Running water is by far the most dominating geomorphic agent in shaping the Earth’s surface in humid as well as in arid climates. Explain. (150 Words)
Running water is the main denudation agent, eroding and transporting sediments and actively shaping the landforms. It acts through process of attrition, vertical and lateral erosion and deposition to shape earth’s surface.
In humid areas running water creates a variety of landforms (aided by others) such as valleys, gorges, etc. in the highlands. Hill slopes devoid of trees are eroded to form rills and gullies. It creates extensive depositional plains in its lower course where the process of deposition becomes dominant, the Indus-Ganga-Brahmaputra plains is a prime example.
In the arid areas (deserts primarily) the scant but suddenly occurring rainfall shapes the landforms creating deep ravines and dry steep valleys called vadiya. The water transports copious amount of sediments, in a landscape deprived of any vegetation to check erosion, creating depositional bajadas and extensive peneplains.
Write a critical note on the effect of soil erosion on the environment and methods used in soil conservation. (200 Words)
Soil is the earth’s fragile skin that anchors all life on earth. It is comprised of countless species that create a dynamic and complex ecosystem and is among the most precious resources to humans. Soil erosion results in the loss of soil fertility and makes the land barren. Soil erosion impacts the agriculture as well as the natural environment.
Effects:
- Loses its most nutrient-rich layer, and therefore soil quality is reduced.
- Poor soil quality means smaller crop yields therefore more use of fertilizer and chemical which contaminate water.
- Weaken the soil’s ability to hold water, leaving the field susceptible to weather conditions such as droughts.
- Contaminates drinking water and disrupts ecosystems of lakes and wetlands which negatively impact the fish and wildlife.
- Sediments that accumulate down slope of the erosion can obstruct the flow of water in streams and drainage canals, leading to flooding.
Methods for soil conservation:
- Increased vegetation cover, planting tall trees which act as a wind breaker.
- Contour farming
- Interculturing operation will kill the weed and soil mulches help the plant to be rooted firmly on the ground called mulching.
- Crop rotation
- Dry farming method
- Construction of ponds
- Building small dams in gullies to slowdown water runoff
- Over grazing should be avoided
- Adequate drainage system