Students can go through AP State Board 7th Class Social Studies Notes Chapter 3 Tanks and Ground Water to understand and remember the concept easily.
AP State Board Syllabus 7th Class Social Studies Notes Chapter 3 Tanks and Ground Water
→ The Kakatiya and Vijayanagara kings and Nayaks built a large number of tanks in Telangana and Rayalaseema. This enabled the extension of agriculture into these areas.
→ The tanks were usually built by building a strong wall of stones and mud across a small stream in such a way that with a wall on just one side a large lake could be formed.
→ The tanks helped the people not only in giving them and their animals drinking water but also in irrigating their fields in such a way that even in drought years they could raise at least some crops.
→ Most important thing is that the tanks helped to prevent the run-off of rainwater and the erosion of topsoils.
→ During the last twenty or thirty years, the tanks have been neglected and have been allowed to break down.
→ Rocks that have cracks or pores in them and can contain water are called previous rocks. & Rocks like granite, Kadapa limestone, are very compact and do not have pores in them.
→ Water cannot enter into them. These are called impervious rocks.
→ The layer of water which accumulates under the ground among rocks is called an aquifer.
→ The level of groundwater, which is also called the water table.
→ Most of the rocks under the soil in Andhra Pradesh consist of granites, which are hard and impervious.
→ If we draw more water than what percolates down, the groundwater will decrease over time.
→ Vegetation like trees, grasses, and bunds are used to enhance groundwater.
→ Groundwater is usually mixed with many minerals.
→ Many times water Is polluted due to the excessive use of fertilizers, pesticides, or poor drainage.
→ Groundwater like the rivers is the common resource of all people and not just of those who have landed over aquifers.
→ Those who own land over aquifers tend to over-use the water, which decreases the water table for all neighboring people.
→ Today’s generation has received water from the past as a sacred asset. We should give it to the future generation just as we received it.
→ Previous rocks Rocks which have cracks or pores (minute holes) in them and can contain water are caLled pervious rocks
→ Impervious rocks: Some rocks like granite, Kadapa limestone, are very compact and do not have pores in them. Water cannot enter into them. Groundwater usually accumulates above such rocks Since the water can’t go beneath them, these are caLled impervious rocks
→ Vegetation: The vegetation means trees and grasses and buns etc.
→ Aquifers: The layer of water which accumulates under the ground among rocks is an aquifer.
→ Megalithic age: The stone boulders are known as megaliths. These were arranged by people and were used to mark burial sites.
→ Water table: The level below which the ground is saturated with water.
→ Tanks: The tanks were usually built by building a strong wall of stones and mud across a small stream in such a way that with a wall on just one side a large lake could be formed.
→ Groundwater: Rainwater that goes down into the soil accumulates below the ground in the gaps between rocks, pebbles, sand, etc. This is the groundwater.
→ Minerals: The minerals like Sodium, Fluoride, Chloride, Iron, Nitrate, etc., come from the rocks and soils underneath