The Lancang-Mekong River in China, Laos, Thailand, Myanmar, Cambodia, and Vietnam is the soul and heart of mainland Southeast Asia. Over 60 million people depend on the river and its tributaries for food, transportati...The Lancang-Mekong River in China, Laos, Thailand, Myanmar, Cambodia, and Vietnam is the soul and heart of mainland Southeast Asia. Over 60 million people depend on the river and its tributaries for food, transportation, water, and other necessities of life. The river supports one of the world’s most diverse fisheries, second only to Brazil’s Amazon River. Lancang-Mekong and tributaries are already heavily dammed primarily in China, Laos, Thailand, and Cambodia, with many more dams planned or under construction. Dams can worsen the impact of periodic droughts in the Lancang-Mekong basin and block the river’s “pulse effect” that spreads water and nutrients needed for fishing and farming onto the floodplains and delta. The headwaters of the Lancang are in China and its waters are considered a national resource. China regards the Lancang, Yangtze and Yellow rivers as a free resource rather than a shared resource. The primary difference between these rivers is the Lancang flows from China into and through other countries and not directly into a sea or ocean. China and Myanmar have not joined the Mekong River Commission (MRC) as full members but have been Dialogue Partners since 1996. Over the past thirty years, China’s Lancang policies and actions have reflected its national resource interests. China has actively engaged with individual transboundary countries at various levels including environmental, conservation, and economic agreements. The primary objective of this study is to assess the environmental and human impacts of all Lancang-Mekong mainstem and tributary dams and the plans by many countries for more hydropower utilizing the potential of the river as the continent’s energy lifeline. Future dams need to include fish ladders and navigation locks to reduce the environmental impacts on fish populations, natural resources, navigation, and livelihoods. Strengthening of international collaboration via the MRC or by individual or multiple country agreements to address Lancang-Mekong’s sustainable transboundary development goals is recommended. When new Lancang-Mekong and tributary dams are built within any of the transboundary watershed countries, additional communities will need to be resettled. Significant environmental and human impacts are observed. Steps will have to be taken by all the concerned countries to prevent these problems and to ensure that people’s livelihoods are restored after resettlement.展开更多
Mekong River is one of the major international freshwater sources in the world. The Lower Mekong Basin (LMB) comprised of four downstream countries, including Thailand, Lao PDR, Cambodia, and Vietnam. The utilization ...Mekong River is one of the major international freshwater sources in the world. The Lower Mekong Basin (LMB) comprised of four downstream countries, including Thailand, Lao PDR, Cambodia, and Vietnam. The utilization of the basin’s water brings not only substantial benefits to the region ranging from hydropower to navigation, but also negative impacts caused by the unbalanced water using. The essential role of Mekong River requires all member nations to cooperate effectively for the sustainable development of the region. One of the most popular methods in the field of water resource management is a trustable tool called the Analytical Hierarchy Process (AHP). AHP is much appropriate for water resource policymaking. The literature, however, points out that there is no study to both structure the water using hierarchy and employ quantitative (objective) criteria to the AHP model in LMB case. With regard to water resource management, there are no previous studies applying AHP models to evaluating sustainable development of transboundary water resource in LMB case. This paper explores the evolution of water cooperation among Mekong countries and subsequently evaluates the water development scenarios in the LMB based on the water cooperation preferences of four LMB countries This study proposes a novel approach to analyzing, assessing water resource development scenarios characterized by sustainability indicators and to assisting in developing a suitable water policy in LMB according to the best cooperation scenario.展开更多
The Lancang-Mekong River has attracted much attention from researchers, but the cooperation on water issues in this river basin has been limited, even after the establishment of the Mekong River Commission(MRC). Coope...The Lancang-Mekong River has attracted much attention from researchers, but the cooperation on water issues in this river basin has been limited, even after the establishment of the Mekong River Commission(MRC). Cooperation on water resources has been determined as one of the key priority areas in the Lancang-Mekong Cooperation Mechanism, but there are no details of targets. In order to establish the priorities of water cooperation under the mechanism, we adopted nine categories to classify the objectives of 87 water cooperation events based on the ‘Lancang-Mekong Water Cooperative Events Database' from 1995 to 2015. Based on the occurrence of cooperative events, cooperative objectives, cooperative scales, and approaches to cooperation, we conducted statistical, correlation, and text analyses. Our analyses indicated the following results: under the impact of economic conditions inside and outside the river basin, full cooperation appeared more difficult than bilateral and multilateral cooperation. Each of the partners adopted different preferences for cooperation targets. Cooperation with more definite objectives was easier to establish than cooperation with broader and more complex objectives. The potential objectives for water cooperation were navigation, hydropower, joint management, data sharing, flood control and water use. Because hydropower development is controversial, and because water cooperation is avoided by most existing regional cooperation mechanisms due to its complexity, we suggest the following priority areas for water cooperation in the Lancang-Mekong River Basin. 1) Navigation and flood control/drought relief are attractive objectives for all the riparian countries across the whole watershed. 2) Data sharing should be a priority for cooperation in the watershed due to its laying the foundation for the equitable and reasonable utilization of transboundary waters. 3) Hydropower is an objective best implemented mainly through bilateral cooperation, and on tributaries.展开更多
For centuries, explorers and scientists from different countries had made their own conclusions on the source of the Mekong. However, the geographic source of the Mekong is still arguable because of the complexity of ...For centuries, explorers and scientists from different countries had made their own conclusions on the source of the Mekong. However, the geographic source of the Mekong is still arguable because of the complexity of the Mekong source water system, inaccessible environment and the varied technologies used by those explorers and scientists. The satellite remote sensing technology has been used to pinpoint the source of the Mekong, associated with the on-the-spot investigations made by the authors in June 1999 and September 2002. The actual length of the Mekong has also been calculated.展开更多
The Mekong supports one of the richest inland fisheries in the world, with many of the fish migrating long distance to spawn. Little is known about the fisheries and migration strategies of the Upper Mekong whilst it ...The Mekong supports one of the richest inland fisheries in the world, with many of the fish migrating long distance to spawn. Little is known about the fisheries and migration strategies of the Upper Mekong whilst it is supposed that many fish species move between the Lower and Upper Mekong. Most likely, natural fish migration in the river has been altered by dam construction across the mainstream of the Upper Mekong. In this paper, the interconnectivity of fish species between different sections of the Mekong and negative impacts of dams on migratory fish are studied. Of the 162 fish species in the Upper Mekong and the 869 species in the Lower Mekong, 61 species are common. Results show that there is no significant difference at order level between the UM and LM. Similarity coefficients are used to evaluate interconnectivity at species, genus and family levels among four different sections of the Upper Mekong with each other and with the Lower Mekong as a whole. The highest similarity is found between the middle and lower reach of the Upper Mekong at species and genus levels and the middle and upper reach at family level. Of the eight cascade dams, Mengsong Dam in planning is considered as the biggest threat to migratory fish from the Lower Mekong and should be particularly concerned.展开更多
The Lancang–Mekong River basin(LMRB) is under increasing threat from global warming. In this paper, the projection of future climate in the LMRB is explored by focusing on the temperature change and extreme temperatu...The Lancang–Mekong River basin(LMRB) is under increasing threat from global warming. In this paper, the projection of future climate in the LMRB is explored by focusing on the temperature change and extreme temperature events. First, the authors evaluate the bias of temperature simulated by the Weather Research and Forecasting model. Then, correction is made for the simulation by comparing with observation based on the non-parametric quantile mapping using robust empirical quantiles(RQUANT) method. Furthermore, using the corrected model results, the future climate projections of temperature and extreme temperature events in this basin during 2016–35, 2046–65, and 2080–99 are analyzed. The study shows that RQUANT can effectively reduce the bias of simulation results. After correction, the simulation can capture the spatial features and trends of mean temperature over the LMRB, as well as the extreme temperature events. Besides, it can reproduce the spatial and temporal distributions of the major modes. In the future, the temperature will keep increasing, and the warming in the southern basin will be more intense in the wet season than the dry season. The number of extreme high-temperature days exhibits an increasing trend, while the number of extreme low-temperature days shows a decreasing trend. Based on empirical orthogonal function analysis, the dominant feature of temperature over this basin shows a consistent change. The second mode shows a seesaw pattern.展开更多
Tonle Sap Lake is the largest river-connected lake, buffer area and ecological zone of Mekong River, which plays a huge role in dispelling flood peak and compensating water, and the conservation of biological diversit...Tonle Sap Lake is the largest river-connected lake, buffer area and ecological zone of Mekong River, which plays a huge role in dispelling flood peak and compensating water, and the conservation of biological diversity. The river-lake relationship between Mekong River and Tonle Sap Lake is unique and has always been a major focus in the international community. The land terrain and under-water topography were used to analyze the morphological characteristics of Cambodia Mekong Delta and Tonle Sap Lake. Long series of hydrological data of river-lake controlling stations were used to analyze the water level variation characteristics and water volume exchange pattern between Mekong River and Tonle Sap Lake, and the response relationship to river-lake morphological characteristics were also researched. The results show that: Cambodia Mekong Delta and Tonle Sap Lake Area is low-lying and flat with gentle channel gradient and water surface gradient, making the relationship between water level and area (or volume) smooth. The channel storage capacity of Mekong River and Tonle Sap River is not enough compared to the inflow, so vast flooding plain is extremely prone to be inundated, making the flood relationships between the left and right banks become very complicated. Tonle Sap Lake is a seasonal freshwater lake with water flowing in and flowing out, and the timing and intensity of water exchange with Mekong River are closely related to the water flow resistance at the exit section of Tonle Sap Lake and the cross-sectional area of Tonle Sap River, which can be reflected by the river-lake water level difference and the water level of Tonle Sap River. Affected by the river-lake morphological characteristics, the water exchange intensity between Mekong River and Tonle Sap Lake is great. Tonle Sap Lake not only stores 14.4% of flood volume (39.7 billion m3) from the Mekong River every year, but also supplies 29.7% of dry water (69.4 billion m3) to the Mekong River. Influenced by the adjustment of the floodplain, the water level fluctuation of Mekong River and Tonle Sap Lake is slow, and the rising and droop rates of water level are positively correlated with the floodplain storage area. The research results will help to understand the relationship mechanism between Mekong River and Tonle Sap Lake and provide a scientific basis for the comprehensive governance of Cambodia Mekong Delta and Tonle Sap Lake Area.展开更多
Satellite-based products with high spatial and temporal resolution provide useful precipitation information for data-sparse or ungauged large-scale watersheds. In the Lower Lancang-Mekong River Basin, rainfall station...Satellite-based products with high spatial and temporal resolution provide useful precipitation information for data-sparse or ungauged large-scale watersheds. In the Lower Lancang-Mekong River Basin, rainfall stations are sparse and unevenly distributed, and the transboundary characteristic makes the collection of precipitation data more difficult, which has restricted hydrological processes simulation. In this study, daily precipitation data from four datasets(gauge observations, inverse distance weighted(IDW) data, Tropical Rainfall Measuring Mission(TRMM) estimates, and Climate Hazards Group InfraRed Precipitation with Stations(CHIRPS) estimates), were applied to drive the Soil and Water Assessment Tool(SWAT) model, and then their capability for hydrological simulation in the Lower Lancang-Mekong River Basin were examined. TRMM and CHIRPS data showed good performances on precipitation estimation in the Lower Lancang-Mekong River Basin, with the better performance for TRMM product. The Nash-Sutcliffe efficiency(NSE) values of gauge, IDW, TRMM, and CHIRPS simulations during the calibration period were 0.87, 0.86, 0.95, and 0.93 for monthly flow, respectively, and those for daily flow were 0.75, 0.77, 0.86, and 0.84, respectively. TRMM and CHIRPS data were superior to rain gauge and IDW data for driving the hydrological model, and TRMM data produced the best simulation performance. Satellite-based precipitation estimates could be suitable data sources when simulating hydrological processes for large data-poor or ungauged watersheds, especially in international river basins for which precipitation observations are difficult to collect. CHIRPS data provide long precipitation time series from 1981 to near present and thus could be used as an alternative precipitation input for hydrological simulation, especially for the period without TRMM data. For satellite-based precipitation products, the differences in the occurrence frequencies and amounts of precipitation with different intensities would affect simulation results of water balance components, which should be comprehensively considered in water resources estimation and planning.展开更多
The Lancnag Mekong River is the most important international river across China and Southeast Asia, If it is developed according to 'Great Mekong Subregional Cooperation Plan' [9] prepared by ADB, the area di...The Lancnag Mekong River is the most important international river across China and Southeast Asia, If it is developed according to 'Great Mekong Subregional Cooperation Plan' [9] prepared by ADB, the area directly affected will be up to over 2.32 million km 2, the population over 220 million, and the natural environment, and socio-economic conditions within a large area will be greatly changed. 'Agreement on Cooperation for Sustainable Development of Mekong Basin' signed by the four riparian countries along the lower Mekong River on April 5, 1995 provides a new opportunity for sustainable development of the Basin. According to preliminary analysis, if the multipurpose utilization of the water resources is the target for carrying out integrated planning and management, and the efforts are made 1) to focus on energy exploitation on the Lancang River Mainstream and the tributaries of the lower Mekong River; 2) to build gated weirs at Tonle Sam; 3) to construct spillways at the Mekong Delta; 4) to facilitate flood dykes in big cities and on both banks of the mainstream which are concentrated with population and farmland and liable to be flooded, and 5) to strengthen networks for forecasting hydrological and meteorological conditions, then all problems such as power demand, irrigation, flood, salt water intrusion as well as acid water erosion to soil could be solved without constructing large cascaded stations and dams on the lower Mekong Mainstream. This will not only avoid input of great number of fund, large scale resettlement and land inundation, but also prevent aquatic organisms living in Mekong River from being injured due to dam construction, and promote the sustainable development of the Basin.展开更多
According to a lot of hydrological and environmental monitoring data, the condition of soil and water loss in the Lancang River Mekong River watershed (in Yunnan section, China) is described. The occurrence and devel...According to a lot of hydrological and environmental monitoring data, the condition of soil and water loss in the Lancang River Mekong River watershed (in Yunnan section, China) is described. The occurrence and development of soil and water loss is analyzed. The conclusion is that: (1) generally, the situation of soil and water loss in the Lancang River Mekong River watershed (in Yunnan section, China) is light, however, soil and water loss in some regions is serious, especially in the middle reach area of the river; (2) soil and water loss in the Lancang River Mekong River (in Yunnan section, China) watershed presents developing tendency and it is mainly caused by human beings. In accordance with these results, the control measures for soil and water loss are discussed.展开更多
The Lower Mekong Delta in Vietnam experiences widespread flooding annually. About 17 million people live in the Delta with agriculture as the major economic activity. The suspended sediment load in the Mekong River pl...The Lower Mekong Delta in Vietnam experiences widespread flooding annually. About 17 million people live in the Delta with agriculture as the major economic activity. The suspended sediment load in the Mekong River plays an important role in carrying contaminants and nutrients to the delta and changing the geomorphology of the delta river system. In recent decades, it is generally perceived that the flow and sediment transport in the Mekong River have changed due to climate change and development activities, but observed sediment data are lacking. Moreover, after natural floodplains, the sediment deposition has replaced by dense river systems as resulting in floodplain compartments protected by embankments. This study is aimed to investigate impacts of changing water flow on erosion/deposition in the Lower Mekong Delta. We used Mike 11 hydrodynamic model and sediment transport model for simulating the flow and sediment transport. Various scenarios were simulated based on anticipated upstream discharges. Our findings provide the positive and negative impacts to the changes in sediment transport on agriculture cultivation in the Lower Mekong Delta.展开更多
The Quadrangle Economic Cooperation Zone in Great Mekong Region, where the Golden Triangle is located, is composed with the border areas of China, Laos, Thailand and Myanmar. The poorest and inaccessible remote Golden...The Quadrangle Economic Cooperation Zone in Great Mekong Region, where the Golden Triangle is located, is composed with the border areas of China, Laos, Thailand and Myanmar. The poorest and inaccessible remote Golden Triangle now faces the opportunity to develop and participate in the global economic system. Not only has the traditional border tourism between two countries in this region been growing rapidly and various tourism products cross the regions also have been developed. The article attempts to explore the multiplier effects of tourism on regional cooperation. These consequences of tourism cooperation take effect through the infrastructure improvement, facilitation of the flee movement, improvement of communication and promotion of the alternative economy. The study also points out the unexpected negative consequences to limit its role as a regional cooperative engine due to the lack of consideration of the dual economic and social structure in tourism development. The special attention should be drawn to consider the limited benefits for the marginalized community, the high transaction of the social costs related with the drug tourism and sex tourism. The paper calls for more rigorous cooperative regional plans and policies to the complexity of tourism development in this region.展开更多
Groundwater resources have considerable influences on the human population and socioeconomic development of Vietnam and the Mekong River Delta(MRD). This paper presents an overview of the relationship between climate ...Groundwater resources have considerable influences on the human population and socioeconomic development of Vietnam and the Mekong River Delta(MRD). This paper presents an overview of the relationship between climate change and groundwater in the MRD, including the challenges, strategies and technical measures. Our results showed that groundwater levels are related to other climate and hydrological variables(i.e., rainfall, river levels, etc.); therefore, the impacts of climate change on the groundwater resources of the Mekong delta are significant, especially on groundwater recharge. Based on the results of this study, it is recommended that groundwater development in the future should focus on reducing groundwater harvesting, enhancing groundwater quantity by establishing artificial works and exploiting surface water. This study suggests that the Artificial Neural Network(ANN) model is an effective tool for forecasting groundwater levels in periods of 1 month and 3 months for aquifers in the natural and tidal regime areas of the delta.展开更多
The transboundary Mekong River is shared by six SE Asia countries (China, Myanmar, Thailand, Lao PDR, Cambodia, and Vietnam). In this paper the livelihoods of farmers and fishers of Lao PDR, Cambodia and Vietnam are e...The transboundary Mekong River is shared by six SE Asia countries (China, Myanmar, Thailand, Lao PDR, Cambodia, and Vietnam). In this paper the livelihoods of farmers and fishers of Lao PDR, Cambodia and Vietnam are examined to assess impacts of Mekong River development and modernization projects on the rural peoples of the Mekong River and Delta. A high proportion of the 190 million rural people of the Mekong basin are dependent on the diverse and abundant resources of the Mekong River and its tributaries for food security and basic necessities, livelihoods, and cultural identities. Although rice farming and fisheries occupations are primary income sources, many livelihoods involve a diversity of on-farm and off-farm activities. Agricultural specialization and intensification and hydropower dam construction on the Mekong main stem and tributaries are altering traditional rural patterns of household food security, income, and cultural ways of living at an increasingly rapid pace. Rural transformation projects must better assess how these modernization efforts change the ecology of the Mekong River and in turn affect the capacity of rural people to adapt in ways that ensure food security and improve household livelihoods. It will be critical that development efforts recognize, value, and invest in rural people’s roles in producing a stable, affordable food system and managing the integrity of river ecosystems upon which future prosperity depends. Interventions are needed to prevent degradation of the Mekong Basin soil and water resources from large-scale agricultural intensification, water diversion and overbuilding of hydropower dams which are threats to small-scale land holdings and farmers and fishers capacities to provide daily food for their own consumption and to feed SE Asia’s growing urban populations.展开更多
An Giang province in the Mekong Delta is the most vulnerable province the impact of flooding and climate variability. Thousand of households are at risk due to severe annual floods. This study applied the LVI (liveli...An Giang province in the Mekong Delta is the most vulnerable province the impact of flooding and climate variability. Thousand of households are at risk due to severe annual floods. This study applied the LVI (livelihood vulnerability index) to estimate flood vulnerability of Phu Huu and Ta Danh villages in An Giang province. Data on socio-demographics, livelihoods, health, social networks, physical, financial and natural resources, natural disasters and climate variability were collected from a survey of 120 households in each village. From these data the LVI of each village was calculated. Results show that the overall LV1 of Phu Huu village, located in the early flooded zone, is higher than that of Ta Danh village, located in the late flooded zone. The analysis also indicated that this practical method can be applied for other purposes such as to monitor vulnerability, evaluate development programs or policy effectiveness by incorporating with scenario comparison.展开更多
Land subsidence and rising sea levels could result in 40% of the Mekong Delta being covered by the South China Sea within the next few decades. The impact of groundwater withdrawal, in the SE Asia mega deltas of Gange...Land subsidence and rising sea levels could result in 40% of the Mekong Delta being covered by the South China Sea within the next few decades. The impact of groundwater withdrawal, in the SE Asia mega deltas of Ganges-Brahmaputra Delta, Jakarta Delta, Chao Phraya Delta and Mekong Delta, is a major reason these deltas are sinking. There are lessons to be learned from both failures and successful remediation efforts in other mega deltas as Vietnam policy makers seek to address Mekong Delta subsidence. Without a significant Vietnam government remediation and mitigation efforts, land subsidence in the Mekong Delta will continue. Land subsidence has occurred in the Mekong Delta as a result of the retention of sediments behind the China and Laos dams on the main stem of the Mekong River, reduced flooding peaks, climate change, sea level rise, storm surges and flooding. In addition, subsidence has been exascerbated by compaction, groundwater extraction for shrimp ponds, rice paddies and the household and drinking water needs of approximately 20 million people living on the Mekong Delta in Vietnam and Cambodia. The Mekong Delta shorelines are eroding and significant land areas, including wetlands, are becoming open water. The wetlands and land mass are also subsiding as a result of the reduction in sediment deposition. Large dams on the mainstem of the Mekong River in China and Laos have reduced peak flows and reduced sediment loads in lower Mekong River. Population and industrial growth have increased groundwater extraction and salt water intrusion as the delta subsides leading to consolidation and reduction in the current plumes flowing into the South China Sea. The primary objective of this paper is to assess the impact of groundwater withdrawals for rice paddies, shrimp ponds, aquaculture, industry and drinking water on Mekong Delta land subsidence. The secondary objective is to identify mitigation efforts used in other Southeast Asia deltas and make remediation recommendations for the sinking Mekong Delta. Promising mitigation approaches are injecting river water deep into the underlying alluvial sediments, return of the sediments trapped in China and Laos reservoirs to the Mekong River mainstem, increase in the Mekong River flooding peaks, and construction of sea and floodwalls, dykes, polders and levees. The addition of Mekong River sediments to build up existing floodplains, the reduction of coastal shoreline erosion, the planting of mangroves and protection of urban and agricultural areas from being covered by the South China Sea are strategies that could help remediate land subsidence in the Mekong Delta.展开更多
An ichthyofaunistic survey of Mekong tributaries in Lincang Prefecture, Yunnan Province, China yielded a new species of nemacheilid loach, herein described as Schistura sexnubes species nova. The new species is readil...An ichthyofaunistic survey of Mekong tributaries in Lincang Prefecture, Yunnan Province, China yielded a new species of nemacheilid loach, herein described as Schistura sexnubes species nova. The new species is readily distinguishable from its congeners by the following combination of characters: 8+8 branched caudal fin rays, an incomplete lateral line, a dissociated caudal bar, a shallow caudal peduncle depth (7.6%-9.6% SL; respectively caudal peduncle 1.76-1.95 times longer than deep), a diminutive size of less than 50 mm SL, and no sexual dimorphism. A dorsocephalic pattern consisting of a black, forward directed V-shaped formation located between the nares, and a white, ovoid blotch on the upper operculum serves as an autapomorphy.展开更多
Mekong River Basin is a life for many people in six south East Asian countries. The river basin is very productive and has crucial activities like: fishing, agriculture, hydroelectric power, transportation, biodiversi...Mekong River Basin is a life for many people in six south East Asian countries. The river basin is very productive and has crucial activities like: fishing, agriculture, hydroelectric power, transportation, biodiversity and so on. However, due to mismanagement, political intentions and one way interest only for development, the river basin has already started experiencing complications. The major challenges found out were, huge hydroelectric dam constructions and other projects, high population pressure, lack of cooperation among riparian states (especially upper Mekong region and lower one), and lack of proper management system. This leads to inequitable resource use, impact on water quality, biodiversity loss, and disasters like flooding. It is a high time to make a joint venture among riparian countries for sustainable use of the resource. Multi lateral cooperation and commitment among user countries by consulting all stakeholders will benefit all to use this precious resource equitably without major ecological impacts on the river basin.展开更多
Changes in the climatic system introduce uncertainties in the supply and management of water resources. The Intergovernmental Panel on Climate Change(IPCC) predicts an increase of 2 to 4 °C over the next 100 year...Changes in the climatic system introduce uncertainties in the supply and management of water resources. The Intergovernmental Panel on Climate Change(IPCC) predicts an increase of 2 to 4 °C over the next 100 years. Temperature increases will impact the hydrologic cycle by directly increasing the evaporation of surface water sources. Consequently, changes in precipitation will indirectly impact the flux and storage of water in surface and subsurface reservoirs(i.e., lakes, soil moisture, groundwater, etc.). In addition, increases in temperature contribute to increases in the sea level, which may lead to sea water intrusions, water quality deterioration, potable water shortages, etc. Climate change has direct impacts on the surface water and the control of storage in rivers, lakes and reservoirs, which indirectly controls the groundwater recharge process. The main and direct impact of climate change on groundwater is changes in the volume and distribution of groundwater recharge. The impact of climate change on groundwater resources requires reliable forecasting of changes in the major climatic variables and accurate estimations of groundwater recharge. A number of Global Climate Models(GCMs) are available for understanding climate and projecting climate change.These GCMs can be downscaled to a basin scale, and when they are coupled with relevant hydrological models, the output of these coupled models can be used to quantify the groundwater recharge, which will facilitate the adoption of appropriate adaptation strategies under the impact of climate change.展开更多
Purpose: Vietnam rice has long been a product of international stature. In the commodity export of Vietnam, rice always plays as key agricultural commodities, with contributions billions of dollars each year in total ...Purpose: Vietnam rice has long been a product of international stature. In the commodity export of Vietnam, rice always plays as key agricultural commodities, with contributions billions of dollars each year in total export value. It not only contributes to the overall growth of the economy, but also gradually affirms Vietnam’s position on the international rice market. According to General Statistics Office, in 2012, Vietnam produced 43.7 million tonnes of rice and exported record 8.047 million tonnes of rice, contributing to the total export value of $3.689 million. However, it has not still been commensurate with the value and potential of rice from Vietnam. In addition, the fact is that in recent years, although export rice increased sharply, bringing many records for Vietnam, it had lower prices than other rice exporting countries (Thailand, India, Pakistan). So what is the cause and solution to enhance competitiveness and promote export of rice products in Viet Nam? In the increasingly complex international context, besides socio-economic development, security and national defense, food security has become a matter of international concern. The article first discusses the competitiveness, the value of rice exports and the need to improve competitiveness and export value of rice in the Mekong Delta. Then, there are some solutions proposed to improve the competitiveness and export of rice in the Mekong Delta in the coming time.展开更多
文摘The Lancang-Mekong River in China, Laos, Thailand, Myanmar, Cambodia, and Vietnam is the soul and heart of mainland Southeast Asia. Over 60 million people depend on the river and its tributaries for food, transportation, water, and other necessities of life. The river supports one of the world’s most diverse fisheries, second only to Brazil’s Amazon River. Lancang-Mekong and tributaries are already heavily dammed primarily in China, Laos, Thailand, and Cambodia, with many more dams planned or under construction. Dams can worsen the impact of periodic droughts in the Lancang-Mekong basin and block the river’s “pulse effect” that spreads water and nutrients needed for fishing and farming onto the floodplains and delta. The headwaters of the Lancang are in China and its waters are considered a national resource. China regards the Lancang, Yangtze and Yellow rivers as a free resource rather than a shared resource. The primary difference between these rivers is the Lancang flows from China into and through other countries and not directly into a sea or ocean. China and Myanmar have not joined the Mekong River Commission (MRC) as full members but have been Dialogue Partners since 1996. Over the past thirty years, China’s Lancang policies and actions have reflected its national resource interests. China has actively engaged with individual transboundary countries at various levels including environmental, conservation, and economic agreements. The primary objective of this study is to assess the environmental and human impacts of all Lancang-Mekong mainstem and tributary dams and the plans by many countries for more hydropower utilizing the potential of the river as the continent’s energy lifeline. Future dams need to include fish ladders and navigation locks to reduce the environmental impacts on fish populations, natural resources, navigation, and livelihoods. Strengthening of international collaboration via the MRC or by individual or multiple country agreements to address Lancang-Mekong’s sustainable transboundary development goals is recommended. When new Lancang-Mekong and tributary dams are built within any of the transboundary watershed countries, additional communities will need to be resettled. Significant environmental and human impacts are observed. Steps will have to be taken by all the concerned countries to prevent these problems and to ensure that people’s livelihoods are restored after resettlement.
文摘Mekong River is one of the major international freshwater sources in the world. The Lower Mekong Basin (LMB) comprised of four downstream countries, including Thailand, Lao PDR, Cambodia, and Vietnam. The utilization of the basin’s water brings not only substantial benefits to the region ranging from hydropower to navigation, but also negative impacts caused by the unbalanced water using. The essential role of Mekong River requires all member nations to cooperate effectively for the sustainable development of the region. One of the most popular methods in the field of water resource management is a trustable tool called the Analytical Hierarchy Process (AHP). AHP is much appropriate for water resource policymaking. The literature, however, points out that there is no study to both structure the water using hierarchy and employ quantitative (objective) criteria to the AHP model in LMB case. With regard to water resource management, there are no previous studies applying AHP models to evaluating sustainable development of transboundary water resource in LMB case. This paper explores the evolution of water cooperation among Mekong countries and subsequently evaluates the water development scenarios in the LMB based on the water cooperation preferences of four LMB countries This study proposes a novel approach to analyzing, assessing water resource development scenarios characterized by sustainability indicators and to assisting in developing a suitable water policy in LMB according to the best cooperation scenario.
基金the National Key R&D Program of China(No.2016YFA0601601)Natural Science Foundation of China-International Center for Integrated Mountain Development(NSFC-ICIMOD)Joint Research Program(No.41661144044)
文摘The Lancang-Mekong River has attracted much attention from researchers, but the cooperation on water issues in this river basin has been limited, even after the establishment of the Mekong River Commission(MRC). Cooperation on water resources has been determined as one of the key priority areas in the Lancang-Mekong Cooperation Mechanism, but there are no details of targets. In order to establish the priorities of water cooperation under the mechanism, we adopted nine categories to classify the objectives of 87 water cooperation events based on the ‘Lancang-Mekong Water Cooperative Events Database' from 1995 to 2015. Based on the occurrence of cooperative events, cooperative objectives, cooperative scales, and approaches to cooperation, we conducted statistical, correlation, and text analyses. Our analyses indicated the following results: under the impact of economic conditions inside and outside the river basin, full cooperation appeared more difficult than bilateral and multilateral cooperation. Each of the partners adopted different preferences for cooperation targets. Cooperation with more definite objectives was easier to establish than cooperation with broader and more complex objectives. The potential objectives for water cooperation were navigation, hydropower, joint management, data sharing, flood control and water use. Because hydropower development is controversial, and because water cooperation is avoided by most existing regional cooperation mechanisms due to its complexity, we suggest the following priority areas for water cooperation in the Lancang-Mekong River Basin. 1) Navigation and flood control/drought relief are attractive objectives for all the riparian countries across the whole watershed. 2) Data sharing should be a priority for cooperation in the watershed due to its laying the foundation for the equitable and reasonable utilization of transboundary waters. 3) Hydropower is an objective best implemented mainly through bilateral cooperation, and on tributaries.
基金Supported by the National 863 Program of China (No.2003AA131170)the Special Funds of Director of Institute of Remote SensingApplications, Chinese Academy of Sciences+1 种基金the Funds of State Key Laboratory of Remote Sensing Sciencesthe Funds of StateKey Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing.
文摘For centuries, explorers and scientists from different countries had made their own conclusions on the source of the Mekong. However, the geographic source of the Mekong is still arguable because of the complexity of the Mekong source water system, inaccessible environment and the varied technologies used by those explorers and scientists. The satellite remote sensing technology has been used to pinpoint the source of the Mekong, associated with the on-the-spot investigations made by the authors in June 1999 and September 2002. The actual length of the Mekong has also been calculated.
基金Supported by National Natural Science Foundation of China (No. 40601096)
文摘The Mekong supports one of the richest inland fisheries in the world, with many of the fish migrating long distance to spawn. Little is known about the fisheries and migration strategies of the Upper Mekong whilst it is supposed that many fish species move between the Lower and Upper Mekong. Most likely, natural fish migration in the river has been altered by dam construction across the mainstream of the Upper Mekong. In this paper, the interconnectivity of fish species between different sections of the Mekong and negative impacts of dams on migratory fish are studied. Of the 162 fish species in the Upper Mekong and the 869 species in the Lower Mekong, 61 species are common. Results show that there is no significant difference at order level between the UM and LM. Similarity coefficients are used to evaluate interconnectivity at species, genus and family levels among four different sections of the Upper Mekong with each other and with the Lower Mekong as a whole. The highest similarity is found between the middle and lower reach of the Upper Mekong at species and genus levels and the middle and upper reach at family level. Of the eight cascade dams, Mengsong Dam in planning is considered as the biggest threat to migratory fish from the Lower Mekong and should be particularly concerned.
基金This work was supported by the External Cooperation Program of Bureau of International Co-operation,Chinese Academy of Sciences[grant number GJHZ1729]the Key Program of the Natural Science Foundation of Yunnan Province of China[grant number 2016FA041].
文摘The Lancang–Mekong River basin(LMRB) is under increasing threat from global warming. In this paper, the projection of future climate in the LMRB is explored by focusing on the temperature change and extreme temperature events. First, the authors evaluate the bias of temperature simulated by the Weather Research and Forecasting model. Then, correction is made for the simulation by comparing with observation based on the non-parametric quantile mapping using robust empirical quantiles(RQUANT) method. Furthermore, using the corrected model results, the future climate projections of temperature and extreme temperature events in this basin during 2016–35, 2046–65, and 2080–99 are analyzed. The study shows that RQUANT can effectively reduce the bias of simulation results. After correction, the simulation can capture the spatial features and trends of mean temperature over the LMRB, as well as the extreme temperature events. Besides, it can reproduce the spatial and temporal distributions of the major modes. In the future, the temperature will keep increasing, and the warming in the southern basin will be more intense in the wet season than the dry season. The number of extreme high-temperature days exhibits an increasing trend, while the number of extreme low-temperature days shows a decreasing trend. Based on empirical orthogonal function analysis, the dominant feature of temperature over this basin shows a consistent change. The second mode shows a seesaw pattern.
文摘Tonle Sap Lake is the largest river-connected lake, buffer area and ecological zone of Mekong River, which plays a huge role in dispelling flood peak and compensating water, and the conservation of biological diversity. The river-lake relationship between Mekong River and Tonle Sap Lake is unique and has always been a major focus in the international community. The land terrain and under-water topography were used to analyze the morphological characteristics of Cambodia Mekong Delta and Tonle Sap Lake. Long series of hydrological data of river-lake controlling stations were used to analyze the water level variation characteristics and water volume exchange pattern between Mekong River and Tonle Sap Lake, and the response relationship to river-lake morphological characteristics were also researched. The results show that: Cambodia Mekong Delta and Tonle Sap Lake Area is low-lying and flat with gentle channel gradient and water surface gradient, making the relationship between water level and area (or volume) smooth. The channel storage capacity of Mekong River and Tonle Sap River is not enough compared to the inflow, so vast flooding plain is extremely prone to be inundated, making the flood relationships between the left and right banks become very complicated. Tonle Sap Lake is a seasonal freshwater lake with water flowing in and flowing out, and the timing and intensity of water exchange with Mekong River are closely related to the water flow resistance at the exit section of Tonle Sap Lake and the cross-sectional area of Tonle Sap River, which can be reflected by the river-lake water level difference and the water level of Tonle Sap River. Affected by the river-lake morphological characteristics, the water exchange intensity between Mekong River and Tonle Sap Lake is great. Tonle Sap Lake not only stores 14.4% of flood volume (39.7 billion m3) from the Mekong River every year, but also supplies 29.7% of dry water (69.4 billion m3) to the Mekong River. Influenced by the adjustment of the floodplain, the water level fluctuation of Mekong River and Tonle Sap Lake is slow, and the rising and droop rates of water level are positively correlated with the floodplain storage area. The research results will help to understand the relationship mechanism between Mekong River and Tonle Sap Lake and provide a scientific basis for the comprehensive governance of Cambodia Mekong Delta and Tonle Sap Lake Area.
基金National Key R&D Program of China(No.2016YFA0601601)National Natural Science Foundation of China(No.41601026,41661099)Science and Technology Planning Project of Yunnan Province,China(No.2017FB073)
文摘Satellite-based products with high spatial and temporal resolution provide useful precipitation information for data-sparse or ungauged large-scale watersheds. In the Lower Lancang-Mekong River Basin, rainfall stations are sparse and unevenly distributed, and the transboundary characteristic makes the collection of precipitation data more difficult, which has restricted hydrological processes simulation. In this study, daily precipitation data from four datasets(gauge observations, inverse distance weighted(IDW) data, Tropical Rainfall Measuring Mission(TRMM) estimates, and Climate Hazards Group InfraRed Precipitation with Stations(CHIRPS) estimates), were applied to drive the Soil and Water Assessment Tool(SWAT) model, and then their capability for hydrological simulation in the Lower Lancang-Mekong River Basin were examined. TRMM and CHIRPS data showed good performances on precipitation estimation in the Lower Lancang-Mekong River Basin, with the better performance for TRMM product. The Nash-Sutcliffe efficiency(NSE) values of gauge, IDW, TRMM, and CHIRPS simulations during the calibration period were 0.87, 0.86, 0.95, and 0.93 for monthly flow, respectively, and those for daily flow were 0.75, 0.77, 0.86, and 0.84, respectively. TRMM and CHIRPS data were superior to rain gauge and IDW data for driving the hydrological model, and TRMM data produced the best simulation performance. Satellite-based precipitation estimates could be suitable data sources when simulating hydrological processes for large data-poor or ungauged watersheds, especially in international river basins for which precipitation observations are difficult to collect. CHIRPS data provide long precipitation time series from 1981 to near present and thus could be used as an alternative precipitation input for hydrological simulation, especially for the period without TRMM data. For satellite-based precipitation products, the differences in the occurrence frequencies and amounts of precipitation with different intensities would affect simulation results of water balance components, which should be comprehensively considered in water resources estimation and planning.
文摘The Lancnag Mekong River is the most important international river across China and Southeast Asia, If it is developed according to 'Great Mekong Subregional Cooperation Plan' [9] prepared by ADB, the area directly affected will be up to over 2.32 million km 2, the population over 220 million, and the natural environment, and socio-economic conditions within a large area will be greatly changed. 'Agreement on Cooperation for Sustainable Development of Mekong Basin' signed by the four riparian countries along the lower Mekong River on April 5, 1995 provides a new opportunity for sustainable development of the Basin. According to preliminary analysis, if the multipurpose utilization of the water resources is the target for carrying out integrated planning and management, and the efforts are made 1) to focus on energy exploitation on the Lancang River Mainstream and the tributaries of the lower Mekong River; 2) to build gated weirs at Tonle Sam; 3) to construct spillways at the Mekong Delta; 4) to facilitate flood dykes in big cities and on both banks of the mainstream which are concentrated with population and farmland and liable to be flooded, and 5) to strengthen networks for forecasting hydrological and meteorological conditions, then all problems such as power demand, irrigation, flood, salt water intrusion as well as acid water erosion to soil could be solved without constructing large cascaded stations and dams on the lower Mekong Mainstream. This will not only avoid input of great number of fund, large scale resettlement and land inundation, but also prevent aquatic organisms living in Mekong River from being injured due to dam construction, and promote the sustainable development of the Basin.
文摘According to a lot of hydrological and environmental monitoring data, the condition of soil and water loss in the Lancang River Mekong River watershed (in Yunnan section, China) is described. The occurrence and development of soil and water loss is analyzed. The conclusion is that: (1) generally, the situation of soil and water loss in the Lancang River Mekong River watershed (in Yunnan section, China) is light, however, soil and water loss in some regions is serious, especially in the middle reach area of the river; (2) soil and water loss in the Lancang River Mekong River (in Yunnan section, China) watershed presents developing tendency and it is mainly caused by human beings. In accordance with these results, the control measures for soil and water loss are discussed.
文摘The Lower Mekong Delta in Vietnam experiences widespread flooding annually. About 17 million people live in the Delta with agriculture as the major economic activity. The suspended sediment load in the Mekong River plays an important role in carrying contaminants and nutrients to the delta and changing the geomorphology of the delta river system. In recent decades, it is generally perceived that the flow and sediment transport in the Mekong River have changed due to climate change and development activities, but observed sediment data are lacking. Moreover, after natural floodplains, the sediment deposition has replaced by dense river systems as resulting in floodplain compartments protected by embankments. This study is aimed to investigate impacts of changing water flow on erosion/deposition in the Lower Mekong Delta. We used Mike 11 hydrodynamic model and sediment transport model for simulating the flow and sediment transport. Various scenarios were simulated based on anticipated upstream discharges. Our findings provide the positive and negative impacts to the changes in sediment transport on agriculture cultivation in the Lower Mekong Delta.
文摘The Quadrangle Economic Cooperation Zone in Great Mekong Region, where the Golden Triangle is located, is composed with the border areas of China, Laos, Thailand and Myanmar. The poorest and inaccessible remote Golden Triangle now faces the opportunity to develop and participate in the global economic system. Not only has the traditional border tourism between two countries in this region been growing rapidly and various tourism products cross the regions also have been developed. The article attempts to explore the multiplier effects of tourism on regional cooperation. These consequences of tourism cooperation take effect through the infrastructure improvement, facilitation of the flee movement, improvement of communication and promotion of the alternative economy. The study also points out the unexpected negative consequences to limit its role as a regional cooperative engine due to the lack of consideration of the dual economic and social structure in tourism development. The special attention should be drawn to consider the limited benefits for the marginalized community, the high transaction of the social costs related with the drug tourism and sex tourism. The paper calls for more rigorous cooperative regional plans and policies to the complexity of tourism development in this region.
文摘Groundwater resources have considerable influences on the human population and socioeconomic development of Vietnam and the Mekong River Delta(MRD). This paper presents an overview of the relationship between climate change and groundwater in the MRD, including the challenges, strategies and technical measures. Our results showed that groundwater levels are related to other climate and hydrological variables(i.e., rainfall, river levels, etc.); therefore, the impacts of climate change on the groundwater resources of the Mekong delta are significant, especially on groundwater recharge. Based on the results of this study, it is recommended that groundwater development in the future should focus on reducing groundwater harvesting, enhancing groundwater quantity by establishing artificial works and exploiting surface water. This study suggests that the Artificial Neural Network(ANN) model is an effective tool for forecasting groundwater levels in periods of 1 month and 3 months for aquifers in the natural and tidal regime areas of the delta.
文摘The transboundary Mekong River is shared by six SE Asia countries (China, Myanmar, Thailand, Lao PDR, Cambodia, and Vietnam). In this paper the livelihoods of farmers and fishers of Lao PDR, Cambodia and Vietnam are examined to assess impacts of Mekong River development and modernization projects on the rural peoples of the Mekong River and Delta. A high proportion of the 190 million rural people of the Mekong basin are dependent on the diverse and abundant resources of the Mekong River and its tributaries for food security and basic necessities, livelihoods, and cultural identities. Although rice farming and fisheries occupations are primary income sources, many livelihoods involve a diversity of on-farm and off-farm activities. Agricultural specialization and intensification and hydropower dam construction on the Mekong main stem and tributaries are altering traditional rural patterns of household food security, income, and cultural ways of living at an increasingly rapid pace. Rural transformation projects must better assess how these modernization efforts change the ecology of the Mekong River and in turn affect the capacity of rural people to adapt in ways that ensure food security and improve household livelihoods. It will be critical that development efforts recognize, value, and invest in rural people’s roles in producing a stable, affordable food system and managing the integrity of river ecosystems upon which future prosperity depends. Interventions are needed to prevent degradation of the Mekong Basin soil and water resources from large-scale agricultural intensification, water diversion and overbuilding of hydropower dams which are threats to small-scale land holdings and farmers and fishers capacities to provide daily food for their own consumption and to feed SE Asia’s growing urban populations.
文摘An Giang province in the Mekong Delta is the most vulnerable province the impact of flooding and climate variability. Thousand of households are at risk due to severe annual floods. This study applied the LVI (livelihood vulnerability index) to estimate flood vulnerability of Phu Huu and Ta Danh villages in An Giang province. Data on socio-demographics, livelihoods, health, social networks, physical, financial and natural resources, natural disasters and climate variability were collected from a survey of 120 households in each village. From these data the LVI of each village was calculated. Results show that the overall LV1 of Phu Huu village, located in the early flooded zone, is higher than that of Ta Danh village, located in the late flooded zone. The analysis also indicated that this practical method can be applied for other purposes such as to monitor vulnerability, evaluate development programs or policy effectiveness by incorporating with scenario comparison.
文摘Land subsidence and rising sea levels could result in 40% of the Mekong Delta being covered by the South China Sea within the next few decades. The impact of groundwater withdrawal, in the SE Asia mega deltas of Ganges-Brahmaputra Delta, Jakarta Delta, Chao Phraya Delta and Mekong Delta, is a major reason these deltas are sinking. There are lessons to be learned from both failures and successful remediation efforts in other mega deltas as Vietnam policy makers seek to address Mekong Delta subsidence. Without a significant Vietnam government remediation and mitigation efforts, land subsidence in the Mekong Delta will continue. Land subsidence has occurred in the Mekong Delta as a result of the retention of sediments behind the China and Laos dams on the main stem of the Mekong River, reduced flooding peaks, climate change, sea level rise, storm surges and flooding. In addition, subsidence has been exascerbated by compaction, groundwater extraction for shrimp ponds, rice paddies and the household and drinking water needs of approximately 20 million people living on the Mekong Delta in Vietnam and Cambodia. The Mekong Delta shorelines are eroding and significant land areas, including wetlands, are becoming open water. The wetlands and land mass are also subsiding as a result of the reduction in sediment deposition. Large dams on the mainstem of the Mekong River in China and Laos have reduced peak flows and reduced sediment loads in lower Mekong River. Population and industrial growth have increased groundwater extraction and salt water intrusion as the delta subsides leading to consolidation and reduction in the current plumes flowing into the South China Sea. The primary objective of this paper is to assess the impact of groundwater withdrawals for rice paddies, shrimp ponds, aquaculture, industry and drinking water on Mekong Delta land subsidence. The secondary objective is to identify mitigation efforts used in other Southeast Asia deltas and make remediation recommendations for the sinking Mekong Delta. Promising mitigation approaches are injecting river water deep into the underlying alluvial sediments, return of the sediments trapped in China and Laos reservoirs to the Mekong River mainstem, increase in the Mekong River flooding peaks, and construction of sea and floodwalls, dykes, polders and levees. The addition of Mekong River sediments to build up existing floodplains, the reduction of coastal shoreline erosion, the planting of mangroves and protection of urban and agricultural areas from being covered by the South China Sea are strategies that could help remediate land subsidence in the Mekong Delta.
基金Special acknowledgement to Jing WANG for her tremendous support during the preparation and organization of the excursion as well as encouragement during the paper's compilation, Peng-Fei SHANG and Ming-Tao CUI for their helpful assistance, Lina Du, Kunming Institute of Zoology (KIZ), Chinese Academy of Sciences, for her patience with me reviewing specimens in the institute's collection, Xiao- Yong CHEN and Jun-Xing YANG, both K/Z, for their support in terms of literature and material, my travel companion Michael Bisset, Tsinghua University, Beijing, for his overall support and help during the excursion.
文摘An ichthyofaunistic survey of Mekong tributaries in Lincang Prefecture, Yunnan Province, China yielded a new species of nemacheilid loach, herein described as Schistura sexnubes species nova. The new species is readily distinguishable from its congeners by the following combination of characters: 8+8 branched caudal fin rays, an incomplete lateral line, a dissociated caudal bar, a shallow caudal peduncle depth (7.6%-9.6% SL; respectively caudal peduncle 1.76-1.95 times longer than deep), a diminutive size of less than 50 mm SL, and no sexual dimorphism. A dorsocephalic pattern consisting of a black, forward directed V-shaped formation located between the nares, and a white, ovoid blotch on the upper operculum serves as an autapomorphy.
文摘Mekong River Basin is a life for many people in six south East Asian countries. The river basin is very productive and has crucial activities like: fishing, agriculture, hydroelectric power, transportation, biodiversity and so on. However, due to mismanagement, political intentions and one way interest only for development, the river basin has already started experiencing complications. The major challenges found out were, huge hydroelectric dam constructions and other projects, high population pressure, lack of cooperation among riparian states (especially upper Mekong region and lower one), and lack of proper management system. This leads to inequitable resource use, impact on water quality, biodiversity loss, and disasters like flooding. It is a high time to make a joint venture among riparian countries for sustainable use of the resource. Multi lateral cooperation and commitment among user countries by consulting all stakeholders will benefit all to use this precious resource equitably without major ecological impacts on the river basin.
文摘Changes in the climatic system introduce uncertainties in the supply and management of water resources. The Intergovernmental Panel on Climate Change(IPCC) predicts an increase of 2 to 4 °C over the next 100 years. Temperature increases will impact the hydrologic cycle by directly increasing the evaporation of surface water sources. Consequently, changes in precipitation will indirectly impact the flux and storage of water in surface and subsurface reservoirs(i.e., lakes, soil moisture, groundwater, etc.). In addition, increases in temperature contribute to increases in the sea level, which may lead to sea water intrusions, water quality deterioration, potable water shortages, etc. Climate change has direct impacts on the surface water and the control of storage in rivers, lakes and reservoirs, which indirectly controls the groundwater recharge process. The main and direct impact of climate change on groundwater is changes in the volume and distribution of groundwater recharge. The impact of climate change on groundwater resources requires reliable forecasting of changes in the major climatic variables and accurate estimations of groundwater recharge. A number of Global Climate Models(GCMs) are available for understanding climate and projecting climate change.These GCMs can be downscaled to a basin scale, and when they are coupled with relevant hydrological models, the output of these coupled models can be used to quantify the groundwater recharge, which will facilitate the adoption of appropriate adaptation strategies under the impact of climate change.
文摘Purpose: Vietnam rice has long been a product of international stature. In the commodity export of Vietnam, rice always plays as key agricultural commodities, with contributions billions of dollars each year in total export value. It not only contributes to the overall growth of the economy, but also gradually affirms Vietnam’s position on the international rice market. According to General Statistics Office, in 2012, Vietnam produced 43.7 million tonnes of rice and exported record 8.047 million tonnes of rice, contributing to the total export value of $3.689 million. However, it has not still been commensurate with the value and potential of rice from Vietnam. In addition, the fact is that in recent years, although export rice increased sharply, bringing many records for Vietnam, it had lower prices than other rice exporting countries (Thailand, India, Pakistan). So what is the cause and solution to enhance competitiveness and promote export of rice products in Viet Nam? In the increasingly complex international context, besides socio-economic development, security and national defense, food security has become a matter of international concern. The article first discusses the competitiveness, the value of rice exports and the need to improve competitiveness and export value of rice in the Mekong Delta. Then, there are some solutions proposed to improve the competitiveness and export of rice in the Mekong Delta in the coming time.