极端暴雨条件下黄土高原水平梯田损毁情况调查分析——以岔巴沟流域“7·26”特大暴雨为例
《水土保持研究》[ISSN:1005-3409/CN:61-1272/P]
卷:
26
期数:
2019年06期
页码:
107-113
栏目:
出版日期:
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
- 关键词:
- Keywords:
- 分类号:
- S157.1
- 摘要:
- 2017年7月25日20时至26日8时，陕西榆林市11个县区遭遇特大暴雨侵袭，我们于当年10月对位于暴雨中心的岔巴沟流域的梯田损毁情况进行了专项调查。首先通过室内Google Earth近实时影像结合GIS绘图在流域内确定梯田位置和数量，根据修建时间、利用和植被类型将这些梯田分类。在流域内空间分布均匀地选择不同类型典型梯田并进行野外实地测量，统计各类型梯田的损毁情况、损毁形式并估算各类型梯田的土壤侵蚀模数及其流域平均侵蚀模数。结果表明：岔巴沟流域梯田以≤ 4 hm2规模为主，梯田数量上占91.4%，面积上占了50.7%。暴雨造成梯田的损毁形式以田埂表层结皮脱落、田埂滑塌崩塌、田埂冲毁、田面陷穴穿洞为主，有人为干扰时会产生更加剧烈的后果。暴雨造成的梯田损毁侵蚀坑大部分为深度0~0.5 m的侵蚀。老梯田农地、老梯田乔木和老梯田草地侵蚀坑发生频率远远多于新机修梯田，保持在20~36处/100 m。新机修梯田的侵蚀测坑发生频次少，为5处/100 m，但深度可达4.8 m，后果严重。不同类型梯田损毁产生侵蚀模数差异较大，老梯田农地、老梯田草地和老梯田乔木的侵蚀模数为34 000~37 000 t/km2，新机修梯田为19 404.3 t/km2，老梯田灌木侵蚀模数最低，为5 958.4 t/km2。流域内梯田平均侵蚀模数为30 733.4 t/km2。通过本次调查，掌握不同类型梯田在极端暴雨条件下的损毁情况，为黄土高原梯田保护及修复提供数据支持。
- 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.
参考文献/References:
相似文献/References:
备注/Memo
更新日期/Last Update:
1900-01-01