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Work of Groundwater

Work of Groundwater, Karst Topography, Pools, Sinkholes and Limestone Pavements are important topics for UPSC Geography Class 11

The surface water flows smoothly on rocks that are perforated, settled in a small bed, and are very compact and cracked.

After sinking to a certain depth, groundwater flows horizontally through the bedding undulations or objects themselves. Mechanical removal of groundwater is not essential to improving soil formation and therefore the effects of groundwater activity cannot be observed on all types of rocks. In rocks having high mineral content, surface water and groundwater flows through these minerals and intervenes in the chemical process of dissolving and precipitating. Rainwater develops a wide variety of soils. 

Erosional Landforms (Karst Topography)

Karst Topography: Any limestone or dolomite region that reflects the general state of the world is produced by the action of groundwater by the process of dissolution. This is named after the common landscape built on limestone rocks in the Karst region of the Balkans near the Adriatic Sea.

Pools, Sinkholes, and Limestone Pavements:

  1. Slab contraction joints should intersect at the openings for columns.
  2. Sinkhole: It is a hole in the top or bottom that is round and shaped like a vertical one having a size of a sq.m to the hectare.
  3. Some of these forms are in a mixture initially and if the base of the hole creates the cover of a gate or underground cave, it may shrink leaving a huge hollow space in the cave or basement (fall sinks). Doline is sometimes used to target falling sinks.
  4. Solution sinks are more common than falling sinks. The water cascades down from the swallow holes and then sinks and flows like underground streams and then flows away from the river through a hole in the cave.
  5. If the sinkholes and dolls meet due to the collapse of the surrounding material or due to the collapse of the roof of the caves, long, narrow and wide canals are formed which are called valley sinks or Uvulas.
  6. Gradually, most of the limestone surface is eroded by holes and crevices, leaving little or no space for points, cracks, and ridges.
  7. Limestone Pavements: The limestone field may eventually turn smooth.


  1. Caves are mainly formed in areas having interchangeable rock beds (shale, sandstone) having high mineral content in or in zones having limestone rocks which are dense, large, and appear as floors having a lot of depth.
  2. Water flows to the ground through the uneven surface and laterally near sleeping planes.
  3. Caves: These are lengthy and thin spaces that are built when limestone is melted in sleeping planes. Caves usually have a hole through which the streams flow.
  4. Tunnels: These caves have holes on both ends.

Depositional Landforms by Groundwater: 

  1. The chemical in limestone is calcium carbonate which dissolves easily in carbonated water (rainwater absorbs carbon dioxide).
  2. This calcium carbonate is formed when the water it carries to the ground evaporates or loses carbon dioxide as it flows over the rough rocks.

Stalactites, Stalagmites and Pillars: 

  • Stalactites: These are hanging pieces of ice of different sizes, and are often broad in their bases and shrink to free limits that are manifested in various ways
  • Stalagmites: These climb up from the bottom of caves and build up as the leakage of surface water pushes them upwards, they occur in pairs with a thin, stalactite pipe above it and may take the shape of a column, or disk, with a sloping, circular crater
  • Stalagmites and stalactites eventually merge to form columns of varying widths