Interim report on deposition of river bed material for Ganga river and its tributaries in the matter of Vijay Verma Vs Uttarakhand Forest Development Corporation & Others filed before NGT, 19/11/2018. National Green Tribunal had restrained mining activity on seven river viz.

With the growing recognition that effective action on climate change will require a combination of emissions reductions and carbon sequestration, protecting, enhancing and restoring natural carbon sinks have become political priorities. Mangrove forests are considered some of the most carbon-dense ecosystems in the world with most of the carbon stored in the soil. In order for mangrove forests to be included in climate mitigation efforts, knowledge of the spatial distribution of mangrove soil carbon stocks are critical.

Bed sediment samples were collected along the 9.5 km long inlet channel of Chilika lagoon, east coast of India during low freshwater discharge and low rainfall condition. Distributions of bed sediment along with its texture were studied in detail. Bivariate plots between mean, sorting, skewness and kurtosis of sediments revealed definite grouping pattern. The study, through C-M plot, indicates that the prime factors for transportation of sediment within inlet channel of Chilika lagoon are rolling and bottom suspension during period of low discharge and low rainfall (November-June).

Increased energy demand has led to plans for building many new dams in the western Amazon, mostly in the Andean region. Historical data and mechanistic scenarios are used to examine potential impacts above and below six of the largest dams planned for the region, including reductions in downstream sediment and nutrient supplies, changes in downstream flood pulse, changes in upstream and downstream fish yields, reservoir siltation, greenhouse gas emissions and mercury contamination.

Egypt’s Nile delta, only ~1 m above mean sea level at the Mediterranean coast, is subject to uneven rates of submergence. This is a response to several factors leading to increasing land lowering (subsidence) of the northern delta and adjacent seafloor, plus an accelerating rise in eustatic (world) sea level in the Mediterranean. An average eustatic sea-level rise of ~3 mm/yr represents only ~26% to 45% of total relative sea-level rise measured along this margin.

Debris flows often cause devastating damage to property and can injure or kill residents in mountainous areas. The construction of check dams in debris-flow valleys is considered a useful strategy for mitigating the damages downstream. In this paper, a new type of spillway structure with lateral contraction was proposed to distribute debris flows after the check dam storage filled up.

The world’s rivers deliver 19 billion tonnes of sediment to the coastal zone annually1, with a considerable fraction being sequestered in large deltas, home to over 500 million people. Most (more than 70 per cent) large deltas are under threat from a combination of rising sea levels, ground surface subsidence and anthropogenic sediment trapping2, 3, and a sustainable supply of fluvial sediment is therefore critical to prevent deltas being ‘drowned’ by rising relative sea levels2, 3, 4.

Economic development relies critically on infrastructure development. Yet, without careful planning, the services provided by hydropower facilities and dams are at risk.

The effects of climate change and variability on river flows have been widely studied. However the impacts of such changes on sediment transport have received comparatively little attention. In part this is because modelling sediment production and transport processes introduces additional uncertainty, but it also results from the fact that, alongside the climate change signal, there have been and are projected to be significant changes in land cover which strongly affect sediment-related processes.

Deltas around the globe are facing a multitude of intensifying environmental change and development-linked pressures. One key concern is the reduction in the quantity of suspended sediment reaching and building floodplains. Sediment deposition provides multiple services to deltaic social-ecological systems, in particular, countering the subsidence of the delta-body, and providing plentiful nutrients. Experiencing particularly rapid change is the Vietnamese Mekong Delta (VMD).

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