Sediment Yield in Dam-Controlled Watersheds in the Pisha Sandstone Region on the Northern Loess Plateau, China

Soil erosion has become the dominant environmental issue endangering sustainable development in agriculture and the ecosystem on the Loess Plateau. Determination of watershed soil erosion rates and sediment yields is essential for reasonable utilization of water resources and soil loss control. In this study, we employed unmanned aerial vehicles (UAVs) and structure-from-motion (SfM) photogrammetry to determine the sediment yields in 24 dam-controlled watersheds in the Pisha sandstone region of the northern Loess Plateau. High differences in total sediment were trapped before the check dams due to their running periods and sediment yields. The estimated specific sediment yield ranged from 34.32 t/(ha∙a) to 123.80 t/(ha∙a) with an average of 63.55 t/(ha∙a), which indicated that the Pisha sandstone region had an intense soil erosion rate. Furthermore, the modified Sediment Distributed Delivery (SEDD) model was applied to identify the erosion-prone areas in the watersheds, and the sediment retained in the check dams were used for model calibration. The performance of the model was acceptable, and the modeling results indicated that the steep Pisha sandstone was the major sediment source for the watersheds, accounting for approximately 87.37% of the sediment yield. Catchment area, erosive precipitation, and badland proportion were the key factors for sediment yield in the dam-controlled watersheds of the Pisha sandstone region, according to multiple regression analyses. These findings indicated that the modified SEDD model is very efficient in identifying spatial heterogeneities of sediment yield in the watershed but requires comprehensive calibration and validation with long-term observations. The Pisha sandstone region is still the key area of soil erosion control in the Loess Plateau, which needs more attention for soil and water conservation due to high sediment yield.

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Effects of Vegetation Restoration on Soil Erosion on the Loess Plateau: A Case Study in the Ansai Watershed

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18126266 ◽

2021 ◽

Vol 18 (12) ◽

pp. 6266

Author(s):

Hui Wei ◽

Wenwu Zhao ◽

Han Wang

Keyword(s):

Land Use ◽

Soil Erosion ◽

Loess Plateau ◽

Water Conservation ◽

Large Scale ◽

Land Use Changes ◽

Vegetation Restoration ◽

The Loess Plateau ◽

Local Soil ◽

Erosion Environment

Large-scale vegetation restoration greatly changed the soil erosion environment in the Loess Plateau since the implementation of the “Grain for Green Project” (GGP) in 1999. Evaluating the effects of vegetation restoration on soil erosion is significant to local soil and water conservation and vegetation construction. Taking the Ansai Watershed as the case area, this study calculated the soil erosion modulus from 2000 to 2015 under the initial and current scenarios of vegetation restoration, using the Chinese Soil Loess Equation (CSLE), based on rainfall and soil data, remote sensing images and socio-economic data. The effect of vegetation restoration on soil erosion was evaluated by comparing the average annual soil erosion modulus under two scenarios among 16 years. The results showed: (1) vegetation restoration significantly changed the local land use, characterized by the conversion of farmland to grassland, arboreal land, and shrub land. From 2000 to 2015, the area of arboreal land, shrub land, and grassland increased from 19.46 km2, 19.43 km2, and 719.49 km2 to 99.26 km2, 75.97 km2, and 1084.24 km2; while the farmland area decreased from 547.90 km2 to 34.35 km2; (2) the average annual soil erosion modulus from 2000 to 2015 under the initial and current scenarios of vegetation restoration was 114.44 t/(hm²·a) and 78.42 t/(hm²·a), respectively, with an average annual reduction of 4.81 × 106 t of soil erosion amount thanks to the vegetation restoration; (3) the dominant soil erosion intensity changed from “severe and light erosion” to “moderate and light erosion”, vegetation restoration greatly improved the soil erosion environment in the study area; (4) areas with increased erosion and decreased erosion were alternately distributed, accounting for 48% and 52% of the total land area, and mainly distributed in the northwest and southeast of the watershed, respectively. Irrational land use changes in local areas (such as the conversion of farmland and grassland into construction land, etc.) and the ineffective implementation of vegetation restoration are the main reasons leading to the existence of areas with increased erosion.

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Soil and water conservation on the Loess Plateau in China: review and perspective

Progress in Physical Geography Earth and Environment ◽

10.1177/0309133307081290 ◽

2007 ◽

Vol 31 (4) ◽

pp. 389-403 ◽

Cited By ~ 236

Author(s):

Liding Chen ◽

Wei Wei ◽

Bojie Fu ◽

Yihe Lü

Keyword(s):

Land Use ◽

Soil Erosion ◽

Loess Plateau ◽

Water Conservation ◽

Vegetation Restoration ◽

Soil And Water Conservation ◽

The Loess Plateau ◽

The Past ◽

Soil And Water ◽

Made In

The Loess Plateau, China, has long been suffering from serious soil erosion. About 2000 years ago, larger areas were used for grain production and soil erosion was thus becoming severe with increase in human activity. Severe soil and water loss led to widespread land degradation. During the past decades, great efforts were made in vegetation restoration to reduce soil erosion. However, the efficiency of vegetation restoration was not as satisfactory as expected due to water shortage. China initiated another state-funded scheme, the `Grain-for-Green' project in 1999, on the Loess Plateau to reduce soil erosion and improve land quality. However, the control of soil erosion effectively by land-use modification raised problems. In this paper, the lessons and experiences regarding soil and water conservation in the Loess Plateau in the past decades are analysed first. Urgent problems are then elaborated, such as the contradiction between land resource and human population, shortage of water both in amount and tempospatial distribution for vegetation growth, weak awareness of the problems of soil conservation by local officials, and poor public participation in soil and water conservation. Finally, suggestions regarding soil and water conservation in the Loess Plateau are given. In order to control soil erosion and improve vegetation, a scientific and detailed land-use plan for the Loess Plateau has to be made, in the first instance, and then planning for wise use of water resources should be undertaken to control mass movement effectively and to improve land productivity. Methods of improving public awareness of environmental conservation and public involvement in vegetation rehabilitation are also important.

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Effects of vegetation cover and slope on soil erosion in the Eastern Chinese Loess Plateau under different rainfall regimes

PeerJ ◽

10.7717/peerj.11226 ◽

2021 ◽

Vol 9 ◽

pp. e11226

Author(s):

Congjian Sun ◽

Huixin Hou ◽

Wei Chen

Keyword(s):

Soil Erosion ◽

Loess Plateau ◽

Water Conservation ◽

Vegetation Cover ◽

Interactive Effects ◽

Chinese Loess Plateau ◽

Slope Gradient ◽

Chinese Loess ◽

Sediment Yields ◽

Erosion Processes

Soil erosion is a critical environmental problem of the Chinese Loess Plateau (CLP). The effects of vegetation cover on soil erosion reduction under different rainfall types are not well understood especially in the eastern Chinese Loess Plateau (ECLP). In this study, we monitored runoff and sediment yield at the Fengjiagou water and soil conservation station with five types of vegetation cover (arbor trees (ARC), shrubs (SHC), arable (ABC), natural vegetation (NVC), and artificial grass (APC)) and three slope gradients (10°, 15°, and 20°) in the ECLP. Based on long-term monitoring data, five rainfall types were classified by the maximum 30 min rainfall intensity (I30). We also quantitatively revealed the interactive effects of different types precipitation, vegetation cover and slope gradients on regional soil erosion. The results showed that (1) The RII (13 times) and RIII (eight times) type are the most threatening erosive rainfall in this region. (2) The ARC and SHC type were most beneficial for soil and water conservation in the ECLP; The APC and ABC are not conductive to the prevention of regional soil erosion. (3) Runoff and sediment yields increased with the slope gradient. The farmland is vulnerable to soil erosion when the slope gradient exceeds 10°. The results of this study can improve the understanding of regional soil erosion processes on the ECLP and provide useful information for managing regional water and land resources.

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Soil erosion and sediment interception by check dams in a watershed for an extreme rainstorm on the Loess Plateau, China

International Journal of Sediment Research ◽

10.1016/j.ijsrc.2020.03.005 ◽

2020 ◽

Vol 35 (4) ◽

pp. 408-416 ◽

Cited By ~ 5

Author(s):

Leichao Bai ◽

Nan Wang ◽

Juying Jiao ◽

Yixian Chen ◽

Bingzhe Tang ◽

...

Keyword(s):

Soil Erosion ◽

Loess Plateau ◽

The Loess Plateau ◽

Check Dams

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Influence of Check Dams on Flood and Erosion Dynamic Processes of a Small Watershed in the Loss Plateau

Water ◽

10.3390/w11040834 ◽

2019 ◽

Vol 11 (4) ◽

pp. 834 ◽

Cited By ~ 4

Author(s):

Shuilong Yuan ◽

Zhanbin Li ◽

Peng Li ◽

Guoce Xu ◽

Haidong Gao ◽

...

Keyword(s):

Loess Plateau ◽

Water Conservation ◽

Large Scale ◽

Dynamic Processes ◽

Outlet Section ◽

Small Watershed ◽

The Loess Plateau ◽

Flood Peak ◽

Check Dams ◽

Flood Volume

As an important soil and water conservation engineering measure, check dams have been constructed on a large scale in the Loess Plateau of China. However, their effects on runoff and sediment processes in the basin are still unclear. In this study, the hydrodynamic processes of the Wangmaogou watershed located in the Loess Plateau were simulated, and the influence of check dams on the flood and erosion dynamic processes in this watershed were also evaluated. The results showed that the check dams obviously reduced the flood peak and flood volume and mitigated the flood process. After the dam system was completed, the flood peak and flood volume were reduced by 65.34% and 58.67%, respectively. The erosion dynamic distribution of the main channel in the small watershed was changed to different extents by the different dam type combinations, and the erosion dynamic parameters of the channel decreased most after the dam system was completed, when the velocity and runoff shear stress of the outlet section were reduced by 10.69% and 31.08%, respectively. Additionally, the benefits of sediment reduction were most obvious after the check dam system was completed, with the sediment discharge in the watershed being reduced by 83.92%. The results of this study would provide specific implications for construction and management of check dams in the Loess plateau.

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Soil erosion and sediment interception by check dam in watershed under extreme rainstorm on the Loess Plateau, China

10.5194/egusphere-egu2020-1227 ◽

2020 ◽

Author(s):

leichao bai

Keyword(s):

Soil Erosion ◽

Loess Plateau ◽

Sediment Deposition ◽

Delivery Ratio ◽

Construction Technology ◽

Check Dam ◽

The Loess Plateau ◽

Check Dams ◽

Hydrological Station ◽

Extreme Rainstorms

The magnitude of soil erosion and sediment reduction efficiency of check dams under extreme rainstorms are long-standing concerns. This paper aims to use check dams to deduce the amount of soil erosion under extreme rainstorms in watersheds and to identify the difference of sediment intercepting efficiency of different types of check dams. Based on the sediment deposition of 12 check dams with 100% sediment intercepting efficiency and sub-catchment clustering by taking 12 check dams-controlled catchments as standard separately, the amount of soil erosion caused by an extreme rainstorm event on July 26th, 2017 (named &#8220;7&#183;26&#8221; extreme rainstorm) was deduced in the Chabagou watershed in the hill and gully region of the Loess Plateau. The differences of sediment intercepting efficiency among check dams in the watershed were analysed according to the field observation 17 check dams. The results showed that the average erosion intensity under the &#8216;7&#183;26&#8217; extreme rainstorm was approximately 2.03&#215;104 t&#183;km-2, which was 5 times that in the second erosive rainfall in 2017 (4.15&#215;103 t&#183;km-2) and 11-384 times that in 2018 (0.53&#215;102 t&#183;km-2 - 1.81&#215;103 t&#183;km-2). Under the &#8216;7&#183;26&#8217; extreme rainstorm, the amount of soil erosion in the Chabagou watershed above Caoping hydrological station was 4.20&#215;106 tons. The sediment intercepting efficiencies check dams with drainage canals (including the destroyed check dams) and with drainage culverts was 6.48% and 39.49%, respectively. The total actual sediment amount trapped by the check dam was 1.11&#215;106 tons, accounting for 26.36% of the total soil erosion amount. In contrast, 3.09&#215;106 tons of sediment was inputted to the downstream channel, and the sediment deposition in the channel was 2.23&#215;106 tons, accounting for 53.15% of the total amount of soil erosion. The amount of sediment transport at the hydrological station was 8.60&#215;105 tons. The sediment delivery ratio (SDR) under the &#8220;7&#183;26&#8221; extreme rainstorm was 0.21. The results indicated that the amount of soil erosion was huge, and the sediment intercepting efficiency of check dams was greatly reduced under extreme rainstorms. It is necessary to strengthen the management and construction technology standards of check dams to improve the sediment intercepting efficiency and flood safety in the watershed.

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The response of extreme rainstorm to global climate pattern changes in the loess plateau

10.5194/egusphere-egu2020-16507 ◽

2020 ◽

Author(s):

shaobo long

Keyword(s):

Water Resources ◽

Soil Erosion ◽

Loess Plateau ◽

Water Conservation ◽

Global Climate ◽

Soil And Water Conservation ◽

The Loess Plateau ◽

Sst Anomaly ◽

Academy Of Sciences ◽

Soil And Water

The response of extreme rainstorm to global climate pattern changes in the loess plateauShaobo Long1,3&#12289;Jianen Gao1,2,3*&#12289;Huijuan Li5&#12289;Zhe Gao4&#12289;minmin Qiang1,3&#12289;Sixuan Liu1,3<ol><li>Institute of Soil and Water Conservation, Northwest Agriculture and Forestry University, 712100, Yangling, Shaanxi, China.</li> <li>Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, 712100, Yangling, Shaanxi, China.</li> <li>Research Center on Soil and Water Conservation, Ministry of Water Resources, 712100, Yangling, Shannxi, China.</li> <li>College of Water Resources and Architectural Engineering, Northwest Agriculture and Forestry University, 712100, Yangling, Shaanxi, China.</li> <li>Institute of Geographic Sciences and Natural Research, CAS, 100101, Beijing, China.</li> </ol>Abstract: The loess plateau is the region with the most serious soil and water problems in the world, the soil erosion mainly occurs in the season of rainfall, especially the extreme rainstorm has great influence on soil erosion. In recent years, under the background of global climate change, extreme rainstorm occurs frequently in the loess plateau, causes a series of soil damage, was difficult to predict. Therefore, it is a great significance to study the rule of extreme rainstorm for the soil erosion in the loess plateau. Based on the daily rainfall data of 56 meteorological stations and global sea surface temperatures (SST) data in the last 60 years, the effects of El Ni&#241;o on extreme rainstorm were studied by using empirical orthogonal function (EOF), wavelet transform, and other statistical methods. The results show:<ul><li>(1) The extreme rainstorm has obvious spatial distribution characteristics, which decreases gradually from the south to the north of the loess plateau; Temporal variation of extreme rainstorm has obvious decadal oscillation, showing a decreasing trend from 1982 to 2012 and an increasing trend after 2012.</li> <li>(2) There was a significant positive correlation between the time coefficient of EOF1 for SST and the extreme rainstorm (P < 0.05). Wavelet analysis shows that Both extreme rainstorm and SST anomaly have a 30-year cycle, with the time change becoming more dramatic after 2012.</li> <li>(3) El Ni&#241;o has obvious influence on the extreme rainstorm in the loess plateau region. Extreme rainstorm can be predicted about 1 year in advance by the change of SST anomaly. This is of great significance to the study of extreme rainfall erosion in the loess plateau.</li> </ul>Keywords: The loess plateau; Extreme rainstorm; El Ni&#241;oFunding:<ol><li>The National key Research and Development Program of China (No.2017YFC0504703).</li> <li>National Natural Science Foundation of China (No. 41877078, 41371276).</li> <li>Knowledge Innovation Program of the Chinese Academy of Sciences (No.A315021615).</li> </ol>

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Variation in the sediment deposition behind check-dams under different soil erosion conditions on the Loess Plateau, China

Earth Surface Processes and Landforms ◽

10.1002/esp.4364 ◽

2018 ◽

Vol 43 (9) ◽

pp. 1899-1912 ◽

Cited By ~ 7

Author(s):

Yanhong Wei ◽

Zhong He ◽

Juying Jiao ◽

Yujin Li ◽

Yixian Chen ◽

...

Keyword(s):

Soil Erosion ◽

Loess Plateau ◽

Sediment Deposition ◽

The Loess Plateau ◽

Check Dams

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Capacity of soil loss control in the Loess Plateau based on soil erosion control degree

Journal of Geographical Sciences ◽

10.1007/s11442-016-1279-y ◽

2016 ◽

Vol 26 (4) ◽

pp. 457-472 ◽

Cited By ~ 23

Author(s):

Haidong Gao ◽

Zhanbin Li ◽

Lianlian Jia ◽

Peng Li ◽

Guoce Xu ◽

...

Keyword(s):

Soil Erosion ◽

Loess Plateau ◽

Soil Loss ◽

Erosion Control ◽

The Loess Plateau ◽

Soil Erosion Control ◽

Control Degree ◽

Loss Control

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Influences of conservation measures on runoff and sediment yield in different intra-event-based flood regimes in the Chabagou watershed

Scientific Reports ◽

10.1038/s41598-021-95111-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Shan-Shan Wang ◽

Zhan-Bin Li ◽

Le-Tao Zhang ◽

Bo Ma

Keyword(s):

Soil Erosion ◽

Loess Plateau ◽

Sediment Yield ◽

Suspended Sediment Concentration ◽

Sediment Concentration ◽

The Loess Plateau ◽

Flood Duration ◽

Conservation Measures ◽

Event Based ◽

Measurement Period

AbstractThe Loess Plateau in China has suffered severe soil erosion. To control soil erosion, extensive conservation measures aimed at redistributing rainfall, hindering flow velocity and intercepting sediment were implemented on the Loess Plateau. To accurately evaluate the combined effect of conservation measures in the Chabagou watershed, this study classified intra-event-based floods into four regimes via cluster and discriminant analyses. Regime A was characterized by short flood duration and low erosive energy, regime B was characterized by short flood duration and high erosive energy, regime C was characterized by long flood duration and low erosive energy, and regime D was characterized by long flood duration and high erosive energy. The results indicated that peak discharge (qp), runoff depth (H), mean discharge (qm), and runoff erosion power (E) decreased by 75.2%, 56.0%, 68.0% and 89.2%, respectively, in response to conservation measures. Moreover, area-specific sediment yield (SSY), average suspended sediment concentration (SCE), and maximum suspended sediment concentration (MSCE) decreased by 69.2%, 33.3% and 11.9%, respectively, due to conservation measures. The nonlinear regression analysis revealed a power function relationship between SSY and E in both the baseline (1961–1969) and measurement period (1971–1990) in all regimes. Conservation measures reduced sediment yield by not only reducing the runoff amount and soil erosion energy but also transforming the flood regime, for example, transforming a high-sediment-yield regime into a low-sediment-yield regime. Moreover, conservation measures altered the SSY-E relationship in regime A, whereas no obvious difference in regime B or C/D was observed between the measurement period and the baseline period. This study provides a better understanding of the mechanism of runoff regulation and the sediment yield reduction under comprehensive conservation measures in a small watershed on the Chinese Loess Plateau.

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