Eco-Hydrological Footprint of a River Basin in Western Ghats

Ramachandra, T. V. V., et al., 2018. Yale Journal of Biology and Medicine

Original research (primary data)
View External Publication Link

Abstract

Eco-Hydrological footprint of a river basin refers to the hydrologic regime for sustaining vital ecological functions considering the appropriation of water by biotic components (including humans). It provides crucial information about the ecological status of a river, while addressing the divergence from natural conditions of the actual hydrological regime. Thus, this highlights the implicit relationship of hydrologic regime in meeting the demand of the biota. Unplanned developmental activities have altered the catchment integrity which has threatened the regional water security due to the conversion of perennial streams to seasonal ones. This has necessitated prudent catchment management strategies to maintain the ecological water requirements so as to maintain the aquatic and terrestrial biodiversity and to sustain water resources. The skewed strategies oriented mainly towards societal benefits have led to large-scale degradation of the landscape. Large-scale alterations of the landscape structure have led to erosion in the ecosystem supportive capacity that plays a major role in sustaining the hydrological regime. Insights of eco-hydrological footprint in the catchment would aid in formulating policies to sustain the hydrologic regime and natural resources. The current study focuses on the assessment of the eco-hydrological footprint in the Kali River of central Western Ghats, Karnataka. Land use dynamics assessment using the temporal remote sensing data of four decades reveal decline of evergreen forest cover from 61.8 percent to 37.5 percent in the Kali river basin between 1973-2016. Computation of eco-hydrological indices shows that the sub-catchments in the Ghats with higher proportion of forest cover with native species has a better eco-hydrological index as against the plain. This highlights the vital ecological function of a catchment in sustaining the hydrologic regime when covered with the vegetation of native species. The presence of perennial streams in sub-catchment dominated by native vegetation compared to the seasonal streams in the catchment dominated by anthropogenic activities with monoculture plantations. Eco-Hydrological Status/Hydrological footprint reflected similar results as that of the eco hydrological index demonstrating the role of forests in maintaining the hydrological regime. Inter annual water budgeting across sub basins showed that the Ghats and Coastal areas are sustainable with perennial waters in the river as against the plains in the east which showed deficit of resource indicating water stress.

Case studies

Basic information

  • Case ID: INT-245-1
  • Intervention type: Created habitats
  • Intervention description:

    Monoculture plantations of social forestry (Aca- cia sp.) and horticulture (Areca) has increased from 1.66 percent to 16.8 percent. Large scale conversion of forests to monoculture plantation near the eastern plains is due to the industrial demand by the Dandeli paper mill and other purposes.

  • Landscape/sea scape ecosystem management: Yes
  • Climate change impacts Effect of Nbs on CCI Effect measures
    Reduced water availability  Negative Water availability - Negative effect Eco-hydrological index is quantified as the ratio of infiltration to evapotranspiration in the catchment. Lower the values of infiltration i.e., less than 1 indicates poor water availability and values greater than 1 indicates better water availability sustaining the domestic and ecological demands. Hydrologi- cal supply and ecological demand were analyzed monthly to understand the eco-hydrological status. The region in- dicates deficit (supply demand) situation. “Sub-basins with higher forest cover had higher eco-hy- drological index supplementing that the availability of water can satisfactorily maintain the demands, where sub-basins dominated by monoculture had low index indicates water scarcity. ” “the transition zones and plain lands with higher monoculture, agricultural activ- ities has led to water scarcity between 4 to 9 months. ” Based on flow in the river the sub-basins were classi ed into 4 categories (A, B, C, D). Perennial rivers are cate- gorized under A (with 12 months ow), intermittent river with 9 to 11 months ow (category B), 8 to 6 months (cat- egory C), whereas seasonal river stretches were classi ed under D category. Accordingly, the Ghats and coasts have perennial river system as against the upper plainlands. “The presence of perennial streams in sub-catchment dominated by native vegetation compared to the seasonal streams in the catchment dominated by anthropogenic activities with monoculture plantations.”
  • Approach implemented in the field: Yes
  • Specific location:

    the Kali river basin of central Western Ghats

  • Country: India
  • Habitat/Biome type: Created forest |
  • Issue specific term: Not applicable

Evidence

  • Notes on intervention effectivness: Effectiveness assessed by comparing plantations to native forests which may act as a control as plantations were converted from this state although the study does reference to the presence of wildlife reserves in some parts of the catchment, intent is not to test effectiveness of these. Its to test effect of native forests in general against other land-uses including plantations and agriculture. Yes in some parts these native forests may have reserves but not across the whole landscape (evident from increasing forest cover loss over the years) and the authors are not attempting to isolate the effects of these reserves versus native forests in general. therefore only plantations are coded for
  • Is the assessment original?: Yes
  • Broadtype of intervention considered: Not applicable
  • Compare effectivness?: No
  • Compared to the non-NBS approach: Not applicable
  • Report greenhouse gas mitigation?: No
  • Impacts on GHG: Not applicable
  • Assess outcomes of the intervention on natural ecosystems: No
  • Impacts for the ecosystem: Not reported
  • Ecosystem measures: N/A
  • Assess outcomes of the intervention on people: No
  • Impacts for people: Not reported
  • People measures: N/A
  • Considers economic costs: No
  • Economic appraisal conducted: No
  • Economic appraisal described:
  • Economic costs of alternative considered: No
  • Compared to an alternative: Not reported

Evaluation methodology

  • Type of data: Quantitative
  • Is it experimental: Yes
  • Experimental evalution done: In-situ/field
  • Non-experimental evalution done: Not applicable
  • Study is systematic: