be appropriately classified as a non-perennial river system and as an intermittent river. Finally, this review paper concludes through a personal reflection, which stresses upon studying the Chitravati River in Puttaparthi and how the literature reviews will help in this regard. [ABSTRACT FROM AUTHOR]

Reforestations and check-dams are two commonly used measures to reduce soil erosion rates and sediment export from highly eroding catchments. Here, we evaluated the impact of the construction of 94 check-dams and land use changes (caused by agricultural abandonment and reforestations) on sediment yield in the Upper Taibilla catchment (320 km2, SE Spain) from 1956 to 2000. We combined land use change analysis, field surveys, and application of the WaTEM-SEDEM erosion and sediment yield prediction model for nine scenarios combining land use maps (1956, 1987, and 2000) and different numbers of check-dams throughout the catchment. Land use changes alone reduced sediment yield up to 14%, but in combination with check-dams, the reduction in sediment yield reached 44 ± 6%. Sediment yield reduction was higher in smaller sub-catchments, with, on average, a higher transport capacity than larger catchments, illustrating the scale dependency of human impacts on sediment fluxes and the buffer capacity of larger catchments. From an economical perspective, the construction of check-dams was estimated to be more expensive than reforestation programs in the studied catchment, while adding more check-dams did not always result in a proportional reduction of sediment yield. This indicates that optimizing check-dam distribution relative to land use patterns is crucial to decrease catchment sediment yield. Check-dams have a large and instantaneous impact on sediment yield over a restricted time period, while reforestations have important sustained effects at a lower economic cost. These contrasting effects require a careful evaluation for optimal effective catchment management. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Copyright of Cuadernos de Investigación Geográfica is the property of Universidad de la Rioja, Servicio de Publicaciones and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article discusses the analysis of channel form, sediment calibre and vegetation around check-dams in the headwater reaches of mountain torrents in Calabria, Italy. Several analysis and surveys were developed to investigate the impact of the installation of check-dams within the confined headwaters of steep streams. The data were used to evaluate active channel form, sediment calibre, and the feature development of riparian vegetation. Detailed field measurements determined the results of the study including the estimates of indices of vegetation extent and downstream gradient. Data set analysis of the results suggest that significant changes in channel form and sediment calibre upstream of check-dams were associated with more consistent vegetation development across the active channel.

The article offers information on the effect of land use change and check-dams on catchment sediment yield. A study was conduced in Spain to determine the impact of reforestation and abandonment of agricultural activities on soil sediment. It examines the extent of erosion processes at the catchment scale as effect of extensive land use change with or without sediment controlled structures, such as check-dams. The result of the study revealed that in a scenario without check-dams, the land use change caused a progressive decrease in sediment yield. About seventy sevent percent of the sediment yield was retained by the used of dams. It is showed that check-dam efficiency depends on the specific environmental condition of the area.

The Loess Mesa Ravine Region and the Loess Hill Ravine Region, cover 200,000 km2 of the Loess Plateau in China and have serious problems of soil and water erosion. Two primary ways to control the sediment pouring into the Yellow River from this area are planting and engineering measures. The former is not suitable for the Loess Plateau due to the arid climate and the barren soil, while some of the latter means, such as terrace farmlands, are vulnerable to floods. As a widespread engineering measure, the check-dam system in gullies is one of the most effective ways to conserve soil and water in the Loess Plateau. At present, the amount of sediment retained by check-dam systems is the largest of all methods and the potential is promising. The dam farmlands so created have become important high-yield croplands or orchards with enriched fertile soil and ample water. This paper reviews the history and principles of check-dams and discusses future theoretical and experimental studies which are needed for the further implementation of this system. [Copyright &y& Elsevier]

This study has evaluated the runoff and erosion rates in torrents of Southern Italy, two forested headwaters with very similar climatic, hydrological and geomorphological characteristics; in one headwater, 15 check dams were installed in the mid-1950s, while the other is not regulated with engineering works. To this aim, the hydrological variables have been modeled over 15 years after check dam installation using the HEC-HMS (Hydrologic Engineering Center-Hydrologic Modeling System) model coupled to the MUSLE (Modified Universal Soil Loss Equation) equation. The model simulations have shown that check dams have not played a significant role in reducing the surface runoff compared to the unregulated torrent; in both catchments, the well-developed forest cover determined very low runoff coefficients (lower than 0.3%) with a scarce runoff generation capacity. Additionally, the reduction in peak flow due to the check dams was not significant, on average −7.4% compared to the unregulated headwater. Check dams have retained sediments for about 8–10 years after their installation, reducing erosion by about 35%, although soil loss was much lower than the tolerance limit in both catchments. After the sediment retention capacity of the dam sediment wedge was depleted, the sediment yield in the regulated torrent was even higher (by about 20%) compared to the unregulated catchment. Overall, the study has shown that the use of check dams as a catchment management strategy of forested headwaters under semi-arid Mediterranean conditions should be considered with caution, since the structures could be ineffective to reduce water and sediment flows during floods or, in some cases, check dams may increase erosion rates. [ABSTRACT FROM AUTHOR]