The role of terrestrial river systems in the global carbon cycle on a long timescale has been a subject of interest, especially in the context of past climate changes such as the global cooling in the Cenozoic. The discharges of water and carbon into the ocean from the Himalayan watersheds are among the highest in the world. However, there are few reliable geochemical data from the Ayeyarwady River. This study focused on reevaluating chemical weathering in the Himalayan watersheds based on samples taken from the Ayeyarwady, Mekong, and Chao Phraya Rivers and on chemical analysis of the composition of dissolved substances in these rivers. Comparisons of water quality showed that, unlike in previous studies, the total alkalinity budgets of the Ayeyarwady are dominated by carbonate rather than silicate weathering. Long-term CO 2 consumption by silicate weathering in the Ayeyarwady is estimated to be only 63-145 × 10 9 mol yr À1 , which is only 10% of the previous estimate. Our results also suggest that the total Himalayan watersheds account for only about 10% of the total global CO 2 consumption by silicate weathering. Although we need further studies, chemical weathering and associated CO 2 uptake in the Himalayas likely played a lesser role in long-term global cooling in the past than previously appreciated.

This paper aims to assess changes in the extreme climate indices of the Lower Songkhram River Basin of Thailand under Representative Concentration Pathways (RCPs) scenarios. A linear scaling method was used to correct climate data bias in three Regional Climate Models (RCMs) under RCP 4.5 and RCP 8.5 scenarios. Thereafter, extreme climate indices related to temperature and rainfall were analysed for the wet and dry seasons in upstream and downstream areas of the basin. A total of 14 climate indices were analysed for three time periods: the 2030s (2020-2044), 2055s (2045-2069), and 2080s (2070-2094) and compared with the baseline climate from 1980-2004. The results show that considerable variability is expected in the extreme climate of the basin in future. The average annual and monthly maximum and minimum temperature is projected to increase, with a lesser increase in the near future and higher in the far future. Heat events (TXx, TXn) are projected to increase while the cold events (TNx, TNn) are projected to decrease in both dry and wet seasons upstream and downstream of the basin. The future average annual rainfall in the basin is projected to decrease under RCP 4.5 and RCP 8.5 scenarios for all three periods. However, the variability in average monthly rainfall is expected to increase in the dry season (Jan-May) and decrease in the wet (Aug-Dec). The most intense rainfall in one day (RX1Day) and five consecutive days (RX5Day) in the wet season is observed to increase in future, with a higher increase in the near future and a lower increase in the far future. The very heavy rainfall days (R20) (the number of days receiving more than 20 mm/day in the basin) are observed to decrease in both wet and dry seasons under RCP 4.5 and RCP 8.5 scenarios in both locations. The results of this study will be helpful for the planning and management of natural resources as well as disaster risk reduction in the Lower Songkhram River Basin.

Cities have become integral in the quest to achieving universal sustainable development. For example, the United Nations in 2015 as part of the 17 Sustainable Development Goals called for cities and human settlements to be inclusive, safe, resilient and sustainable (Goal 11). This was in line with the 2012 National Urban Policy of Ghana which seeks to promote a sustainable, spatially integrated and orderly development of urban settlements with adequate housing, infra-structure and services, efficient institutions, and a sound living and working environment for all people to support the rapid socioeconomic development of Ghana. Six years into the imple-mentation of the National Urban Policy by the government, what is the sustainability status of the Ghanaian city? The aim of this study was to comprehensively evaluate the sustainability status of Accra Metropolitan Area, the capital city of Ghana. The study adopted a set of city sustainability indicators that revealed the weak and strong points of Accra metropolis. Forty-one Accra Sustainability Indicators were defined and classified into Economic, Environment, Social and Institutional (local governance) dimensions. The evaluation was for a period of 4 years, (2012 to 2015) during which the 2012 Urban Policy and its action plan were being implemented. Ques-tionnaires were developed based on the indicators and administered to stakeholders. The quanti-tative data collected was analyzed using Statistical Package for Social Sciences (SPSS) and Microsoft Excel. The results showed Accra’s economic dimension approaching sustainability while environmental and institutional dimensions performed poorly. The social dimension, thoughperformed below average, rose marginally over the period. Overall sustainability index of Accra was below average and showed a progression towards sustainability over the last 4 years, rising from 0.48 in 2012 to 0.51 in 2015. The findings of this study are helpful to local authorities for sustainable city planning and management.

This study assesses the vulnerability of farm households in the Ayeyarwady Region, Myanmar. Fifty-nine farm households were purposively sampled to conduct a questionnaire survey, and secondary data were collected in 2016. In order to assess variability in household vulnerability, the Livelihood Vulnerability Index (LVI), based on five types of ‘capital’ as identified in the Sustainable Livelihoods Framework, was adopted and modified according to the local context. Vulnerability scores ranged from 0 (low vulnerability) to 1 (highly vulnerable), with an average LVI of 0.442, indicating moderate overall vulnerability across the study area. Regarding the five types of ‘capital’, households were most vulnerable in terms of financial capital with an average value of 0.530, followed by natural capital (0.515) and physical capital (0.418). Households were classified into three vulnerability groups (low, moderate, and high) to identify those households most likely to need special attention. The survey found that the vulnerability of each asset they suffered was different across the township. The results also revealed that the production area of households classed as highly financially vulnerable found in the flood-prone and saline intrusion areas. It is clear that in order to reduce the vulnerability of farm households, more interventions are needed to enhance access to agricultural credit, diversifying livelihoods, provision of farm technology, inputs and knowledge as well as upgrading of basic infrastructure.

This study considers an agricultural land use plan using multi-agent simulation in the agricultural area of Nakhon Pathom Prefecture, Thailand, where small-scale croplands of various products exist. In formulating the simulation, interviews with farmers were conducted and a research index of the area was used so that the opinion of the stakeholders will be reflected in the plan. This study is comprised of the following research and analysis. 1) Interviews with farmers concerning future land use 2) Field study of the size of the croplands and the kinds of products 3) Construction of the simulation 4) Calculation of the transportation distance, transportation cost and impact on the environment As a result of the simulation to integrate the croplands of the same products, it was found that pursuing integration to the end does not necessarily reduce the transportation cost and environmental impact. It is effective to conduct integration while paying attention to the cost effectiveness.