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Laboratory and Field Protocol for Estimating Sheet Erosion Rates from Dendrogeomorphology
Published on: January 7, 2019
[Temporal variations of clay content in eroded sediment under different rainfall condition]
Feng-Zhi Wu1, Zhi-Hua Shi, Nu-Fang Fang
1State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling 712100, China. wuyang.426@163.com
Huan Jing Ke Xue= Huanjing Kexue
|September 26, 2012
Summary
Simulated rainfall experiments reveal that clay content in eroded sediment increases with rainfall intensity and slope length on Loess Plateau soils. Most clay particles remain aggregated, crucial for understanding soil erosion and nutrient transfer.
Area of Science:
- Soil Science
- Environmental Science
- Geomorphology
Background:
- Soil erosion is a significant environmental issue, particularly in cultivated areas like the Loess Plateau.
- Understanding sediment characteristics is vital for effective erosion control and land management.
- The aggregation state of clay particles influences sediment transport and nutrient dynamics.
Purpose of the Study:
- To investigate the size distribution and aggregation of eroded sediment from two cultivated soils under simulated rainfall.
- To determine the aggregation ratio (AR) and enrichment ratio (ER) of clay in eroded sediments.
- To enhance the understanding of erosion and sedimentation processes for improved erosion modeling.
Main Methods:
- Simulated rainfall experiments were conducted on two cultivated soil types from the Loess Plateau.
- Eroded sediment samples were analyzed for particle size distribution in both non-dispersed and dispersed states.
- Aggregation ratio (AR) and enrichment ratio (ER) were calculated to assess clay dispersion and aggregation.
Main Results:
- Clay content in eroded sediment increased with increasing slope length and rainfall intensity.
- Loessial soil showed higher increases in clay content (8.77% and 2.43%) compared to Lou soil (2.76% and 0.4%) with increasing slope length and rainfall intensity, respectively.
- Aggregation ratio (AR) values were consistently below 1, and enrichment ratio (ER) values were above 1, indicating slight clay dispersion and a prevalence of clay aggregates in the sediment.
Conclusions:
- The findings suggest that clay particles in eroded sediments from the Loess Plateau are predominantly in aggregated forms.
- Understanding the aggregation state of clay is critical for accurate erosion modeling and predicting nutrient transport on hillslopes.
- This research provides valuable data for improving soil erosion models and land management strategies in vulnerable regions.
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