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1.
The aim of this work is to study the actual evapotranspiration and surface resistance of the savannah using the Bowen-ratio method for two contrasted periods, dry and rainy season. The reliability of this method has been assessed by comparison with the Monteith equation and the soil-water balance method in a 90% Loudetia arundinacea dominated savannah (Pointe Noire, Congo). Our results relate to the period from 18 September to 11 October 1998 (24 days): (a) from 18 to 29 September (“dry season”), the soil-water content was less than 70% of the soil-water content at field capacity (63–70% of R FC; large soil-water stress; T/E P from 0.2 to 0.4); (b) from 30 September to 11 October (“rainy season”) soil-water content close to 90–92% of RFC; no soil-water stress; T/E P from 0.73 to 0.77). The mean daily surface resistance reulting from the Bowen-ratio method was 317 s m?1, 355 s m?1 during the “dry season” and 279 s m?1 during the “rainy season”. The total actual evapotranspiration (E a) resulting from the Bowen-ratio method, Penman-Monteith equation and soil-water balance method were, respectively of 58.6–57.8 and 56.2 mm, with the mean daily Ea of 2.4–2.4 and 2.3 mm day?1 (2.4–1.5 and 2.2 mm day?1 in “dry season” and of 2.5–3.4 and 2.5 mm day?1 in “rainy season”). The Bowen-ratio method was used for the assessment of the actual evapotranspiration from the temperature and specific humidity differences, net radiation and the soil heat flux measurement: its advantages are a rapidity of installation, a temporal resolution of measurement in less than one hour and a good integration of the heterogeneousness of the savannah’s latent flux of vaporization. This method is adapted to eco-physiological studies in tropical conditions with reduced teams.  相似文献   

2.
Regional Environmental Change - Increasing demands, climate change and variability, and over-allocation pose tremendous challenges for the sustainable management of water resources. Federal river...  相似文献   

3.
There is a mounting body of literature dealing generally with the dynamics of transitions of human systems towards sustainability and specifically with the different stages and processes of transitions. However, the question of why transition processes occur in the first place remains largely unexplained. This paper explores the concept of transition triggers, such as culture or material resource scarcity, and provides a theoretical framework to explain the emergence of a transition and its relation to recent developments in Spanish water policy. We adapt the general framework provided by current transition theory and gather empirical evidence and insights from processes occurring within the Spanish policy context and the Ebro river basin in particular. Our results show that the sole existence of biophysical limits to water use or development cannot explain the start of a possible sustainability transition in this domain in Spain. Changes in the existing water policies in the direction of sustainability were not ignited by people directly affected by water scarcities but by a coalition of sensitive agents, mostly from academia, NGOs and local constituencies, who managed to articulate new identities, integrate multiple sources of policy relevant knowledge, and develop new values under the umbrella of the new water culture movement.
Akgun IlhanEmail:
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4.
Environment, Development and Sustainability - This study aims at exploring the impact of ESG scores on the value and FP of firms in the airline industry. The potential moderating role of firm size...  相似文献   

5.
The twelve major tributaries of the Venice Lagoon (accounting for the 97% of the inputs from the drainage basin) were monitored in the framework of the DRAIN project (1998-2000) in order to obtain a detailed knowledge on the hydrological regimes and to measure the mean annual freshwater discharge from surface runoff. The study represents an essential step in the estimate of the pollutant load delivered to the lagoon that must necessarily be based on a solid understanding of the fluxes of material out of the drainage basin. Due to the influence of the tide in the majority of the gauging sections, a specific methodology for the measurement of the discharge was developed. The main results of the study are described, underlining the differences in the regime of the investigated streams. A rainfall-runoff analysis evidenced the different characteristics of the monitored tributaries, in terms of specific hydrological features, morphology of the individual sub-basins, management of the water resource and spatial distribution of rainfall. An estimate of the maximum peak discharge from the drainage basin is finally obtained from data of an extreme flood event occurred in November 1999.  相似文献   

6.
Pollutant loads from the drainage basin to the Venice Lagoon (Italy)   总被引:4,自引:0,他引:4  
In order to assess the actual pollutant loads from the drainage basin, the twelve major tributaries of the Venice Lagoon were monitored and studied in the period 1998-2000 in the framework of the DRAIN project. A specific sampling scheme was designed to investigate the effects of the different regimes, including floods, in the transport of total and dissolved metals, nitrogen and phosphorous species as well as organic micropollutants. The loads were calculated from data collected during the year of 1999, since this year displayed a value close to the mean in terms of the distribution of total rainfall on the drainage basin. The annual values for the different pollutants are reported and discussed. A comparison with the estimates of previous investigations highlights the significant advancement provided by the DRAIN project results in the understanding of the drainage basin contribution to the pollution of the lagoon. Finally, the importance of flood events on the overall balance of materials and pollutants delivered to the lagoon is emphasized.  相似文献   

7.
Improper disposal of post-consumer Polythylene Terephthalate (PET) bottles constitutes an eyesore to the environmental landscape and gives rise to numerous environmental and health-related nuisances. These problems impact negatively on the flourishing tourism industry in Mauritius. The present study was therefore undertaken to determine a sustainable disposal method among four selected disposal alternatives of post-consumer PET bottles in Mauritius. The disposal scenarios investigated were: 100 % landfilling (scenario 1); 75 % incineration with energy recovery and 25 % landfilling (scenario 2); 40 % flake production (partial recycling) and 60 % landfilling (scenario 3); and 75 % flake production and 25 % landfilling (scenario 4). Environmental impacts of the disposal alternatives were determined using ISO standardized life cycle assessment (LCA) and the SimaPro 7.1 software. Cost-effectiveness was determined using Life cycle costing (LCC) as described by the recent Code of Practice on LCC. An excel-based model was constructed to calculate the various costs. Social impacts were evaluated using Social Life Cycle Assessment (S-LCA) based on the UNEP/SETAC Guidelines for Social Life Cycle Assessment. For this purpose, a new and simple social life cycle impact assessment method was developed for aggregating inventory results. Finally, Life Cycle Sustainability Assessment (LCSA) was conducted to conclude the sustainable disposal route of post-consumer PET bottles in Mauritius. The methodology proposed to work out LCSA was to combine the three assessment tools: LCA, LCC and S-LCA using the Analytical Hierarchy Process. The results indicated that scenario 4 was the sustainable disposal method of post-consumer PET bottles. Scenario 1 was found to be the worst scenario.  相似文献   

8.
In many arid and semiarid regions, water scarcity, population increase and frequent droughts are exerting great pressures on water resources. Presently, the Mid-route of the South-to-North Water Transfer Project (MRSN) was built to mitigate the water crisis in the north of China by long-distance transfer of water from the Yangtze River in southern China. This study investigated the running condition of the MRSN, including operation management, freezing situation and water quality. Water samples were also taken from different sites and then analyzed in laboratory. Results suggest that the project was reasonably designed and the project management was excellent. Closed management was adopted in the project to protect water quality. The sediment concentrations and water turbidities of the water samples were in the range of 0.2–0.8 kg/m3 and 0.8–1.7 NTU, respectively, which met or were close to the standards of drinking water in China. Water freezing is also not a problem, since the thickest ice was only 0.9 cm even in the coldest season as the authors measured the investigation, and at the same time, the ice booms worked well. In the future, it is promising that to effectively integrate the methods of self-rescuing and water importing could fundamentally conquer water shortage, reasonably allocate water resources and finally achieve the harmonious development of economics, ecology and society.  相似文献   

9.
Environment, Development and Sustainability - Recorded seasonal variation and uneven distribution of rainfall is one of the major issues to the agrarian society and the domestic water users today....  相似文献   

10.
A study is presented on the distribution of 234U, 238U, 235U isotopes in surface water of the Llobregat river basin (Northeast Spain), from 2001 to 2006. Sixty-six superficial water samples were collected at 16 points distributed throughout the Llobregat river basin. Uranium isotopes were measured by alpha spectrometry (PIPS detectors). The test procedure was validated according to the quality requirements of the ISO17025 standard. The activity concentration for the total dissolved uranium ranges from 20 to 261 mBq L−1. The highest concentrations of uranium were detected in an area with formations of sedimentary rock, limestone and lignite. A high degree of radioactive disequilibrium was noted among the uranium isotopes. The 234U/238U activity ratio varied between 1.1 and 1.9 and the waters with the lowest uranium activity registered the highest level of 234U/238U activity ratio. Correlations between uranium activity in the tested water and chemical and physical characteristics of the aquifer were found.  相似文献   

11.
After its infant stage, a new science usually starts reflexing on its identity and theoretical roots. Sustainability science is not an exception, and the needs of self-reflection are even more pressing because of its inter- and trans-disciplinary characters, which involve a plenty of different approaches, theories and practices. In fact, such a variety does not provide a consistent ground for its future development. Without a solid grounding on a reliable base, the plethora of different theories that currently crowds its arena could in the near future produce a rejection from disciplinary specialized researchers, thus confining sustainability science to a scientific fad. Convincing theoretical roots can be found in systems science and cybernetics, and in particular second-order cybernetics, once amended from autopoiesis theory and radical constructivism, which raise serious doubts of validity and applicability. If sustainability science acknowledged its systemic and cybernetic nature and adopted second-order cybernetics in its amended version, it would gain a powerful reference paradigm and a theoretical common denominator and language to support its researchers and facilitate their knowledge exchange. From their part, systems science and cybernetics would be better understood and embraced as powerful sources of knowledge for understanding modern challenging problems, and second-order cybernetics, after decades of scarce relevance for other scientific disciplines, would be revitalized and would finally evolve adequately in a promising science and social practice.  相似文献   

12.
A major problem for sustainable development in the Amazon is the difficulty of supplying electric power to isolated communities, which represent a considerable share of the population. This problem has been a major obstacle to productive activities (especially extractive and agricultural) in such communities, thus significantly contributing to rural drift and creating social problems in larger cities. In that case, one way to supply electric power would be to use the huge network of small rivers in the region by implementing Micro Hydroelectric Power Plants (MHPs). However, this type of hydropower project requires a set of technical assessments in order to obtain better value for its cost-effectiveness from the perspective of sustainable development. Thus, based on a survey of energy demand and the local hydrological and topographical characteristics, two possible MHP designs for the hydrological site under analysis were suggested. Assessments of hydropower, economic and environmental aspects were developed. MHP designs were compared with the diesel generator design of the community under focus. Comparison showed that the MHP designs are feasible in terms of energy to meet local demand; economically, they are more feasible than the diesel generator and are environmentally sustainable, mainly because such designs involve low-head, run-of-river MHPs and the flooded areas were simulated and are not larger than 0.02 km2. Therefore, the information provided by these assessments constitutes important data, serving as subsidies for MHP implementation projects, which shall contribute to sustainable development in the region.  相似文献   

13.
As a new discipline, sustainability science poses a challenge to researchers focused on issues in sustainable development world wide. Although definitions vary, three characteristics appear to be fundamental: sustainability science is transdisciplinary, provides integrated analysis, and is aimed at action. There is clearly a need for such a science to address complex contemporary issues. Yet the question remains how to go about advancing this new integrated approach. The ICSS2009 conference was organized to address this question. This article, based on the conference report, provides a summary of the deliberations and highlights recommendations to advance this new science including creation of a global network of networks in sustainability science.  相似文献   

14.
Regional Environmental Change - Past and present gold mining operations scattered throughout the Kharaa River basin, Mongolia, have been identified as a major source of heavy metal and metalloid...  相似文献   

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17.
The Great Lakes are an important environmental and economic resource for Canada and the United States. The ecological integrity of the Great Lakes, however, is becoming increasingly threatened by a number of persistent, bio-accumulative and harmful chemicals that enter the Great Lakes ecosystem through fluvial and atmospheric deposition. Polybrominated diphenyl ethers (PBDEs), a class of brominated flame retardant, are among such chemicals, whose concentration in the Great Lakes has greatly increased in recent years. Despite growing concern over the possible health and environmental effects of these compounds, only four of the eight Great Lakes states have enacted regulations to ban/restrict the use of PBDE while the two Canadian Great Lakes provinces are yet to endorse any regulation. Of the three main commercial PBDE mixtures (pentaBDE, octaBDE and decaBDE), penta- and octaBDE are no longer manufactured or imported into the United States and Canada. DecaBDE, however, still finds use in a variety of products. In the present paper, the authors review the current regulations and policies for managing PBDEs in the Great Lakes jurisdictions and briefly review commercially available non-bromine chemical alternatives to PBDE. As these alternatives are comparatively more expensive than PBDE, future adoption of more eco-friendly flame retardants by the polymer industry will likely depend on stricter legislation regulating the use of PBDE and/or an increased public demand for PBDE-free products.  相似文献   

18.
Since United Nations adopted the global Sustainable Development Goals (SDGs) for the next 15 years (2016–2030), sustainable development will further become a core concept and main principle to guide global and national economic and social development. According to this background, strengthening the integrative research on the theories and methodologies of sustainable development has been a strategically important mission. This article provided an analytic framework for sustainability science, named the object-subject-process (OSP) framework for examining the key issues encountered during the theoretical research and policy analysis. This study emphasized that, on the object dimension, sustainable development means to seek for economic and social development within biophysical limits of the earth and the relationship of environment, society, and economy should be containing and complementary rather than parallel and substitute; on the process dimension, sustainable development should adopt both the responsive and proactive strategies for the whole process management which employing pressure-state-response (PRS) model rather than dealing with one part of them; on the subject dimension, sustainable development research should involve the key stakeholders who are kind of collaborate governance rather than separate each other. From the perspective of sustainability science, green economy was utilized as a case study to explore the issues of object, process and subject and also the significance of green economy was discussed in this study.  相似文献   

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20.
A near field study was set up to follow the effects of the Temelin nuclear power plant construction. Reference levels of artificial radionuclides were monitored in the Vltava River upper course and its tributaries in the period 1990-2001. Monitoring continued even after the waste water release startup during the pilot operation in 2002. The assessment of the (90)Sr and (137)Cs concentrations histories in ground water, river bottom sediments and fish showed a decreasing trend. This trend was not influenced by the nuclear power plant pilot operation. In the case of tritium, trend of increasing concentration had been already observed since the pilot operation startup. The monitoring of changes in concentrations of artificial and natural radionuclides in influenced and uninfluenced profiles will be maintained to assess the possible influence of the operation of the Temelin nuclear power plant.  相似文献   

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