Seasonal water storage change of the Yangtze River basin detected by GRACE

1 Introduction Large-scale mass redistribution, or temporal varia- tion of mass within the Earth system, the driving force of interactions between solid Earth and geophysical fluids envelope (i.e., atmosphere, ocean, and hydro- sphere), is an important geophysical process critical to human life. Most of the interactions between solid Earth and the atmosphere/oceans happen at seasonal and inter-annual time scales. One important contribu- tor of mass redistribution at seasonal and inter-annual …     

Gravity change and its mechanism after the first water impoundment in Three Gorges Project

Introduction During and before the construction of the Three Gorges Project, the annual observation was continuously undertaken by the Three Gorges gravity observation network established around the head area of the reservoir (the section between Sandouping and Badong). This network has pro-vided substantial high precise data related to seismic activity. However, the annual gravity survey together monitoring of the existed observation stations can hardly effective monitor some potential sei…     

Stochastic competitive analysis of hydropower and water supplies within an energy–water nexus

Energy and water are scarce resources and understanding the complicated energy–water nexus is an important issue for effective resource management. The purpose of this research was to analyze the competitive and cooperative relationships involving energy and water production and use. Specifically, tradeoff and integrated management of hydropower generation and water supplies are analyzed for energy–water systems. A Nash–Cournot model was established to analyze strategic behaviors among participants in energy–water systems. In the model, tradeoff analysis and integrated management of hydropower and water supplies were simulated for a reservoir system. In addition, hydropower and thermal power generation in competitive energy markets was examined. A case study of Dajia River reservoirs in the Tai-Chung and Chang-Hwa energy–water systems is presented. Dajia River is the second longest river in central Taiwan; the reservoirs system of Dajia River generates hydropower with installed capacity of 1150 MW. Strategic competitive and cooperative behaviors regarding energy–water linkage were quantified in the results. The results show that integrated management of hydropower and water supplies can increase renewable energy production, lower electricity equilibrium price, and decrease carbon dioxide emission.     

Research and application of multi-angle polarization characteristics of water body mirror reflection

On the basis of the multi-angle polarized reflection spectrum of the water samples,the water body mirror reflection polarization characteristics and mechanism are described systematically. By altering such influential factors as the angle of incidence,detecting angle,detecting azimuth angle and polari-zation angle,ubiquitous laws for the multi-angle polarized reflection spectrum of the water samples are obtained. Combining multi-angle remote sensing with polarized light,the multi-angle polarized reflec-tion method about eliminating the water body mirror reflection and the suitable time of the polarized remote sensing of the water body are proposed. This study provides technical references for the ap-plication of multi-angle polarization technology on water body remote sensing.     

Disinfection by-products and ecotoxicity of ballast water after oxidative treatment – Results and experiences from seven years of full-scale testing of ballast water management systems

Since 2005, five different ballast water management systems (BWMSs) based on chlorination treatment have been tested by Norwegian Institute for Water Research (NIVA) according to guidelines from the International Maritime Organization (IMO). 25% and >50% of all the tested discharge samples exhibited acute and chronic toxic effects on algae, respectively. In most cases this toxicity was plausibly caused by a high free residual oxidant (FRO) level (>0.08 mg Cl/l). Of the 22 disinfection by-products (DBPs) that were identified in treated water at discharge, four compounds were at times found at concentrations that may pose a risk to the local aquatic environment. However, there seemed to be no clear indication that the measured DBP concentrations contributed to the observed algal toxicity. The addition of methylcellulose instead of lignin in the test water to comply with IMO requirements seemed to limit the formation of DBP.     

Characteristics of the difference and change in the comprehensive physical properties of rocks

Introduction The medium of the earth is made up of gas, liquid, and solid. The solid is the main material to form the structure of the earth, so it is very significant to study the solid matter of the earth. Rock, as a solid medium of the earth is a common object studied by geophysicists. The measurement of the comprehensive physical properties of rocks (ZHAO, et al, 1996; GUO, et al, 1989) considered that the minimal cell of rock is the atoms of chemical element, and all sorts of the rock …     

Simulation and control of the linked systems of water quantity–water quality–socio-economics in the Huaihe River basin

Abstract

This work makes explicit an algebraic expression giving the matrix of transient influence coefficients associated with a one-dimensional semi-confined aquifer model. The domain studied is divided into a series of connected and completely mixed compartments over which the governing equation is discretized. The discrete equations obtained are solved for the compartmental hydraulic head and used to derive the algebraic expression in question. The basic properties of the so-called algebraic influence coefficients are investigated. In particular, their consistency with the exact Green function is highlighted. Finally, the newly derived influence coefficients are applied to a simplified aquifer system in order to formulate and solve the problem of identifying illegal groundwater pumping.     

The performance of benthic indicators of ecological change in Adriatic coastal lagoons: throwing the baby with the water?

The ecological quality of 127 stations from six Adriatic coastal lagoons was assessed using a suite of biotic indices: H', d, 1-lambda', Delta(*), Delta(+), W, AMBI, BOPA and FINE. The analysis indicated the difficulties in deriving and using the existing indices from benthic communities in highly variable environmental conditions in coastal lagoons. Different metrics rendered different results: the use of H' resulted in the classification of all stations as "Moderate/Poor/Bad", whereas BOPA classified the majority of the stations as "Good/High". Using Delta(+), most of the stations resulted as "Not anthropogenically impacted", while the W-statistics gave 82 stations as "Undisturbed" and 45 as "Moderately/Grossly disturbed". AMBI classified 55 stations as "High/Good" and 72 as "Moderate/Poor/Bad", whereas those were 32 and 95 with FINE, respectively. The latter, which was developed just for Italian coastal lagoons, was the most conservative among the indices studied. Yet, it showed the highest correlation with the species/abundance matrix. Using indices developed for coastal waters in lagoons can give the distorted indication that the water body is degraded, when it might be just a natural, low diversity, high abundance community, i.e. a lagoonal community. Moreover, the outcome of the use of a certain index has a financial dimension such that lagoons misclassified as being "poor status" will then require expensive remediation measures. For the lagoons studied, there is probably an adequate quality and quantity of benthic data available for making management decisions, but this study highlights the limits of the existing indices for lagoonal ecosystems. The challenge for the next future is to couple long term conservation of the natural environment with the highly productive activities carried out in lagoonal ecosystems.     

Combination of drainage, water supply and environmental protection as well as rational distribution of water resource in Zhengzhou mining district

It is forecasted that before the 2050s, coal would still make up 50%-60% of once energy constitution in China, but unfortunately, in most part of our coal districts and peripheral regions, we generally face the contradiction and conflict among the threat of water hazard, shortage of water resource and environmental protection, which are becoming more and more serious especially with a gradual increase in mining depth of the shaft and recovery of lower coal beds. The concrete expression is as f…     

Modelling regional impacts of climate change on water resources: the Júcar basin,Spain

Abstract

In this paper we analyse all currently available simulated climate scenarios, proposed by the Spanish Agency of Meteorology (AEMET), for the period 2010–2040 on the geographical area covered by the Júcar River basin, located in eastern Spain. This is done through the validation of these scenarios using historical records, and by assessing the impact on water resources for the next 30 years by means of a hydrological model. By taking the period 1960–1990 as the control period, a careful comparison of its historical records against AEMET scenarios is performed. Although temperature records are modelled properly, precipitation data are widely underestimated in a range from 8% to 29%. This wide variability observed in the control period is also found in the precipitation scenarios for the period 2010–2040. The impact on water resources shows a great degree of dispersion, ranging from –13.45% to 18.1% with a mean value of –2.13%.

Editor Z.W. Kundzewicz; Associate editor F. Hattermann     

Seasonal variations and environmental control of water use efficiency in subtropical plantation

To understand the seasonal variations of water use efficiency (WUE) of coniferous plantation in the subtropical monsoon area, the experiment was conducted in 2003 and 2004 which presented two distinguished climatic conditions (severe summer drought in 2003 and normal climatic condition in 2004). The water stress influenced WUE greatly, which caused a special seasonal WUE pattern. WUE reached the minimum in summer drought and the maximum in winter, which was contrary to the variation of gross primary production (GPP) and canopy evaporation (Fw). In winter, GPP and Fw increased along with the increasing of air temperature and vapor pressure deficit (VPD), with the similar increasing rate. However, in drought summer, there was an adverse trend among GPP/Fw and air temperature and VPD, and the decreasing rate of GPP was far larger than that of Fw. In summer, the conservation of WUE was changed because of the environmental factors, resulting in the decreasing WUE. The photosynthesis and transpiration of vegetation were mainly controlled by the environmental factors in winter, and the impact of stomatal regulation was relatively weak. In summer, Fw was mainly controlled by the stomatal closure and GPP by both environmental factors and stomatal closure.     

Hydrochemical characteristics and water quality of the Mušnica River catchment,Bosnia and Herzegovina

Abstract

The spatial position of the Mu?nica River catchment in the Dinaric Karst results in specific conditions of the drainage, distribution and chemical characteristics of the surface water and groundwater. This catchment is mountainous, located between 930 and 1985 m above sea level. The chemical characteristics of the waters are strongly dependent on the local lithological composition and the precipitation regime. The dominant cations are Ca²⁺ and Mg²⁺, and anions HCO₃ ^- and SO₄ ^2-. The surface water is characterized by low and medium mineralization, with resultant soft, medium-hard and very-hard total hardness levels. The groundwater is more mineralized than the surface water. Gacko Town and its associated thermal power plant, Gacko 1, which are located in the southern part of the Mu?nica River catchment, have no modern facilities for sewage and wastewater transport or treatment. In order to prevent further water quality deterioration and to enable its sustainable use, it is recommended to ensure adequate protection measures in the catchment area.

Editor Z.W. Kundzewicz; Associate editor S. Faye

Citation Banjak, D. and Nikoli?, J., 2012. Hydrochemical characteristics and water quality of the Mu?nica River catchment, Bosnia and Herzegovina. Hydrological Sciences Journal, 57 (3), 562–575.     

Distribution and origin of biologically available phosphorus in the water of the Meiliang Bay in summer

The investigation and continuous monitoring with an innovative iron oxide embedded cellulose acetate membrane (FeO/CAM) on the concentrations of biologically available phosphorus (BAP) were conducted in the Meiliang Bay of the Taihu Lake during summer in 2004. The results showed that the concentrations of dissolved (FeO-DP), particulate (FeO-PP) and total bioavailable phosphorus (FeO-P) had similar horizontal distribution. The BAP concentrations were the highest in those estuaries in the northern bay. With the decrease of the distance to the estuary or long shore, there was little difference between BAP concentrations in an open lake area. During the observation period, algal blooms occurred in most waters of the northern bay, which was reflected from the high concentrations of chlorophyll a (Chl-a). While they were not highest in the estuarine waters of those major rivers, this is the case for the BAP concentrations. The concentrations of Chl-a had a significantly positive correlation with those of bioavailable phosphorus in the open area of the Meiliang Bay. With the sediment resuspension induced by wind and wave, BAP concentrations increased in a short-term, indicating that the riverine P inputs mainly contribute to the concentrations of BAP in the estuarine water while internal P release was the major source of BAP in the open lake area. In the eutrophic shallow lake, the blooms of alga may cause pH increase and further result in internal P release. The above results showed that the new membrane of FeO/CAM can be used to monitor the concentrations of BAP and provide the scientific justifications for the control strategy of the lake eu-trophication.     

Effect of seasonal freeze–thaw process on spatial and temporal distribution of soil water and its infiltration to recharge groundwater

Clarifying the distribution and dynamics of soil moisture during the freeze–thaw process is crucial for surface ecology and is an objective requirement to investigate the mechanism of changes during the groundwater recharge process in a freeze–thaw zone. Based on the monitoring data of soil moisture and temperature in the Changbai Mountain area, the freeze–thaw process is classified into four periods. This study investigates the hydrothermal migration processes during different periods. The simultaneous heat and water model is used to simulate and analyse the infiltration of soil moisture into groundwater under five precipitation insurance rates. The results are as follows: (1) The smaller the soil depth, the stronger is the correlation between soil temperature and air temperature during the freeze–thaw process. (2) The redistribution of soil moisture before and after freeze–thaw is significantly affected by the soil texture, and soil permeability affects the recharge of soil moisture from the upper region to the lower region during the thawing period. (3) Groundwater receives vertical infiltration recharge mainly during non-freezing and is supplied by freezing and snowmelt recharge during the stable thawing period. The percentage of soil water infiltration during the stable thawing period in the total annual infiltration increases gradually with the precipitation insurance rate.     

Influence of water temperature and salinity on seasonal occurrences of Vibrio cholerae and enteric bacteria in oyster-producing areas of Veracruz, México

The influence of temperature and salinity on the occurrence of Vibrio cholerae, Escherichia coli and Salmonella spp. associated with water and oyster samples was investigated in two lagoons on the Atlantic Coast of Veracruz, Mexico over a 1-year period. The results indicated that seasonal salinity variability and warm temperatures, as well as nutrient influx, may influence the occurrence of V. cholera. non-O1 and O1. The conditions found in the Alvarado (31.12 °C, 6.27‰, pH = 8.74) and La Mancha lagoons (31.38 °C, 24.18‰, pH = 9.15) during the rainy season 2002 favored the occurrence of V. cholera O1 Inaba enterotoxin positive traced in oysters. Vibrio alginolyticus was detected in Alvarado lagoon water samples during the winter season. E. coli and Salmonella spp. were isolated from water samples from the La Mancha (90–96.7% and 86.7–96.7%) and Alvarado (88.6–97.1% and 88.6–100%) lagoons. Occurrence of bacteria may be due to effluents from urban, agricultural and industrial areas.     

Features and trends of the environmental change in the arid areas in Central Asia

RS-monitoring index systems of ecological environment changes at a large scale, based on empirical data and trends in environmental change in Central Asia, are developed using NOAA and MODIS data. Moreover, with the help of mathematical statistics and GIS spatial analysis, the degrees, hazards and distribution extent of various possible ecological problems are discussed, environmental changes in Central Asia in 1990 and 2005 are separately evaluated, and dynamic changes in the environment in Central Asia over a 15-year period are analyzed. The results reveal that during the 15-year period from 1990 to 2005, areas of degenerated vegetation in Kazakhstan, Uzbekistan, Turkmenistan, Kirghizstan and Tadzhikistan were enlarged by 0.069×105 km2, 0.081×105 km2, 0.296×105 km2, 0.022×105 km2 and 0.112×105 km2, respectively. The ecological environment in Central Asia was in the state of significant degeneration and even deterioration. This study proves that NOAA and MODIS data can be used to successfully monitor the environment and provide useful results.     

Effect of water stress on ecosystem photosynthesis and respiration of a Leymus chinensis steppe in Inner Mongolia

Many studies on global climate have forecast major changes in the amounts and spatial patterns of precipitation that may significantly affect temperate grasslands in arid and semi-arid regions. As a part of ChinaFLUX, eddy covariance flux measurements were made at a semi-arid Leymus chinensis steppe in Inner Mongolia, China during 2003-2004 to quantify the response of carbon exchange to environmental changes. Results showed that gross ecosystem production (FGEP) and ecosystem respiration (Reco) of the steppe were significantly depressed by water stress due to lack of precipitation during the growing season. Temperature was the dominant factor affecting FGEP and Reco in 2003, whereas soil moisture imposed a significant influence on both Reco and FGEP in 2004. Under wet conditions, Reco showed an exponentially increasing trend with temperature (Q10 = 2.0), but an apparent reduction in the value of Reco and its temperature sensitivity were observed during the periods of water stress (Q10=1.6). Both heat and water stress can cause decrease in FGEP. The sea-sonality of ecosystem carbon exchange was strongly correlated with the variation of precipitation. With less precipitation in 2003, the steppe sequestrated carbon in June and July, and went into a senescence in early August due to water stress. As compared to 2003, the severe drought during the spring of 2004 delayed the growth of the steppe until late June, and the steppe became a CO2 sink from early July until mid-September, with ample precipitation in August. The semi-arid steppe released a total of 9.7 g C·m-2 from May 16 to the end of September 2003, whereas the net carbon budget during the same period in 2004 was close to zero. Long-term measurements over various grasslands are needed to quantify carbon balance in temperate grasslands.