Transboundary Flow Research Articles

2D and 3D coexisting modes of thermal convection in fractured hydrothermal systems - Implications for transboundary flow in the Lower Yarmouk Gorge

Numerical investigations of 2D and 3D modes of large-scale convection in faulted aquifers are presented with the aim to infer possible transport mechanisms supporting the formation of thermal springs through fractured aquicludes. The transient finite elements models are based on idealized structural features that can characterize many hydrothermal systems. The sensitivity analysis of the fault permeability showed that faults cross-cutting the main regional flow direction allow groundwater to be driven laterally by convective forces within the fault planes. Therein thermal waters can either discharge along the fault traces or exit the fault through adjacent permeable aquifers. In the latter case, the resulting flow is helicoidally and transient. The location and the spacing between discharge areas can migrate with time, is not strictly constrained to the damage zones and reflects the wavelength of the multicellular regime in the fault zone.An illustrative example based on simplified structural data of the Lower Yarmouk Gorge (LYG) is presented. The numerical calculations indicate that crossing flow paths result from the coexistence of fault convection, developing for example along NE-SW oriented faults within the Gorge, and additional flow fields. The latter are induced either by topography NS gradients, e.g. perpendicular to the major axe of the Gorge, or by local thermal convection in permeable aquifers below the Eocene aquiclude. Sensitivity analysis of fault hydraulic conductivity (K) and the analytical solutions based on viscous-dependent Rayleigh theory show that K values between 2.3e−7 m/s and 9.3e– 7 m/s (i.e. 7 m/yr and 30 m/yr, respectively) favor coexisting transport processes. The uprising thermal plumes spread over several hundred meters forming clusters of springs, in agreement with observation, and which temperature fall within the measured ranges, i.e. 20 °C−60 °C. To some extent the models also reproduced the transient behavior of the spring temperature. Owing to the idealized nature of the presented models, the numerical results and the associated analytical solution can be applied to study the onset of thermal convection and resulting flow patterns of any fractured hydrothermal basin.

Assessment of temporal hydrologic anomalies coupled with drought impact for a transboundary river flow regime: The Diyala watershed case study

Recent increases in human activities in shared river basins have unquestionably raised concerns about potential hydrological impacts, especially impacts of dams and large-scale water withdrawal schemes in the highlands. Anthropogenic pressures twinned with drought impacts have exacerbated water management challenges. This article assesses the cumulative consequences of upstream anthropogenic pressures and drought spells on temporal river flow regimes for the downstream country. The size and complexity of problems confronting transboundary river watersheds makes it necessary to use a representative example basin to study the problems and potential solutions. The Diyala (Sīrvān) river basin, which shares dozens of transboundary watersheds between Iraq and Iran, has been selected as a representative case study. A subset of the Indicators of Hydrologic Alteration (IHA) was utilised and climate variability was considered in assessing the combined effect of various forms of upstream human-river regulations and climatic conditions on natural flow regimes in the downstream state. Findings indicated that the anthropogenic river-regulation coupled with the impact of drought periods have noticeably modified the natural flow paradigm. The yearly average runoffs, which are no longer available for the downstream country, have soared to very high levels, particularly over the last fifteen years. More adverse impacts were detected in the non-rainy season. Findings reveal also that damming and considerable water diversion to large-scale irrigation projects in the upstream state are the main regulations affecting the management of shared water resources in the downstream country.

Proof of Concept of an Altimeter-Based River Forecasting System for Transboundary Flow Inside Bangladesh

Recent work by Biancamaria (Geophysical Research Letters, 2011) has demonstrated the potential of satellite altimetry to forecast incoming transboundary flow for downstream nations by detecting river levels at locations in upstream nations. Using the Ganges-Brahmaputra (GB) basin as an example, we assessed the operational feasibility of using JASON-2 satellite altimetry for forecasting such transboundary flow at locations further inside the downstream nation of Bangladesh by propagating forecasts derived from upstream (Indian) locations through a hydrodynamic river model. The 5-day forecast of river levels at upstream boundary points inside Bangladesh were used to initialize daily simulation of the hydrodynamic river model and yield the 5-day forecast river level further downstream inside Bangladesh. The forecast river levels were then compared with the 5-day-later “nowcast” simulation by the river model based on in-situ river level at the upstream boundary points in Bangladesh. Results show that JASON-2 retains good fidelity at 5-day lead forecast with an average RMSE (relative to nowcast) ranging from 0.5 m to 1.5 m and a mean bias (underestimation) of 0.25 m to 1.25 m in river water level estimation. Based on the proof-of-concept feasibility, a 4 month-long capacity building of the Bangladesh flood forecasting agency was undertaken. This facilitated a 20-day JASON-2 based forecasting of flooding during Aug 1, 2012 to Aug 20, 2012 up to a 5 day lead time in a real-time operational environment. Comparison against observed water levels at select river stations revealed an average error of forecast ranging from -0.4 m to 0.4 m and an RMSE ranging from 0.2 m to 0.7 m. In general, this study shows that satellite altimeter such as JASON-2 can indeed be an efficient and practical tool for building a robust forecasting system for transboundary flow.

Features of groundwaters in basins shared between Ethiopia and Kenya and the implications for international legislation on transboundary aquifers

The implementation of laws relating to transboundary aquifers necessitates field knowledge so that the laws can be coincident with reality on the ground. The definition of ‘shared aquifer’ is more complex than the mere physically shared body of groundwater flowing from country A to country B. The border between Ethiopia and Kenya is characterized by low-volume groundwater storage and low transboundary flows. However, groundwater has visible environmental, social and economic functions. The characteristics of groundwater flow and storage in aquifers shared between Ethiopia and Kenya are different from those used in setting the foundation of the international legal framework on shared aquifers. By describing the characteristics of the groundwaters that are shared between Ethiopia and Kenya, this work demonstrates that the international legal framework is inadequate when applied in this region. The main inadequacies are: (1) international law does not specify the minimum volume of transboundary flow in an aquifer for it to qualify to be treated under the law, and (2) the physical aspects of water get more emphasis than the functions of groundwater. A more adequate international legal framework would be one that considers specific types of groundwater and local needs.

Variation in transboundary flow of Nujiang River and its correlation with summer monsoon under the effect of the Longitudinal Range-Gorge

The relationship between the variations of the Nujiang River transboundary flow and the summer monsoon activity under the topographical effect of the Longitudinal Range-Gorge (LRG) is examined. The study is based on statistical analysis of the observed river flow data, and their correlation with the reanalyzed U/V wind fields of the National Centers for Environment Prediction (NCEP) and the National Center for Atmospheric Research (NCAR), and the data of the Outgoing Longwave Radiation (OLR) of the National Oceanic and Atmospheric Administration (NOAA). It is concluded that the transboundary river flow is predominantly concentrated in the wet or rainy season (from May to October), particularly in the summer or flood season (from June to August). There is a clear tendency for the transboundary river flow to increase with time since 1970s, particularly apparent since 1980s. Due to the topographical “east-west barrier and north-south corridor” effects of the LRG, the summer river flow variations are largely correlated with winds of the southerly and northerly at both high and low altitudes. In contrast, the river flow variations are apparently correlated with winds of the easterly and westerly only at the high altitudes, not at the low altitudes. Negative correlation between the OLR and the river flow variations is also apparent. These relationships are quantitatively described using two summer monsoon indices proposed in this paper. The index MI2 includes both dynamical and thermodynamical effects and gives a generally good representation of the transboundary river flow variations in the LRG region of the Nujiang River basin. Larger MI2 represents stronger summer monsoon activity and higher transboundary river flow, while smaller MI2 suggests weaker monsoon circulation and lower water flow.

Sources and Occurrence of Dacthal in the Canadian Atmosphere

Dacthal is a herbicide that can undergo long-range atmospheric transport. Due to limited use in Canada, its occurrence in the Canadian environment is likely associated with transboundary flow from the United States where 100 times more dacthal is used. To investigate its atmospheric distribution and possible sources, two sampling strategies were applied. First, polyurethane foam-disk passive air samplers were deployed across the country from the spring to summer of 2004 and 2005. Results showed highest dacthal concentrations at two sites in southern Ontario (max: 50 pg m(-3)) and much lower concentrations in other agricultural regions across Canada. Second, daily high-volume air samples were collected at a field site in north Toronto (Downsview). Sampling at this site was triggered by real-time meteorological forecast models that indicated when air flow to the site originated in the United States. Two such events, one in late June and one in late September 2005, were sampled. In both cases, elevated dacthal concentrations were captured (e.g., up to 319 pg m(-3) in the June event) and they were well correlated with transboundary flow from the United States. Finally, the octanol--air partition coefficient (K(OA)) of dacthal and other current-use pesticides was measured. K(OA) was used to derive a particle--gas partitioning coefficient (K(p)) for dacthal (Log K(p) = -4.1), indicating that this compound should exist mainly in the gas phase.

Transboundary Flow Modeling: The Zohor Depression of Austria and the Slovak Republic

Estimation of available ground water is a basic aspect of ground water management. Mathematical modeling is one of the methods that can be effectively used to obtain such estimates. A numerical model was used to calculate available ground water in the Zohor depression-an aquifer transcending national boundaries between the Slovak Republic and Austria. The aquifer, formed by Quaternary sediments overlying Neogene sequences, is composed of various clays interbedded with layers of sand, gravel, sandstones, and conglomerates. The AQUA computer model package was used to simulate flow in the aquifer. For model compilation, the following data were used: (1) effective precipitation; (2) surface water levels in surface water gauging profiles; and (3) withdrawal amounts. Hydraulic parameters of the aquifer were estimated based on information from 86 wells located in the area. The model was verified using data on ground water levels from a monitoring network. The simulation of the aquifer system permitted the estimation of the available ground water in the study area, showing that an additional 587 L/s can be abstracted. Ground water inflows to the Morava River, which flows through the region, range from 745 to 3100 L/s.

Public participation to improve water resource management in Uzbekistan

At present Uzbekistan uses about 42 km3 of transboundary river flow and 27 km3 of this is from the Amu Darya. Annual average flow entering the upper reaches of Amu Darya within Uzbekistan is over 60 x 10(9) m3, which is already contaminated, but significant adverse water quality changes occur downstream where the river is the main source of drinking water. After independence Uzbekistan made a commitment to transfer management of farms and the rural economy from the public sector to private hands. Living conditions have deteriorated severely throughout Uzbekistan, but rural areas have been hit hardest. Several studies and projects in Uzbekistan have adopted the integrated water management-based environmental approach. A structured public participation and consultation process was followed during these projects including a social and the environmental assessment. This paper presents the two case studies to illustrate the effects of uniting the potential of all interested participants to improve water management and environmental safety. Consultation between the two main groups of stakeholders is essential for the future of the water sector. There is substantial support for WUAs among all stakeholders, at all levels, including among those stakeholders who currently manage the existing system.

Transfers to sustain dynamic core-theoretic cooperation in international stock pollutant control

For international environmental agreements aiming at world efficiency in the presence of transboundary flow pollution, it is known that, in a static context, efficiency and stability in the sense of the core of a cooperative game can be achieved using appropriately defined transfers between the countries involved. However, for accumulating pollutants, such as CO 2 in the atmosphere, a dynamic analysis is required. This paper provides a transfer scheme for which a core property is proved analytically in a dynamic (closed-loop) game theoretic context. The characteristic function of the cooperative dynamic game yielding this result is discussed and an algorithm to compute the transfers numerically is presented and tested on an example. The transfers are also compared with an open-loop formulation of the model.

Strategy of transboundary return flow use in the Aral Sea basin

The Aral Sea Basin, which is shared by 5 countries of the former Soviet Union — Kazakhstan, Kyrgyzstan, Tadjikistan, Turkmenistan and Uzbekistan is well known to the world due to the large scale water development in the Soviet period, which caused many ecological problems in the region. One of them is the problem of return waters, which are unmanaged and unused in now acceptable form. The total Transboundary Return Water (TRW) volume formed in the territory of 5 states is 36–40 km2. The two main reasons for the worsening of water quality in the major rivers of the Aral Sea basin — Amudarya and Syrdarya are: water withdrawal from the rivers for irrigation purposes and release return flow to the river of a large content of salts and other pollutants from irrigated lands. Spontaneous formation, dissemination and accumulation of return waters can, and already have caused considerable negative effects in environment and social development. For the development of a program for the use and management of these waters and its approval by the region's countries, measures preventing these effects must be taken in order to be of mutual benefit to all the countries involved and, simultaneously, to transform these waters into a source of life, biodiversity, sustainability and prosperity in the Aral Sea basin on a scale, that would influence the world community. For stabilization of these water bodies at the regional, and, thus at a global scale, it is necessary to eliminate the following threats: instability of whole scope and especially TRW regime in terms of quantity and quality; uncontrolled allocation and use of such waters; injurious use, including poaching. It must be taken into account that transboundary waters' sustainable development and use require permanent monitoring and management over a range of criteria, providing their ecological stability and safety as well as long-term bioproductivity and biodiversity of ecosystems supported by them. The principle provisions of management system on TRW are proposed for each stage: type of return water use; direction of possible use; stability criterion; restrictions; control.

Global technology spillover and its impact on industry's R&D strategies

A dramatic increase in the transboundary flow of people, goods and information together with an increase in technology complementarity with capital stock and labor forces has accelerated the growth and spread of global technology spillovers. Facing the R&D stagnation, effective utilization of technology from the global marketplace gathered from multiple sources has become an important competitive strategy leading to greater concern for assimilation capacity of spillover technology (the ability to utilize this spillover technology). In fact, how to effectively utilize this substitution potential has become one of the most crucial R&D strategies for industry. Notwithstanding its strong assimilation capacity up until the 1980s, Japan's capacity has deteriorated in the 1990s and the remediation of this problem has become urgent. This paper, uses both theoretical and empirical analyses of the mechanisms of (i) technology spillover contribution to production increase, and (ii) the role of assimilation, in addition to numerical analyses of the trends in assimilation capacity and the governing factors of this capacity. Furthermore, this investigation attempts to identify the sources and mechanism governing assimilation capacity, in order to extract suggestions for restructuring industry's R&D strategy.

National Recourses for International Pollution: Towards a United States, Canada Solution

The most prominent transboundary concern is, of course, acid rain, caused by the long-range transport of industrial and automotive pollution. But long-range air pollution transport also results in several other serious but less publicized transboundary problems such as the movement across national boundaries of oxidant pollution, which is impairing agricultural productivity in southern Ontario and elsewhere, and the transboundary flow of toxic air pollutants, a phenomenon which may already be affecting the Great Lakes. The Environmental Law Institute has conducted a series of studies of the institutional framework governing control of international pollution problems. A major conclusion of this research effort is that current national and international legal structures are poorly suited to the effective control of transboundary pollution. The international legal structure offers useful principles of environmental responsibility, but they are neither sufficiently defined nor sufficiently enforceable to support effective application to specific controversies. Despite the recent increase in the number and severity of international environmental problems, governments continue to make energy policy, pollution control, and land use decisions without explicit consideration of transboundary impact. There are forward-looking provisions in the Clean Air Acts of both the U.S. and Canada requiring control of emissions causing transboundary problems (U.S. Cleanmore » Air Act Section 115 and Canadian Clean Air Act Section 21.1). A recently completed ELI study focused on a new approach which would make the largely ignored U.S. and Canadian Clean Air Act provisions for control of international air pollution work more effectively, and in concert.« less