Assessing poverty and livelihood vulnerability of the fishing communities in the context of pollution of the Churni River, India

A systematic review of the impacts of oil spillage on residents of oil-producing communities in Nigeria

Oil spillage is common in oil-producing communities of Nigeria, and it impacts negatively on the residents of these communities. This study analysed available research data on oil spillage incidents in these communities to determine their main causes and impacts on the residents. This study highlights the immediate and long-term consequences of oil spills on residents of oil-host communities in Nigeria. A systematic review of published studies was carried out, and 22 studies were identified from the literature search. The main causes of oil spills were identified as sabotage (87%), leakage from corroded pipelines (62%), and equipment failure (45%). Others were mystery spills and operational failures. Unemployment, abject poverty, marginalization, and inaction of government regulatory agencies are enabling factors for sabotage and vandalism of oil pipelines. It was found that exposure to oil spills impacts directly and indirectly on residents of oil-host communities, with accompanying health, socioeconomic, and environmental implications. Oil spills in these communities impact on all facets of their life, thereby infringing on their rights to existence and survival. The major interventions were targeted at improving health services, education, infrastructure, skill acquisition, and employment. These in turn reduced the occurrence of violence, insurgency, and human trafficking in the oil-producing communities. It is recommended that government regulatory agencies should be revamped and repositioned to effectively perform their duties. Interventions should be targeted at addressing the causes of agitation by indigenes by involving them in the decision-making process. Also, appropriate remediation strategies should be adopted to clean up the oil spills.

Measuring anthropogenic impact of the ox-bow lakes in moribund Ganges deltaic India

Measuring the anthropogenic impact score (AIS) of the ox-bow lakes in order to explore the present situation and future ways of restoration is very necessary, particularly in highly populated areas. The present work targeted to do this considering 68 contributing parameters under eight AIS constituting components like pollution impact score (PIS), habitat alteration impact score (HAIS), hydrological alteration impact score (HYAIS), landscape alteration impact score (LAIS), etc. and tried to explore the major determinants behind. Machine learning (ML) algorithms were applied for computing component level and overall, AIS. A supervised correlation attribute evaluator (CAE) was applied for detecting major determinants. The result revealed out of total 44 major ox-bow lakes 40.90 % to 59.09 % (9.97 km2 to 14.69 km2) were identified as highly impacted both at the component level and overall scale as per the best predicted Random Forest (RF) model. Hydrologically connected lakes were less impacted than isolated ones. Genetically main river (Bhagirathi-Hooghly) left ox-bow lakes are less affected than those of the off-shoot channel. Larger size lakes witnessed less impact than medium and smaller lakes. Pollution, habitat, and hydrological components were found as the most dominant components of AIS. Reclamation, pollution, and eutrophication factors were identified as the dominant factors. AIS is negatively associated with fish yield and positively associated with the livelihood vulnerability of the dependent fishermen community. Since hydrological connectivity is a big issue; maintenance of it could be a good approach to its sustainability.

Anthropogenic risk assessment of riverine habitat using geospatial modelling tools for conservation and restoration planning: a case study from a tropical river Pranhita, India

The riverine ecosystem provides multiple benefits to human community and contributes to the sustainable development of the ecoregion. The growing dependency on these ecosystems has largely contributed to aggravating the ecological risks, habitat degradation, and loss of ecosystem services. The present study evaluates the ecological risk emanating from nine anthropogenic stressors including river use, hydro-morphology, catchment pollution, and biological stressor on river Pranhita in Godavari Basin of Peninsular India using InVEST (Integrated Valuation of Ecosystem Services and Tradeoffs) Habitat Risk Assessment model. The primary field survey, remote sensing, and secondary data-assisted spatial modelling results revealed low ecological risk (R = 0.65 of 3) in river Pranhita due to anthropogenic activities. Sediment loading, the inflow of nitrogen, and habitat fragmentation were the major stressors with relatively higher risk score (> 1); influence on a sizeable portion of riverine habitat (29-75% of the total area under high-risk zone) indicates the mounting threat from catchment activities. The low-risk value observed in protected river reaches as compared to unprotected areas is likely to be influenced by the abundant presence of intact riparian vegetation which mitigate the catchment stressors and minimal anthropogenic activity within protected areas. This study demonstrates the application of InVEST HRA model for ecological risk assessment of riverine ecosystems and fish assemblages along with their input data generation framework. This has the potential for prioritization of sensitive habitats based on computed ecological risk and stressor identification based on their exposure and consequences for developing appropriate mitigation measures. This model is spatially explicit and accommodates user-defined criteria for ecosystem-level assessment at a regional and national scale to facilitate the resource managers and policymakers for conservation and restoration planning and implementation of targeted management measures for sustainable development.

Wetland transformation and its impact on the livelihood of the fishing community in a flood plain river basin of India

Discretely wetland transformations and livelihood vulnerability related works are profoundly found worldwide, but their linkage is not investigated often. The present study aimed to explore the after damming transformation of wetland's eco-hydrological status and water quality and assessed its effects on livelihood vulnerability state of the fishermen community in the lower part of the Tangon river basin. Based on 15 field and satellite image-driven indicators of transformation, multiple machine learning (ML) algorithms were used to model the eco-hydrological state (EHS) of the wetland. Livelihood Vulnerability Index (LVI) of 45 fishing-dominated villages was computed using a balanced weighted LVI score. The result revealed that 60.55 % wetland area was obliterated between the pre- dam and post-dam periods, and the existing wetland area (21.06 km²) witnessed noticeable eco-hydrological and water quality degradation. Correlation and kernel density estimation (KDE) plot clearly revealed that rate of EHS degradation and water quality changes was negatively associated (at ≤0.01 level of significance) and both controlled LVI. So, such changes not only pose pressure on the aquatic species like fishes but also hampered the well-being of the fishermen communities evolving. The findings of the work would be useful in this transition while deciding the alternative strategies to build a resilient community. Moreover, since the eco-hydrological state were explored this would be effective for wetland restoration planning.

Environmental flow in the context of dams and development with special reference to the Damodar Valley Project, India: a review

Environmental flow is the minimum flow required in a fluvial system to maintain its ecological health and to promote socio-economic sustainability. The present work critically examines the concept of the environmental flow in the context of dams and development using a systematic methodology to find out the previous works published during the last 3 decades (1990-2020) in different search engines and websites. The study reviews that structural interventions in the form of dams, barrages, weirs, etc. impede the natural flow of the rivers. Moreover, other forms of development such as industrialization, urbanization, and expansion of modern agriculture also exacerbate the problems of environmental flow across the world, especially in monsoon Asia. The present case of the environmental flow for the Damodar River portrays that the construction of dams and barrages under the Damodar Valley Project have significantly altered the flow duration, flood frequency, and magnitude (high-frequency low magnitude events in the post-dam period), while urban-industrial growth in the basin has polluted the river water (e.g., lower dissolved oxygen and higher biological oxygen demand). This typical alteration in the flow characteristics and water quality has threatened aquatic organisms, especially fish diversity and community structure. This review will make the readers aware of the long-term result of dam-induced fluvial metamorphosis in the environment through the assessment of environmental flow, species diversity, flow fluctuation, and river pollution. The study may be useful for policy-making for ushering in the sustainable development pattern that will attract future researchers, planners, and stakeholders.