岩溶洼地 meaning in English

karst depression

( 3 ) ancient landform in the district may be divided to three belts : karst highland ( piyaman area ) , karst incliningcthe centre in the area ) and karst depression ( three depressive sink from west to east in the north area )
( 3 )研究区内的古地貌可划分为三个带：岩溶高地(皮牙曼地区) 、岩溶斜坡(研究区中部地区) 、岩溶洼地(由研究区北部自西向东的三个洼陷构成) 。
The research include : 1 ) measuring co2 concentration in the soil air and vegetation air by using co2 measuring instruments ; 2 ) measuring the releasing rate of co2 coming from soil surface by using alkaline absorbing method ; 3 ) measuring the hydrochemical indexes of soil water . the research results are as follows : ( 1 ) the author has made field observation of depth distribution of soil air co2 in the mt . jinfo karst experiment site . the results show that two concentration gradient , soil to atmosphere and soil to carbonate rock , are form
本次实验以典型的亚热带岩溶分布区?金佛山自然保护区为例，选择了岩溶洼地内的高山草甸和靠洼地边缘地带的方竹林、裸地以及石林内的乔木林4个样地，对土壤co _ 2浓度空间分布规律以及昼夜动态和日动态变化状况进行了观测，获得了如下新的认识： ( 1 )土壤中co _ 2浓度分布的观测结果表明，土壤中具有土壤-大气、土壤-碳酸盐岩两个方向的co _ 2浓度梯度。