LANDSLIDES
Introduction/ Thesis
Landslides threaten lives and property throughout New Zealand. Given the typography of New Zealand and the increasing rainfall, landslide mitigation becomes more important. We have to find the solution for this natural hazard and what's causing it to damage our environment. Horizontal drains should be used to mitigate the effects of landslides. Drilling in pipes through the slope will help prevent the causing of a landslide from occurring and help in its most effective way. The pipes planted into the slope will drain out the water preventing the mountain from soaking up all the rainwater preventing a landslide.
What is a landslide?
Landslides a mass collapse of rocks or falling rocks from a slope. They collapse on roads, other areas and some buildings. Landslides that involve the collapse of material from a cliff or steep slope. They are similar to a Avalanche because they both remain on edges, cliffs and sides. Avalanches collapse into huddles and .andslides collapse into big and small pieces of rocks or muddy dirt. New Zealand has steep mountains with rocks weakened by earthquakes, and hillsides of soft rock.
What causes landslides and what do they affect?
Landslides are caused by disturbances in the natural stability of a slope. They can accompany heavy rains or follow droughts, earthquakes, or volcanic eruptions. Mudslides develop when water rapidly accumulates in the ground and results in a surge of water saturated rock, earth and debris. Landslides can be caused by humans. They cause them by building roads and structures without adequate grading of slopes, poorly planned alteration of drainage patterns, and disturbing old landslides. The landslides are massive slides that collapse and the effect is that it takes anything above or underneath with it. Landslides increase the amount of damage cost and usage about $250 million to $300 million in damage cost each year in New Zealand. The main impact is the huge amounts of silt that end up getting into our rivers and sea, which kill lots of creatures in those environments.
How do you know if a landslide will occur?
Ground shaking, Rocks falling. You can feel the urge of a landslide occurring. The trees are trembling, rain rising and the temperature. Landslides occur when masses of rock, earth, or debris move down a slope. Slight rocks fall. Where do they occur? There are thousands of landslides every year in New Zealand, but the vast majority are in uninhabited places so they aren't recorded. Unfortunately, there's no single organization responsible for landslides, so there aren't any easily accessed records to say how many there are. Landslides tend to occur on steep slopes, but can occur on very shallow slopes (as low as seven degrees) if the geology is particularly weak. They are more common where the land has been altered, for example by deforestation or by road building.
How can we reduce the impact of landslides on humans?
To reduce the impact of a landslide on humans is by using the methods in strengthening and securing the slope.Covering the land with impermeable membranes in order to prevent water infiltration in the landslide; Directing surface water sources away from the landslides; Draining groundwater streams away from the landslides; Minimizing irrigation on the surface of the soil. Consider adding nets, retaining walls, and planting sturdy vegetation to protect your home and property from landslides, especially on slopes or in areas where wildfire has destroyed plants and trees. Remove any plants that may aid in erosion prevention. Sandbags should be placed in exposed places.
What can be done to prevent landslides? How can we reduce the risk of a landslide?
Some methods that have been used and have proven to work are Soil nailing using grouted, tension-resisting steel elements (nails) to reinforce in situ soils and create a gravity retaining wall for permanent or temporary excavation support. Concrete to prevent the landslide from its original form that will stop it from causing a huge incredible amount of damage. By sealing off the slope and stopping it. Our solution Horizontal Drains. They prevent the landslide to cause less damage by draining the groundwater. It hardens the slope and makes the slope stable enough to prevent a landslide from causing.
What effects do landslides have on the community and environment?
The impact of a landslide can be extensive including loss of life. Affecting multiple sources in our environment like destructive infrastructure, damage to land and loss of natural resources. Landslide material can also block rivers and increase the risk of floods. Do they affect our community more than before? Yes. As our population has grown, and the "easy, flat" land has been used up, residential, water and transport infrastructure in New Zealand has been developed into steeper landscapes, especially in urban areas, due to the lack of level space available. These areas are vulnerable to slope instability, either naturally inherent or created by human development and activity. These issues may be already evident under normal conditions but are expected to be exacerbated and widespread in seismic events. They will become more and more evident in the future and may be compounded by the effects of climate change.
Conclusion
Going over our statements, we are hoping we have interested you into liking more about landslides and learning them. As we included from the beginning of our presentation, we have found horizontal drains should mitigate the negative effects of a landslide. Thanks to our expert we have finally got the answers we needed.
Thank you for your time.