[1]GUO Jinwei,HE Liang,PEI Zhilin,et al.Investigation and Analysis of Damage of Horizontal Terraced Fields Under Extreme Rainstorm Conditions in the Loess Plateau—Taking the 7·26 Torrential Rain in the Chabagou Watershed as an Example[J].Research of Soil and Water Conservation,2019,26(06):107-113.
Copy
Research of Soil and Water Conservation[ISSN 1005-3409/CN 61-1272/P] Volume:
26
Number of periods:
2019 06
Page number:
107-113
Column:
Public date:
2019-10-17
- Title:
-
Investigation and Analysis of Damage of Horizontal Terraced Fields Under Extreme Rainstorm Conditions in the Loess Plateau—Taking the 7·26 Torrential Rain in the Chabagou Watershed as an Example
- Author(s):
-
GUO Jinwei, HE Liang, PEI Zhilin, Lü Du, LEI Siyue, ZHANG Xiaoping
-
State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A & F University, Yangling, Shannxi 712100, China
-
- Keywords:
-
extreme rainstorm; horizontal terraces; damage; soil erosion; Chabagou watershed
- CLC:
-
S157.1
- DOI:
-
-
- Abstract:
-
From 20:00 on July 25 to 8:00 on July 26, 2017, 11 counties or districts in Yulin, Shaanxi Province were hit by torrential rains. In October of that year, we conducted a special investigation on the damage of terraces in the Chabagou Valley in the rainstorm center. First, the location and number of terraces were determined in the basin by Google Earth imagery combined with GIS mapping, and these terraces were classified according to construction time, utilization and vegetation type. We evenly selected different types of typical terraces in the basin in the spatial distribution and conducted field measurements on terraces. We calculated the damage and damage patterns of various types of terraces and estimated the soil erosion modulus of each type of terraces and the average erosion modulus of the basin. The results show that the number and area of terraces in the Chabagou watershed are the main scale of <4 hm2, accounting for 91.4% of the number and 50.7% of the area, the surface crust removal of terrace wall, terrace wall collapse, the ridge damage, and the hole development of terrace surface were the main damage forms of the terrace. The failure of the terrace was very severe under human disturbance. The depth of the eroded pits caused by heavy rain in the terraces ranged from 0 m to 0.5 m. The frequency of erosive pit occurrence of old terraced farming fields, old terraced meadow fields, and old terraced forestland was basically the same, and it was much greater than the newly machine-built terraces, which was 20~36 pits/100 m. The erosion pit of newly machine-built terrace has a low frequency of occurrence, which was 5 pits/100 m, but the maximum depth of the pit was 4.8 m, it caused the serious damage to the machine-built terrace. The erosion modulus of different types of terraced fields was quite different. The erosion modulus of old terraced farming fields, old terraced meadow fields and old terraced forestland ranged from 34 000 t/km2 to 37 000 t/km2, the soil erosion modulus of the newly machine-built terraces was 19 404.3 t/km2, and old terraced shrub field had the lowest erosion modulus which was 5 958.4 t/km2. The average erosion modulus of terraces in the basin was 30 733.4 t/km2. Through this survey, we will grasp the damages of different types of terraced fields under extreme rain conditions, and provide data support for the protection and restoration of terraces in the Loess Plateau.