FIRST and foremost, we wish to express our deepest condolences to the families who have lost their loved ones and our heartfelt sympathy to all those affected by the recent natural disasters such as floods and landslides across many districts in Sabah.
This natural disaster has caused widespread hardship, disruption, and the tragic loss of lives. As engineers, we stand in solidarity with the affected communities during this difficult time.
These events are also a sobering reminder that while we cannot control nature, we can take steps to live more safely with it. For those whose homes are built on or near slopes, knowledge, vigilance, and preparedness are key to reducing risks.
This article is intended to provide homeowners with a comprehensive understanding of the risks linked to hillside living, the indicators of potential hazards, recommended safety practices, and the critical importance of emergency preparednessWhy Landslides Occur in SabahSabah is blessed with breath-taking landscapes of hills, valleys, and mountains. However, this natural beauty comes with geological challenges. Landslides occur when soil, rock, or debris suddenly lose stability and move downslope, often triggered by intense or prolonged rainfall.
In our State, several interrelated factors combine to create higher risks:1. Steep TerrainMuch of Sabah’s housing and infrastructure is built on or near hilly terrain. While scenic, these slopes are naturally unstable as gravity constantly pulls soil and rock downward.
* Cut slope areas for housing and roads When hillsides are cut to form building platforms or road alignments, the natural balance of the slope is disturbed. Without engineered retaining structures and adequate drainage, such slopes are vulnerable to collapse.
* Fill slope areasIn some developments, low-lying areas are filled with soil to create level platforms. If compaction and drainage are poor, these slopes can fail even under moderate rainfall.
2. Soil CharacteristicsSabah’s diverse geology means different soil types respond differently to rain:For example, the Colluvium (loose surface deposits) which is found at the base of many hillsides, it erodes easily and slides when saturated. Residual soils from weathered sandstone and mudstone which are commonly found in many districts, these soils lose strength quickly once soaked.
Clay-rich soils which this soil becomes stable when dry, they swell, soften, and become slippery after heavy rainfall. Developments located on such soils are particularly at risk if protective measures are lacking.
3. Heavy RainfallSabah receives some of the highest annual rainfall in Malaysia, averaging 3,200-4,000mm. Monsoon rains and localized storms can saturate slopes rapidly. When this happens the pore water pressure increases, weakening soil strength.
Then the slope becomes heavier, adding downward force. Drainage is being overwhelmed, causing erosion and runoff. Due to this, the soil can no longer resist these stresses, a landslide may occur suddenly and with little warning.
4. Climate Change Intensifying RisksClimate change has worsened these challenges. Rainfall has become more intense, unpredictable, and prolonged. What was once considered a “50-year storm” may now occur every few years.
Shifting weather patterns and higher temperatures also stress both natural and human-made slopes. Hillsides that have stood stable for decades may now fail after back-to-back storms.
5. Human Activities Increasing VulnerabilityWhile natural factors play a major role, human actions often tip the balance by uncontrolled hill cutting for housing, roads, or farming; poorly maintained or blocked drains, leading to water infiltration; deforestation and vegetation removal, which strip slopes of natural root reinforcement; dumping of construction debris or household waste on slopes, adding dangerous weight.
Even small-scale activities can destabilise slopes, especially during rainy seasons.
6. Local Triggers to Watch ForCommunities should watch for early signs of slope stress, such as: Cracks in the ground, retaining walls, or pavements; tilting of trees, poles, or fences; water seepage or muddy flows emerging from the slope face; small rock or soil falls after heavy rain. These are red flags that require immediate professional attention.
Warning Signs of Slope FailureBefore a slope collapses, there are often visible or audible warnings. Unfortunately, these are frequently overlooked. Homeowners should remain alert to the following indicators such as cracks in soil, walls, or pavements – Fresh cracks appearing suddenly signal ground movement.
Doors or windows that jam and sudden sticking may indicate foundation shifts. Bulging soil at the base of a slope which is a common precursor to slope failure. Unusual water patterns for examples cloudy tap water, new seepage, or changes in surface runoff may indicate underground movement.
Tilting or leaning structures – Trees, fences, poles, or retaining walls shifting out of alignment are serious warning signs.
If any of these occur, seek professional advice immediately. In some cases, it may be wise to temporarily relocate your family until the slope has been inspected by a qualified geotechnical engineer.
Practical Steps to Safeguard Your HomeNo measure can eliminate risk completely, but proactive steps can reduce danger significantly.
I. Engage Qualified ProfessionalsIf your home is near or on a slope, obtain a professional risk assessment. Only a qualified geotechnical engineer has the expertise to evaluate slope stability and recommend solutions. Do not rely on general contractors or non-specialists for this work.
II. Manage Surface Water ProperlyWater is the most common trigger of landslides. Good drainage is essential to keep gutters, drains, and downpipes clear of debris; to construct proper channels to divert rainwater safely away from slopes and to avoid directing water, even small flows, onto a slope surface.
III. Avoid Unsafe Land ModificationsCertain activities greatly increase the risk of slope failure for example excavating or cutting into the base of a slope and or placing heavy fill material, soil, or vehicles at the top of a slope. Always consult professionals before making land alterations.
IV. Use Vegetation WiselyDeep-rooted plants help stabilise slopes naturally by binding the soil. However, large trees too close to houses can create risks if their roots are undermined. Seek expert advice on the best vegetation for slope stability in your area.
Homeowner ResponsibilitiesWhile the government provides policies and technical guidelines, homeowners have a direct role in slope safety. Responsible slope management is part of good citizenship and neighbourliness:1. Check approvals To ensure any construction or modification has approval from local authorities.
2. Know your risk zone To consult JKR, JMG Sabah or your local authorities to check if your property lies in a landslide-prone area.
3. Protect your community To avoid unsafe practices that could endanger neighbours living downhill.
Emergency PreparednessPreparedness can save lives. Every family near a slope should have an emergency plan such as Evacuation route – to identify and practice the safest path to leave your home quickly; Emergency bag – to keep essential documents, medicines, and supplies packed and ready; Follow evacuation orders especially if authorities instruct evacuation, act immediately.
A “wait and see” attitude can be deadly.
Building a Culture of SafetyThe lessons from Sabah’s recent disasters are clear: we must move from reacting to events toward building a culture of prevention and preparedness.
Government agencies have developed frameworks such as the National Slope Master Plan, but these must be supported by public participation. Local communities, residents’ associations, and NGOs can play key roles by organising slope safety awareness programmes; sharing expert knowledge with residents; encouraging routine maintenance of drainage and slopes.
Safety is not just an individual matter and in fact it is a collective responsibility.
ConclusionThe tragic events in Sabah remind us of the delicate balance between our homes and the natural environment. Living in hillside areas brings both privilege and responsibility.
By remaining vigilant, recognising warning signs, taking preventive action, and preparing for emergencies, homeowners can greatly reduce the risks posed by landslides.
As engineers, we stand shoulder-to-shoulder with the people of Sabah. Together, let us turn these painful lessons into a stronger culture of safety, ensuring that our magnificent hillsides remain safe and secure for generations to come
