Main Water Body Research Articles

Status of macrobenthic communities in the hypersaline waters of the Gulf of Salwa, Arabian Gulf

The spatial extent of hypersaline marine ecosystems is very limited and therefore they have received only little scientific study. Here, we present the status of macrobenthic communities in a hypersaline water body, the Gulf of Salwa (Saudi Arabia part), in the Arabian Gulf and assess the natural stress, if any, in the communities. The Gulf of Salwa is nearly isolated from the main water body of the Arabian Gulf and shows a progressive southward increases in salinity (up to 63 during summer) and temperature (up to 40°C during summer) due to the southward decrease in tidal flushing. The study reveals that the benthic communities in the southern region (south of 25° 10′ N) of the Gulf of Salwa are under natural stress, while the deeper, the northern, and the inner bay regions have healthier benthic communities than the south. In the southern region, there were 87 to 93% reduction in polychaete species, 49 to 57% reduction in species diversity of polychaetes and 70 to 71% in non-polychaete taxa compared to the northern region. The present study identified some opportunistic taxa such as Fabricia sp., Heteromastus filiformis, Platynereis insolita and Nereis sp. 1 and non-polychaetes such as chironomid larvae, podocops and cumaceans capable of adapting to the hypersaline environment in the Gulf of Salwa when salinity exceeded 60 and temperature exceeded 35°C during summer.

Determining riverine sediment storage mechanisms of biologically reactive phosphorus in situ using DGT.

Phosphorus (P) is the main reason many surficial water bodies in the UK are currently failing to meet the chemical standards set by the Water Framework Directive (WFD). This work focuses on the role of sediments in the upper reaches of the River Taw in the South West of the UK. Point and diffuse sources of P have been identified as well as a number of mitigation measures applied or planned to address the issues. However, it is unknown what effect these sources have had on the river's sediments and how they will react to diminishing inputs of P into the water column in the future. The diffusive gradient in thin-films (DGT) method is utilised in situ to quantify and identify labile, potentially bioavailable P fluxes and potential storage mechanisms at sites of known diffuse and point P inputs. In the vicinity of a heavily contaminated point source, data present here shows that sediments are still acting as a sink. The proposed mechanism for this is the formation of a 'calcium cap' which provides a geochemical barrier between the sediment and overlying water to prevent loss of labile P. The strong correlation between calcium and total P under most circumstances supports this hypothesis. This conclusion provides some confidence that even though P concentrations in some sediments are significantly elevated, mobility between the sediment and overlying water is restricted. In the context of routine monitoring against WFD targets, the molybdenum blue method generally employed to determine soluble reactive phosphorus was shown to not be equivalent to the DGT labile P pool, especially at pristine or moderately point/diffuse influenced sites. This is likely due to desorption of weakly bound P from colloids, which is unavailable to DGT devices. These results have the potential to be scaled up to the full catchment or other catchments which exhibit similar physical and chemical sediment composition and provide a stronger foundation for management and target setting than current monitoring approaches.

The hydrological and environmental evolution of shallow Lake Melincué, central Argentinean Pampas, during the last millennium

Summary Lake Melincue, located in the central Pampean Plains of Argentina, is a shallow (∼4 m), subsaline lake (TDS > 2000 ppm), highly sensitive to hydrological changes. The modern shallow lake system is composed of: (a) a supralittoral area, which includes a narrow mudflat, a vegetated mudflat and wetlands subenvironments; and (b) the main water body, comprising lacustrine marginal and inner areas. The development and extension of these subenvironments are strongly conditioned upon lake surface fluctuations. Past environmental changes were reconstructed through sedimentological, physical and geochemical proxy analyses of two short sedimentary cores (∼127 cm). Well-constrained 210 Pb ages profiles were modeled and radiocarbon chronologies were determined, covering a period from ∼AD 800 to the present. The analyzed sedimentary cores from Lake Melincue allowed for the reconstruction of past hydrological scenarios and associated environmental variability, ranging from extremely low lake levels during dry phases to pronounced highstands at wet periods. The paleohydrological reconstruction revealed very shallow conditions in the period between AD 806 and AD 1880, which was registered by massive deposits with low organic matter. Relatively wetter phases disrupting this dry period were represented by organic matter increases. A major wet phase was registered by AD 1454, after the end of the Medieval Climate Anomaly. A subsequent abrupt shift from this wet phase to drier conditions could be matching the transition between the end of the Medieval Climatic Anomaly and the beginning of the Little Ice Age. The occurrence of sedimentary hiatuses between AD 1492 and AD 1880 in Melincue sequence could correspond to intensive droughts during the Little Ice Age. After AD 1880, banded and laminated, autochthonous, organic matter-rich sediments registered an important lacustrine transgression and the onset of a permanent shallow lake, corresponding to the beginning of the current warm period. The uppermost recent fine-grained, low salinity, organic sediments represent a lake transgression occurred in the 1970s, coeval with a general increase in precipitation across southeastern South America. This transgression is registered regionally in other Pampean lakes and in the 20th century instrumental records of Lake Melincue. This paleoenvironmental reconstruction provides a new high-resolution record that registers striking hydroclimatic changes occurred at a regional scale across the Pampean Plains during the last millennium and it contributes to understand the past climatic history in southeastern South America.

Bottom topography change patterns of the Lake Poyang and their influence mechanisms in recent 30 years

利用鄱阳湖1980、1998和2010年3期湖盆水下地形数据,结合出、入湖泥沙输移数据以及流域水土流失、水库建设等资料,较为系统地研究鄱阳湖近30年来湖盆冲淤的时空变化特征及其影响因素.研究表明,19801998年,松门山以南主湖体位置淤积现象明显,平均淤高0.82m,该淤积主要是由这一阶段内流域水土流失加剧所引起的;19982010年,在大规模植树造林和水库建设等人类活动影响下,鄱阳湖淤积现象减缓.但是在入江水道上湖盆高程显著下降,平均下降速率高达30.75cm/a,这与入江水道处持续采砂和水流冲刷等因素有关;近30年来,“五河”入湖的洲滩区域冲淤变化及趋势有所差异,修水、抚河及赣江三角洲呈现逐渐降低的趋势,饶河入湖漫滩总体上以淤积为主,且地形坡度趋于变缓.研究结果对鄱阳湖水资源合理开发、水利工程建设及航运管理等均具有一定的实践和参考价值.;In this study, extensive investigation was done on the changes in bottom topography across the Lake Poyang through geographical information systems(GIS) techniques and comparison of underwater topography data of 1980, 1998 and 2010. Possible mechanisms behind the topographic changes were also discussed based on watershed hydrological data(e.g. sediment transport, soil erosion and reservoir construction). The results showed that (1) the main water body region was obviously deposited with an average deposition value of 0.82 m during 1980-1998. These alterations of bottom topography were frequently caused by the increased soil erosion in the upstream of the basin. (2) During 1998-2010, the deposition trend of the bottom topography among Lake Poyang was slowed down to some extent. This was probably caused by the afforestation and reservoir construction program. However, in this period, bottom topography in the channel entrance was decreased remarkably with the average declining rate of 30.75 cm/a. The increases in flow discharge and gravel extraction have been considered as the main causes of this topographic change in the region. (3) In recent 30 years, the changing trends of deposition/erosion among five rivers' alluvial cone were different. Bottom topography elevation in Xiushui, Fuhe and Ganjiang alluvial cone expressed gradually decreasing trend, while Raohe alluvial bay showed a rising tendency as a whole. The results of the study are of great theoretical and practical significance to water resources reasonable utilization, dam construction and shipping management across the Lake Poyang.

Analysis of the mixing processes in the subtropical Advancetown Lake, Australia

Summary This paper presents an extensive investigation of the mixing processes occurring in the subtropical monomictic Advancetown Lake, which is the main water body supplying the Gold Coast City in Australia. Meteorological, chemical and physical data were collected from weather stations, laboratory analysis of grab samples and an in-situ Vertical Profiling System (VPS), for the period 2008–2012. This comprehensive, high frequency dataset was utilised to develop a one-dimensional model of the vertical transport and mixing processes occurring along the water column. Multivariate analysis revealed that air temperature and rain forecasts enabled a reliable prediction of the strength of the lake stratification. Vertical diffusion is the main process driving vertical mixing, particularly during winter circulation. However, a high reservoir volume and warm winters can limit the degree of winter mixing, causing only partial circulation to occur, as was the case in 2013. This research study provides a comprehensive approach for understanding and predicting mixing processes for similar lakes, whenever high-frequency data are available from VPS or other autonomous water monitoring systems.

Geochemical mechanisms controlling the chemical composition of groundwater and surface water in the southwest of the Pampean plain (Argentina)

The Pampean plain is one of the most extended regions of the world. In this plain there are numerous shallow lakes that have different origins associated with climate changes at the end of the Quaternary period. Chasicó Lake is the main waterbody in the southwest of the Chaco-Pampean plain. It shows some differences from the typical Pampean shallow lakes. The aim of this paper is to explain the geochemical process that determines the chemical composition of the water of Chasico Lake. The results show that the groundwater is sodium bicarbonate type. Chebotarev's diagram indicates that the catión-exchange takes place in groundwater. The surface water of Chasicó Lake is sodium chloride type. Gibbs's diagram shows that the geochemical processes that affects the Chasicó Lake are evaporation and crystallization, being the water of the lake similar to seawater. The BEI (Base Exchange Index) shows that the process of cation-exchange in the water is not relevant. As, F and V concentrations were studied in surface and groundwater showing significant correlations in groundwater between As vs. F (r=0.99, p<0.05), As vs. V (r=0.99, p<0.05) and V vs. F (r=0.99, p<0.05), while in surface water it was only found for As vs. F (r=0.91, p<0.05). The As, F and V concentration values were higher and more widely dispersed in surface water than in groundwater, as a consequence of evaporation. The fact that these elements do not correlate in surface water may also indicate a different origin.

Is the hydrological function of Lake Wigry changing?

Abstract The paper considers whether in recent years there have been changes in the structure of the water circulation in Lake Wigry, the main water body of the Wigry National Park. The volume and trends in the streams of water exchange in the lake have been assessed. They show that in recent years the horizontal water exchange is being reduced as the inflow to the lake is growing, mainly due to its main tributary, the Czarna Hańcza, while the outflow from the lake is decreasing. The paper examines whether these changes are reflected in the structure of the lake water circulation, which has been assessed on the basis of the lake water balance

Ice–ocean interaction and calving front morphology at two west Greenland tidewater outlet glaciers

Abstract. Warm, subtropical-originating Atlantic water (AW) has been identified as a primary driver of mass loss across the marine sectors of the Greenland Ice Sheet (GrIS), yet the specific processes by which this water mass interacts with and erodes the calving front of tidewater glaciers is frequently modelled and much speculated upon but remains largely unobserved. We present a suite of fjord salinity, temperature, turbidity versus depth casts along with glacial runoff estimation from Rink and Store glaciers, two major marine outlets draining the western sector of the GrIS during 2009 and 2010. We characterise the main water bodies present and interpret their interaction with their respective calving fronts. We identify two distinct processes of ice–ocean interaction which have distinct spatial and temporal footprints: (1) homogenous free convective melting which occurs across the calving front where AW is in direct contact with the ice mass, and (2) localised upwelling-driven melt by turbulent subglacial runoff mixing with fjord water which occurs at distinct injection points across the calving front. Throughout the study, AW at 2.8 ± 0.2 °C was consistently observed in contact with both glaciers below 450 m depth, yielding homogenous, free convective submarine melting up to ~200 m depth. Above this bottom layer, multiple interactions are identified, primarily controlled by the rate of subglacial fresh-water discharge which results in localised and discrete upwelling plumes. In the record melt year of 2010, the Store Glacier calving face was dominated by these runoff-driven plumes which led to a highly crenulated frontal geometry characterised by large embayments at the subglacial portals separated by headlands which are dominated by calving. Rink Glacier, which is significantly deeper than Store has a larger proportion of its submerged calving face exposed to AW, which results in a uniform, relatively flat overall frontal geometry.

Impact of lake inflow and the Yangtze River flow alterations on water levels in Poyang Lake, China

As China's largest freshwater lake, Poyang Lake is essential to regional development and global ecological conservation, but its interaction with the Yangtze River complicates prediction of lake level changes. To evaluate potential impacts of lake inflow and the Yangtze River flow alterations caused by climate variability and human activities, a hydrodynamic model that considers river–lake interactions was adopted to compute the specific change of water level and surface area in Poyang Lake corresponding to given lake inflow and/or Yangtze river flow alterations under 3 groups of scenarios. Results indicated that both lake inflow and the Yangtze River flow alterations significantly impact the Poyang Lake level. The lake level was more sensitive to alterations in lake inflow than equivalent alterations from the Yangtze River discharge. Both sources of alterations had respective influences on water level magnitude and pattern due to the discrepancy in hydraulic connectivity between the main waterbodies in the lake. Lake inflow alterations caused approximately uniform water level change in Poyang Lake, while Yangtze River alterations mainly affected the northern lake, especially at low water levels. Consequently, Poyang Lake management should take a basin-scale approach, especially under the new flow regimes in the Yangtze River resulting from the normal operation of the Three Gorges Dam.

Arsenic, Fluoride, and Vanadium in surface water (Chasicó Lake, Argentina)

Chasico Lake is the main water body in the southwest of the Chaco-Pampean plain. It shows some differences from the typical Pampean shallow lakes, such as high salinity and high arsenic and fluoride levels. The aim of this paper is to analyze the trace elements [arsenic (As), fluoride (F-) and vanadium (V)] present in Chasico Lake. Surface and groundwater were sampled in dry and wet periods, during 2010 and 2011. Fluoride was determined with a selective electrode. As and V were determined by Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES). Significant correlation in surface water was only found for As and F- (r=0.978, p<0.01). The As, F- and V concentration values were higher and more widely dispersed in surface water than in groundwater, as a consequence of evaporation. The fact that these elements do not correlate in surface water may also indicates that groundwater would not be the main source of origin of As, F- and V in surface water. The origin of these trace elements is from volcanic glass from Pampean loess. As, F- and V concentration were higher than in national and international guideline levels for the protection of aquatic biota. Hence, this issue is relevant since the silverside (Odontesthes bonariensis) is the most important commercial species in Chasico Lake. This fish is both consumed locally and exported to other South-American countries through commercial and sport fishing.

Bouse Formation in the Bristol basin near Amboy, California, USA

Limestone beds underlain and overlain by alluvial fan conglomerate near Amboy, California, are very similar in many respects to parts of the Bouse Formation, suggesting that an arm of the Pliocene Bouse water body extended across a wide part of the southern Mojave Desert. The deposits are north of the town of Amboy at and below an elevation of 290 m, along the northern piedmont of the Bristol “dry” Lake basin. The Amboy outcrops contain the Lawlor Tuff (4.83 Ma), which is also found in an outcrop of the Bouse Formation in the Blythe basin near Buzzards Peak in the Chocolate Mountains, 180 km southeast of Amboy. Bouse exposures near Amboy are ∼3.4 m thick, white, distinctly bedded, with limestone and calcareous sandstone as well as stromatolite mounds; we interpret these as nearshore deposits. The Bouse at Amboy contains ostracodes, diatoms, and mollusks that indicate saline lake or estuarine environments with an admixture of fresh-water forms. Along with wading bird tracks and a spine from a marine fish, these fossils suggest that the deposits formed in saline waters near a fresh-water source such as a perennial stream. Beds of the outcrop dip southward and are 113 m above the surface of Bristol Playa, where similar age sediments are buried 270+ m deep, indicating significant faulting and vertical tectonics in this part of the Eastern California Shear Zone during the past 5 m.y. Confirmation of the Bouse Formation at Amboy strengthens previous assignments to the Bouse Formation for mudstones in driller logs at Danby “dry” Lake, California, and suggests that areally extensive arms of the Bouse water body were west of the Blythe basin. The Bristol basin arm of the lower Bouse basin probably was restricted from the main water body by narrow passages, but Bouse sediment there is similar to that in the Blythe basin, suggesting generally similar water chemistry and environmental conditions. Examining the degree to which Bouse deposits in the western arms differed from Bouse deposits in the Blythe basin offers an approach to test whether the southernmost Bouse water body was deposited in an estuarine or lacustrine setting.

Neglected tropical diseases: prevalence and risk factors for schistosomiasis and soil-transmitted helminthiasis in a region of Minas Gerais State, Brazil

Among the neglected tropical diseases (NTDs), schistosomiasis and the three main soil-transmitted helminthiases (STHs), i.e., ascariasis, trichuriasis and hookworm infection, represent the most common infections in developing countries. In Brazil, there is a lack of epidemiological data in many parts of the country, which favors the unawareness of the real situation concerning these diseases. Due to this, we investigated the occurrence of schistosomiasis and STHs in a region of Minas Gerais State, Brazil. One stool sample was collected from 503 individuals, whose ages ranged from 0.1 to 91.2 years, and screened using both the Kato-Katz and the Formol-Ether methods. In parallel, a malacological survey was carried out in the main water bodies of the district, and Biomphalaria susceptibility assays and kernel-based techniques were also performed. No individual was found infected with Ascaris lumbricoides or hookworm. Schistosoma mansoni was the most common parasite found (1.6%). The prevalence was higher in males and the chance of acquiring the disease increased by 43.35 times with contact with a body of water. None of the Biomphalaria tenagophila and B. glabrata specimens were found naturally infected, but B. glabrata was highly susceptible to infection with Schistosoma mansoni. Using kernel-based techniques, clusters of Biomphalaria were found near the households where the infected individuals lived. Schistosomiasis was the most prevalent parasitic infection found. Our findings show that the occurrence of this disease has been underestimated by the local health care service, and highlight the importance of epidemiological surveillance in areas of low prevalence for schistosomiasis.

Temporal and spatial changes of water quality and management strategies of Dianchi Lake in southwest China

Abstract. Temporal and spatial changes to the water quality of Dianchi Lake in southwest China were investigated using monthly monitoring data from 2005 to 2012. Dianchi Lake is divided into two parts, Caohai Lake and Waihai Lake, by a man-made dike. Caohai Lake lies at the north of Dianchi Lake, while Waihai Lake is the main water body of Dianchi Lake and accounts for 96.7% of the whole area of the lake. Based on the analysis of total phosphorus (TP), total nitrogen (TN), and chlorophyll a (Chl a) concentrations, it was determined that, in Caohai Lake, the annual concentrations of these variables ranged from 0.19–1.46 mg L−1, 6.11–16.79 mg L−1, 0.06–0.14 mg L−1, respectively. In addition, the annual concentrations of TP, TN and Chl a in Waihai Lake ranged between 0.13 and 0.20 mg L−1, 1.82 and 3.01 mg L−1, and 0.04 and 0.09 mg L−1, respectively. Cluster analysis (CA) classified the 10 monitoring sites into two clusters (cluster A and cluster B) based on similarities of water quality characteristics. Our data revealed that the current status of water quality within Caohai Lake was much worse than that of Waihai Lake. Water quality was seriously degraded during the economic boom near the period of the "Eleventh Five-Year Plan" (2005–2010), and gradually improved from 2010 to 2012 because of the "standard emission directive to industry". The main factors that influenced the spatial and temporal changes to water quality were natural factors including lake evolution and regional characteristic as well as human factors such as pollution load into the lake and management strategies that were already adopted. Some activities and regulations were implemented to enhance the lake environment by controlling wastewater emissions and establishing regulations to protect the lakes in the Yunnan Province. However, problems with institutional fragmentation (horizontal and vertical), simple treatment methods, low-intensity investment in pollution control, and lack of meaningful endogenous pollution control strategies were still present in the lake management strategy. To solve these problems, suitable control measures are needed, especially considering the current old-age status of Dianchi Lake. The fundamental improvement of the water quality within Caohai Lake was dependent on the measures taken in the upper reaches of the Caohai Watershed, including further recovery of submerged plants, resource utilization by floating plants and the reinforcement of sediment disposal. Management strategies for endogenous pollution in Waihai Lake were mainly dependent on restocking algae-eating fish and the ecological restoration of macrophytes. In this way, the swamping trend and the ageing process that is occurring in Dianchi Lake can be stunted. And the management strategies would be a contribution to the management of water conflicts between mankind and ecosystems in similar lakes.

Ecological validity of river-floodplain system assessment by planktonic crustacean survey (Branchiata: Branchiopoda)

Studies of the Slovakian Danube have indicated profound changes in the structures of several invertebrate assemblages in the section of the river bypassed by the Gabčíkovo hydroelectric project in 1992 and in adjacent floodplain water bodies. The present study investigates the relationship between hydrological connectivity and species diversity in the old main channel and adjacent left-bank water bodies, using resident cladocerans as indicators of the ecological integrity of the river-floodplain system. The work aimed to quantify cladoceran habitat preferences using habitat values (HV) and indication weights (IW) calculated from data accumulated during long-term monitoring of planktonic communities of the Danube floodplain (1,840.5-1,804rkm) and supplemented with data from the literature. Although not listed as an indicator group in the European Union Water Framework Directive, cladocerans are shown to be highly apposite in the ecological assessment of river-floodplain systems. Of 71 recorded cladoceran species, 19 taxa showed a preference for eupotamal habitats, 24 species preferred eupotamal B/parapotamal waters, and 28 cladocerans were found to prefer the plesiopotamal/paleopotamal habitat type. Identified habitat types follow a gradient of hydrological connectivity with the main river channel, ranging from the eupotamal to more or less isolated floodplain water bodies. A secondary aim was to use the calculated values to assess the ecological integrity of the river-floodplain system. The key element of this procedure is the calculation of the Floodplain Index (FI) (Chovanec et al. Large Rivers, 15(1-4), 169-185 2005) from the summation of the habitat values and indication weights of all species present at the sampling sites. Calculated index values indicate the extent of disruption to lateral connectivity in the floodplain area.

High-resolution temperature sensing in the Dead Sea using fiber optics

The thermal stratification of the Dead Sea was observed in high spatial and temporal resolution by means of fiber-optics temperature sensing. The aim of the research was to employ the novel high-resolution profiler in studying the dynamics of the thermal structure of the Dead Sea and the related processes including the investigation of the metalimnion fluctuations. The 18 cm resolution profiling system was placed vertically through the water column supported by a buoy 450 m from shore, from 2 m above to 53 m below the water surface (just above the local seafloor), covering the entire seasonal upper layer (the metalimnion had an average depth of ∼20 m). Temperature profiles were recorded every 5 min. The May to July 2012 data set allowed quantitative investigation of the thermal morphology dynamics, including objective definitions of key locations within the metalimnion based on the temperature depth profile and its first and second depth derivatives. Analysis of the fluctuation of the defined metalimnion locations showed strong anticorrelation to measured sea level fluctuations. The slope of the sea level versus metalimnion depth was found to be related to the density ratio of the upper layer and the underlying main water body, according to the prediction of a two-layer model. The heat content of the entire water column was calculated by integrating the temperature profiles. The vertically integrated apparent heat content was seen to vary by 50% in a few hours. These fluctuations were not correlated to the atmospheric heat fluxes, nor to the momentum transfer, but were highly correlated to the metalimnion and the sea level fluctuations (r = 0.84). The instantaneous apparent heat flux was 3 orders of magnitude larger than that delivered by radiation, with no direct correlation to the frequency of radiation and wind in the lake. This suggests that the source of the momentary heat flux is lateral advection due to internal waves (with no direct relation to the diurnal cycle). In practice, it is shown that snap-shot profiles of the Dead Sea as obtained with standard thermal profilers will not represent the seasonal typical status in terms of heat content of the upper layer.

Historical mercury trends recorded in sediments from the Laguna del Plata, Córdoba, Argentina

The main carrying phases of mercury (Hg) were analyzed in a 120cm sediment core taken at the Laguna del Plata (LP), a small lake connected to the main water body of Laguna Mar Chiquita (LMC) during highstands. LMC is considered to be one of the largest saline lakes in the world representing a sensitive climatic indicator due to its frequent lake level variations at millennial and interdecadal scale like the last ones that started early in the 1970s and after 2004. Total particulate Hg (HgTP) concentrations vary between ∼13 and ∼131μgkg−1 indicating a system with low pollution. Selective extractions with ascorbate, HCl and H2O2 were performed in the sediments and they revealed that Hg is associated mainly to reactive sulphides in the base of the core, while in the middle and upper part the organic matter seems to be the main Hg-bearing phase. The highest and most important peak was found in sediments accumulated between 1991 and 1995. More than a punctual source of pollution, this peak is likely related to two eruptive events occurred in the Andean Cordillera in this period: the eruption of Hudson volcano in southern Patagonia that occurred in 1991 and the one of the Láscar volcano in northern Chile that occurred in 1993. In both cases, the respective ash plumes were documented to have reached the Laguna del Plata region.

Data mining techniques for water ecotoxicity classification for application on water resources management

Among the various forms of action that promote sustainability, technological innovation can be considered one of the most important. This paper applied data mining techniques to discover knowledge in the field of water quality monitoring data, providing useful and relevant support for decision-making in environmental management systems. At the current stage of research, a predictive modelling technique, known as rule-based classification, was used to find rules that can, based on the values of certain chemical parameters, predict the ecotoxicity level of a water sample. We used data from water analyses from main water bodies of Sao Paulo state in Brazil, from 2005 to 2010. We expect to get a reliable, fast and effective way to predict the ecotoxicity levels of water in rivers, lakes and reservoirs based on analyses of chemical parameters, or indicate the complementarity of these measurements for optimisation of monitoring networks and the consequent improvement natural resources management.

Assessment of the topsoil heavy metals pollution in the Sarno River basin, south Italy

The Sarno River basin area is one of the most polluted in Europe and it is due to the waste products of the tomato industry, the leather tanneries and the pharmaceutical industry. This area also has been densely populated and urbanized since the Middle Bronze Age, as testified by the presence of numerous archeological sites, including the ancient Pompeii town, and environmental degradation that characterizes the area is absolutely unacceptable. This paper represents a detailed study to assess the potentially harmful element content of topsoils. In total, 283 soil samples were collected and analyzed, after an aqua regia extraction, by a combination of inductively coupled plasma atomic emission and inductively coupled plasma mass spectrometry for 53 elements. Univariate and multivariate analyses were carried out to show the single-element geochemical distribution and the distribution of factor scores of the elemental associations resulting from R-mode factor analysis. Maps showing elements and the association factor score distributions have been obtained using GeoDAS and ArcGIS software. The assessment of the soil contamination was also carried out using the contamination factor and degree of contamination. The results obtained indicate that soil pollution has different anthropogenic sources. Specifically, Cr pollution derives from tanneries discharging wastewaters in the main water bodies of the basin while Cu contamination seems to depend on widespread agricultural practices. Tin, Pb, Hg, Zn, Cd, Sb anomalies are found mainly in urban and industrial areas, sometimes close to roads with high traffic levels while there is a substantial coincidence with background values for other elements (Co, Ni, Se, Tl and V).

Factors affecting wild boar ( Sus scrofa ) abundance in southern Tuscany

Hunting bags should be a good measure of wild boar ( Sus scrofa ) abundance and/or density and can be used to analyse habitat population relationships. For this reason, the wild boar harvest of fifteen hunting areas located in southern Tuscany (from 2001 to 2005) was investigated in order to evaluate the effect of fifteen environmental variables measured by a G.I.S. software. For each hunting area the percentage of 13 land use classes was measured by intersecting hunting areas with a digitalized land-use map. Moreover the percentage of perimeter of hunting areas bordering with protected woody areas and the percentage of main water bodies were measured. Correlation and regression analyses were carried out considering the harvest density as a dependent variable. Twelve multiple regression models each including three environmental variables were ranked by the information-theroetic approach (modified Akaike’s information criterion). Protected woody areas (Parks and Wildlife Refuges), where hunting it is not allowed, resulted the most important variable predicting positively wild boar hunting yealds and may play a role in over-abundance of this species. Also young woodlands (naturally regenerated or by coppice), chestnut woods and conifer woods showed a positive effect. Models obtained from hunting data and digitalized land use maps can be very useful to plan wild boar population management at local scale. These data are generally available or quickly collectables. However habitat population relationships should be carefully interpreted considering the possible land use modifications from maps elaboration as a consequence of forest management and evolution. Download the complete issue.

Study on the Extraction of the Water Bodies from Remote Sensing Image Using ENVI Software – Applied to the River Environmental Protection in Qinzhou

In this study, the main water body of remote sensing image was extracted with the maximum likelihood algorithm of ENVI software based on Qinzhou's remote sensing images 2008 and 2011. From the remote sensing images, it was found that the area of the water body was greatly reduced, and also the water body has been polluted differently. In this paper, the urgent environmental protections of Qinzhou's main rivers are analyzed in view of the reduced water body, and also some suggestions on water body conservation are proposed. Overview of Qinzhou Qinzhou is located between V20°52 and 22°41 N, and 107°27 and 109°56 S. The total area of Qinzhou is about 10842.73 square kilometers. It is in the corner of the South China Sea, and is the core base of the north gulf economic region. Thus, it takes an absolute advantage in logistics. The national patriotism education bases for elementary and middle schools in Qinzhou are the former homes of two national heroes (Yongfu LIU, and Zicai FENG). In Qinzhou, there is a coastline of more than 520 kilometers, and many excellently natural harbors such as Qinzhou Port, Longmen Port, Shajing Port, and Siluo Port are available here. Also, there are abundant product advantages. The climate is hot. Many rivers and water reservoirs are available. Soil and plants are flourishing greatly. Since the new century, Qinzhou government as well as the governments of all counties greatly invest Qinzhou, carry out urban and rural clean engineering, urban infrastructure project construction, and agricultural preferential policies, and establish multi-form and multi-dimensional economic and technical cooperation with foreign and domestic companies, in which business is easy to process and the procedures are simple to handle. In 2013, the high-speed rail has brought a new era to Qinzhou. Qinzhou's advantages in climate conditions, rain conditions, and water resources Qinzhou is located in the subtropical zone and features a transitional marine monsoon climate. The overall terrain forms are mountains, hills, terraces plains, and coastal mud flats from northwest to southeast. From east to north, the main mountain is LIUWAN Mountain. From west to north, the main mountain is SHIWAN Mountain. The annual average temperature is 22°C; the absolute maximum temperature was 37.5°C (July 28, 1968), and the absolute lowest temperature was-1.8°C (January 12, 1955). The average annual rainfall is about 1600mm; the average sunshine period is about 1800 hours, and the frost-free period is more than 350 days. The solar radiation amount is 104.6~108.8 kilocalorie/cm2; the annual sunshine duration is 1633.6~1801.4 hours; the annual average temperature is 21.4°C~22°C; the annual total accumulated temperature is 7800°C~ 8200°C. The average frost-free period of previous years was 329~354 days. The water resources advantages of Qinzhou include humid temperature, abundant rain, and annual rainfall of 1600mm~1900mm. Major rivers include Qinjiang, Maolingjiang, Nanliujiang, and Dafengjiang, and the annual runoff is 11.728 billion cubic meters. The gross storage capacity of small, middle, and large reservoirs has reached 805 million cubic meters. Qinzhou's remote sensing image and the river remote sensing images of recent years The water yield of the main rivers in Qinzhou is abundant and falls greatly, so the hydropower resource is rich. The rivers in Qinzhou are small and medium-sized, own a large quantity of flow, and flow into the sea, but do not form drainage.