Thiruvalla, alternately spelled Tiruvalla, is a town in Kerala and the Headquarters of the Taluk of the same name located in Pathanamthitta district in the State of Kerala, India. The town is spread over an area of . It lies on the banks of the Pambas and Manimala rivers, and is a land-locked region surrounded by irrigating streams and rivers.It is the largest town in the district and central Travancore. Thiruvalla is regarded as the "Land of Non resident Indians". It is the financial,educational,cultural and commercial capital of central travancore. Demographics The town spans a geographic area of with a population of 52,883 as of 2011, a decline from the 57,800 recorded in the previous census. Males constitute 48% of the population and females 52%. In Thiruvalla, 5% of the population is under 6 years of age. Etymology Tradition tells that the name Thiruvalla comes from the word "Valla Vaay", named after the river Manimala which was known as Vallayār in ancient times. Before roads were developed, Thiruvalla village developed at the mouth of the river Vallayar, connected far and near places through waterways, and hence was known as Valla vāi(vāy in old Malayalam means mouth of river). Later the Thamizh Prefix 'Thiru (means holy /revered) attached to it and became Thiruvalla. Sree Vallabha is the presiding deity of the Thiruvalla Temple and argues that shreevallabha Puram (Land of Vallabhan) became Thiruvalla. Thiruvalla as per the Sanskrit work "श्रीवल्लभ क्षेत्र माहात्म्यम्" (ശ്രീവല്ലഭ ക്ഷേത്ര മാഹാത്മ്യം) (śrīvallabha kṣētra māhātmyaṁ) is "श्रीवल्लभपुरम्" (ശ്രീവല്ലഭപുരം)(śrīvallabhapuraṁ). The work is said to be of 10th-century CE. Geography and climate Thiruvalla lies at an altitude of 9 meters above sea level on the basin of the Pamba and Manimala rivers. Thiruvalla is dotted with several natural canal streams (called "thodu" in Malayalam) like Chanthathodu, Manippuzha, Mullelithodu, and several others. The city area has riverine alluvial soil, and eastern parts have a laterite loam kind of soil classified under "Southern Midlands" agro-ecological zone, while the western suburbs like Niranam have a more sandy type of soil that resembles beaches. (Kuttanad agro-ecological zone) The reason for this is believed to be the older status of Niranam as a port, before reclamation of Kuttanad from sea occurred. The Upper Kuttanad region in Thiruvalla has the "Karappadam" type of soil, which is clay loam in texture, has high organic matter, and is situated in areas about 1–2 m above sea level. Thiruvalla