09 SEPTEMBER 2022 - DAILY QUESTIONS & MODEL ANSWERS:
Q1. Explain about landslides, its causes and types.
Paper & Topic: GS I Geography
Model Answer:
A landslide is an unexpected, gravity-driven collapse of dirt, plants, and rock down a hill. It could be caused by extreme human interference with slope stability or by natural forces like torrential rain or earthquakes.
To construct homes, tunnels, railroads, and other structures, man smashes rock. Landslides occur under these circumstances as a result of loose rocks.
Earth flow, mass movement, mudflow, rotating slip, and avalanches are just a few examples of the many diverse types of slides that can occur.
Landslides are not frequently as large as seismic or volcanic disasters. However, the extent and intensity of the landslide are influenced by the geological structure, slope angle, kind of sedimentary materials, and human contact with the slope.
Kinds of landslides:
Falls: These happen when enormous geologic masses, including rocks and boulders, suddenly slide away from cliff walls or steep slopes.
Topples: This happens when a unit or units, influenced by gravity, forces from neighbouring units, or fluids through fractures, rotate forward about a pivot point that is low or below the unit.
Slides: In this type, the elements that make slopes flow through the soil, rocks, or other debris.
Spread: It often occurs on flat terrain or at relatively low gradients.
Causes of landslides include:
1.Snow and rain falling:
The presence of intense or prolonged rainfall may result in massive landslides in areas with steep slopes where National Highways and roads have been developed.
In the Jammu and Kashmir region of Nashri, between Batote-Ramban-Ramsu and Banihal, landslides frequently happen. The wet and winter seasons, when the vehicular traffic is disrupted for several days, are when the landslides in this area are most severe.
2.Seismic activity and volcanic eruptions:
Landslides in folded mountainous regions are primarily generated by earthquakes. Landslides are more frequent in Tertiary-era folded mountains in India, such as the Himalayas.
Many thousands of people perished as a result of the landslides that the 1905 earthquake in the Kashmir valley triggered in the lesser and greater Himalayas.
Volcanic eruptions in mountainous places can potentially cause landslides.
Building roads, mining, and quarrying:
The continual mining and quarrying of coal, minerals, and stones as well as the building of roads by cutting through the steep slopes of folded mountains can result in landslides.
The Eastern and Western Ghats, as well as the Himalayas, have experienced these landslides.
4.Construction-related loads for homes:
Landslides are largely caused by unplanned urban development in steep terrain without rock and soil testing.
The eastern slope of Nanital (Uttarakhand) is sinking as a result of the weight of the lodging and residential structures.
5.Cutting down of forests:
Deforestation and other human activities, such as landslides, are two examples. Most of the landslides contain tiny blocks that are only a few metres across. Some, though, are huge enough to trigger a catastrophe. Various infrastructure, including roads and buildings, could be buried.
Limiting deforestation on mountain slopes, following local building codes, and avoiding building on steep slopes can all help to reduce the detrimental effects of landslides.
Strategy for Mitigation:
In addition to installing monitoring and early warning systems in specific locations, it is necessary to identify hazardous zones and control and stabilise particular slides.
To find regions that are frequently prone to landslides, hazard mapping should be done. In order to effectively combat landslides, localised strategies should be adopted.
It is important to implement restrictions on substantial community growth in susceptible locations, as well as limitations on building and other developmental activities like roads and dams. Valleys and locations with a moderate slope should be the only places where agriculture is allowed.
Q2. What is Miyawaki Method.
Paper & Topic: GS I Environmental Conservation
Model Answer:
Akira Miyawaki, a Japanese botanist, developed the Miyawaki technique, which speeds up the process of creating dense, natural forests.
The concept of urban afforestation has been revolutionised by its transformation of backyards into miniature forests.
This method recommends placing trees (only native species) as close to one another as you can in the same location in order to conserve space. The saplings that were planted aid one another in growth and prevent weed growth by obstructing sunlight from accessing the soil.
After their first three years, saplings are no longer in need of upkeep (self-sustaining).
The proposal calls for 10 times faster plant growth and a finished plantation that is 30 times denser than usual.
The Miyawaki method can produce a forest in 20 to 30 years as opposed to 200 to 300 years when utilising conventional methods.
Miyawaki Technique:
The natural trees in the area are divided into the four categories of shrub, sub-tree, tree, and canopy.
In order to increase the soil’s permeability, water retention, and nitrogen retention, its quality is assessed before biomass is added.
Once a mound of soil has been created, three to five saplings are planted per square metre in the seeds.
The ground is covered with a heavy layer of mulch.
Concerns:
Such trees lack some attributes of natural forests, such as their capacity to create rain and their medicinal value.
They are wood lots, which are portions of woodlands or forests that can be used for recreational pursuits like bird watching, bushwalking, and appreciating wildflowers as well as small-scale production of forest goods like wood fuel, sap for maple syrup, sawlogs, and pulpwood. These quickly growing plantations aren’t actually forests; rather, they are rapidly expanding plantations.
Environmentalists have questioned the efficacy of a method that seeks to match a forest’s complex ecosystem while accelerating tree growth (as it is not a good idea to force plants to photosynthesize fast).
