Geography
Lakes
झीलें
In Class 9 Geography, the topic “Lakes” explains how these water bodies form part of the drainage system and differ from rivers in their shape, movement, and location. Students learn about natural lakes formed by tectonic activity, glaciers, river courses, and coastal processes, as well as human-made reservoirs. Indian examples such as Wular, Dal, Sambhar, Chilika, and Kolleru help connect ideas with maps and landscapes. The topic also examines how lakes store water, support irrigation, hydropower, fisheries, biodiversity, tourism, and flood regulation.
Practice questions
If a lake's natural outlet is blocked and evaporation is high which change is most logical?ExpertLevel 38Why can the risk of sudden outburst of glacial lakes increase?ExpertLevel 38Which lake is correctly linked with freshwater and the Krishna Godavari delta region?ExpertLevel 38Why is dissolved oxygen an important indicator of lake water quality?ExpertLevel 38Under which condition will the risk of biomagnification in lakes increase?ExpertLevel 38What does the term backwater indicate while understanding Vembanad Lake?ExpertLevel 38Under which condition can thermal stratification of lakes be more evident?ExpertLevel 38If the sea mouth of a lagoon lake like Chilika becomes highly blocked what effect may occur?ExpertLevel 38Why can encroachment on lakes increase flood risk?ExpertLevel 38Which lake is most correctly matched with both state and feature?ExpertLevel 38How can excessive spread of water hyacinth affect lake water quality?ExpertLevel 38Why can lake water become unsuitable for agricultural irrigation?ExpertLevel 38Why is control on water withdrawal important for sustainable use of lakes?ExpertLevel 38In which situation can the natural purification system of a lake fail?ExpertLevel 38Which statement most accurately analyses a coastal lake and an inland saline lake?ExpertLevel 38What gives the broadest analysis of lake water level change?ExpertLevel 38When can a lake's role in groundwater recharge be more effective?ExpertLevel 38Which lake feature can be best linked with wetland conservation?ExpertLevel 38Which combination is most suitable for identifying Pulicat Lake?ExpertLevel 38What combined effect may occur when sedimentation and nutrient pollution increase together in lakes?ExpertLevel 38