Environmental flow assessment in a lotic ecosystem of Central Western Ghats, India
Energy and Wetlands Research Group, Centre for Ecological Sciences [CES], Indian Institute of Science, Bangalore – 560012, India.
Web URL: http://ces.iisc.ernet.in/energy; http://ces.iisc.ernet.in/foss
*Corresponding author:
cestvr@ces.iisc.ernet.in

MATERIALS AND METHOD

2.1 Study area: Yettinaholé catchment has a pristine ecosystem with rich biodiversity (Figure 1 and Table 1), extend from 12044’N to 12058’N Latitude and 75037’E to 75047’E longitude encompassing total area of 179.68 km2. The terrain (Figure 2) is undulating with altitude varying from 666m above MSL to 1292m above MSL leading to higher density of stream network (Figure 3). Geologically, rock types consist of Gneiss, the soils are loamy ranging from sandy loamy to clay loamy. Soils (Figure 4) in the region are fertile and highly permeable, hence allowing the precipitated water to percolate easily into the subsurface recharging ground water and storing water in the sub surfaces and hence keeping the water source perennial to the catchment and the downstream users during and post monsoon.
Decadal population in Sakleshpura taluk (spatial extent 1034 sq. km) of Hassan district is given in Figure 5 and Table 2 shows a declining trend due to migration to cities during post 2001. Population dynamics of the catchments also follows the dynamics of Sakleshpura taluk. Total Population of all the catchments with respect to census data [24, 25] was estimated as 17005 in 2001, has declined to 16345 in 2011 at a decadal rate of 3.88%. Population for the year 2014 was calculated as 16156 based on the temporal data. Population density for each of the sub catchments are as depicted in Figure 6 and Table 3.


Table 1: Study Area


Sub basin id

Stream Name

Area (Ha)

1

Yettinaholé

4878.7

2

Yettinaholé T2

781.1

3

Yettinaholé T1

991.1

4

Kadumane holé 2

761.4

5

Kadumane holé 1

1362.4

6

Hongada halla

5676.6

7

Keri holé

2198.3

8

Yettinaholé lower reach

1319.1

Table 2: Population Growth of Sakleshpura Taluk [24, 25]


Census Year

1921

1931

1941

1951

1961

Population

44115

44300

43765

53398

77522

Census Year

1971

1981

1991

2001

2011

Population

91175

114008

124753

133657

128633

 


Figure 1: Study Area – Yettinaholé catchment, Karnataka, India