back slope meaning in English

背坡
内坡

Then , a thunderous sound came from the rear of the house . the kitchen on the back slope had collapsed under the sudden onslaught of a torrential flow of muddy water , and had fallen on the last row of concrete houses on the slope . rocks of all sizes , washed down by the muddy water , smashed through the windows into the rooms and then rushed through the doors into the living room and out into the courtyard at lower levels
谢师兄在打坐中依稀听到爸爸走进客厅的声音，突然一声山崩地裂的巨响从屋后传来，后山腰的厨房被突如其来的土石流冲击倒塌，压到斜坡上最后一排的钢筋房子，土石流冲破两三间房间的窗户玻璃，大小石块挟杂在洪水中，从窗口冲进房间，又从房门窜流出来，直奔地势较低的客厅和庭院，家顿时变成土石流的出水口。