LANDSCAPES AND HYDROLOGICAL REGIME LINKAGES: CASE STUDY OF CHANDIHOLÉ, AGHANASHINI

Vinay S, Vishnu D M, Srikanth N, Subash Chandran M D, Bharath S, Shashishankar A, Ramachandra T V

Abstract: Landscape is a mosaic of heterogeneous elements and the structure of a landscape decides the functional ability – hydrologic, bio-geo-chemical cycling, etc. The current study focusses on the landcover dynamics linkages with the hydrologic regime in Chandiholé sub-catchments of Aghnashini River. Various sub catchments are Yaana, Beilangi, Aanegundi(Chandiholé) and Masihalla. Land use in each sub-catchment was analysed using spatial data acquired through space borne Indian Remote Sensing sensors (IRS LISS4 FMX), through supervised classifier based on Gaussian Maximum likelihood algorithm. Land use analysis indicated that Yaana was dominated by evergreen forests (over 95%), where as other sub-catchments had mixed landscapes. Hydrological yield is assessed based on monitoring stream discharges during May 2014 and April 2016 through area velocity method. Yaana stream is perennial (with 12 months of discharge) and yield varying between 1.3 to 97.4 mm/day followed by Aanegundi a mixed catchment fed by Yaana stream was intermittent (flow variability 10 – 12 month) across seasons has water yield of 0.07 mm/day to 82.39mm/day, Mastihalla and Beilangi were also intermittent with 7 to 10 month of water yield. Yaana stream had higher base flow where as other catchments had higher overlandflows during monsoon. Despite lower rainfall during 2015, water discharges were observed during all 12 months in Yaana stream with the relatively higher water yield. The study confirms the linkages of hydrological and catchment vegetation cover (undisturbed forest patches in Yaana) in sustaining water while catering to the societal and environmental water requirements.

Keywords: Hydrological Regime, Land use, Stream Gauging, Water shed management

DOI: https://doi.org/10.15623/ijret.2017.0614006