Investigation of water induced damages triggered by rainfall in east Gansu and the implications

Abstract

Flood-induced disaster caused by rainfall in loess area often occurs, causing serious engineering disasters and casualties. The investigation and cause analysis of existing flood-induced disaster can provide experience for disaster prevention and control areas. From mid-August to early October, 2021, more than 50 days of rainfall triggered a large number of Flood-induced disaster in the loess area of east Gansu Province. The damages made G211 national highway close for two weeks. This paper introduces the on-the-spot investigation of the flood disaster caused by this rainfall in villages and towns along route 211 and its vicinity, it happened in the villages and towns are mainly the collapse of loess living caves, collapse of earth-houses and fall of earth-walls. Geo-disasters on the road are subsidence and cracking of the soil filling subgrade, collapse of the cutting slope at inner side of the road, shallow flow-slide of the main slope. These disasters are small in scale and weak in influence, but it is large in number and serious in disastrous. We also investigated the positive and passive effects of vegetation on the loess slope. Based on investigation of the flood-induced disaster, this paper analyzes its causes, and puts forward some preventive measures in the construction of villages, towns and roads.

Keywords

• east gansu province
• flood-induced disaster
• loess living cave
• shallow slide
• landslide-mudflow
• slope collapse