Uncertainty of slope length derived from digital elevation models of the Loess Plateau, China

ABSTRACTThe purpose of this paper was to study the interaction effects of rainfall regime and slope length on runoff and soil loss under different land uses. Event runoff and soil loss in forest, shrub and grass were measured in plots with lengths of 5, 9 and 13m in the Loess Plateau from 2008 to 2016. A total of 59 erosive rainfall events were recorded and classified into three rainfall regimes. Firstly, the results showed that the runoff coefficient was grass>shrub>forest, and soil loss was grass>forest>shrub, but the differences between forest and shrub in runoff and between grass and forest in soil loss did not reach significant levels. Secondly, rainfall regimes had an important effect on runoff and soil loss under different land uses. The lowest runoff coefficients and the highest soil loss in regime 2 were found in shrub and forest land, respectively, which differed from that of regime 1. In total, rainfall regime 1 had the highest runoff coefficient of 0.84–2.06%, followed by regime 3 with 0.33–0.88% and regime 2 with 0.04–0.06%. Soil loss in forest and grass land had a different order of regime 3>regime 1>regime 2. Thirdly, both the runoff coefficient and soil loss decreased with increasing plot length, while the effect of slope length on runoff/soil loss were influenced by land use type and rainfall regimes.

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Terrace extraction based on remote sensing images and digital elevation model in the loess plateau, China

Earth Science Informatics ◽

10.1007/s12145-020-00444-x ◽

2020 ◽

Vol 13 (2) ◽

pp. 433-446 ◽

Cited By ~ 2

Author(s):

Lanhua Luo ◽

Fayuan Li ◽

Ziyang Dai ◽

Xue Yang ◽

Wei Liu ◽

...

Keyword(s):

Remote Sensing ◽

Digital Elevation Model ◽

Loess Plateau ◽

The Loess Plateau ◽

Remote Sensing Images ◽

Digital Elevation ◽

Elevation Model

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Deep learning-based approach for landform classification from integrated data sources of digital elevation model and imagery

10.5194/egusphere-egu2020-22334 ◽

2020 ◽

Author(s):

Sijin Li ◽

Liyang Xiong ◽

Guoan Tang ◽

Josef Strobl

Keyword(s):

Deep Learning ◽

Loess Plateau ◽

Data Sources ◽

The Loess Plateau ◽

Transitional Area ◽

Landform Classification ◽

The Earth ◽

Digital Elevation ◽

Elevation Model ◽

External Forces

<p>Landform classification is one of the most important aspects in geomorphological research, dividing the Earth&#8217;s surface into diverse geomorphological types. Thus, an accurate classification of landforms is a key procedure in describing the topographic characteristics of a given area and understanding their inner geomorphological formation processes. However, landform types are not always independent of one another due to the complexity and dynamics of interior and external forces. Furthermore, transitional landforms with gradually changing surface morphologies are widely distributed on the Earth&#8217;s surface. With this situation, classifying these complex and transitional landforms with traditional landform classification methods is hard. In this study, a deep learning (DL) algorithm was introduced, aiming at automatically classifying complex and transitional landforms. This algorithm was trained to learn and extract landform features from integrated data sources. These integrated data sources contain different combinations of imagery, digital elevation models (DEMs), and terrain derivatives. The Loess Plateau in China, which contains complex and transitional loess landforms, was selected as the study area for data training. In addition, two sample areas in the Loess Plateau with complex and transitional loess hill and ridge landforms were used to validate the classified landform types by using the proposed DL method. Meanwhile, a comparative analysis between the proposed DL and random forest (RF) methods was also conducted to investigate their capabilities in landform classification. The proposed DL approach can achieve the highest landform classification accuracy of 87% in the transitional area with data combination of DEMs and images. In addition, the proposed DL method can achieve a higher accuracy of landform classification with better defined landform boundaries compared to the RF method. The classified loess landforms indicate the different landform development stages in this area. Finally, the proposed DL method can be extended to other landform areas for classifying their complex and transitional landforms.</p>

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Digital elevation model-based watershed geomorphic entropy for the study of landscape evolution of a watershed geomorphic system in the loess landforms of China

Progress in Physical Geography Earth and Environment ◽

10.1177/0309133316669091 ◽

2016 ◽

Vol 41 (2) ◽

pp. 139-153

Author(s):

Weidong Zhao ◽

Guoan Tang ◽

Lei Ma ◽

Jitang Zhao ◽

Wan Zhou ◽

...

Keyword(s):

Digital Elevation Model ◽

Loess Plateau ◽

Landscape Evolution ◽

The Loess Plateau ◽

Experimental Conditions ◽

Method Of Calculation ◽

Sediment Yields ◽

Digital Elevation ◽

Elevation Model ◽

Evolutional Process

Although the concept of entropy in landscape evolution was proposed over 40 years ago, previous studies of geomorphic entropy paid little attention to the applications of geomorphic entropy in the erosional watershed geomorphic system on the Loess Plateau in China. Therefore, we propose a new concept of entropy called watershed geomorphic entropy (WGE) and its method of calculation based on a digital elevation model and the principles of system theory. To study the geomorphic significances of WGE, we applied the WGE to an artificial rainfall experiment that was originally designed to study erosional processes in a small open watershed geomorphic system on the Loess Plateau. Our study shows that the decrease of WGE in an open watershed geomorphic system means a gradual erosional or erosion-dominated landscape evolutional process and the change of WGE shows a perfectly positive linear correlation with the measured sediment yields of the outlet of the watershed system under our experimental conditions. In addition, to some extent, the decrease of the change of WGE also reflects the reduction of total potential energy of a specific erosional, or erosion-dominated, open watershed geomorphic system.

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Soil Erosion and Controls in the Slope-Gully System of the Loess Plateau of China: A Review

Frontiers in Environmental Science ◽

10.3389/fenvs.2021.657030 ◽

2021 ◽

Vol 9 ◽

Author(s):

Bingbing Zhu ◽

Zhengchao Zhou ◽

Zhanbin Li

Keyword(s):

Soil Erosion ◽

Loess Plateau ◽

Overland Flow ◽

Vegetation Pattern ◽

Sediment Source ◽

The Loess Plateau ◽

Erosion Process ◽

Slope Length ◽

Base Level ◽

Erosion Processes

The Loess Plateau has long been suffering from serious soil erosion of which erosion from the slope-gully system is now dominant. The slope-gully system is characterized with distinctive erosion distribution zones consisting of inner and inter gully areas wherein erosion patterns spatially vary, acting as both sediment source and the dominant sediment and water transport mechanism. In this paper, a substantial body of research is reviewed concentrating on the soil erosion processes and control practices in the slope-gully system. The inner gully area is identified as the main sediment source while runoff and sediment from the inter-gully upland is found to significantly affect down slope erosion processes. Correspondingly, the protective vegetation pattern and coverage should be strategically designed for different erosion zones with an emphasis on the critical vegetation cover and pattern to reduce sediment yield of the whole slope-gully system. Check-dam could change the base level of erosion and reduce the slope length of the gully side, which will further decrease the possibility and magnitude of gravity erosion. We concluded that understanding the erosion processes and implementing erosion practices for the slope-gully system are of importance and require more research efforts that emphasize: 1) the influence of upland runoff on erosion processes at downslope; 2) the relationship between hydraulic characteristics of overland flow and erosion process at a slope-gully system scale; 3) physical mechanisms of different vegetation patterns on the slope-gully erosion process.

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Transitional relation exploration for typical loess geomorphologic types based on slope spectrum characteristics

Earth Surface Dynamics ◽

10.5194/esurf-2-433-2014 ◽

2014 ◽

Vol 2 (2) ◽

pp. 433-441 ◽

Cited By ~ 2

Author(s):

S. Zhao ◽

W. Cheng

Keyword(s):

Loess Plateau ◽

Final Stage ◽

General Rule ◽

Shuttle Radar Topography Mission ◽

The Loess Plateau ◽

Topographic Analysis ◽

Slope Spectrum ◽

Digital Elevation ◽

Spectrum Characteristics ◽

Elevation Model

Abstract. Based on the Chinese Geomorphologic Database at 1 : 1 000 000 scales, the distribution of the typical loess geomorphologic types (such as the loess tableland, loess ridge and loess knoll) is acquired in the Loess Plateau of China. Then, based on the SRTM (Shuttle Radar Topography Mission) digital elevation model (DEM) data and topographic analysis methods, the slope spectrums are computed for the typical loess geomorphologic types and their subtypes. Through achieving the tendency line of the slope spectrum and analysing the slope spectrum characteristics of the loess typical geomorphologic types, the transitional relationships are explored: (1) the general rule is that loess tableland transitions to loess ridge, and then to loess knoll. (2) The specific relationships for the subtypes are as follows: in loess tableland, the transition is from loess terrace to complete tableland, then to residual tableland, and finally to beam tableland. In the loess ridge, the transition is from oblique ridge to knoll ridge, and the final stage is the loess knoll.

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