It's also known as leapfrog development (Gordon and Richardson, 1977; K. Madhavi Lata, 2009), and it's seen in all of the world's major cities. The pattern of new urban and residential roads represents an essentially permanent backbone that shapes new urban form and land use in the world’s cities (Christopher Barrington-Leigh and Adam Millard-Ball). Roads, for example, are a key spatial determinant of urban expansion, with significant implications for human activities, the environment, and socioeconomic development. Understanding the pattern

The Mandya Taluk lies between North latitude 12^o 44' 42.6'' to 12^o 25' 50.7'' and East longitudes 76^o 42' 05.6'' to 77^o 0' 22.9'' falling in the survey of India degree sheet Nos -57 H and 57D. The total geographical area of the Taluk is 705 km². The taluk is divided into one town and 175 villages distributed around the Mandya city. The soils in Mandya taluk are thin gravelly and underlain with marram zone containing weathered rock. The soils are highly leached and poor in bases. The taluk enjoys a sub-tropical climate with temperatures ranging between 160 and 350 C. April is the hottest month and with the onset of southwest monsoon in June, the temperature drops considerably. December is the coldest month. The rainfall is generally uniform in the district except in the western sector where it is slightly higher.

The satellite images for Mandya Taluk are obtained from the Global Land Cover Facility provided by the United States Geological Survey for three different decades. The subsisted satellite images of Mandya Taluk are shown below.

The data used for the present study are based on secondary sources. The satellite images of Landsat 5 TM, Landsat 7 ETM+ and Landsat 8 OLI/TIRS sensors for years 1995, 2005 and 2018 respectively is collected from Earth Explorer provided by United States of Geographical Survey. The images were subsisted using Arc GIS and classified for different years using ERDAS Imagine. The Urban growth of Mandya Taluk in different decades is also analysed. Downloaded data are layer stacked, subsetted using shape file of the study area which is downloaded from Diva GIS, supervised classification was also carried out for the study areas using ERDAS Imagine 2014, finally agricultural thematic map derived from this. Using ARC GIS 10.2 location map and layouts of thematic maps are prepared.

One of the most powerful perspectives on growth is direction; it provides an ideal view of both the rate and direction of growth at the same time. ArcGIS was used to create the directional map and the cover area for the directions. North, North-East, East, South-East, South, South-West, West, and North-West are the eight sections of the directional map. From the heart of the Mandya Taluk, the directional change in built-up area was calculated. The most directional change is seen in the last decade in between 2005-2018. The south east and south directions have the most fluctuation and expansion of urban growth, followed by the north, north east, and North West directions. The fluctuations of urban growth in south particularly are because of its closeness to Mysore City. The urban expansion, on the other hand, appears to be uniform in all directions of the taluk. Between the years 2005 and 2018, the rate of urban area expansion spikes the most, whereas the rate of expansion does not spike much in the first decade.

Table 2

Year	Directions
	N	NE	E	SE	S	SW	W	NW
1995	2.39	2.42	1.61	11.15	6.29	2.16	2.54	2.06
2005	5.62	3.50	3.02	14.33	7.46	6.50	5.32	4.78
2018	12.51	5.56	4.08	24.86	16.56	8.11	5.62	6.85
1995-2005	3.23	1.08	1.40	3.18	1.17	4.34	2.77	2.72
2005-2018	6.89	2.05	1.06	10.53	9.09	1.60	0.30	2.06
Rate (sq.km/year) 1995-2005	0.32	0.10	0.14	0.31	0.11	0.43	0.27	0.27
Rate (sq.km/year) 2005-2018	0.62	0.18	0.09	0.95	0.82	0.14	0.02	0.18

Figure 3

Figure 4

The transportation network is one of the most important ways to connect cities, and the road is the most common mode of transportation for connecting them. For ease of communication and transportation, people prefer to live near major highways and road networks. In the Mandya taluk, there are two major roads, according to India's transportation map. The main road in Mandya taluk connected Mysore and Bangalore taluks, and the second major road in Mandya city crossed the first and went to Hassan taluk. The growth seems to be more within 500 sq.km and tends to increase to 2000sq km till 2018.

During the research period, the urban area has maximally extended towards the 0-500 m buffer of major roads by about 19.73 km2 in 2018 and 13.03 km2 in 2005 and 7.67 km2 in 1995, while the minimum expansion has occurred towards the buffer 1500-2000 m, which was about 5.42 km2 in 2018 and 2.99 km2 in 2005 and 1.64 km2 in 1995. The expansion of road network within a buffer of 0-500 m seems to be denser as compared to the distance. During the study period (1995-2018) the urban growth increases as the table.

Figure 6

Figure 7

Figure 8

According the equations as per calculations of the rate and area of urban growth, it is found that, the urban growth tends to increase according to the result of change in land use/land cover between 1995 to 2018. The rate of expansion of land use and landcover area tends to double in every decade. As per prediction of rate of change is 3.7% in year 2050. The average increase rate is 0.64 sq. km/year, which the increase of built-up area was calculated till 2050 as shown in the table below. The area of expansion and change in land use and land cover covers an area of 30.7 sq. km in 1995 which is now increased to 152.6 sq. km in 2020. The future prediction seems to double in the year 2050 which will be 385.8 sq. km.

Half of the world's population has begun to settle in towns and cities as the world becomes increasingly urbanised. In terms of population and urban area expansion, the taluk of Mandya had experienced a remarkable rate of urban growth. After all of the debate over Mandya taluk's urbanisation growth, it is clear that the taluk has maintained a high level of urbanisation for the past three decades. The majority of people migrated from rural to urban areas for trade, jobs, and education, which is the main reason for urban expansion and growthThe most significant changes occurred in the south east and south directions, with expansions ranging from 3.2 square kilometres to 10.5 square kilometres in 1995 to 2005 and 1.2 square kilometres to 9.1 square kilometres in 2005 to 2018. The directions of south west, west, and north west, on the other hand, result in a very slow rate of urbanisation. In 1995, the rate of urban growth and changes in land use/landcover was only 0.1 percent, covering an area of about 30.7 square kilometres, which has now grown to about 152.6 square kilometres. Every ten years, the growth rate tends to double, rising to 1.5 percent in 2030 and 3.7 percent in 2050, respectively.