Piecewise prediction model for watershed-scale erosion and sediment yield of individual rainfall events on the Loess Plateau, China

2013 ◽  
Vol 28 (21) ◽  
pp. 5322-5336 ◽  
Author(s):  
Yu Guo-Qiang ◽  
Zhang Mao-Sheng ◽  
Li Zhan-Bin ◽  
Li Peng ◽  
Zhang Xia ◽  
...  
Keyword(s):  
Prediction Model ◽  
Loess Plateau ◽  
Sediment Yield ◽  
Watershed Scale ◽  
The Loess Plateau ◽  
Rainfall Events

scholarly journals The Thresholds of Sediment-Generating Rainfall from Hillslope to Watershed Scales in the Loess Plateau, China

Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2392
Author(s):  
Liang ◽  
Jiao ◽  
Dang ◽  
Cao
Keyword(s):  
Loess Plateau ◽  
Sediment Yield ◽  
Spatial Scales ◽  
Water Erosion ◽  
Rainfall Amount ◽  
Rainfall Erosivity ◽  
Watershed Scale ◽  
The Loess Plateau ◽  
Erosive Rainfall ◽  
Hillslope Scale

Obtaining practical thresholds for erosive rainfall plays a crucial role in calculating rainfall erosivity and predicting water erosion. Nevertheless, the study of thresholds on subwatershed and watershed scales remains scarce. Given this, we presented the critical rainfall that generated the outflows of subwatersheds and watersheds as the threshold of sediment-generating rainfall. On the basis of the observation of twelve nested topographical units at the Peijiamaogou watershed in the Loess Plateau of China, we fitted regression relationships between rainfall indexes (rainfall amount, maximum 30-min intensity, maximum 60-min intensity, rainfall amount multiply maximum 30-min intensity, and rainfall amount multiply maximum 60-min intensity) and the proportion of cumulative sediment yield to the total sediment yield. We determined the thresholds of sediment-generating rainfall and explored the variabilities of thresholds across different spatial scales. Moreover, the covering area proportion (CAP) with rainfall indexes higher than the thresholds was also employed as thresholds at the subwatershed and watershed scales. The thresholds of CAP for P and I30 were 50.5% and 47.6% at the subwatershed scale, while 31.0% and 30.3% at the watershed scale. The thresholds of P and I30 at the subwatershed scale were higher than those of hillslope scale, while the threshold of I30 at the watershed scale was smaller compared to the other scales. In general, I30 was viewed as the best threshold among single rainfall indexes across different spatial scales, while P was not recommended as a practical threshold. This study can improve the prediction accuracy of water erosion across different spatial scales and develop the spatial scale effect of sediment yield in the loess hilly areas.

Water and sediment evolution in areas with high and coarse sediment yield of the Loess Plateau

2013 ◽  
Vol 28 (4) ◽  
pp. 448-457 ◽  
Author(s):  
Jia-hong LIU ◽  
Guang-qian WANG ◽  
Hai-hong LI ◽  
Jia-guo GONG ◽  
Jing-yi HAN
Keyword(s):  
Loess Plateau ◽  
Sediment Yield ◽  
The Loess Plateau ◽  
Coarse Sediment ◽  
Water And Sediment

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.

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 Assessment of soil erosion at large watershed scale using RUSLE and GIS: a case study in the Loess Plateau of China

2005 ◽  
Vol 16 (1) ◽  
pp. 73-85 ◽  
Author(s):  
B. J. Fu ◽  
W. W. Zhao ◽  
L. D. Chen ◽  
Q. J. Zhang ◽  
Y. H. Lü ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Loess Plateau ◽  
Watershed Scale ◽  
The Loess Plateau

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

Land ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1264
Author(s):  
Fabing Xie ◽  
Guangju Zhao ◽  
Xingmin Mu ◽  
Peng Tian ◽  
Peng Gao ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Loess Plateau ◽  
Sediment Yield ◽  
Water Conservation ◽  
The Loess Plateau ◽  
Sediment Yields ◽  
Erosion Rates ◽  
Soil Erosion Rate ◽  
Check Dams ◽  
Loss Control

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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