Is China's fifth-largest inland lake to dry-up? Incorporated hydrological and satellite-based methods for forecasting Hulun Lake water levels

Hulun Lake, China’s fifth-largest inland lake, experienced severe declines in water level in the period of 2000-2010. This has prompted concerns whether the lake is drying up gradually. A multi-million US dollar engineering project to construct a water channel to transfer part of the river flow from a nearby river to maintain the water level was completed in August 2010. This study aimed to advance the understanding of the key processes controlling the lake water level variation over the last five decades, as well as investigate the impact of the river transfer engineering project on the water level. A water balance model was developed to investigate the lake water level variations over the last five decades, using hydrological and climatic data as well as satellite-based measurements and results from land surface modelling. The investigation reveals that the severe reduction of river discharge (- 364±64 mm/yr, ~70% of the five-decade average) into the lake was the key factor behind the decline of the lake water level between 2000 and 2010. The decline of river discharge was due to the reduction of total runoff from the lake watershed. This was a result of the reduction of soil moisture due to the decrease of precipitation (-49±45 mm/yr) over this period. The water budget calculation suggests that the groundwater component from the surrounding lake area as well as surface run off from the un-gauged area surrounding the lake contributed ~ net 210 Mm3/yr (equivalent to ~ 100 mm/yr) water inflows into the lake. The results also show that the water diversion project did prevent a further water level decline of over 0.5 m by the end of 2012. Overall, the monthly water balance model gave an excellent prediction of the lake water level fluctuation over the last five decades and can be a useful tool to manage lake water resources in the future.

Performing the Local and the Global : The Theatre Festivals of Lake Constance

Wilkinson, Jane, Performing the Local and the Global: The Theatre Festivals of Lake Constance (Peter Lang, 2007), pp.286 RAE2008

Arthur Douglas : missionary on Lake Nyasa, the story of his life

http://www.archive.org/details/arthurdouglasmi00douguoft

Analysis of institutional arrangements and common pool resources governance: the case of Lake Tana sub-basin, Ethiopia

Although Common Pool Resources (CPRs) make up a significant share of total income for rural households in Ethiopia and elsewhere in developing world, limited access to these resources and environmental degradation threaten local livelihoods. As a result, the issues of management, governance of CPRs and how to prevent their over-exploitation are of great importance for development policy. This study examines the current state and dynamics of CPRs and overall resource governance system of the Lake Tana sub-basin. This research employed the modified form of Institutional Analysis and Development (IAD) framework. The framework integrates the concept of Socio-Ecological Systems (SES) and Interactive Governance (IG) perspectives where social actors, institutions, the politico-economic context, discourses and ecological features across governance and government levels were considered. It has been observed that overexploitation, degradation and encroachment of CPRs have increased dramatically and this threatens the sustainability of Lake Tana ecosystem. The stakeholder analysis result reveals that there are multiple stakeholders with diverse interest in and power over CPRs. The analysis of institutional arrangements reveals that the existing formal rules and regulations governing access to and control over CPRs could not be implemented and were not effective to legally bind and govern CPR user’s behavior at the operational level. The study also shows that a top-down and non-participatory policy formulation, law and decision making process overlooks the local contexts (local knowledge and informal institutions). The outcomes of examining the participation of local resource users, as an alternative to a centralized, command-and-control, and hierarchical approach to resource management and governance, have called for a fundamental shift in CPR use, management and governance to facilitate the participation of stakeholders in decision making. Therefore, establishing a multi-level stakeholder governance system as an institutional structure and process is necessary to sustain stakeholder participation in decision-making regarding CPR use, management and governance.

Geochemistry, mineralogy, and chemical modeling of the acid crater lake of Kawah Ijen volcano, Indonesia

The Kawah Ijen volcano-with a record of phreatic eruptions-has its 1000 m wide crater filled with a lake that has existed for at least one century. At present, the lake waters are hot (T ≈ 37°C), strongly mineralized (TDS = 105 g/L) and extremely acidic (pH ≈ 0.4). By its volume, the Javanese lake is probably the largest accumulation in the world of such acidic waters. Mineralogy of the suspended solids within the lake waters suggests that concentrations of Si, Ca, Ti, and Ba are controlled by precipitation of silica, gypsum, anatase, and barite. Lake sediment is composed of chemical precipitates with composition similar to the suspended solids. Thermodynamic calculations predict that the lake waters have reached equilibrium with respect to α-cristobalite, barite, gypsum, anglesite, celestite, and amorphous silica, in agreement with the analytical observations. Significant concentrations of ferric iron suggest that the current lake waters are fairly oxidized. Sulfides are absent in the water column but are always present in the native S spherules that form porous aggregates which float on the lake. The presence of native S provides direct evidence of more reduced conditions at the lake floor where H2S is probably being injected into the lake. With progressive addition of H2S to the acid waters, native S, pyrite, and enargite are theoretically predicted to be saturated. Reactions between upward streaming H2S-bearing gases discharged by subaqueous fumaroles, and metals dissolved in the acidic waters could initiate precipitation of these sulfides. A model of direct absorption of hot magmatic gases into cool water accounts for the extreme acidity of the crater lake. Results show that strongly acidic, sulfate-rich solutions are formed under oxidizing conditions at high gas/water ratios. Reactions between the acidic fluids and the Ijen andesite were modeled to account for elevated cation concentrations in lake water. Current concentrations of conservative rockforming elements are produced by dissolution of approximately 60 g of andesite per kg of acid solution. Complete neutralization of the acid lake waters by reaction with the wallrock produces a theoretical alteration assemblage equivalent to that observed in volcano-hosted, acid-sulfate epithermal ore deposits. © 1994.

Natural streamflow regime alterations: Damming of the Piave river basin (Italy)

A novel approach is proposed to estimate the natural streamflow regime of a river and to assess the extent of the alterations induced by dam operation related to anthropogenic (e.g., agricultural, hydropower) water uses in engineered river basins. The method consists in the comparison between the seasonal probability density function (pdf) of observed streamflows and the purportedly natural streamflow pdf obtained by a recently proposed and validated probabilistic model. The model employs a minimum of landscape and climate parameters and unequivocally separates the effects of anthropogenic regulations from those produced by hydroclimatic fluctuations. The approach is applied to evaluate the extent of the alterations of intra-annual streamflow variability in a highly engineered alpine catchment of north-eastern Italy, the Piave river. Streamflows observed downstream of the regulation devices in the Piave catchment are found to exhibit smaller means/modes, larger coefficients of variation, and more pronounced peaks than the flows that would be observed in the absence of anthropogenic regulation, suggesting that the anthropogenic disturbance leads to remarkable reductions of river flows, with an increase of the streamflow variability and of the frequency of preferential states far from the mean. Some structural limitations of management approaches based on minimum streamflow requirements (widely used to guide water policies) as opposed to criteria based on whole distributions are also discussed. Copyright © 2010 by the American Geophysical Union.

Laparoscopic Appendectomy in Italy: An Appraisal of 26,863 Cases

Objective: To evaluate the practice of laparoscopic appendectomy (LA) in Italy. Methods: On behalf of the Italian Society of Young Surgeons (SPIGC), an audit of LA was carried out through a written questionnaire sent to 800 institutions in Italy. The questions concerned the diffusion of laparoscopic surgery and LA over the period 1990 through 2001, surgery-related morbidity and mortality rates, indications for LA, the diagnostic algorithm adopted prior to surgery, and use of LA among young surgeons (<40 years). Results: A total of 182 institutions (22.7%) participated in the current audit, and accounted for a total number of 26863 LA. Laparoscopic surgery is performed in 173 (95%) institutions, with 144 (83.2%) routinely performing LA. The mean interval from introduction of laparoscopic surgery to inception of LA was 3.4 ± 2.5 years. There was an emergent basis for 8809 (32.8%) LA procedures (<6 hours of admission); 10314 (38.4%) procedures were performed on an urgent basis (<24 hours of admission); while 7740 (28.8%) procedures were elective. The conversion rate was 2.1% (561 cases) and was due to intraoperative complications in 197 cases (35.1%). Intraoperative complications ranged as high as 0.32%, while postoperative complications were reported in 1.2% of successfully completed LA. The mean hospital stay for successfully completed LA was 2.5 ± 1.05 days. The highest rate of intraoperative complications was reported as occurring during the learning curve phase of their experience (in their first 10 procedures) by 39.7% of the surgeons. LA was indicated for every case of suspected acute appendiceal disease by 51.8% of surgeons, and 44.8% order abdominal ultrasound (US) prior to surgery. A gynecologic counseling is deemed necessary only by 34.5% surgeons, while an abdominal CT scan is required only by 1.5%. The procedure is completed laparoscopically in the absence of gross appendiceal inflammation by 83%; 79.8% try to complete the procedure laparoscopically in the presence of concomitant disease; while 10.4% convert to open surgery in cases of suspected malignancy. Of responding surgeons aged under 40, 76.3% can perform LA, compared to 47.3% surgeons of all age categories. Conclusions: The low response rate of the present survey does not allow us to assess the diffusion of LA in Italy, but rather to appraise its practice in centers routinely performing laparoscopic surgery. In the hands of experienced surgeons, LA has morbidity rates comparable to those of international series. The higher diagnostic yield of laparoscopy makes it an invaluable tool in the management algorithm of women of childbearing age; its advantages in the presence of severe peritonitis are less clear-cut. Surgeons remain the main limiting factor preventing a wider diffusion of LA in our country, since only 47.3% of surgeons from the audited institutions can perform LA on a routine basis.

Analytical laboratory comparison of major and minor constituents in an active crater lake

info:eu-repo/semantics/published