Effects of slope length and steepness with regard to soil erosion

Cameron Highlands, an idyllic highland resort in Malaysia, possesses many steep slopes, which are nowadays developed either into vegetable farms or tea plantations. However, with the rapid pace of development in this highland resort recently, many hill slopes have been gazetted to pave way for development projects, which include construction of residential houses and hotels, apartments and golf courses. As a price that we have to pay for developing the hill slopes too rapidly without taking proper mitigating measures, a spate of landslips and flash floods incurring loss of lives in this famous highland resort had since occurred lately. This serves as a call from mother nature to remind and create awareness to the public about the ill-effects of over development in the highland resort areas. Though development in highland areas that brings benefits to the country should be carried out especially to enhance tourism in this country, it should, however, be environmentally sound and sustainable. In this regard, a case study on the determination of Slope Length and Steepness factor (LS) of the Universal Soil Loss Equation (USLE) is certainly timely as this parameter emphasizes on the effects of slope length and steepness in the study area and the impacts it has on the amount of soil erosion loss. Determination of the LS factor has been carried out using the topographic maps with information on the contours in the study area. With respect to this study the Tringkap location in Cameron Highlands has been found out as having the highest erosion risk/loss based on the LS factor of the USLE. This can be well supported and justified by the fact that this location recorded the highest ranking for areas having steep slopes (LS bigger than 20). Conversely, the Boh Tea Plantation location shows the lowest erosion risk with only 11.21% of this area having steep slopes (LS bigger than 20). Furthermore, this location is rather flat with undulating slopes. Results of this study potentially highlight some of the steep slope areas at various locations in Cameron Highlands, as it would give some indication about the possibility of future erosion risk/loss. Coupled with this knowledge of the LS factor, better information is now available for the State and Federal Governments and developers in carrying out proposed project developments so that the developments could be carried out at areas with least erosion risks. Alternatively, proper safety measures should be implemented and undertaken if there is no choice of developing any new projects at high potential erosion risk areas.