Question 2: Answer the following questions briefly. (i) What are the controls affecting the climate of India? (ii) Why does India have a monsoon type of climate? (iii) Which part of India does experience the highest diurnal range of temperature and why? (iv) Which winds account for rainfall along the Malabar Coast? (v) What are jet streams and how do they affect the climate of India? (vi) Define monsoons. What do you understand by “break” in monsoon? (vii) Why is the monsoon considered a unifying bond? * ------------------------------------------------- Answer * -------------------------------------------------
Discussion * ------------------------------------------------- Share (i) The controls affecting the climate of India are: latitude, altitude, pressure and wind system, distance from the sea, ocean currents and relief features. (ii) The climate of India is strongly influenced by monsoon winds. Hence, it has a monsoon type of climate. (iii) The north-western part of India comprising the Indian Desert experiences the highest diurnal range of temperature. This is because of the fact that sand (found in ample quantity in this region) gains and loses heat very quickly.
As a result of this phenomenon, there is a wide difference between day and night temperatures in this region. The day temperature may rise to 50°C and drop down to near 15°C the same night. (iv) The south-west monsoon winds are responsible for rainfall along the Malabar Coast. (v) Jet streams are a narrow belt of high-altitude winds in the troposphere. The sub-tropical westerly jet stream blowing south of the Himalayas are responsible for the western cyclonic disturbances experienced in the north and north-western parts of the country during the winter months.
The sub-tropical easterly jet stream blowing over peninsular India is responsible for the tropical cyclones that affect the eastern coastal regions of India during the monsoon as well as during the October to November period. (vi) Monsoon refers to the complete reversal of winds over a large area leading to a change of seasons. “Break” in monsoon refers to the wet and dry spells of the monsoon. In other words, the monsoon rains take place for a few days at a time. They are interspersed with rainless intervals. vii) Despite variations in temperature conditions across India, a sense of unity is imposed by the monsoon. The seasonal alteration of the wind systems and the associated weather conditions provide a rhythmic cycle of seasons that binds the entire country. Question 3: Why does the rainfall decrease from the east to the west in Northern India? * ------------------------------------------------- Answer * ------------------------------------------------- Discussion * ------------------------------------------------- Share
The amount of rainfall decreases from east to west in Northern India because of the progressive decrease in the humidity of the winds. As the moisture-bearing winds of the Bay of Bengal branch of the southwest monsoon move further and further inland, they exhaust most of the moisture they carry along with them. This consequently leads to a gradual decrease in the amount of rainfall from east to west. Question 4: Give reasons as to why. (i) Seasonal reversal of wind direction takes place over the Indian subcontinent? (ii) The bulk of rainfall in India is concentrated over a few months. iii) The Tamil Nadu coast receives winter rainfall. (iv) The delta region of the eastern coast is frequently struck by cyclones. (v) Parts of Rajasthan, Gujarat and the leeward side of the Western Ghats are drought-prone. * ------------------------------------------------- Answer * ------------------------------------------------- Discussion * ------------------------------------------------- Share (i) The seasonal reversal of wind direction over the Indian subcontinent is the result of the Coriolis force. It is an apparent force caused by the Earth's rotation.
The Coriolois force is responsible for deflecting winds towards the right in the northern hemisphere and towards the left in the southern hemisphere. (ii) The rainfall received by India is largely due to the south-west monsoon winds. The duration of the monsoon is between 100 to 120 days. Hence, the bulk of rainfall received by the country is concentrated over a few months. (iii) During the winter season, north-east trade winds prevail over India. They blow from land to sea and hence, for most part of the country, it is a dry season.
However, the Tamil Nadu Coast receives winter rainfall due to these winds. This is because in this region these winds blow from sea to land, thereby carrying moisture along with them. (iv) The delta region of the eastern coast of India is frequently struck by cyclones. This is because the cyclonic depressions that originate over the Andaman Sea are brought in by the sub-tropical easterly jet stream blowing over peninsular India during the monsoon as well as during the October to November period. v) Parts of Rajasthan, Gujarat and the leeward side of the Western Ghats are drought-prone because of the scanty rainfall received by these regions during the monsoon rains. The progressive decrease in the humidity of the winds of the Bay of Bengal branch causes the amount of rainfall to decrease from east to west in northern India. As the leeward side is the rain-shadow area, the regions lying in this region receive very little rain from the Arabian Sea branch. It is the windward side of the Ghats that receives the maximum rain. Climate (Social Science)| Close X |
Exercise «Prev Page 40 Next»| | Q5 Q6 Q7 Q8| Question 8: Give the characteristics and effects of the monsoon rainfall in India. * ------------------------------------------------- Answer * ------------------------------------------------- Discussion * ------------------------------------------------- Share Characteristics of monsoon rainfall in India: (i) The duration of the monsoon is between 100 to 120 days from early June to mid-September. (ii) Around the time of its arrival, the normal rainfall increases suddenly and continues for several days.
This is known as the ‘burst’ of the monsoon. (iii) The monsoon has characteristic wet and dry spells or ‘breaks’ in rainfall. The monsoon rains take place only for a few days at a time. They are interspersed with rainless intervals. (iv) The moisture is carried by pulsating south westerlies that are affected by different atmospheric conditions, thereby giving monsoon rains an uncertain character. The annual rainfall is highly variable from year to year (v) The rainfall is unevenly distributed across the Indian landscape.
Parts of the western coast and north-eastern India receive the maximum rainfall. Regions such as parts of Rajasthan, Gujarat, Leh and the leeward side of the Western Ghats receive very little rainfall. Effects of monsoon rainfall in India: (a) Indian agriculture is largely dependent upon the water from the monsoon rains. Late, low or excessive rains have a negative impact upon crops. (b) Due to the uneven distribution of rainfall across the country, there are some regions that are drought prone and some that are flood afflicted. c) The monsoon provides India with a distinct climatic pattern. Hence, in spite of the presence of great regional variations, it has a unifying influence upon the country and its people. Question 3: (i) Name two rainiest stations. (ii) Name two driest stations. (iii) Two stations with most equable climate. (iv) Two stations with most extreme climate. (v) Two stations most influenced by the Arabian branch of southwest monsoons. (vi) Two stations most influenced by the Bay of Bengal branch of south-west monsoons. vii) Two stations influenced by both branches of the south-west monsoons (viii) Two stations influenced by retreating and north-east monsoons. (ix) Two stations receiving winter showers from the western disturbances. (x) The two hottest stations in the months of (a) February (b) April (c) May (d) June * ------------------------------------------------- Answer * ------------------------------------------------- Discussion * ------------------------------------------------- Share (i) Two rainiest stations: Shillong and Mumbai (ii) Two driest stations: Leh and Jodhpur iii) Two stations with most equable climate: Bangalore and Tiruvanantapuram (iv) Two stations with most extreme climate: Leh and Jodhpur (v) Two stations most influenced by the Arabian branch of southwest monsoons: Tiruvanatapuram and Mumbai (vi) Two stations most influenced by the Bay of Bengal branch of south-west monsoons: Shillong and Kolkata (vii) Two stations influenced by both branches of the south-west monsoons: Delhi and Kolkata (viii) Two stations influenced by retreating and north-east monsoons: Chennai and Bangalore (ix) Two stations receiving winter showers from the western disturbances: Jodhpur and Delhi (x) The two hottest stations ? (a) In the month February: Tiruvanatapuram and Chennai (b) In the month April: Nagpur and Kolkata (c) In the month of May: Nagpur and Jodhpur (d) In the month of June: Jodhpur and Delhi
