scholarly journals Rill morphological change characteristics and influencing factors on different soil types in the Loess Plateau, China

2021 ◽  
Author(s):  
zimiao he ◽  
xinxiao yu ◽  
Qiang Cai ◽  
Jijun He ◽  
shilong hao ◽  
...  
Keyword(s):  
Loess Plateau ◽  
Rainfall Intensity ◽  
Sandy Loam ◽  
Slope Angle ◽  
Heavy Rain ◽  
Structure Stability ◽  
Rill Erosion ◽  
Shape Parameters ◽  
The Loess Plateau ◽  
Positive Effect

Soil properties play an important role in rill development and erosion. In this investigation, rill morphology developmental processes under sandy loam (SL), light loam (LL), medium loam (ML) and heavy loam (HL) soils on the Loess Plateau, China, were compared using laboratory experiments. Experimental analysis included two rainfall intensities (90 and 120 mm/h) and four slope treatments (0°, 15°, 20° and 25%). Results indicate that HL is the most prone to rill development, and SL, LL and ML are prone to rill development under heavy rain, with SL rill erosion being the most sensitive to heavy rain. The development of rills in SL are mainly characterized by an increase in rill width and merging nodes; rills in HL were mainly characterized by an increase in rill length, merging nodes and rill number. LL and ML rill development indices were between SL and HL. Differences in runoff collection caused by rill morphology differences further promoted differences in soil erosion. Rainfall intensity has a positive effect on rill shape parameters of all soils; slope has a positive and negative double effect on SL, LL and ML rill shape parameters, and only a positive effect on HL rill shape parameters. The sensitivity of rill parameters to rainfall intensity and slope angle depends on soil infiltration performance, surface soil stability and soil structure stability. Based on soil characteristic factors and rill morphological parameters, an empirical model of slope erosion in the loess region was established.

scholarly journals Individual Rainfall Change Based on Observed Hourly Precipitation Records on the Chinese Loess Plateau from 1983 to 2012

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2268
Author(s):  
Wenbin Ding ◽  
Fei Wang ◽  
Kai Jin ◽  
Jianqiao Han ◽  
Qiang Yu ◽  
...  
Keyword(s):  
Loess Plateau ◽  
Heavy Rainfall ◽  
Rainfall Intensity ◽  
Rainfall Amount ◽  
The Loess Plateau ◽  
Total Rainfall ◽  
Rainfall Events ◽  
Rainfall Duration ◽  
Rainfall Frequency ◽  
Annual Total

The magnitude and spatiotemporal distribution of precipitation are the main drivers of hydrologic and agricultural processes in soil moisture, runoff generation, soil erosion, vegetation growth and agriculture activities on the Loess Plateau (LP). This study detects the spatiotemporal variations of individual rainfall events during a rainy season (RS) from May to September based on the hourly precipitation data measured at 87 stations on the LP from 1983 to 2012. The incidence and contribution rates were calculated for all classes of rainfall duration and intensity to identify the dominant contribution to the rainfall amount and frequency variations. The trend rates of regional mean annual total rainfall amount (ATR) and annual mean rainfall intensity (ARI) were 0.43 mm/year and 0.002 mm/h/year in the RS for 1983–2012, respectively. However, the regional mean annual total rainfall frequency (ARF) and rainfall events (ATE) were −0.27 h/year and −0.11 times/year, respectively. In terms of spatial patterns, an increase in ATR appeared in most areas except for the southwest, while the ARI increased throughout the study region, with particularly higher values in the northwest and southeast. Areas of decreasing ARF occurred mainly in the northwest and central south of the LP, while ATE was found in most areas except for the northeast. Short-duration (≤6 h) and light rainfall events occurred mostly on the LP, accounting for 69.89% and 72.48% of total rainfall events, respectively. Long-duration (≥7 h) and moderate rainfall events contributed to the total rainfall amount by 70.64% and 66.73% of the total rainfall amount, respectively. Rainfall frequency contributed the most to the variations of rainfall amount for light and moderate rainfall events, while rainfall intensity played an important role in heavy rainfall and rainstorms. The variation in rainfall frequency for moderate rainfall, heavy rainfall, and rainstorms is mainly affected by rainfall duration, while rainfall event was identified as a critical factor for light rainfall. The characteristics in rainfall variations on the Loess Plateau revealed in this study can provide useful information for sustainable water resources management and plans.

scholarly journals Cumulative effects of 20-year exclusion of livestock grazing on above- and belowground biomass of typical steppe communities in arid areas of the Loess Plateau, China

2011 ◽  
Vol 57 (No. 1) ◽  
pp. 40-44 ◽  
Author(s):  
J. Cheng ◽  
G.L. Wu ◽  
L.P. Zhao ◽  
Y. Li ◽  
W. Li ◽  
...  
Keyword(s):  
Loess Plateau ◽  
Management Practices ◽  
Belowground Biomass ◽  
Livestock Grazing ◽  
Cumulative Effects ◽  
The Loess Plateau ◽  
Typical Steppe ◽  
Steppe Communities ◽  
Positive Effect

Overgrazing affects typical steppe community in ways similar to grasslands in other areas. Exclusion of livestock grazing is one of the main management practices used to protect grasslands. However, it is not known if long-term exclusion of livestock grazing has positive effect on above- and belowground community properties in typical steppe of the Loess Plateau. We studied the long-term (20-year) cumulative effects of exclusion of livestock grazing on above- and belowground community properties compared with that before exclusion of livestock grazing in a typical steppe of the Loess Plateau, NW China. Our results show that twenty-year exclusion of livestock grazing significantly increased above- and belowground biomass, species richness, cover and height for five different communities. Most of belowground biomass was in the 0–20 cm horizon and grazing exclusion increased biomass especially at the depth of 0–10 cm. Our study suggests that long-term exclusion of livestock grazing can greatly improve community properties of typical steppe in the Loess Plateau.  

The Geo-Hazards Triggered of Serial Reclamation Land of Extreme Precipitation in Typical Regions of the Loess Plateau

2020 ◽  
Author(s):  
Zhe Gao
Keyword(s):  
Loess Plateau ◽  
Water Conservation ◽  
Rainfall Intensity ◽  
Soil And Water Conservation ◽  
Land Consolidation ◽  
Geological Hazards ◽  
The Loess Plateau ◽  
The World ◽  
Soil And Water ◽  
Land Consolidation Project

<p>The Geo-Hazards Triggered of Serial Reclamation Land of Extreme Precipitation in Typical Regions of the Loess Plateau<br>Gao Zhe<sup>1</sup>,Zhang Genguang <sup>1*</sup>,Gao Jian'en<sup>1,2,3</sup>,Li Xingyao<sup>1</sup>,Han Jianqiao<sup>2,3</sup>,Kang Youcai<sup>3</sup>,Guo Zihao<sup>3</sup>,Long Shaobo<sup>2</sup>,Dou Shaohui<sup>2</sup>,Zhang Yuanyuan<sup>3</sup><br>1. College of Water Resources and Architectural Engineering, Northwest A&F University, 712100, Yangling, Shaanxi, China;<br>2. Institute of Soil and Water Conservation, Northwest A&F University, 712100, Yangling, Shaanxi, China;<br>3. Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, 712100, Yangling, Shaanxi, China;</p><p>The “Gully Land Consolidation Project”(GLCP) was widely carried out all over the world, such as Spain, the United States and China. It was a new attempt to solve the shortage of regional land resources. Aiming at the problem that the influence of extreme rainstorms on the “Gully Land Consolidation Project”(GLCP) on the Loess Plateau.By using the method of actual measurement and analysis of categorical data, the erosion disaster in July 26 2017 was investigated in Niu Xue Gully of Wuding River Watershed in Zizhou County of the Central part of the Loess Plateau. The results showed : </p><p>(1) The Niu Xue Gully Small Watershed in Zizhou County (109°55'25"E, 37°39'46"N), which was located in the central part of the Loess Plateau and belonged to the northern Shaanxi Loess Hilly-Gully region. The Niu Xuegou catchment covered an area of 0.48 km<sup>2</sup> and the average altitude of the region in about 1000-1200 meters, land consolidation in the basin about 38 mu（25333.3m<sup>2</sup>）since 2014.</p><p>(2) This storm was characterized by "long duration and large precipitation", the accumulated rainfall was 147.9 mm, the average rainfall intensity was 13.45 mm/h, the maximum rainfall intensity was close to 5 mm/min, the maximum flood peak discharge was 44.64 m<sup>3</sup>/s, the flood duration was about 11 hours, and the flood recurrence period was more than once in a hundred years.</p><p>(3) The storm caused nearly a thousand geological hazards at the channel of the basin. The main types of disasters were as follows, gravity erosion types, such as landslides, landslides, and mudflows, account for 14.85% of the conventional geological hazards; secondary disasters of water erosion types, such as trench erosion and dam erosion, occurring at different locations on the slope, accounted for 51.05% and composite new-derived land destruction and dam break disasters account for nearly 10% .</p><p>(4) The damage of cascade land preparation was closely related to the average flood discharge, embankment height and ecological vegetation cover in the watershed.<br>The investigation provided technical support for the consolidation of the Chinese implementation of the "Cropland to Forest (Grass)" results on the Loess Plateau, and also provided theoretical support for the safe implementation of the “Gully Land Consolidation Project”(GLCP) around the world.<br><br></p><p>Keywords: The loess plateau; Extreme rainstorm;The “Gully Land Consolidation Project”(GLCP)</p><p>Funding:(National Key R&D Program of China: 2017YFC0504703)；(National Natural Science Foundation of China,41877078,41371276,51879227);(Research and Development and Integrated demonstration of key Technologies in soil and Water Conservation Engineering,A315021615)</p><p><strong>        </strong></p>

Estimating Raindrop Kinetic Energy: Evaluation of a Low-Cost Method

2017 ◽  
Vol 33 (4) ◽  
pp. 551-558 ◽  
Author(s):  
Jian Wang ◽  
Dexter B. Watts ◽  
Qinqian Meng ◽  
Thomas R. Way ◽  
Qingfeng Zhang
Keyword(s):  
Soil Erosion ◽  
Kinetic Energy ◽  
Loess Plateau ◽  
Filter Paper ◽  
Rainfall Intensity ◽  
Low Cost ◽  
Rotating Disks ◽  
The Loess Plateau ◽  
Rainfall Events ◽  
Raindrop Impact

Abstract. The Loess Plateau of China is regarded as the most intensively eroded region in the world and soil erosion caused by raindrop impact is a common occurrence on agricultural land within this region. Therefore, understanding the influence of rainfall energy on the soil surface is needed to improve prescriptions for best management practices aimed at mitigating erosion. Disdrometers for measuring rainfall energy are presently available; however, these are relatively expensive and their use may not be justified for determining raindrop energy for predictive soil erosion models in regions where there are limited economic resources. To overcome this constraint, a device was tested for evaluating size and velocity of water drops during rainfall events. This device utilized two rotating disks combined with filter paper to obtain raindrop diameter and velocity which can then be used for determining the kinetic energy of falling raindrops. With this device, raindrop diameter was determined from the resultant raindrop stain left on the filter paper during rainfall events and velocity was calculated from the time it took a falling raindrop to travel between the pair of rotating disks. Measurements were taken for approximately 10 minutes during each of six rainfall events of different intensities over a three month period (from June to August of 2013). The smallest raindrop measured was 0.39 mm diameter and the largest was 5.92 mm diameter. The event average raindrop diameter increased with increasing event rainfall intensity. The minimum raindrop impact velocity was 1.47 m s-1, the maximum was 9.45 m s-1, and the event average terminal velocity increased as event rainfall intensity increased. Estimated raindrop kinetic energy ranged from 0.04 × 10-6 J to 4728.21 × 10-6 J, with event mean raindrop kinetic energy ranging from 40.33 x 10-6 J to 276.94 × 10-6 J. The relationship between estimated event rainfall kinetic energy and event rainfall intensity was represented by an exponential function. The disk device was also compared to an optical disdrometer. The data collected for rainfall intensity, raindrop diameter, and velocity were statistically similar between the two devices. Results from this study show that this low-cost method can be used to estimate rainfall kinetic energy in the Loess Plateau region of Northwest China. Keywords: Loess Plateau, Raindrop diameter, Raindrop velocity, Rainfall intensity.

scholarly journals Effects of rainfall intensity on the sediment concentration in the Loess Plateau, China

2020 ◽  
Vol 30 (3) ◽  
pp. 455-467
Author(s):  
Xiaoyan Liu ◽  
Suzhen Dang ◽  
Changming Liu ◽  
Guotao Dong
Keyword(s):  
Loess Plateau ◽  
Rainfall Intensity ◽  
Sediment Concentration ◽  
The Loess Plateau

Multi-temporal UAV data for assessing rapid rill erosion in typical gully heads on the largest tableland of the Loess Plateau, China

2019 ◽  
Vol 79 (4) ◽  
pp. 1861-1877 ◽  
Author(s):  
Pinglang Kou ◽  
Qiang Xu ◽  
Ali P. Yunus ◽  
Yuanzhen Ju ◽  
Chen Guo ◽  
...  
Keyword(s):  
Loess Plateau ◽  
Rill Erosion ◽  
The Loess Plateau ◽  
Multi Temporal

The drought trend and its relationship with rainfall intensity in the Loess Plateau of China

2015 ◽  
Vol 77 (1) ◽  
pp. 479-495 ◽  
Author(s):  
L. N. Wang ◽  
Q. K. Zhu ◽  
W. J. Zhao ◽  
X. K. Zhao
Keyword(s):  
Loess Plateau ◽  
Rainfall Intensity ◽  
The Loess Plateau

scholarly journals A New Method to Predict Gully Head Erosion in the Loess Plateau of China Based on SBAS-InSAR

2021 ◽  
Vol 13 (3) ◽  
pp. 421
Author(s):  
Chengcheng Jiang ◽  
Wen Fan ◽  
Ningyu Yu ◽  
Yalin Nan
Keyword(s):  
Loess Plateau ◽  
Erosion Rate ◽  
Surface Deformation ◽  
Slope Angle ◽  
Slope Aspect ◽  
Small Scale ◽  
The Loess Plateau ◽  
Topographic Wetness Index ◽  
Sbas Insar ◽  
Gully Head

Gully head erosion causes serious land degradation in semiarid regions. The existing studies on gully head erosion are mainly based on measuring the gully volume in small-scale catchments, which is a labor-intensive and time-consuming approach. Therefore, it is necessary to explore an accurate method quantitatively over large areas and long periods. The objective of this study was to develop a model to assess gully head erosion in the Loess Plateau of China using a method based on the SBAS-InSAR technique. The gully heads were extracted from the digital elevation model and validated by field investigation and aerial images. The surface deformation was estimated with SBAS-InSAR and 22 descending ALOS PALSAR datasets from 2007 to 2011. A gully head erosion model was developed; this model can incorporate terrain factors and soil types, as well as provides erosion rate predictions consistent with the SBAS-InSAR measurements (R2 = 0.889). The results show that gully head erosion significantly depends on the slope angle above the gully head, slope length, topographic wetness index, and catchment area. The relationship between these factors and the gully head erosion rate is a power function, and the average rate of gully head erosion is 7.5 m3/m2/year, indicating the high erosional vulnerability of the area. The accuracy of the model can be further improved by considering other factors, such as the stream power factor, curvature, and slope aspect. This study indicates that the erosion rate of gully heads is almost unaffected by soil type in the research area. An advantage of this model is that the gully head area and surface deformation can be easily extracted and measured from satellite images, which is effective for assessing gully head erosion at a large scale in combination with SBAS-InSAR results and terrain attributes.

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