The Physical Environment
Karnataka State is in the southwestern part of India. It is mainly a tableland and an extension of Deccan plateau. It is rhomboid in shape. The state extends to 805 km from north to south and to about 283 km from east to west. The total area of the state is 192,493 sq. km.
Mysuru district lies in the Southern Maidan (Southern Plateau) and it is in the southernmost part of Karnataka State. Physiographically, the region in which the district is found may be classified as partly maidan and partly semimalnad (malnad hilly lands). The district forms the southern part of the Deccan peninsula with Tamil Nadu to its southeast, the Kodagu district to its west, Mandya district to its north, Hassan district to its northwest and Bangalore district to its northeast.
Mysuru district forms a distinct land unit, besides being a cultural entity lying between 11°30' N to 12°50' N latitudes and 75°45' E to 77°45' E longitudes. It covers an area of 6854 sq. km. that is, 3.57 per cent of the state’s total geographical area. It holds the sixth place in the state in terms of the area with a population of 2.641 million in 2001.
Location and Area
Physiographically, it lies between maiden and semi-malnad range at an altitude of 610 metres from the mean sea level. The district covers a total geographical area of 6,76,382 hectares of which 62,851 hectares constitutes the forest land. The net cultivable land is 4,86,410 hectares and of this 1,14,010 hectares of land is irrigated. The prominent river of the district is the Cauvery. Mysuru district is considered as one of the prosperous district of the state based on the development and utilization of irrigation facilities, abundance of forest wealth and sericultural products.
Agro - Climatic Conditions
The climatic conditions of the district are favourable to crops like paddy, jowar, ragi, pulses, sugarcane and tobacco. The district can be divided into two major agro-climatic zones: the Southern Dry Zone comprising of 4 taluks namely, Nanjangud, T. Narasipur, Mysuru and K. R. Nagar and the Southern Transition Zone consisting of H. D. Kote, Hunsur, and Periyapatna taluks. Soil is red sandy loam in most of the areas of the district. The annual rainfall ranges from 670 mm to 888.6 mm in dry zones and from about 612 mm to 1054 mm in the transition zone. The average annual rainfall of the district is 782 mm. The temperature ranges from 11°C to 38°C. Thus the climate of Mysuru district is temperate with moderate variations in temperature in different seasons.
Mysuru district is an undulating tableland with granitic rocks protruding at odd intervals. The general elevation of the district ranges between 700 and 900 metres above the mean sea level. The mountain ranges in the district originate from the Nilgiris along its southern borders and runs in a northwest and northeast direction. There are the Ghats and, in between them lies the Mysuru plateau, which is peneplaine with an average elevation of 700 metres. Except in the north, the district is almost entirely surrounded by the Western Ghats which at places are an elevation of more than 1200 meters above the mean sea level. Only along the southeast, the mountain ring is broken, where the river Cauvery takes its course towards the Ghats and plunges into the famous Gaganachukki and Barachukki falls at Shivansamudram.
Geologically, the district is mainly composed of igneous and metamorphic rocks of Pre-Cambrian age either exposed at the surface or covered with a thin mantle of residual and transported soils. The rock formation in the district falls into two groups, charnockite series and granite genesis and gneissic granite. A fairly wide area of the district consists of charnokites series of rocks, particularly along the southeastern borders of Yelandur and Biligirirangana hills and also at the western border near Hangod in Hunsur Taluk. The intervening ground consists of granitic genesis with thin beds, lenses and elongated runs of various hornblendic rocks, pyroxenites and durities containing chromate and magnesite. Dolerites are in large numbers to the west of Hunsur and Gundlupet taluks.
The Sargur schist belt in H. D. Kote taluk extends from Sargur to Mysuru city for about 40 km. This belt was named as Sargur series. The series comprise of a complex series of metasediments and basic igneous rocks. The garnets illuminate gneiss and the associated norites occurring as patches within the genesis of southern Mysuru represent the remnants of the older khondalite - charnockite system.
The between Bettadabidu and Doddakanya is essentially a flat lying genesis terrain with numerous enclaves of meta-sedimentary units consisting of quartzites, pelitic schists, crystalliner limestone, cal-silicates and ferruginous quartzites into which the ultramafic and the basic rocks have been emplaced. The enclaves of the schistose units vary in size from just maple units to whole hill ranges, for example, the Konnainabetta ranges.
In the H. D. Kote and Gundlupet regions, the bands of highly altered rocks of kyanite, staurolite, siliceous schists and also bands of limestone and quartizites are found. These rocks are of great economic importance because of the presence of graphite, corundum and granets in them. They extend from Bilikere region up to the southern border of the district in the south-southwest direction for nearly 50 km. Fine textured granite beds are found in Mysuru taluk and around Mysuru city.
The climate of the study area is agreeable. The district enjoys cool and equable temperatures. Mysuru district shares the wider climatic pattern of the state as a whole, although there are some distinctive features. The climate of the district may be described
as essentially tropical monsoon type which is a product of the interplay of the two opposing air-masses of the southwest and northeast monsoons. Over the greater part of the district, summers are languorously warm and winters bracingly cool. By and large, Mysuru district is endowed with a delightful or salubrious climate.
Generally, the following four seasons are applicable to Mysuru district.
1. Cold Weather Season
2. Hot Weather Season
3. South-west Monsoon
4. North-east Monsoon
Cold Weather Season
The cold weather season begins early in January and continues till the end of February. In this season, the weather is cool and moist in the taluks of H D Kote, Hunsur and Periyapatna, but in the remaining taluks of the district it is comparatively dry except in the catchments areas of the rivers. There are wide variations in between day and night temperatures. The temperature is lower than in the hot weather season but the average temperature does not go below 16.5°C. January is the typical cold month and records very low temperatures. The temperatures during the cold weather season (November to February) ranges form 16.1°C to 31.3°C.
Hot Weather Season
The Hot Weather Season begins in the month of March and increases in its intensity towards the end of May. In this season, the temperature ranges from 19.7°C to 35.1°C. Land becomes very hot and there is a wide range of variations between day and night temperatures. However, there is occasional relief from per-monsoon thunderstorms.
The southwest monsoon sets in about the end of May or early June and it continues with some intervals till the end of September. It is dominant in the district and also it brings heavy rains to this region. The district receives a major portion of its rainfall from the southwest monsoon. The normal annual rainfall is around 760 mm, spread over a period of seven months, from the later half of April to October. Rainfall is gradually decreasing from west to east. The annual average rainfall ranges between 600 mm and 1,100 mm.
The northeast monsoon commences in October and ceases by the end of December. The monsoon winds bring some rains to the eastern parts of the district. The duration of the monsoon is shorter and rains are also very low and they are confined to smaller area of the district.
Temperature influences considerably the socio-economic activities of the people in a region. The district in general enjoys cool and equable temperatures. In the period from March to May, there is a continuous rise in temperature. April is the hottest month with the mean daily maximum temperature at 34.5°C and the daily minimum at 21.1°C. On normal days, the day temperatures during summer may exceed 39°C. There is welcome relief from the heat when thunder showers occur during April and May. With the advance of the southwest monsoon about the beginning of June, the day temperatures drop appreciably and throughout the southwest monsoon period, the weather is pleasant. After mid-November, both day and night temperatures decrease progressively. January is the coldest month with mean daily maximum at 11°C. On some days during the period November to January, the minimum temperature may go below 11°C.
The highest maximum temperature recorded at Mysuru was 39.4°C on the 4th of April 1917. The lowest minimum temperature was 10.6°C on the 13th of December 1945. The temperature remains nearly the same for several months but begins to rise in February and touches the peak in either April or May, in both maximum and minimum. Minimum is near about 20° C and the maximum is near about 30° C for several months.
Relative humidities are generally high during the southwest monsoon season. Relative humidities are about 70 per cent and over in the mornings throughout the year, while in the afternoons, humidities are comparatively lower except during the southwest monsoon. The period January to April is the driest part of the year with relative humidities of about 30 per cent and still lower in the afternoons.
The variation in the annual rainfall from year to year is not large during the 85 years from 1901 to 1985, the highest annual rainfall amounting to 156 per cent of the annual rainfall that occurred in 1903 and the lowest occurred in 1918. In the same 85 year period, the annual rainfall was less than 80 per cent of the normal rainfall in 7 years, none of them consecutive, considering the rainfall at the individual stations. However, two or three consecutive years of good rainfall occurred once or twice at fifty two out of sixty five rain gauge stations. It is observed that the average annual rainfall in the district was between 600 mm and 900 mm in 66 years out of the 85 years.
Monthly Distribution of Rainfall
The distribution in the district is confined to the months of April to November. September is the rainiest month with 180.86 mm. January receives the lowest rainfall of 2.02 mm. The rainfall from June to September constitutes only about 55.07 per cent of the annual rainfall. The rainfall during the pre-monsoon months of April and May and during the post-monsoon months of October and November are as much as 25.37 percent and 15.13 per cent, of the annual rainfall respectively.
Distribution of Rainfall by Taluks
H. D. Kote, Hunsur, and Periyapatna taluks are cool and moist during winter and rainy season and these taluks are in the semimalnad areas. The remaining taluks are comparatively dry (except the regions of rivers) during the year. In 1960, the highest rainfall was recorded in H D Kote at 920.1 mm and the lowest in Hunsur taluk with only 762.8 mm. The distribution of rainfall in the district was satisfactory and it was more than 762 mm. In 1965, the distribution of rainfall in the district was not satisfactory. The highest rainfall was recorded in H D Kote at 817 mm and the lowest was in Nanjangud at 420.9 mm. In the year 1985, low rainfall was recorded in the district. The amount of rainfall received has been considerable from 1980 to 1985 and however during 1985-86, 1021 villages out of 1,837 villages were declared as drought hit areas as the rainfall was much below the average. The highest actual rainfall during 2003 was in H. D. Kote taluk with 811.8 mm and the lowest actual rainfall in K. R. Nagar was 507.9mm.
Special Weather Phenomena
During October and November, some of the depressions and cyclonic storms which originate in the Bay of Bengal, cross the east coast and move across the peninsula. Such depressions and storms pass through or remain in the neighborhood of the district causing widespread, heavy rains and high winds. Thunderstorms are common during the hot season and the post-monsoon months. Rainfall during the monsoon season is also sometimes associated with thunder.
Mysuru district is endowed with a number of perennial and non-perennial rivers. The Cauvery which is the major system of the district traverses the Mysuru plateau from northwest to east along with its tributaries Kabini, Suvarnavathi, Laxmanathirtha and others.
The Cauvery rises at Talacauvery in Kodagu district and flows along the boundary of Periyapatna taluk, enters into the district through K R Nagar taluk. It further moves into T. Narasipur and Kollegal before reaching Tamil Nadu.
The total catchments area of the river is the second largest in the State and it covers nearly 18 per cent of the land area of the State. It is the only river which has been harnessed for irrigation from ancient times and it is estimated that as much as 95 per cent of its surface flow is put to use before it enters into the Bay of Bengal.
River Kabini raises at Wynad in Kerala State comes into the State at Siddapura in Kodagu district and enters into the district at H D Kote taluk. The important tributaries of this river are the Gundluhole, the Nuguhole, and small streams such as the Taraka, the Vodehattihole and the Sarathihole which flow from H D. Kote and reach the Kabini river only in the rainy season. The river Laxmanathirtha rises in Kodagu district and flows into Hunsur taluk and finally reaches Krishna Raja Sagar Dam. The total catchment is nearly 178.2 sq.km. The Gundluhole (hole = river) originates in Gundlupet taluk at the Gopalaswamy Betta and enters into Nanjangud taluk and reaches the Kabini river. The Nuguhole has also its origin at H D Kote taluk, flows into Nanjangud taluk and reaches the Kabini river.
The soils of the districts can be broadly classified as the laterite, red loam, sandy loam, red clay and black cotton soils. The laterite soil occurs mostly in the western part of the district while the red loam is found in the northwest. These two account for nearly half the area of the district. The black cotton soil is found mostly in the northeastern parts of the district. The red sandy loam soils are derived from the granites and gneisses. The western taluks of Periyapatna, H D Kote and Hunsur are covered with hilly terrain and contain red, shallow gravelly soils. In the taluks of T. Narasipura and Nanjanagud, there is deep red loam occasionally interspersed with black soils. The red soils are shallow to deep well drained and do not contain lime nodules. The black soils are 1 to 1.5 metre in bases with good water holding capacity for a longer time.
The area covered by forest is 4,126.45 sq. km, 34.52 per cent of the total area, of which 3,875.6 sq. km, are reserved forest, and 250.9 sq. km. are classified as forests. Mysuru has two types of forests and they are moist deciduous where the rainfall is 900-1100 mm and dry deciduous where the rainfall is 700 – 900 mm
Mysuru district is the third richest in forest wealth in the State. The forest belt in the district begins from the western part of Hunsur taluk, spreads along the border of Kerala and Tamil Nadu into the south and east. The thickest and richest forest areas are in H D Kote. The Principal species of trees in the forests are teak, honne, rosewood, dindiga, eucalyptus and sandalwood. It is only in the hilly areas, there is however a resemblance of evergreen forests.
The major produce of the forests in the district consists of teak, matchwood, sandalwood, rosewood and building materials. Indirectly, forests of the region confer various ecological benefits on the land such as salubrious climate and good rainfall. They are above all ecosystem habitats.