The Nallamala Ghat form a part of this region, The Godavari, the Krishna and the Penner which drain this region have formed broad valley plains. The area lying to the north of Krishna is called Telengana and south of Krishna comprising of Chittor, Cuddapah Kurnool and Anantapur district is called Rayalaseema.
In ancient geological time faulting has caused two basins of this region, one along the lower Godavari and the other in Rayalaseema.
Sand-stones and coal were deposited along the Godavari Valley during the Gondwana period. The basin of Rayalaseema was laid with limestone’s, slates and shales. Workable deposits of steatite, asbestos and barytes occur in the sedimentary rocks of Rayalaseema. Steatite, used in paints, ceramics and talcum powder, is produced in a small quantity and so also asbestos.
Tropical Steppe climate is dominant in this region except narrow strip of Godavari. Maximum rainfall is received during summer monsoon season.
The rainfall varies from about 100 cm. in the north-east, that is, in the Lower Godavari Valley to about 50 cm. in the south-west, that is, in Raichur and Bellary districts. Rayalaseema gets insufficient rain because it is surrounded by hills in east and Karnataka plateau in the south west. Droughts followed by famines are, therefore, not uncommon in the south-western dry region. The temperature is generally about 21 °C even in December, the coldest month.
Monsoon savanna vegetation is found. Large areas are covered with thorny shrubs. It is in the north, along the Godavari Valley the annual rainfall is about 100 cm. where forests occur. Bamboo and teak are found in these forests. During rains, grasses grow and may cover the otherwise bare ground.
There is drought like condition in whole area due to near scarcity and unreliable rainfall. Therefore top priority has been given for arranging irrigation in this region. Tanks are the major source of irrigation. Tungbhandra Irrigation and power project has been developed both by Andhra-Pradesh and Karnataka. Prakasam barrage project is built across the Krishna near Vijayawada to irrigate 47000 hectares of land.
Nagarjunasagar project, a 1450 metre long and 125 metre high straight gravity dam across the Krishna in Nalgonda district has been completed. The Right-Bank canal is the largest canal in the world irrigates the area between the Krishna and the Penner in the south and the Left-Bank Canal irrigates the area between the Krishna and the Godavari in the north.
In Telengana nearly 17 per cent of the net area sown is under irrigation. This percentage increase towards more rainy and fertile alluvial belt lying adjacent to the right bank of the Godavari in the north.
In Rayalaseema comparatively less area is under irrigation. Chittoor district in the extreme south has relatively high rainfall. A little more than one-third of the net area sown is under irrigation in this district. Owing to seasonal rainfall and inadequate irrigation facilities very small proportion of the cultivated area is sown more than once.
Net area sown is about 42 per cent of the total area of this region. Food grain crops are again the dominant crops and occupy as much as three-fourths of total cropped area.
Though jowar and rice are raised throughout this region, the crop pattern of Telengana differs from that of Rayalaseema. In Telengana, jowar, rice and pulse are the principal crops and they occupy about 76.0 per cent of the total cropped area.
Groundnut is a popular crop of this region. Light sandy soils, suitable annual rainfall and temperature conditions and demand from foreign countries have encouraged rapid increase in the area under this crop. One-fourth of Rayal-seema district is under this crop.
Castor is a distinctive crop of southern Telengana where climatic and soil conditions for the growth of castor are available. This area is one of the leading castorseed producing areas of India.
Hyderabad and Secunderabad have some industries of the significance. Coal mined at Tandur, Kottagudem, in Godavari valley has played a significant role in establishing large scale industries. There is also a super thermal power station at Ramagundam which supplies power to Hyderabad. There is also large coal-based fertilizer (urea) plant in Ramagundem.
There is a sponge Iron plant near by Kothagudem. Lurgi Company of Germany has supplied the process know-how. This process has enabled the plant to produce sponge iron from lump iron ore by using non-cooking coal instead of cooking coal. The raw materials required for making sponge iron are iron ore, non-cooking coal and limestone. The spongy iron produced by this -process is converted into steel by electric arc furnaces. Hyderabad the capital city of Andhra Pradesh is important.
It has a twin city of Secunderabad having various consumer goods industries. Bellary, Kurnool, Guntakal and Cuddapah are important towns of Rayalaseema. Tirupati, a sacred town and an important pilgrimage centre of South India is in Telengana region.