3.3 Rainfall Simulators with Spouts or Sprayers . . . . . . . . . . . . . . . 36
3.4 Automated Rainfall-Simulation Hall . . . . . . . . . . . . . . . . . . . . . 40
3.5 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
4 An Innovative Measurement Instrument: Topography Meter . . . . . 45
4.1 Quantitative Monitoring of Gravity Erosion . . . . . . . . . . . . . . . 45
4.2 Experimental Setup and Methods . . . . . . . . . . . . . . . . . . . . . . . 47
4.3 Data Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
4.3.1 Method to Calculate Gravity Erosion and Hydraulic
Erosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
4.3.2 Method to Measure Slope Volume . . . . . . . . . . . . . . . 50
4.4 Results and Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
4.4.1 Calibration Test for Measurement of the Slope
Volume and Coordinates . . . . . . . . . . . . . . . . . . . . . . . 53
4.4.2 Case Study for an Individual Failure . . . . . . . . . . . . . . 54
4.4.3 Case Study for the Total Amount of Erosion . . . . . . . . 56
4.4.4 Limitations and Future Developments . . . . . . . . . . . . . 56
4.5 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
5 How to Conduct an Experiment in the Field: A Portable
Laboratory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
5.1 Difficulties to Conduct a Rainfall-Simulation Experiment
in Situ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
5.2 Design of the Measurement System . . . . . . . . . . . . . . . . . . . . . 61
5.2.1 A Movable Tent for Field Study . . . . . . . . . . . . . . . . . 61
5.2.2 Operating Principle of the MX-2010-G
Topography Meter . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
5.2.3 Structure of the MX-2010-G Topography Meter . . . . . . 63
5.3 Applications in the Landslide Experiments . . . . . . . . . . . . . . . . 65
5.3.1 Results of the Landslide Experiments . . . . . . . . . . . . . 65
5.3.2 Methods to Obtain Relatively Clear Video . . . . . . . . . . 67
5.3.3 Assessment of the MX-2010-G Topography Meter . . . . 70
5.4 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
Part II Soil Conservation Experiments: Case Studies
on the Loess Plateau, China
6 A Close Look of the Gravity Erosion on the Loess
Plateau of China . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
6.1 Gravity Erosion: Natural Hazard and Soil Erosion . . . . . . . . . . 75
6.2 Characteristics of the Loess Plateau . . . . . . . . . . . . . . . . . . . . . 77
6.3 Methods and Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
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Contents