Decrease In Water Volume Research Articles

Preliminary Evidence for the Decline in Discharge at Falaj Daris, Nizwa, Oman

Falaj Daris is one of the oldest active aflāj located in Oman and the largest in the Dakhiliyah governorate. It is a 7,999-meter long Dāwūdī-type falaj. Ninety-five percent of water drawn from falaj Daris is used for agricultural irrigation and the remaining five percent is used for domestic purposes. In this paper, we analyzed several datasets including falaj Daris discharge, borehole water levels in wadi al-Abyadh, whose aquifer falaj Daris taps, and GRACE satellite data to determine the historical trend of falaj Daris discharge during 1982-2020. A set of standard statistical methods and data visualization techniques were applied including the Mann-Kendall trend test. Preliminary evidence shows a decline of 226,000 L/day in falaj Daris discharge between 1982-2020. This finding is supported by the overall trends in borehole water levels in wadi al-Abyadh. All these trends were confirmed using GRACE satellite data which shows a decrease in water volume of 6 (WET cm) in the larger basin between 2002-2021. Keywords: qanat; falaj Daris; wadi al-Abyadh; Nizwa, Oman; GRACE satellite.

Long-Term Dynamics of Persistent Organic Pollutants in Water Bodies of the Aral Sea–Syrdarya Basin

The huge decrease in water volume in the Aral Sea, which was caused predominately by enormous water withdrawals from the Aral Sea tributaries, has changed the former world’s fourth-biggest inland lake into a new desert called Aralkum. Due to its long-term use in agriculture, persistent organic pollutants (POPs), including organochlorine pesticides (OCPs), and polychlorinated biphenyls (PCBs) play a special role in the pollution of the Aral Sea tributaries and in the Aral Sea itself. For the first time, POPs, OCPs, and PCBs were studied in the Large Aral Sea, Small Aral Sea, and the Syrdarya River. PCBs and OCPs in the collected water samples were analyzed using gas chromatography. The results of long-term and inter-annual analyses of POPs in water resources of the Kazakh part of the Aral Sea–Syrdarya Basin are presented. The analyses covered the Large and Small Aral Seas, the Syrdarya River, reservoirs, lakes of the river delta, and drainage water of the collectors from irrigation areas. The inflow to the Syrdarya River that came from the collector–drainage water was the main cause of water pollution. The pollution levels of toxic compounds, including the trends of temporal and spatial changes in pollutant concentrations, were analyzed and assessed. The latest studies from 2021 and 2022 show a decrease in pesticide concentrations by tens and hundreds of times.

Adjoint‐Based Inversion of Geodetic Data for Sources of Deformation and Strain

AbstractAn adjoint‐based formulation leads to a particularly efficient approach for inverting geodetic measurements for the source of the deformation. Specifically, the quantities necessary to iteratively improve the fit to the observations can be computed with just three forward calculations, one to obtain the current residuals, another to solve the adjoint problem, and a third to compute the step length. An inversion algorithm utilizing the adjoint‐based gradient is applied to a set of Interferometric Synthetic Aperture Radar (InSAR) data gathered between 2016 and 2018 over the Tulare Basin in California's Central Valley. Because the measured deformation is due to groundwater withdrawal, a penalty function is included in the inversion to avoid placing aquifer volume change in locations that are far from any documented wells. The solution of the inverse problem provides estimates of aquifer compaction that provide a match to the observed range changes while honoring the well data. The solution indicates an average aquifer volume loss of 2.17 /year over the two year period from January 2016 to January 2018, encompassing one drought year (2016) and one wet year (2017). This magnitude of lost volume is compatible with the 3.1 /year decrease in water volume for the entire Central Valley, estimated from GRACE satellite gravity data.

Effects of 1-year treatment with canagliflozin on body composition and total body water in patients with type 2 diabetes.

To characterize the long-term changes in body composition associated with sodium-glucose cotransporter-2 (SGLT2) inhibitors. In this multicentre, single-arm, open-label study, 107 patients with type 2 diabetes were treated with canagliflozin 100 mg, as add-on therapy, for 12 months. Body composition was measured with a body composition analyser (T-SCAN PLUS) using the impedance method to prospectively analyse changes in body components, including percentage of body fat, body fat mass, total body water, muscle mass and mineral mass. Estimated plasma volume (PV) was calculated using the Kaplan formula. Body weight showed a significant decrease from 1month to 12 months of treatment with canagliflozin, with a higher rate of decrease in body fat in body composition. A significant decrease in mineral mass was also observed, but its rate was low. Following treatment with canagliflozin, changes in total body water did not affect intracellular water, and a significant decrease in extracellular water, including plasma components, was observed early and was sustained up to 12 months. Protein mass, a component of muscle mass, was not affected, with only a slight decrease in water volume observed. Canagliflozin decreased extracellular fluid and PV in addition to decreasing fat in the body via calorie loss resulting from urinary glucose excretion. This study suggested that SGLT2 inhibitors might reduce body weight by regulating fat mass or water distribution in the body and might have cardiac and renal protective effects by resetting the homeostasis of fluid balance.

Improvement of environmental and economic indicators of the electrolytic chromium plating process

In most cases, the improvement of technological processes is a beneficial measure to reduce anthropogenic impact of production on the environment. However, it is impossible to solve the problem of elimination of production emissions and wastes only by improving the technological process. That is why more and more integrated and complex measures are required to solve the problem, which include both improvement of technological processes and improvement of emissions purification schemes, waste utilization and recycling. At the same time, the measures should be both technically effective and economically feasible. The obtained results allowed to draw a conclusion about the increase of ecological and economic indicators: decrease of toxic chromium anhydride wear and tear by 2-2,7 times; decrease of water volume polluted in the process of technological cycle; decrease of expenses for lead anodes manufacturing and human resources; increase of operational characteristics of manufactured parts - wear resistance, microhardness.

The effects of extreme drought events on the morphometry of shallow lakes: Implications for sediment resuspension and littoral and pelagic zone distribution

Shallow lakes, because of their depth, are more vulnerable to the effects of wind and changes in precipitation and evaporation that deeper lakes and thus respond more dramatically to extreme climatic events, such as drought. The morphology of shallow lakes influences many of their physical, chemical, biological and sedimentological processes including sediment resuspension. Sediment resuspension can trigger undesired effects such as eutrophication, increase in turbidity, cyanobacterial blooms, and also affects the distribution and extent of the littoral and pelagic zones (habitat distribution) with potentially negative consequences on biodiversity and loss of native species. These problems are an increasing concern in the face of global warming. To understand how changes in lake' morphometry, triggered by extreme drought events influence sediment resuspension and habitat distribution, we studied four shallow lakes located in the southwest of the Argentinean Pampas. Each lake was characterized by its bathymetry, morphometric parameters (including area, shore development, dynamic ratio, critical depth), the spatial distribution of the littoral and pelagic areas, and the effect of the waves on sediment resuspension. We measured the Area and Shore development again during selected extreme drought periods identified through the Standardized Precipitation-Evapotranspiration Index. Then, for the given drought period, we calculated the extent and distribution of littoral and pelagic areas and the critical depth at which sediment resuspension occurred and then estimated the percentage of the lake that would be affected by it. We found that Pampean lakes are profoundly affected by sediment resuspension triggered by wind during extreme dry events. Droughts have different effects depending on lake morphology. Dry periods caused not only a decrease in water volume, but also modified the extension of littoral and pelagic zones and increased sediment resuspension. These results have significant implications for the preservation of these rich ecosystems, especially in the context of global warming.

On the Effectiveness of LID Infrastructures for the Attenuation of Urban Flooding at the Catchment Scale

AbstractThe efficacy of low‐impact development (LID) toward the attenuation of urban flood at the catchment scale is still an unsolved question. This work aims at providing insight into the effectiveness of LID at the catchment scale by a simple hydrological modeling approach that allows for an analytical solution. The paper focuses on LID design, investigating the peak discharge at the catchment outlet as a function of the return period of the rainfall event under unaltered and retrofitted conditions. The model captures the most important effects of LID on flood, that is, the temporal shift and attenuation of water discharge and the decrease of water volume conveyed by the drainage network due to increased hydrological losses. It is found that LID is likely more effective in reducing peak discharge at the local scale, while the effectiveness decreases with increasing catchment size. For some configurations, for example, when retrofit is performed in downstream areas, closer to the outlet, LID may even worsen the flood risk. The effectiveness of LID depends on the combination of several factors, including the fractional area covered by the LID infrastructures, their distribution within the catchment, and their hydraulic properties, as compared with the general hydraulic features of the catchment (network dispersion, detention, lag time, etc.). As a consequence, the LID design should be carried out considering all the relevant scales of the problem, from the local one, at which the LID infrastructure is implemented, to the catchment scale, and the discharge at the outlet in particular, in a comprehensive perspective.

Continuous organic synthesis in water around micro-orifices after flows

Water flows through micro-orifices are important because they occur in various fields, such as biology, medical science, chemistry, and engineering. We have reported in previous work that organic matter was generated in micro-orifices after water flowed through the orifice, and we proposed that the organic matter was synthesized from nonorganic materials, including CO2 and N2 dissolved in water from air, and water via the action of hydroxyl radicals produced by the flow through the micro-orifice. In the present study, we examined whether organic materials are produced in the water outside of the orifices in addition to that in the orifice. We used the decrease in water volume to measure the organic synthesis because water should be consumed during the synthesis, and thus the decrease in water volume should reflect the organic synthesis. We let ultrapure water containing dissolved air flow through a micro-orifice as a pre-flow, we stopped the flow, and then we measured the volume of water enclosed in the mount in which the micro-orifice was set over more than 100 h. The volume of water decreased gradually and substantially over time. We used Raman and infrared spectroscopy to analyze the residue obtained by evaporating the water present around the orifice. The residue contained organic matter, including carotenoids, amides, esters, and sugars, which were similar to those found in the membranes generated in the orifice in our previous paper, suggesting that the organic matter was synthesized in a wide region of water around the orifice as well as in the orifice. These results may be relevant to the origins of life and biology, and may lead to the development of a technology for reducing CO2 in air, as well as applications in many scientific and engineering fields.

POSTFUNDOPLICATION DYSPHAGIA CAUSES SIMILAR WATER INGESTION DYNAMICS AS ACHALASIA

- After surgical treatment of gastroesophageal reflux disease dysphagia is a symptom in the majority of patients, with decrease in intensity over time. However, some patients may have persistent dysphagia. - The objective of this investigation was to evaluate the dynamics of water ingestion in patients with postfundoplication dysphagia compared with patients with dysphagia caused by achalasia, idiopathic or consequent to Chagas' disease, and controls. - Thirty-three patients with postfundoplication dysphagia, assessed more than one year after surgery, together with 50 patients with Chagas' disease, 27 patients with idiopathic achalasia and 88 controls were all evaluated by the water swallow test. They drunk, in triplicate, 50 mL of water without breaks while being precisely timed and the number of swallows counted. Also measured was: (a) inter-swallows interval - the time to complete the task, divided by the number of swallows during the task; (b) swallowing flow - volume drunk divided by the time taken; (c) volume of each swallow - volume drunk divided by the number of swallows. - Patients with postfundoplication dysphagia, Chagas' disease and idiopathic achalasia took longer to ingest all the volume, had an increased number of swallows, an increase in interval between swallows, a decrease in swallowing flow and a decrease in water volume of each swallow compared with the controls. There was no difference between the three groups of patients. There was no correlation between postfundoplication time and the results. - It was concluded that patients with postfundoplication dysphagia have similar water ingestion dynamics as patients with achalasia.

North Pacific Subtropical Mode Water Volume Decrease in 2006–09 Estimated from Argo Observations: Influence of Surface Formation and Basin-Scale Oceanic Variability

Abstract Analysis of Argo temperature and salinity profiles (gridded at 0.5° × 0.5° resolution for 2005–12) shows a strong North Pacific Subtropical Mode Water (NPSTMW) volume and density decrease during 2006–09. In this time period, upper-ocean temperature, stratification, and potential vorticity (PV) all increased within the region in and around the NPSTMW low-PV pool, contributing to the NPSTMW volume decrease in two ways: (i) the volume of water satisfying the low-PV constraint that is part of the “mode water” definition decreased, and (ii) some water that was initially in the NPSTMW density range σθ = 25.0–25.5 kg m−3 was transformed into lighter water. Both changes in density and in PV in the NPSTMW region were a manifestation of basinwide changes. A positive PV anomaly started to propagate westward from the central Pacific in 2005, followed by a negative density anomaly in 2007, which caused a dramatic NPSTMW volume and density decrease. A Walin estimate of surface formation in the NPSTMW density range accounted better (although not entirely) for the interannual variability of the volume of water in the NPSTMW density range without imposing the PV < 2 × 10−10 m−1 s−1 constraint than did the same estimate with the PV constraint imposed. This underlines the importance of the PV constraint in identifying the mode water. The mode water evolution cannot be fully described from a density budget alone; rather, the PV budget must be considered simultaneously.

Comparison between natural and impacted Alpine lakes six years after hydropower exploitation has ceased

AbstractMany lakes in mountain regions have been used for hydropower generation since the 1950s. It has been estimated that as many as 79% of the rivers in the Alps have been affected by the presence of hydropower plants. In this context, the shutting down of hydropower plants on a group of Alpine lakes represented a good opportunity to study the ecological impact on them. We selected nine lakes that had been affected and nine that had not, and analysed the differences in environment, littoral diatoms and zoobenthos, phytoplankton, zooplankton, and fish. Results showed that benthic biota -diatoms and zoobenthos- were the most affected by water-level drawdown during winter months. Even six years after the end of hydroelectric operations, diatom species richness and diversity were lower in impacted lakes. Assemblage structure was different for both diatoms and zoobenthos. Phytoplankton and zooplankton were similar in impacted and unaffected lakes in terms of both species richness (and diversity) and assemblage structure. The degree of impact on fish was unclear because illegal stocking of lakes with allochthonous fish species had taken place. This study showed that compared to limnetic biota, littoral communities were the most affected by the decrease in water volume every winter. Six years after the end of hydroelectric operations, diatoms, and to lesser extent zoobenthos, were still different compared to those in natural (unaffected) lakes. Planktic communities seem to be either more resistant to the disturbances, or else able to recover more quickly to their former condition.

Features of modelling of processes in spent fuel pools using various system codes

Severe accidents have not yet occurred in spent fuel pools, however, the consequences can be very severe and a big amount of radioactive material can be released to the environment. Thus, the modelling of possible accidents using computer codes and analysis of consequences is very important. This paper presents results of modelling of cooling water volume decrease events in the spent fuel pools using four different system codes RELAP5, RELAP/SCDAPSIM, ATHLET-CD and ASTEC. The work is aimed to identify possible unrealistic fuel storage pool parameter states, trends and values and to assess the possible errors caused as a result. The influence of the selected modelling assumptions, approximations and impact of the structure of the models on the substantial nuclear fuel storage pools parameters during the beyond design basis accident were investigated.

六盘山典型森林伴随降水的总有机碳（TOC）通量变化特征

PDF HTML阅读 XML下载 导出引用 引用提醒 六盘山典型森林伴随降水的总有机碳(TOC)通量变化特征 DOI: 10.5846/stxb201302060253 作者: 作者单位: 中国林业科学研究院森林生态环境与保护研究所;中南林业科技大学,中国林业科学研究院森林生态环境与保护研究所,中南林业科技大学,中国林业科学研究院森林生态环境与保护研究所,中国林业科学研究院森林生态环境与保护研究所,中国林业科学研究院森林生态环境与保护研究所 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目(41230852、41390461); 科技部"十二五"农村领域国家科技计划(2012BAD22B030102);中挪合作项目(209696/E10); 国家林业局宁夏六盘山森林生态站资助 The variation of total organic carbon (TOC) flux with rain water in regional forests of Liupan Mountains, China Author: Affiliation: Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry;College of Forestry, Central South University of Forestry and Technology,Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry,,,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:在六盘山香水河小流域,选择6种典型森林样地,测定了2011年生长季的大气降水、穿透水、干流、枯落物渗漏水和主根系层(0-30 cm深)土壤渗漏水的总有机碳(TOC)浓度及其相应的通量变化.结果表明,在降水转化为由穿透雨和干流组成的林下降水中,所有样地的TOC浓度都不同程度地增大;虽然林冠截持使林下降水减小,但因雨水淋洗和与林冠发生碳交换,各样地林下降水携带的生长季TOC通量(kg/hm2)(华北落叶松人工林132.28、华山松次生林106.56、油松人工林94.10、灌木林79.49、桦木林66.52、辽东栎次生林63.01)都比林外降水(53.17)不同程度地明显增大,整体看来,林冠的TOC淋出作用在针叶林很大,在阔叶林较弱.在6种森林样地的枯落物层渗漏水中,其TOC浓度彼此相差不大,平均为24.51 mg/L,高于林冠穿透水的TOC浓度;受枯落物截持部分降水及与枯落物TOC交换的影响,4个样地枯落物渗漏水的TOC通量(kg/hm2)(桦木次生林84.35、野李子灌丛129.35、辽东栎次生林79.21、油松人工林114.93)都比其林下降水TOC通量增加了,但华北落叶松人工林和华山松次生林的TOC通量分别降至90.76和104.90 kg/hm2.在测定的华北落叶松人工林和华山松次生林的主根系层(0-30 cm)土壤渗漏水中,TOC浓度均低于枯落物渗漏水;由于水量减小和与土壤发生碳交换,土壤渗漏水的TOC通量均显著低于枯落物渗漏水,两个林分样地分别降至43.04和66.33 kg/hm2.整体来看,林外降水携带的TOC输入通量在林地TOC输入中占有重要地位,林冠的TOC淋洗使其程度不同地增加TOC通量,枯落物层具有增加或减少TOC通量的作用,但主根系层土壤会显著减少TOC输出通量,所以是固定TOC的重要场所. Abstract:Both flux and concentration of total organic carbon(TOC)from rain water were documented and analyzed from six regional forests growing in the small watershed of Xiangshuihe inside Liupan Mounatins in NW China during the 2011 growing season. The results indicated that TOC concentration of all six forests was increased in term of rain water under canopy. Although the rain water volume under canopy was decreased due to the canopy interception, the TOC flux carried by the rain water under canopy was increased for all six forests as compared them with that carrying by the open field rainfall (53.17 kg/hm2) because of carbon exchange or wash out from canopy. The corresponding TOC flux (kg/hm2) of rain water under canopy was 132.28 for Larix principis-rupprechtii plantation, 106.56 for the secondary forest of Pinus armandii, 94.10 for the plantation of Pinus tabulaeformis, 79.49 for the shrub of Prunus salicina, 66.52 for the secondary forest of Betula platyphylla, and 63.01 for the secondary forest of Quercus liaotungesis. The canopy leaching (or wash out) effect of TOC was high for the coniferous forests, but weak for the broad-leaved forests. The difference of TOC concentrations in the leakage under humus layer was low among the six forest types, with an average of 24.51 mg/L, which was still higher than the TOC concentration in throughfall. As an integrated result of the humus interception loss and the TOC exchange with humus layer, the TOC flux carried by the humus leakage was increased than that carried by throughfall for four forests and they were 84.35 (kg/hm2) for the stand of Betula platyphylla, 129.35 for the bush of Prunus salicina, 79.21 for the stand of Quercus liaotungesis, 114.93 for the stand of Pinus tabulaeformis, but the TOC flux carried by the humus leakage was decreased to 90.76 and 104.90 kg/hm2 for the stand of Larix principis-rupprechtii and Pinus armandii respectively. In the leakage under the soil layer of main root zone (0-30 cm), the TOC concentrations were reduced compared with that in humus leakage for the stands of Larix principis-rupprechtii and Pinus armandii. Affected by the water volume decrease and the TOC exchange with mineral soil, the TOC flux carried by the soil leakage under main root zone was significantly reduced, compared with the TOC flux of humus leakage, to 43.04 kg/hm2 for the stand of Larix principis-rupprechtii and to 66.33 kg/hm2 for the stand of Pinus armandii. In conclusion, the TOC input flux through open field rainfall played an important role in the TOC flux input to forest soil. The canopy of all six forest types could increase the TOC flux due the TOC leaching from canopy surface. The TOC flux in humus layer leakage were usually increased or decreased. However, the mineral soil at the main root zone greatly reduced the TOC flux output, thus the soil layer should be the most important pool for fixing the TOC. 参考文献 相似文献 引证文献

Ingestion Exposure to Nitrosamines in Chlorinated Drinking Water

ObjectivesN-Nitrosodimethylamine (NDMA) is classified as a probable human carcinogen by the United States Environmental Protection Agency (US EPA) and is formed during the chlorination of municipal drinking water. In this study, selected nitrosamines were measured in chlorinated drinking water collected from Chuncheon, Kangwon-do, Republic of Korea, and a risk assessment for NDMA was conducted.MethodsTwelve water samples were collected from 2 treatment plants and 10 household taps. Samples were analyzed for 6 nitrosamines via solid-phase extraction cleanup followed by conversion to dansyl derivatives and high-performance liquid chromatography-fluorescence detection (HPLC-FLD). Considering the dietary patterns of Korean people and the concentration change of NDMA by boiling, a carcinogenic risk assessment from ingestion exposure was conducted following the US EPA guidelines.ResultsNDMA concentrations ranged between 26.1 and 112.0 ng/L. NDMA in water was found to be thermally stable, and thus its concentration at the end of boiling was greater than before thermal treatment owing to the decrease in water volume. The estimated excess lifetime carcinogenic risk exceeded the regulatory baseline risk of 10-5.ConclusionsThis result suggests that more extensive studies need to be conducted on nitrosamine concentration distributions over the country and the source of relatively high nitrosamine concentrations.

Mechanism of photosynthetic response in Microcystis aeruginosa PCC7806 to low inorganic phosphorus

Photosynthetic response of Microcystis aeruginosa PCC7806 to different concentrations of phosphorus supply was studied so as to elucidate if the declining process of Microcystis bloom under freshwater ecosystem is related to soluble reactive phosphorus (SRP) decrease in water volume. Growth rate of M. aeruginosa PCC7806 was significantly reduced under P-deficient conditions, and its photosynthetic activity in terms of rETR max (maximum electron transport rate) decreased significantly after 48 h growth, while it kept elevating and reached to a relative stable value when supplied with rich phosphorus of 0.6 mg/L. With the increasing actinic irradiance along the rapid light curves of M. aeruginosa PCC7806 cultured under low-phosphorus level, qP (photochemical quenching) and rETR (relative electron transport rate) decreased greatly, and the increase in qN (non-photochemical quenching) and Φ PS (actual photochemical efficiency of PSII) was obviously inhibited. The affinity of M. aeruginosa PCC7806 to inorganic carbon was reduced evidently in 0.02 mg/L P compared with in 0.6 mg/L P. When P was reduced from 0.6 to 0.02 mg/L, the decreasing rate of rETR max (77%) was significantly greater than that of photosynthetic carbon assimilation (22%), which indicated that down-regulation of CO 2 affinity caused by P-deficiency was, but not the only reason that resulted in the decline of photosynthetic efficiency. Instantaneous low-temperature significantly limited rETR max under rich-P condition but had no effect on it when P was insufficient, and 1% ethanol could enhance rETR max at low-P level but did not influence it at rich-P level. These two results proved that the decrease in thylakoid membrane fluidity caused by P-deficiency was another important reason that results in the decline of photosynthetic efficiency of M. aruginosa PCC7806.

Maintenance of Positive Diversity-Stability Relations along a Gradient of Environmental Stress

BackgroundEnvironmental stress is widely considered to be an important factor in regulating whether changes in diversity will affect the functioning and stability of ecological communities.Methodology/Principal FindingsWe investigated the effects of a major environmental stressor (a decrease in water volume) on diversity-abundance and diversity-stability relations in laboratory microcosms composed of temperate multi-trophic rock pool communities to identify differences in community and functional group responses to increasing functional group richness along a gradient of environmental stress (low, medium, and high water volume). When a greater number of functional groups were present, communities were less temporally variable and achieved higher abundances. The stabilizing effect of increased functional group richness was observed regardless of the level of environmental stress the community was subjected too. Despite the strong consistent stabilizing effect of increased functional group richness on abundance, the way that individual functional groups were affected by functional group richness differed along the stress gradient. Under low stress, communities with more functional groups present were more productive and showed evidence of strong facilitative interactions. As stress increased, the positive effect of functional group richness on community abundance was no longer observed and compensatory responses became more common. Responses of individual functional groups to functional group richness became increasing heterogeneous are stress increased, prompting shifts from linear diversity-variability/abundance relations under low stress to a mix of linear and non-linear responses under medium and high stress. The strength of relations between functional group richness and both the abundances and temporal variability of functional groups also increased as stress increased.Conclusions/SignificanceWhile stress did not affect the relation between functional group richness and stability per se, the way in which functional groups responded to changes in functional group richness differed as stress increased. These differences, which include increases in the heterogeneity of responses of individual functional groups, increases in compensatory dynamics, and increases in the strength of richness-abundance and richness-variability relations, may be critical to maintaining stability under increasingly stressful environmental conditions.

The Political Ecology of a Ramsar Site Conservation Failure: The Case of Burdur Lake, Turkey

The Burdur Lake basin in Turkey's Mediterranean region has been facing severe environmental damage in the form of increased pollution and a decrease in water volume, despite its Ramsar status as a major wintering site for the endangered white-headed duck ( Oxyura leucocephala). In fact, after the basin was granted Ramsar status it was made the subject of a ‘hard-park’ conservation policy. This in practice disenfranchised and alienated local people but did not lead to the effective preservation of the basin. We aim to shed light on the political ecology of the ongoing degradation, which has layers at local, national, and international levels, by using both quantitative and qualitative methods (consisting of in-depth interviews, focus groups, and face-to-face, randomly selected interviews with 625 people). We specifically explore the possible reasons why local people by and large did not—despite their high level of environmental concern about the site—demand conservation policies or voluntarily take action to preserve their site. Acknowledging that the sources of the problem are multilayered in nature, thus requiring a multilevel solution, we then propose a governance modality tailored for the case at hand. Since many of the problems that Burdur Lake faces are not unique, it is hoped that the conducted analysis will be relevant to other similar sites.

Methods for estimating CO2 storage in saline reservoirs

Abstract Methods for estimating subsurface volumes in porous and permeable geologic formations are routinely applied in oil and gas, ground water, underground natural gas storage, and UIC disposal evaluations. In general, these methods can be divided into two categories: static and dynamic. The static models require only rock and fluid properties, while the dynamic methods require information about active injection, e.g. injection volumes and reservoir pressures. The static models are volumetric and compressibility; the dynamic models are decline curve analyses, mass (or volumetric) balance, and reservoir simulation. The volumetric method requires a simple geometric description of the formation that includes formation height and area, porosity, and some type of factor that reflects the pore volume that CO2 can occupy. The compressibility method relates the change in pore pressure to the change in water and pore volume. Pore pressure will increase as CO2 is injected. This causes a decrease in water volume and an increase in pore volume. The sum of these changes can accommodate space for CO2 storage. This is primarily an issue for closed reservoirs. For active CO2 injection, in addition to the static methods, dynamic methods can be used. Some geologic formations will incur flat or constant injection rates with variable injection pressure, while other formations will have decreasing injection rate with constant injection pressure. This is primarily due to surface operations and the outer boundary condition of the reservoir (closed or open). A decreasing injection rate trend can be analyzed and extrapolated to an uneconomic injection rate to infer the ultimate storage capacity of an active injection well. Mass or volumetric balance can be used to estimate subsurface injected volumes using cumulative injection volume as a function of pore pressure. Based on the geologic unit, combinations of parameters are used to allow straight line projections of the observed trends to make forecasts of the ultimate storage capacity. Injection zone flow simulation models can be used pre- or post injection, require the most input data and can accommodate a very rigorously defined geologic model. Storage estimates can be made readily from simulation for various development scenarios that include completion interval, well-type, injection rates, and multiple injection well spacing. The data requirements, assumptions and limitations for each of these methods are reviewed. Advantages and disadvantages of applying each method to basin-scale and specific site-scale storage estimates are discussed.

Variação espacial e temporal dos fatores limnológicos em riachos da microbacia do rio São Francisco Verdadeiro

Com objetivo de caracterizar espacial e temporalmente os riachos da microbacia do rio São Francisco Verdadeiro, Marechal Cândido Rondon - PR, em função de fatores limnológicos, foram estabelecidas seis estações de coleta em três riachos (Curvado, Ajuricaba e Arroio Fundo), sendo uma estação na foz e outra na nascente. As coletas de água foram obtidas entre junho de 2005 e maio de 2006, totalizando 72 amostras. Foram analisadas as seguintes variáveis: temperatura, pH, condutividade elétrica, oxigênio dissolvido, turbidez, material em suspensão, fósforo total dissolvido, ortofosfato, nitrogênio total e nitrogênio amoniacal. De acordo com a análise de variância, houve baixa variabilidade entre as estações de coleta, porém a variação temporal demonstrou a influência do ciclo hidrológico. A análise de componentes principais (ACP) discriminou o sistema com base nos maiores valores registrados para as variáveis limnológicas, ficando separados os períodos influenciados pelas secas e pelas chuvas. A maior parte das variáveis está associada com o período de chuvas, no entanto há concentrações esporádicas de nutrientes na seca e menores valores de oxigênio dissolvido, demonstrando a dificuldade de diluição nesse período, causada pela diminuição da chuva e, consequentemente, do volume de água dos riachos.

Effects of climatic fluctuations and land-use changes on the hydrology of temperate fluviogenous mire

The upper part of the Narew River valley (NE Poland) belongs to the last extensive undrained, non-reclaimed valley wetlands in Central Europe. However, in recent decades, the fluviogenous mire has experienced a significant change in water resources which may be linked to climatic fluctuations and changes in vegetation. In NE Poland during the last three decades, a clear trend toward milder and drier climate has been observed that has resulted in lower river discharge. Reduction in surface water inflow into the mire, diminished duration and degree of flooding, decrease in summer rainfall and increase in evapotranspiration have led to the substantial fall of the groundwater table in the valley and a decrease in volume of water stored in organic sediments. A comparison of water table measurements made in the 1970s with contemporary observations showed that presently, summer minimum groundwater levels are as much as 60 cm lower than in the past. A significant drop of water table elevation might be additionally attributed to increased ET caused by cessation in agricultural use of the mire and expansion of Phragmites. Between the 1970s and 2002, the total amount of water lost by ET increased by 42%, whereas ET o rose by 7% only. We found that patches of common reed rushes were hot spots for ET across the Narew wetland landscape. The evaluation of the effectiveness of restoration measures aimed at restoration of the water conditions in the Narew mire led us to the conclusion that raising the river water level by use of in-stream structures may be not adequate to make up the summer moisture deficit and ensure a sufficiently high groundwater level in the adjacent wetland. The restoration goal may be partly achieved by large vegetation manipulation in the form of mowing or grazing. Vegetation management could reduce ET by 170 mm m −2 year −1, potentially minimizing the extent and the duration of groundwater drawdowns.