DEVELOPMENT OF EWARNS FORECAST AND REAL-TIME
EARLY WARNING SYSTEM ON EROSION RISKS / HAZARDS
By: Dr. Faisal Hj. Ali, Professor, Department of Civil Engineering, Faculty of Engineering, University of Malaya
Dr. Tew Kia Hui, Director, VT Soil Erosion Research & Consultancy

With many incidences of landslides, mudslides and erosion occurrences lately, especially in highlands in Malaysia, properties were damaged and lives were lost. Seeing the need of resolving and minimizing such untoward incidences, a study has been embarked on developing a forecast and real-time early warning system on erosion risks / hazards so as to provide an early warning to the public, whenever there are signs and probable occurrence of such incidence. Consequently, a case study on Cameron Highlands Catchment was carried out, which involved a detailed baseline database of the study area to be set up first. The highland catchment, which is considered an environmentally sensitive area where many land development for various activities such as agriculture, agro-tourism, property development and road-widening projects had already been carried out and some are still on-going as to-date.

To develop the baseline database, acquisition of the latest Structure Plan, Satellite Imagery, topographical and rainfall information of the catchment area were carried out. Once this is done, development of the early warning system is carried out by adopting real-time rainfall information. This could be done using solar-powered rain sensors, which would be triggered based on the rainfall amount and intensity. A SIM-card based GPRS transmitter, which is attached to the “rain sensing and transmission unit” would then send out e-mails at every minute interval, so that the data could be transferred to a receiving unit. At this point, the e-mail is read and data is processed within the
Geographical Information Systems (GIS) using an automated keyboard simulation programme. The final processed values would then be set against the threshold values, which will trigger an early warning if any of the values exceeds the threshold limits. Similarly, for the early warning forecast on erosion risks / hazards it would be based on the baseline database developed and it is to be confirmed by the weather forecast information as provided by the Malaysian Meteorological Service (MMS). Therefore, it is hoped that the application of this new locally developed system, which has been trademarked under the name EWARNS (Early Warning And Risk Navigation Systems), would be beneficial to the local authorities, highway operators and public in general to provide an early warning especially during periods of heavy rainfall, which could possibly trigger serious occurrences of erosion / landslides / mudslides.

BACKGROUND

With respect to numerous erosion, landslide and mudslide occurrences in Malaysia recently, particularly at hillslopes and highlands, there is a great concern that these areas are extremely sensitive to disturbances of any sort. Events over the past years, such as landslides at the Genting Highlands slip road (1996 & 2004), the collapse of the Highland Tower (1993), landslide at Bukit Antarabangsa (1999), landslides and mudslides at Gua Tempurung (1996 & 2004), landslides at the KL – Karak Highway near Bentong (2003 & 2004), landslides and mudslides in Cameron Highlands (2000 & 2004) and smaller landslides in Fraser’s Hill occurring almost every year, have indicated what
can happen when things go wrong. Seeing the need of resolving and minimizing such untoward incidences, a study has been embarked on developing a forecast and real-time early warning system on erosion risks / hazards so as to provide an early warning to the public, whenever there are signs and probable occurrence of such incidence. A case study on Cameron Highlands Catchment has been carried out, which involved a detailed baseline database of the study area to be set up first. This highland catchment is being considered an environmentally sensitive area where many land development activities such as agriculture, agro-tourism, property development and road-widening projects, had been carried out and some are still on-going as to-date.

OBJECTIVE

The objective of this research and development of EWARNS is to provide an early warning to the authorities, tourists, hoteliers, farmers and public in general within the Cameron Highlands Catchment by monitoring the current situation there more closely, including taking mitigative measures should there be at any time specific locations within their jurisdiction proven to have high erosion risk, which
would possibly induce landslides. This could be done simply by just logging onto a website and check out the situation of the roads, agricultural farms and specific built-up areas on the level of erosion risks / hazards involved as information on these areas would be updated every minute should there be any rainfall event. Tourists and motorists heading to Cameron Highlands would also be well informed and
be able to plan their travel better as such information would be updated constantly via the newly developed EWARNS website (www.ewarns.com.my). Farmers and hoteliers in Cameron Highlands would also be forewarned of the dangers involved and be able to take necessary measures to protect and safeguard their properties. Local authorities and relevant agencies would also be notified via
SMS / e-mail to take precautions and carry out inspections on high-risk areas when there are any incidences of continuous heavy downpour within a specified area.

The scope of research & development would include developing:

• baseline database for the Cameron Highlands Catchment
• rain sensing and transmission unit (RSTU)
• receiving unit, which includes processing of near real-time data
• early warning system panel, which would be up hosted to the EWARNS website

METHODOLOGY

Methodology of research for the development of the EWARNS forecast and real-time early warning system on erosion risks / hazards is firstly the acquisition of baseline data for the study area, Cameron Highlands Catchment. Liaison with various agencies was required to obtain the relevant information, which include the latest Cameron Highlands Structure Plan (1995 – 2020), current land use using SPOT 4 Satellite Imagery dated 7th July 2002 (to be revised using SPOT 5 Satellite Imagery dated 19th April 2005), topographical information using Topographical Map (Sheet 74) and recorded rainfall information from nine existing rainfall stations within the catchment area. Such information would then be used for simulation of data for input into the early warning system.

Once this is completed, a prototype of actual real-time outdoor transmission unit is then developed as shown Figure 1. This could be done using solar-powered rain sensors, which would be triggered based on the rainfall amount and intensity. A SIM-card based GPRS transmitter, which is attached to the interface module of the Rain Sensing and Transmission Unit (RSTU) would then send out e-mails
/ internet file transfers at every minute interval, so that the data could be transferred to a receiving unit (a server connected to high speed Internet line). At this point, the e-mail / transferred file is read and data is processed within the Geographical Information Systems (GIS) using an automated keyboard simulation programme. The final processed values would then be set against the threshold values,
which will trigger an early warning if any of the value exceeds the threshold limits.

Figure 1: EWARNS outdoor Rain Sensing and Transmission Unit (RSTU)

Subsequently, the early warning panel, which is also known as EWARNS Display Panel, would be up hosted to the website (www.ewarns.com.my), whereby such information would be made accessible to the public and authorities involved. The website’s map of erosion risk areas will also be updated every minute as data from the sensors are constantly calculated. A blinking red light with
continuous playback of the ‘warning’ sound would indicate that a certain area is at high risk of erosion (> 1.0 t/ha/day), while yellow is for medium (0.51 – 1.0 t/ha/day), and blue for low risk locations (0 – 0.5 t/ha/yr). Remarks on the percentage of risk area and in acreage for the built-up areas, roads and agricultural areas would also be shown in the display panel.

Flowchart showing the operation of the EWARNS real-time early warning system on erosion risks / hazards is as depicted in Figure 2. Subsequently, Figure 3 shows the sample of EWARNS display panel and corresponding rainfall erosivity (Figure 4) as viewed via the website.

Figure 2: Operation of EWARNS Real-Time Early Warning System on Erosion Risks / Hazards

Figure 3: Real-Time EWARNS Display Panel on Erosion Risks / Hazards

Figure 4: Real-Time EWARNS Display Panel on Rainfall Erosivity

As for the EWARNS forecast on erosion risks / hazards for Cameron Highlands Catchment, the information of at least 10 years rainfall database was acquired to get a picture of the rainfall distribution on the catchment area, so as to use this information for forecasting of the rainfall pattern. However, it would also be very dependent of the weather forecast information as provided by the Malaysian Meteorological Service (MMS). This means that if the weather forecast for a particular day is fair, therefore, the EWARNS forecast on erosion risks / hazards would be a low risk with zero rainfall erosivity predicted. Such information would be updated on a daily basis as the EWARNS website would search of latest weather forecast provided by MMS. Sample of the 7 day forecast on erosion risks / hazards for Cameron Highlands is as shown in Figure 5.

Figure 5: EWARNS 7 Days Forecast on Erosion Risks / Hazards

BASELINE DATA AND EARLY WARNING SYSTEM DEVELOPMENT
Baseline data acquisition was carried out for the Cameron Highlands Catchment to serve as an input to the forecast and real-time early warning system on erosion risks / hazards, which include the latest rainfall, soil, topographical and land use information for the area as shown in Figures 6. This is crucial, as the early warning system requires the latest data to ensure the predicted level of risk to
achieve the best accuracy possible. As for rainfall data, even though these information would subsequently be transmitted by the RSTU in real-time, trial-runs on the system would be required using historical daily rainfall data acquired from the existing rainfall stations within the Cameron Highlands Catchment for purpose of programme simulation and correlation with reported incidences.

Figure 6: Baseline data acquisition and GIS database development

EXAMPLE OF TYPICAL REPORTED INCIDENCE AND WARNING ISSUED

A reported incidence of heavy rain and subsequent landslides occurred within Cameron Highlands Catchment on 5th January 2000. During this incident, rain on that day was heavier than usual and possibly the highest for the year 2000, triggering landslides and soil erosion occurrences on various agricultural farms within Cameron Highlands as well as cutting off access road between Brinchang and Kg. Raja. Simulation of maximum erosivity index recorded was 62 MJ.mm/(ha.hr.day) and EWARNS warning signal (high risk) was issued for all the areas of interest (built-up, roads and agriculture) as shown in Figure 7.

Figure 7. Simulated EWARNS Display Panel observation on 5th January 2000

CONCLUSION

In conclusion, the development of EWARNS forecast and real-time early warning system on erosion risks / hazards would certainly assist various parties including the local authorities, relevant government agencies, and the public, consisting of motorists, tourists, hoteliers, and farmers in highland areas, as it would serve as an early warning in the case of any potential erosion risks or possible landslide occurrences. The EWARNS early warning system, which consists of the transmission unit, receiving unit and EWARNS display panel, is hoped to achieve its purpose in

Blue Valley
Sg. Perlong
Sg. Mensun

providing early warning and alerting the authorities as well as the public in general of the potential high erosion risk areas within the affected areas once there are incidences of heavy downpour.

Finally, with the introduction of EWARNS for Cameron Highlands, it is hoped that better monitoring of the study area, Cameron Highlands Catchment could be provided and more attention should be paid to control indiscriminate or illegal clearing of areas with a potentially high erosion risk. Therefore, preventive and mitigation measures could be initiated early and duly enforced.

AWARD

GOLD MEDAL – Invention and Innovation Category, University Of Malaya 2005 Research, Invention And Innovation Exposition, 14 – 17th June 2005.

ACKNOWLEDGEMENT

Special thanks are extended to various parties for their assistance and contribution, which include: Malaysian Meteorological Service
Malaysian Centre for Remote Sensing
SSJCH Generation Division, Tenaga Nasional Berhad
Hydrology & Water Resources Division, Department of Irrigation and Drainage Malaysia

REFERENCE

Majlis Daerah Cameron Highlands, 1996. Rancangan Struktur Cameron Highlands dan Pihakberkuasa Perancang Tempatan Cameron Highlands (1995 – 2020), Cameron Highlands, Malaysia.
Morgan, R. P. C., 1993. Soil Erosion and Conservation, Longman Scientific & Technical, New York, USA.
Roslan, Z. A. and Tew, K. H., 1995. Erosion Study in Cameron Highlands, Malaysian Science and Technology Congress, Perdanasiswa, Universiti Malaya, Kuala Lumpur, Malaysia.
Rubber Research Institute of Malaysia, 1980. Soil Erosion and Conservation in Peninsular Malaysia, Kuala Lumpur, Malaysia.
Wischmeier, W. H. and Smith, D. D., 1978. Predicting rainfall erosion losses - a guide to conservation planning, USDA, Agriculture Handbook No. 537, USA.
YM Raja Harris R. H. and Usoff Y., 1999. Preliminary Soil Erosion Study on Impacts of Development Affecting Ringlet Reservoir of Cameron Highlands Hydroelectric Scheme, Cameron Highlands, Malaysia.