RESULTS AND DISCUSSIONS

Figure 6 depicts the land use based on the classification of remote sensing data of 2010 and land use statistics are listed in table 3. Sharavathi river basin has a total forest cover of 33.7% followed by forest plantations (22%), and agriculture (14 %). The overall classification accuracy is 91.51% with kappa of 0.90. Figure 7 depicts sub basin wise hydro-meteorological parameters such as net rainfall, runoff, infiltration, ground water recharge, and evapotranspiration.

Figure 6: Land use 2010

Table 3: Land use 2010

Figure7: Hydro-meteorological parameters (all units in Million litres)

The hydrological parameters together contribute to the water supply. The demand given in Figure 8 is estimated as a function of crop water, domestic and livestock water demand, and losses such as evapotranspiration. Water demand is higher in sub-basins with higher human population coupled with agriculture and horticultural activities.

Figure 8: Parameters contributing to the demand

Figure 9 illustrates the water balance in each basin considering water availability and the requirement in each basin. The coastal sub basins experiences water stress, due to higher water demand

Figure 9: Water Balance

Figure 10 groups the basins depending on the availability of water in streams as A, B, C or D. This also highlight the linkages of water availability with the land use as basins with higher cover of forests with native vegetation have water availability all 12 months or A type streams catering all demand (agriculture, domestic, horticulture and livestock), while the basins where large scale landuse changes also witness water scarcity evident from the presence of C or D type streams.

Figure 10: Flow regime