STUDY ON GROWTH OF VETIVER GRASS IN TROPICAL REGION FOR SLOPE PROTECTION

Abstract

River bank erosion and embankment failures happen continuously throughout Bangladesh. From a strictly economic point of view, the cost of remediating these problems is high, and the state budget for such works is never sufficient. This confines rigid structural protection measures to the most acute sections. General reasons of embankment failure are erosion due to rain splash, wave action, overtopping of storm surge. Faulty design, poor maintenance and poor construction also cause failure. The use of cement concrete blocks, stone revetments, geo- bags, and plantation etc. are commonly used for protection of embankment in traditional practices. These materials are expensive and sometimes are not effective to protect the embankments and river bank for an expected design life. On the other hand, slope stability can be augmented by using bio-engineering techniques. Vetiver grass (Vetiveria zizanioides) is being used as an efficient bio-technology for slope protection in many countries, for its special attributes like longer life, strong and long finely structured root system and high tolerance of extreme climatic condition. A few steps have only been taken recently to employ this technique for slope protection purposes in Bangladesh. This paper presents three case studies of vetiver plantation in slope protection against rain-cut and wind-induced erosion. It is found that vetiver grass grows in different soil and climatic conditions of Bangladesh and it is effective for slope protection. Prospect of vetiver plantation in protecting haor low-land is also discussed.