Ramachandra T V, Vinay S, Bharath S, Shashishankar A
Energy and Wetlands Research Group, Centre for Ecological Sciences, Indian Institute of Science, Bengaluru, India.
Department of Civil Engineering, Visvesvaraya Technological University, Belgaum, India.
Yale J Biol Med. 2018 Dec 21;91(4):431-444. eCollection 2018 Dec.
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.
流域的生态水文足迹是指在考虑生物成分（包括人类）对水的占用情况的前提下，维持重要生态功能所需的水文状况。它提供了有关河流生态状况的关键信息，同时揭示了实际水文状况与自然条件的差异。因此，这凸显了水文状况在满足生物群落需求方面的内在关系。无规划的开发活动改变了集水区的完整性，由于常年溪流转变为季节性溪流，这对区域水安全构成了威胁。这就需要审慎的集水区管理策略来维持生态需水量，以维护水生和陆地生物多样性并维持水资源。主要以社会效益为导向的片面策略导致了景观的大规模退化。景观结构的大规模改变导致生态系统支撑能力下降，而生态系统支撑能力在维持水文状况方面发挥着重要作用。对集水区生态水文足迹的深入了解将有助于制定维持水文状况和自然资源的政策。当前的研究聚焦于对卡纳塔克邦西高止山脉中部卡利河的生态水文足迹进行评估。利用四十年的时间序列遥感数据进行土地利用动态评估发现，1973年至2016年间，卡利河流域的常绿森林覆盖率从61.8%降至37.5%。生态水文指数的计算表明，与平原地区相比，高止山脉中森林覆盖率较高且以本地物种为主的子流域具有更好的生态水文指数。这凸显了集水区在被本地物种植被覆盖时，在维持水文状况方面的重要生态功能。与以单一栽培种植园等人为活动为主的集水区中的季节性溪流相比，以本地植被为主的子流域中存在常年溪流。生态水文状况/水文足迹反映出与生态水文指数类似的结果，证明了森林在维持水文状况方面的作用。跨子流域的年际水资源预算显示，高止山脉和沿海地区河流常年有水，具有可持续性，而东部平原地区则显示资源短缺，存在水压力。
