Coal mining in northeast India： an overview of environmental issues and treatment approaches

Northeast India has a good deposit of sub-bituminous tertiary coal. The northeast Indian coals have unusual physico-chemical characteristics such as high sulfur, volatile matter and vitrinite content, and low ash content. In addition, many environmental sensitive organic and mineral bound elements such as Fe, Mg, Bi, AI, V, Cu, Cd, Ni, Pb, and Mn etc. remain enriched in these coals. Such characteristics are associated with more severe environmental impacts due to mining and its utilization in coal based industries. Environmental challenges include large scale landscape damage, soil erosion, loss of forest ecosystem and wildlife habitat, air, water and soil pollution. Several physical and chemical methods are reported in literature for the removal of mineral matter, total sulfur and different forms of sulfur from high sulfur coal in northeast India. This paper may help different researchers and stakeholders to understand current state of research in the field. Initiatives may be taken towards sustainable use of coal resources by adopting innovative clean technologies and by implementing effective control measures and regulatory policies.

Combating climate change calls for a global technological cooperation system built on the concept of ecological civilization

Climate change has been considered as the most paramount global environmental problem and the biggest externality throughout the history of human development. Accordingly, the world is facing unprecedented technological innovation and collaborative demands to deal with climate change. In the 2015 Paris Agreement, a long-term vision of technology development and transfer implementation was proposed, and policy and financial support for technological innovation in the area of climate change was advocated. These terms aim to enable developing countries to acquire the necessary technology in the early stage of the technology cycle to address climate change challenge. However, the traditional technological innovation and cooperation mode based on industrial civilization can hardly meet the technical demands of global climate protection. To ensure the continuous development and deployment of technology in a required scale and pace, a new global technical cooperation system is proposed to develop based on the philosophy of ecological civilization. The core contents of this system are supposed be as follows:to implement all-win cooperation targets, adhering to cooperation principles of Eco-man, adopt cooperation content that reflects synergy, pursue cooperation based on mutual trust, encourage participation of multiple actors, and promote sharing of cooperative outputs.

Numerical modeling of hydrodynamic changes due to coastal reclamation projects in Xiamen Bay,China

Xiamen Bay in South China has experienced extensive coastal exploitation since the 1950s,resulting in some severe environmental problems.Local authorities now have completed or are implementing many environmental restoration projects.Evaluating the cumulative impact of exploitation and restoration activities on the environment is a complicated multi-disciplinary problem.However,hydrodynamic changes in the bay caused by such coastal projects can be characterized directly and definitively through numerical modeling.This paper assesses the cumulative effect of coastal projects on the hydrodynamic setting using a high-resolution numerical modeling method that makes use of tidal current speeds and the tidal prism as two hydrodynamic indices.Changes in tidal velocity and the characteristics of the tidal prism show that hydrodynamic conditions have declined from 1938 to 2007 in the full-tide area.The tidal current speed and tidal prism have decreased by 40% in the western part of the bay and 20% in the eastern part of the bay.Because of the linear relationship between tidal prism and area,the degraded hydrodynamic conditions are anticipated to be restored to 1972 levels following the completion of current and proposed restoration projects,i.e.33% and 15% decrease in the hydrodynamic conditions of 1938 for the western and eastern parts of the bay,respectively.The results indicate that hydrodynamic conditions can be restored to some extent with the implementation of a sustainable coastal development plan,although a full reversal of conditions is not possible.To fully assess the environmental changes in a region,more indices,e.g.,water quality and ecosystem parameters,should be considered in future evaluations.

Hydropower Projects on Se San River Impact on Social Economical Development and Environmental Protection

Se San river is one of main branches of Me Kong river, it has rather rich water resource, and the topographical condition of the catchment and river are very good for hydropower development. The aquatic life in Se San River is rich, both with respect to species diversity and biomass. There are about 120 fish species are recorded, but the number of species is most likely higher, in the range from 200-300 species, fish is a very important food source for the local people. Up to now, in the Vietnam part of the Se San catchment there are 6 hydropower projects along Se San river from upstream to Vietnam – Cambodia boundary, and Se San 4A re-regulation reservoir. In the part catchment in Cambodia, in development plan there will be 3 hydropower projects, they are Se San 5/lower Se San 1, lower Se San 3, and lower Se San 2. The hydropower projects on Se San river have impacts on socio-economical development of the region （Vietnam and Cambodia） such as create new energy sources and product condition for remote and difficult areas of the catchmnet, improve the transportation system and living conditions for the rural areas. These hydropower projects also have impacts on natural environment such as flow regime changes at downstream, sediment in downstream river reaches, and some impacts on the ecosystems along river.

KAM theorems and open problems for infinite-dimensional Hamiltonian with short range

We introduce several KAM theorems for infinite-dimensional Hamiltonian with short range and discuss the relationship between spectra of linearized operator and invariant tori.Especially,we introduce a KAM theorem by Yuan published in CMP(2002),which shows that there are rich KAM tori for a class of Hamiltonian with short range and with linearized operator of pure point spectra.We also present several open problems.