MASS MOVEMENT

• Slump: A slump is a downward and outward movement of rock or unconsolidated material moving as a unit or series of units. Large blocks of material move suddenly downward and outward along a curved plane.
• Rockslide: Rockslides are the most catastrophic type of landslide. They involve a sudden rapid slide of bedrock along planes of weakness. Rockslides are very common in the oversteepened canyons and drainages of Idaho, particularly in those areas like the Salmon River Canyon where more than 5,000 feet of elevation may exist between the ridge tops and the canyon bottoms.
• Debris Slide: A debris slide is a small sudden downslope movement of unconsolidated material. This type of slide produces a hummocky surface of low relief.
• Mudflow: A mudflow is a mass of saturated rock particles of all sizes. This type of landslide is caused by a sudden flood of water from a cloudburst in the semi-arid country or a sudden thaw. The flood waters carry the soil and rocks from a large slope area and wash them to a gulch or canyon. 'Then the water and debris move down the canyon and spread out on the gentle slopes below. Mudflows are very common in the semi-arid areas of southwestern Idaho.
• Earthflow: An earthflow is a downslope movement of soil which has been saturated with water to the extent that the debris moves as a fluid. While flowing, either slowly or rapidly, the mass generally remains covered by a blanket of vegetation. Typically a steep scarp is developed where the moving debris has pulled away from the upper slope. A hummocky lobe forms at the toe or front of the earthflow.
• Talus: A talus slope is developed by an accumulation of rock fragments at the foot of a cliff or ridge. Rock fragments break loose from the cliff above, roll down the slope and pile up in a heap of rock rubble. Individual talus forms as a half-cone with the apex pointing upwards. In most cases, a series of half-cones coalesce around the base of a mountain.

• Historical reasons: The advent of the Green Revolution during the 1960s and the use of HYV (High Yielding Variety) seeds and fertilisers led to the overuse of groundwater resources. Cheap electricity was also one of the main reasons.
• Excessive pumping of water from the ground: Pumping groundwater more frequently is a cause of groundwater shortage. Pumping groundwater at a rapid rate and not allowing it to replenish its levels is a serious cause of concern.
• Increasing population:  With a rapid rise in population and its increasing demand for food, there is an expansion in the area of land under irrigation. This is leading to the uncontrolled exploitation of groundwater in India.
• Natural causes: These include uneven rainfall and climate change that are hindering the process of groundwater recharge. India is mainly dependent on the Indian summer monsoon rainfall and weaker summer monsoons can cause. During such dry periods, water is extracted from the ground to meet various needs leading to a reduction in groundwater levels.
• Deforestation: Plants and trees play an important role in maintaining the water table. Reckless cutting of plants and trees is adding to the problem of groundwater depletion.

• Micro irrigation should be encouraged. Discouraging water-guzzling crops such as sugar cane.
• As aquifers and other groundwater sources are depleted at a rate greater than the recharge rate, artificial recharge is needed to maintain a lasting water supply to prevent the complete withdrawal of groundwater shortly.
• To combat the overpumping of groundwater and achieve stability in the water table, artificial recharge is another water source that will help alleviate the stress on the groundwater supply. For arid climates with little precipitation, recharging groundwater can be achieved through using treated wastewater, natural runoff, and runoff from irrigation. Soil-aquifer treatment (SAT).
• The primary challenge of desalination is its high cost and energy consumption.
• Electricity makes up 63 per cent of the operational costs of seawater desalination plants. The plants contribute to water security but add stress to energy security. 

• Mechanical weathering, also called physical weathering and disaggregation, causes rocks to crumble.
• Water, in either liquid or solid form, is often a key agent of mechanical weathering. For instance, liquid water can seep into cracks and crevices in rock. If temperatures drop low enough, the water will freeze. When water freezes, it expands. The ice then works as a wedge. It slowly widens the cracks and splits the rock.
• Temperature changes can also contribute to mechanical weathering in a process called thermal stress. Changes in temperature cause rock to expand (with heat) and contract (with cold). As this happens over and over again, the structure of the rock weakens. Over time, it crumbles.

• Chemical weathering changes the molecular structure of rocks and soil.
• For instance, carbon dioxide from the air or soil sometimes combines with water in a process called carbonation.
• This produces a weak acid, called carbonic acid, that can dissolve rock.
• Carbonic acid is especially effective at dissolving limestone.
• When carbonic acid seeps through limestone underground, it can open up huge cracks or hollow out vast networks of caves.