| GISdevelopment.net ---> Application ---> Natural Resource Management |
Land Use / Land Cover Mapping of The Sub-Watersheds of North Pennar River Basin Around Pavagada, Karnataka, India using Remote Sensing and GIS Techniques
S Srinivasa Vittala*, S Govindaiah**, H Honne Gowda*
*Karnataka State Remote Sensing Applications Centre, Bangalore-560 033, India
**Department of Geology, University of Mysore, Manasagangothri, Mysore-570 006, India
ABSTRACT
The land use / land cover maps were prepared using satellite images of IRS 1C and 1D LISS III and LISS III and PAN merged data on 1:50,000 scale and topographic maps were used as reference on the same scale. The different land use / land cover classes like settlements, crop land, fallow and agricultural plantations, scrub degraded forest, forest plantation, land with scrub, land without scrub, prosofis juliflora (Bellary jali), salt affected land, barren rocky / stony waste / sheet rock area, rivers, streams and tanks were delineated based on the image characteristics. The cropland may be of either kharif or rabi or double crop (Kharif + Rabi). The major kharif crop identified was groundnut. The double cropped areas are found in command areas like major tanks, either side of stream where deep clay loamy to clayed soil patches found and the double crops identified in the study area are mainly of paddy, ragi and groundnut and noticed in almost all sub-watersheds. The agricultural plantations are mainly of coconut and forest plantations consist of Eucalyptus. The salt affected lands are confined in the eastern and north-eastern parts of the study area. The double cropped area and agricultural plantations are mainly noticed along valleys and tank command areas. Similarly waste lands like stony waste and scrub lands are found in the uplands and along the fringes of the forest area.
INTRODUCTION
Land use refers to "man's activities and the various uses which are carried on land". Land cover refers to, "natural vegetation, water bodies, rock/soil, artificial cover and others resulting due to land transformations". Proper planning, management and monitoring of the natural resources depend on the availability of accurate land use information. Over the years, remote sensing has been used for land use / land cover mapping of different parts of India (Gautam and Narayanan, 1983; Sharma et al., 1984; Jain, 1992; Rathore, 1996; Palaniyandi and Nagarathinam, 1997; Jaiswal et al., 1999; Minakshi et al., 1999; Bhamabhatt et al., 2000).
STUDY AREA
The study area falls between 13º55' to 14º17' N latitude and 77º05' to 77º25' E longitude forms one of the watersheds of North Pennar river basin covering an area of 570 sq.km in Pavagada taluk of Tumkur district and a small portion in Ananthpur district of Andhra Pradesh (Fig. 1). This watershed has been subdivided into nine sub-watersheds based on IMSD Guidelines (NRSA, 1995) namely Dalavayihalli, Maddalenahalli, Talamaradahalli, Puluvalli tank, Nagalamadike, Gowdatimmanahalli, Naliganahalli, Devadabetta and Byadanur which range in area from 49 to 75 sq.km. Geologically, the area forms a part of the hardrock terrain in Tumkur district and includes two rock types, viz., gneisses and granites (GSI, 1981). The gneisses are intruded by a number of dolerite dykes that demarcate the boundaries of some of the sub-watersheds in the basin. Granites form a part of northern extension of Closepet granite batholith, which divides the Dharwar Craton into western and eastern blocks. These younger granites (2500 my) constitute a well-defined narrow range of hills, which run in north-south direction and forms western part of the study area. The climate of the area is semi-arid and is characterized by hot summer months, low rainfall and pleasant monsoon of winter season. The temperature varies from 22.6ºC to 35.3ºC during summer and 16.7ºC to 27.3ºC during winter season. The average annual rainfall is 560 mm. The area has sandy reddish brown soils with thickness varying from 0.50 to 2 m (Reddy and Rangaswamy, 1989).
DATA USED AND METHODOLOGY
In the present study, the land use / land cover maps were prepared using satellite images of IRS 1C and 1D LISS III and LISS III and PAN merged data on 1:50,000 scale in conjunction with collateral data like topographic maps on the same scale. The detail of the IRS satellite data used in the present study is given in Table 1. Various land use / land cover classes were delineated based on the image characteristics like tone, texture, shape, color, association, background etc. following standard visual interpretation techniques suggested by Lillesand and Kiefer (2002).During the interpretation, wherever doubtful units are encountered, ground truth survey was undertaken to verify the same. Classification of various land use / land cover classes in the present study has been carried out based on the methodology given in NRIS Node Design and Standards prepared by NNRMS, 2000.
RESULTS AND DISCUSSION
There are four main land use / land cover classes like built-up land (settlements), agricultural land (crop land, fallow and agricultural plantations), forest (scrub, degraded forest and forest plantation), wastelands (land with scrub, land without scrub, prosofis juliflora, salt affected land and barren rock / stony waste) and water bodies (rivers, streams, tank-dry and tank- water spread) were delineated in the present study. The land use / land cover map has been prepared for each sub-watershed (Fig. 2) and the sub-watershed wise area statistics in sq.km for each land use / land cover classes is also presented in Table 2.
Built-up land (Settlements)
It is defined as an area of human habitation developed due to non-agricultural use and that which has a cover of buildings, transport, communication, utilities in association with water, vegetation and vacant lands. This class is observed in almost all sub-watersheds where Nagalamadike sub-watershed is occupying large area of built-up lands (1.60 sq.km) including Pavagada town and minimum of 0.33 sq.km area in Dalavayihalli sub-watershed (Fig. 2, Table 2).
Agricultural land
It is defined as the land primarily used for farming and for production of food, fiber, and other commercial and horticultural crops. It includes crop land, fallow and agricultural plantations.
Crop land : It includes those lands with standing crop as on the date of the satellite imagery. The crops grown either in kharif or rabi or double crop (Kharif + Rabi) seasons. The Kharif season satellite imageries (Table 1) were used to identify the cropland under kharif season. At the time of field validation the major kharif crop identified was groundnut. This class is extensively found and occupied in all sub-watersheds where the maximum of 51.35 sq.km is found in Nagalamadike and minimum of 28 sq.km is found in Byadanur sub-watershed. Double cropped area have been delineated using both kharif and rabi season imagery. Most of the double cropped areas are found in command areas like major tanks, either side of stream where deep clay loamy to clayed soil patches found. The double crop area consists of mainly of paddy, ragi and groundnut. This crop is also observed in almost all sub-watersheds. In Gowdatimmanahalli sub-watershed this crop occupies a large area (10.40 sq.km) whereas in Nagalamadike sub-watershed it occupies a minimum area of 3.98 sq.km (Fig. 2, Table 2).
Fallow land : It is described as agricultural land, which is taken up for cultivation but is temporarily allowed to rest, un-cropped for one or more seasons. These lands are particularly those, which are seen devoid of crops at the time when the imagery is taken of both seasons. In the present study, this class is observed in only in Dalavayihalli sub-watershed with an area of 0.40 sq.km and is absent in other sub-watersheds (Fig. 2, Table 2).
Agricultural plantation : It is described as an area under agricultural tree crops planted adopting certain agricultural management techniques. Agricultural plantations are identified using summer season data. The agricultural plantations prominently seen in the study area during ground truth verification was mostly of coconut plantations. This class is found in only 5 sub-watersheds of which Gowdatimmanahalli sub-watershed consists of these plantations with a maximum area of 0.14 sq.km and minimum of 0.05 sq.km in Maddalenahalli sub-watershed. These plantations are absent in Byadanur, Nagalamadike, Devadabetta and Talamaradahalli sub-watersheds (Fig. 2, Table 2).
Forest :It is an area (within the notified forest boundary) bearing an association of pre-dominantly of trees and other vegetation types capable of producing timber and other forest produce. This class is distributed in north-west, west, south and south-western parts of study area. The sub-classes under this class have been identified and described.
Scrub forest : It is described as a forest where the vegetative density is less than 20% of the canopy cover. It is the result of both biotic and abiotic influences. Scrub is a stunted tree or bush/ shrub. This class has been identified in almost all sub-watersheds except in Maddalenahalli sub-watershed. In Talamaradahalli sub-watershed, this sub-class occupies a maximum area of 4.99 sq.km and in Devadabetta sub-watershed it occupies a minimum area of 0.01 sq.km (Fig. 2, Table 2).
Degraded forest : In this sub-class, the vegetative density is still less and gradually under degraded stage. This is also the result of both biotic and abiotic influences. This sub-class is observed in 7 sub-watersheds out of which it covers a maximum area of 0.84 sq.km in Naliganahalli sub-watershed and minimum area of 0.18 sq.km in 3 sub-watersheds namely Byadanur, Puluvalli tank and Dalavayihalli sub-watersheds. It is almost absent in Maddalenahalli and Devadabetta sub-watersheds (Fig. 2, Table 2).
Forest plantation : It is described as an area of trees of species of forestry importance and raised on notified forestlands. This sub-class consists mainly of Eucalyptus plantations as observed during field visit. The forest plantation is found in only 2 sub-watersheds namely Puluvalli tank and Gowdatimmanahalli sub-watersheds having an area of 0.57 and 0.30 sq.kms respectively (Fig. 2, Table 2).
Wasteland Wastelands may be described as degraded land which can be brought under vegetative cover with reasonable effort and which is currently under unutilized land. This land is deteriorating due to lack of appropriate water and soil management or on account of natural causes. Wastelands can result from inherent/imposed constraints such as by location, environment, chemical and physical properties of the soil or financial or management constraints. This class includes salt affected land, land with scrub, land without scrub, stony waste and prosofis juliflora (locally named as Bellary jali).
Salt affected land : The salt affected land is generally characterized as the land that has adverse effects on the growth of most plants due to the action or presence of excess soluble or high exchangeable sodium. These features are confined in the eastern and north-eastern parts of the study area and observed in only 4 sub-watershed namely Naliganahalli, Nagalamadike, Maddalenahalli and Dalavayihalli sub-watersheds where maximum of 0.05 sq.km of the area in Maddalenahalli and 0.08 sq.km area in Naliganahalli sub-watershed (Fig. 2, Table 2).
Land with scrub : This sub-class is found usually at relatively higher topography like uplands or high grounds with scrub. These lands are generally prone to degradation or erosion. These exclude hilly and mountainous terrain. It is noticed in all sub-watersheds with an area ranging from 0.05 to 1.62 sq.km. The maximum area is observed in Nagalamadike sub-watershed while the minimum area is observed in Devadabetta sub-watershed (Fig. 2, Table 2).
Land without scrub : These features are also found usually at relatively higher topography like uplands or high grounds without scrub. These lands are generally prone to degradation or erosion. These exclude hilly and mountainous terrain. These features are observed only in Puluvalli tank (0.02 sq.km) and Dalavayihalli sub-watersheds (0.11 sq.km) (Fig. 2, Table 2).
Barren rocky / Stony waste / Sheet rock area : Stony waste may be defined as the rock exposures of varying lithology often barren and devoid of soil cover and vegetation. They occur amidst forest hills as openings or scattered as isolated exposures or loose fragments of boulders or as sheet rocks on plateau and plains, in almost all parts of the study area. Stony wastes have been observed in all the sub-watersheds varying from 3.64 (Devadabetta sub-watershed) to 11.90 sq.km (Dalavayihalli sub-watershed) (Fig. 2, Table 2).
Prosofis juliflora (Bellary jali) : These features are abundantly observed along streams and river courses as bushes and thorns. These features are found only in 4 sub-watersheds (Fig. 2, Table 2) and vary in area from 0.08 sq.km (Gowdatimmanahalli sub-watershed) to 0.46 sq.km (Puluvalli tank sub-watershed).
Water body Water body is an area of impounded water, aerial in extent and often with a regulated flow of water. It includes man-made lakes / tanks besides natural lakes, rivers and streams.
Tanks : Tanks are the natural or man-made enclosed water body with a regulated flow of water. These features are medium/smaller in aerial extent when compared to reservoirs with limited use. Based on the observations on the satellite image in all the three seasons, tanks may be differentiated into tank (dry) and tank (water spread). Tanks are found in almost all the sub-watersheds varying in area from 0.15 sq.km to 2.52 sq.km. The largest tank in the study area is Puluvalli tank near Puluvalli village. There are new tanks have also been identified in the satellite data in Dalavayihalli and Nagalamadike sub-watersheds covering an area of 0.27 and 0.02 sq.km respectively (Srinivasa Vittala et al., 2004).
Streams : These are the natural course of flowing water on the land along definite channels. It includes from a small stream to a big river and its branches. These may be perennial or non-perennial. The small streams are observed only in 6 sub-watersheds in the study area which are finally joining to the river North Pennar (Fig, 1 & 2, Table 2). A stream has changed its course in the northern side of Maddalenahalli village as revealed by the satellite imagery. Field visits to these places confirm the same (Srinivasa Vittala et al., 2004).
CONCLUSION
The land use / land cover maps were prepared using satellite images on 1:50,000 scale and topographic maps were used as reference on the same scale. The different land use / land cover classes like settlements, crop land, fallow and agricultural plantations, scrub degraded forest, forest plantation, land with scrub, land without scrub, prosofis juliflora (Bellary jali), salt affected land, barren rocky / stony waste / sheet rock area, rivers, streams and tanks were delineated based on the image characteristics. The cropland may be of either kharif or rabi or double crop (Kharif + Rabi). The major kharif crop identified was groundnut. The double cropped areas are found in command areas like major tanks, either side of stream where deep clay loamy to clayed soil patches found and the double crops identified in the study area are mainly of paddy, ragi and groundnut and noticed in almost all sub-watersheds. The agricultural plantations are mainly of coconut and forest plantations consist of Eucalyptus. The salt affected lands are confined to the eastern and north-eastern parts of the study area and observed in only 4 sub-watersheds namely Naliganahalli, Nagalamadike, Maddalenahalli and Dalavayihalli sub-watersheds. Stony waste is noticed in almost all parts of the study area. Prosofis juliflora (Bellary jali) are abundantly observed along streams and river courses. Based on the observations using satellite image for all the three seasons, tanks have been differentiated into tank (dry) and tank (water spread). From the land use / land cover mapping, it can be concluded that the double cropped area and agricultural plantations are mainly noticed along valleys and tank command areas. Similarly waste lands like stony waste and scrub lands are found in the uplands and along the fringes of the forest area.
REFERENCE
Fig. 1 : Location map with sub-watershed overlay and geology.
Fig. 2 : Land use / land cover map of each sub-watershed
Table 1 : Details of IRS 1C/1D Satellite data used for classification of land use / land cover mapping.
Table 2 : Sub-watershed wise area statistics (in sq.km) of each land use / land cover classes.
S Srinivasa Vittala*, S Govindaiah**, H Honne Gowda*
*Karnataka State Remote Sensing Applications Centre, Bangalore-560 033, India
**Department of Geology, University of Mysore, Manasagangothri, Mysore-570 006, India
ABSTRACT
The land use / land cover maps were prepared using satellite images of IRS 1C and 1D LISS III and LISS III and PAN merged data on 1:50,000 scale and topographic maps were used as reference on the same scale. The different land use / land cover classes like settlements, crop land, fallow and agricultural plantations, scrub degraded forest, forest plantation, land with scrub, land without scrub, prosofis juliflora (Bellary jali), salt affected land, barren rocky / stony waste / sheet rock area, rivers, streams and tanks were delineated based on the image characteristics. The cropland may be of either kharif or rabi or double crop (Kharif + Rabi). The major kharif crop identified was groundnut. The double cropped areas are found in command areas like major tanks, either side of stream where deep clay loamy to clayed soil patches found and the double crops identified in the study area are mainly of paddy, ragi and groundnut and noticed in almost all sub-watersheds. The agricultural plantations are mainly of coconut and forest plantations consist of Eucalyptus. The salt affected lands are confined in the eastern and north-eastern parts of the study area. The double cropped area and agricultural plantations are mainly noticed along valleys and tank command areas. Similarly waste lands like stony waste and scrub lands are found in the uplands and along the fringes of the forest area.
INTRODUCTION
Land use refers to "man's activities and the various uses which are carried on land". Land cover refers to, "natural vegetation, water bodies, rock/soil, artificial cover and others resulting due to land transformations". Proper planning, management and monitoring of the natural resources depend on the availability of accurate land use information. Over the years, remote sensing has been used for land use / land cover mapping of different parts of India (Gautam and Narayanan, 1983; Sharma et al., 1984; Jain, 1992; Rathore, 1996; Palaniyandi and Nagarathinam, 1997; Jaiswal et al., 1999; Minakshi et al., 1999; Bhamabhatt et al., 2000).
STUDY AREA
The study area falls between 13º55' to 14º17' N latitude and 77º05' to 77º25' E longitude forms one of the watersheds of North Pennar river basin covering an area of 570 sq.km in Pavagada taluk of Tumkur district and a small portion in Ananthpur district of Andhra Pradesh (Fig. 1). This watershed has been subdivided into nine sub-watersheds based on IMSD Guidelines (NRSA, 1995) namely Dalavayihalli, Maddalenahalli, Talamaradahalli, Puluvalli tank, Nagalamadike, Gowdatimmanahalli, Naliganahalli, Devadabetta and Byadanur which range in area from 49 to 75 sq.km. Geologically, the area forms a part of the hardrock terrain in Tumkur district and includes two rock types, viz., gneisses and granites (GSI, 1981). The gneisses are intruded by a number of dolerite dykes that demarcate the boundaries of some of the sub-watersheds in the basin. Granites form a part of northern extension of Closepet granite batholith, which divides the Dharwar Craton into western and eastern blocks. These younger granites (2500 my) constitute a well-defined narrow range of hills, which run in north-south direction and forms western part of the study area. The climate of the area is semi-arid and is characterized by hot summer months, low rainfall and pleasant monsoon of winter season. The temperature varies from 22.6ºC to 35.3ºC during summer and 16.7ºC to 27.3ºC during winter season. The average annual rainfall is 560 mm. The area has sandy reddish brown soils with thickness varying from 0.50 to 2 m (Reddy and Rangaswamy, 1989).
DATA USED AND METHODOLOGY
In the present study, the land use / land cover maps were prepared using satellite images of IRS 1C and 1D LISS III and LISS III and PAN merged data on 1:50,000 scale in conjunction with collateral data like topographic maps on the same scale. The detail of the IRS satellite data used in the present study is given in Table 1. Various land use / land cover classes were delineated based on the image characteristics like tone, texture, shape, color, association, background etc. following standard visual interpretation techniques suggested by Lillesand and Kiefer (2002).During the interpretation, wherever doubtful units are encountered, ground truth survey was undertaken to verify the same. Classification of various land use / land cover classes in the present study has been carried out based on the methodology given in NRIS Node Design and Standards prepared by NNRMS, 2000.
RESULTS AND DISCUSSION
There are four main land use / land cover classes like built-up land (settlements), agricultural land (crop land, fallow and agricultural plantations), forest (scrub, degraded forest and forest plantation), wastelands (land with scrub, land without scrub, prosofis juliflora, salt affected land and barren rock / stony waste) and water bodies (rivers, streams, tank-dry and tank- water spread) were delineated in the present study. The land use / land cover map has been prepared for each sub-watershed (Fig. 2) and the sub-watershed wise area statistics in sq.km for each land use / land cover classes is also presented in Table 2.
Built-up land (Settlements)
It is defined as an area of human habitation developed due to non-agricultural use and that which has a cover of buildings, transport, communication, utilities in association with water, vegetation and vacant lands. This class is observed in almost all sub-watersheds where Nagalamadike sub-watershed is occupying large area of built-up lands (1.60 sq.km) including Pavagada town and minimum of 0.33 sq.km area in Dalavayihalli sub-watershed (Fig. 2, Table 2).
Agricultural land
It is defined as the land primarily used for farming and for production of food, fiber, and other commercial and horticultural crops. It includes crop land, fallow and agricultural plantations.
Crop land : It includes those lands with standing crop as on the date of the satellite imagery. The crops grown either in kharif or rabi or double crop (Kharif + Rabi) seasons. The Kharif season satellite imageries (Table 1) were used to identify the cropland under kharif season. At the time of field validation the major kharif crop identified was groundnut. This class is extensively found and occupied in all sub-watersheds where the maximum of 51.35 sq.km is found in Nagalamadike and minimum of 28 sq.km is found in Byadanur sub-watershed. Double cropped area have been delineated using both kharif and rabi season imagery. Most of the double cropped areas are found in command areas like major tanks, either side of stream where deep clay loamy to clayed soil patches found. The double crop area consists of mainly of paddy, ragi and groundnut. This crop is also observed in almost all sub-watersheds. In Gowdatimmanahalli sub-watershed this crop occupies a large area (10.40 sq.km) whereas in Nagalamadike sub-watershed it occupies a minimum area of 3.98 sq.km (Fig. 2, Table 2).
Fallow land : It is described as agricultural land, which is taken up for cultivation but is temporarily allowed to rest, un-cropped for one or more seasons. These lands are particularly those, which are seen devoid of crops at the time when the imagery is taken of both seasons. In the present study, this class is observed in only in Dalavayihalli sub-watershed with an area of 0.40 sq.km and is absent in other sub-watersheds (Fig. 2, Table 2).
Agricultural plantation : It is described as an area under agricultural tree crops planted adopting certain agricultural management techniques. Agricultural plantations are identified using summer season data. The agricultural plantations prominently seen in the study area during ground truth verification was mostly of coconut plantations. This class is found in only 5 sub-watersheds of which Gowdatimmanahalli sub-watershed consists of these plantations with a maximum area of 0.14 sq.km and minimum of 0.05 sq.km in Maddalenahalli sub-watershed. These plantations are absent in Byadanur, Nagalamadike, Devadabetta and Talamaradahalli sub-watersheds (Fig. 2, Table 2).
Forest :It is an area (within the notified forest boundary) bearing an association of pre-dominantly of trees and other vegetation types capable of producing timber and other forest produce. This class is distributed in north-west, west, south and south-western parts of study area. The sub-classes under this class have been identified and described.
Scrub forest : It is described as a forest where the vegetative density is less than 20% of the canopy cover. It is the result of both biotic and abiotic influences. Scrub is a stunted tree or bush/ shrub. This class has been identified in almost all sub-watersheds except in Maddalenahalli sub-watershed. In Talamaradahalli sub-watershed, this sub-class occupies a maximum area of 4.99 sq.km and in Devadabetta sub-watershed it occupies a minimum area of 0.01 sq.km (Fig. 2, Table 2).
Degraded forest : In this sub-class, the vegetative density is still less and gradually under degraded stage. This is also the result of both biotic and abiotic influences. This sub-class is observed in 7 sub-watersheds out of which it covers a maximum area of 0.84 sq.km in Naliganahalli sub-watershed and minimum area of 0.18 sq.km in 3 sub-watersheds namely Byadanur, Puluvalli tank and Dalavayihalli sub-watersheds. It is almost absent in Maddalenahalli and Devadabetta sub-watersheds (Fig. 2, Table 2).
Forest plantation : It is described as an area of trees of species of forestry importance and raised on notified forestlands. This sub-class consists mainly of Eucalyptus plantations as observed during field visit. The forest plantation is found in only 2 sub-watersheds namely Puluvalli tank and Gowdatimmanahalli sub-watersheds having an area of 0.57 and 0.30 sq.kms respectively (Fig. 2, Table 2).
Wasteland Wastelands may be described as degraded land which can be brought under vegetative cover with reasonable effort and which is currently under unutilized land. This land is deteriorating due to lack of appropriate water and soil management or on account of natural causes. Wastelands can result from inherent/imposed constraints such as by location, environment, chemical and physical properties of the soil or financial or management constraints. This class includes salt affected land, land with scrub, land without scrub, stony waste and prosofis juliflora (locally named as Bellary jali).
Salt affected land : The salt affected land is generally characterized as the land that has adverse effects on the growth of most plants due to the action or presence of excess soluble or high exchangeable sodium. These features are confined in the eastern and north-eastern parts of the study area and observed in only 4 sub-watershed namely Naliganahalli, Nagalamadike, Maddalenahalli and Dalavayihalli sub-watersheds where maximum of 0.05 sq.km of the area in Maddalenahalli and 0.08 sq.km area in Naliganahalli sub-watershed (Fig. 2, Table 2).
Land with scrub : This sub-class is found usually at relatively higher topography like uplands or high grounds with scrub. These lands are generally prone to degradation or erosion. These exclude hilly and mountainous terrain. It is noticed in all sub-watersheds with an area ranging from 0.05 to 1.62 sq.km. The maximum area is observed in Nagalamadike sub-watershed while the minimum area is observed in Devadabetta sub-watershed (Fig. 2, Table 2).
Land without scrub : These features are also found usually at relatively higher topography like uplands or high grounds without scrub. These lands are generally prone to degradation or erosion. These exclude hilly and mountainous terrain. These features are observed only in Puluvalli tank (0.02 sq.km) and Dalavayihalli sub-watersheds (0.11 sq.km) (Fig. 2, Table 2).
Barren rocky / Stony waste / Sheet rock area : Stony waste may be defined as the rock exposures of varying lithology often barren and devoid of soil cover and vegetation. They occur amidst forest hills as openings or scattered as isolated exposures or loose fragments of boulders or as sheet rocks on plateau and plains, in almost all parts of the study area. Stony wastes have been observed in all the sub-watersheds varying from 3.64 (Devadabetta sub-watershed) to 11.90 sq.km (Dalavayihalli sub-watershed) (Fig. 2, Table 2).
Prosofis juliflora (Bellary jali) : These features are abundantly observed along streams and river courses as bushes and thorns. These features are found only in 4 sub-watersheds (Fig. 2, Table 2) and vary in area from 0.08 sq.km (Gowdatimmanahalli sub-watershed) to 0.46 sq.km (Puluvalli tank sub-watershed).
Water body Water body is an area of impounded water, aerial in extent and often with a regulated flow of water. It includes man-made lakes / tanks besides natural lakes, rivers and streams.
Tanks : Tanks are the natural or man-made enclosed water body with a regulated flow of water. These features are medium/smaller in aerial extent when compared to reservoirs with limited use. Based on the observations on the satellite image in all the three seasons, tanks may be differentiated into tank (dry) and tank (water spread). Tanks are found in almost all the sub-watersheds varying in area from 0.15 sq.km to 2.52 sq.km. The largest tank in the study area is Puluvalli tank near Puluvalli village. There are new tanks have also been identified in the satellite data in Dalavayihalli and Nagalamadike sub-watersheds covering an area of 0.27 and 0.02 sq.km respectively (Srinivasa Vittala et al., 2004).
Streams : These are the natural course of flowing water on the land along definite channels. It includes from a small stream to a big river and its branches. These may be perennial or non-perennial. The small streams are observed only in 6 sub-watersheds in the study area which are finally joining to the river North Pennar (Fig, 1 & 2, Table 2). A stream has changed its course in the northern side of Maddalenahalli village as revealed by the satellite imagery. Field visits to these places confirm the same (Srinivasa Vittala et al., 2004).
CONCLUSION
The land use / land cover maps were prepared using satellite images on 1:50,000 scale and topographic maps were used as reference on the same scale. The different land use / land cover classes like settlements, crop land, fallow and agricultural plantations, scrub degraded forest, forest plantation, land with scrub, land without scrub, prosofis juliflora (Bellary jali), salt affected land, barren rocky / stony waste / sheet rock area, rivers, streams and tanks were delineated based on the image characteristics. The cropland may be of either kharif or rabi or double crop (Kharif + Rabi). The major kharif crop identified was groundnut. The double cropped areas are found in command areas like major tanks, either side of stream where deep clay loamy to clayed soil patches found and the double crops identified in the study area are mainly of paddy, ragi and groundnut and noticed in almost all sub-watersheds. The agricultural plantations are mainly of coconut and forest plantations consist of Eucalyptus. The salt affected lands are confined to the eastern and north-eastern parts of the study area and observed in only 4 sub-watersheds namely Naliganahalli, Nagalamadike, Maddalenahalli and Dalavayihalli sub-watersheds. Stony waste is noticed in almost all parts of the study area. Prosofis juliflora (Bellary jali) are abundantly observed along streams and river courses. Based on the observations using satellite image for all the three seasons, tanks have been differentiated into tank (dry) and tank (water spread). From the land use / land cover mapping, it can be concluded that the double cropped area and agricultural plantations are mainly noticed along valleys and tank command areas. Similarly waste lands like stony waste and scrub lands are found in the uplands and along the fringes of the forest area.
REFERENCE
- Bhamabhatt, V.S., Dalwadi, G.B., Chhabra, S.B., Ray, S.S. and Dadhwal, V.K. (2000). Land use / land cover change mapping in Mahi canal command area, Gujarat using multi-temporal satellite data. J. Indian Soc. Remote Sensing, 28(4):221-232.
- Gautam, N.C. and Narayanan, L.R.A. (1983). Landsat MSS data for land use / land cover inventory and mapping: A case study of Andhra Pradesh. J. Indian Soc. Remote Sensing, 11(3):15-28.
- GSI (1981). Geological and Mineralogical Map of Karnataka & Goa, Geological Survey of India.
- Jain, S.K. (1992). Land use mapping of Tawi catchment using satellite data. Repost No. CS-72, National Institute of Hydrology, Roorkee, 52p.
- Jaiswal, R.K., Saxena, R. and Mukherjee, S. (1999). Application of remote sensing technology for land use / land cover change analysis. J. Indian Soc. Remote Sensing, 27(2);123-128.
- Lillesand, T.M. and Kiefer, R.W. (2002). Remote Sensing and Image Interpretation. John Wiley & Sons (ASIA) Pte Ltd, Singapore.
- Minakshi, Chaurasia, R. and Sharma, P.K. (1999). Land use / land cover mapping and change detection using satellite data - a case study of Dehlon Block, Destrict Ludhiana, Punjab, J. Indian Soc. Remote Sensing, 27(2):115-121. NNRMS, (2000). National (Natural) Resources Information System (NRIS) Node Design and Standards, National Natural Resources Management System (NNRMS), ISRO Hqrs., Bangalore. pp.19-21.
- NRSA, (1995). Integrated Mission for Sustainable Development Technical Guidelines, National Remote Sensing Agency, Department of Space, Government of India, Hyderabad.
- Palaniyandi, M. and Nagarathinam, V. (1997). Land use / land cover mapping and change detection using space borne data. J. Indian Soc. Remote Sensing, 25(1);27-33.
- Ramachandra Reddy, P.R. and Rangaswamy, C.Y. (1989). Groundwater Resources of Pavagada Taluk, Tumkur District. Groundwater Studies No. 240. Department of Mines and Geology, Government of Karnataka, Bangalore.
- Rathore, D.S. (1996). Hydrological land use mapping of Narmada basin. Report No. CS(AR)-222, National Institute of Hydrology, Roorkee, 45p.
- Sharma, K.P., Jain, S.C. and Garg, P.K. (1984). Monitoring land use and land cover changes using landsat images. J. Indian Soc. Remote Sensing, 12(2);115-121.
- Srinivasa Vittala, S., Govindaiah, S. and Honne Gowda, H. (2004). Morphometric Analysis of Sub-watersheds in the Pavagada Area of Tumkur District, South India Using Remote Sensing and GIS Techniques. J. Indian Soc. Remote Sensing, 32(4), pp.351-362.
Fig. 1 : Location map with sub-watershed overlay and geology.
Fig. 2 : Land use / land cover map of each sub-watershed