Mechanism of cultivation soil degradation in rocky desertification areas under dry/wet cycles - École des Ponts ParisTech Access content directly
Journal Articles Environmental Earth Sciences Year : 2011

Mechanism of cultivation soil degradation in rocky desertification areas under dry/wet cycles

Wei-Min Ye
  • Function : Author
  • PersonId : 863451
Bao Chen
  • Function : Correspondent author
  • PersonId : 863453

Connectez-vous pour contacter l'auteur
Ji Xie
  • Function : Author
Yu-Jun Cui

Abstract

Karst rocky desertification is a process of land degradation involving serious soil erosion, extensive exposure of basement rocks. It leads to drastic decrease in soil productivity and formation of a desert-like landscape. In this regard, changes in climatic conditions are the main origin of the soils degradation. Indeed, soils subjected to successive dry/wet cycling processes caused by climate change develop swelling and shrinkage deformations which can modify their water retention properties, thus inducing the degradation of soil-water capacity. The eco-logical characteristics of cultivation soils in karst areas, Southwest of China, are extremely easy to be affected by external environmental factors due to its shallow bedding and low vegetation coverage. Based on the analysis of the climate (precipitation) of this region during the past decades, an experimental study has been conducted on a cul- tivated soil obtained from the typical karst area in southwestern China. Firstly, the soil-water properties have been investigated. The measured soil-water retention curve shows that the air-entry value of the soil is between 50 and 60 kPa, while the residual saturation is about 12%. Based on the experimental results, three identifiable stages of de-saturation have been defined. Secondly, a special apparatus was developed to investigate the volume change behavior of the soil with controlled suction cycles. The vapor equilibrium technique was used for the suction control. The obtained results show that under the effect of dry/wet cycles, (1) the void ratio of the cultivated soil is continuously decreasing, leading to a gradual soil compaction. (2) The permeability decreases, giving rise to a deterioration of water transfer ability as well as a deterioration of soil-water retention capacity. It is then obvious that the long-term dry/wet cycling process caused by the climate change induce a continuously compaction and degradation of the cultivated soil in karst rocky desertification areas.

Dates and versions

hal-00693235 , version 1 (02-05-2012)

Identifiers

Cite

Wei-Min Ye, Zi-Yuan Qi, Bao Chen, Ji Xie, Yu Huang, et al.. Mechanism of cultivation soil degradation in rocky desertification areas under dry/wet cycles. Environmental Earth Sciences, 2011, 64, pp.269-276. ⟨10.1007/s12665-010-0846-2⟩. ⟨hal-00693235⟩
130 View
0 Download

Altmetric

Share

Gmail Mastodon Facebook X LinkedIn More