Estimation of potential pollution from mine tailings in the San Pedro River (1993–2005), Mexico–US border

The San Pedro River (SPR) is located in northern Sonora (Mexico) and southeastern Arizona (USA). SPR is a transboundary river that develops along the Sonora (Mexico) and Arizona (USA) border, and is considered the main source of water for a variety of users (human settlements, agriculture, livestock, and industry). The SPR originates in the historic Cananea mining area, which hosts some of the most important copper mineralizations in Mexico. Acid mine drainage derived from mine tailings is currently reaching a tributary of the SPR near Cananea City, resulting in the contamination of the SPR with heavy metals and sulfates in water and sediments. This study documents the accumulation and distribution of heavy metals in surface water along a segment of the SPR from 1993 to 2005. Total concentrations of Cd, Cu, Fe, Mn, Pb, and Zn in surface waters are above maximum permissible levels in sampling sites near mine tailing deposits. Nevertheless, a significant decrease in the Fe and SO₄ ²⁻ in surface water (SO₄ ²⁻: 7,180–460.39 mg/L; Fe: 1,600–9.51 mg/L) as well as a gradual decrease in the heavy and transition metal content were observed during the period from 1994 to 2005. Approximately 2.3 km downstream of the mine tailings, the heavy metal content of the water drops quickly following an increase in pH values due to the discharging of wastewater into the river. The attenuation of the heavy metal content in surface waters is related to stream sediment precipitation (accompanied by metal coprecipitation and sorption) and water dilution. Determining the heavy metal concentration led to the conclusion that the Cananea mining area and the San Pedro River are ecosystems that are impacted by the mining industry and by untreated wastewater discharges arising from the city of Cananea (Sonora, Mexico).     

Farmers’ response to agricultural drought in paddy field of southern China: a case study of temporal dimensions of resilience

Seasonal water scarcity in southern China has been an issue of concern for many years. The increased frequency of low precipitation in the growing season of rice created a flurry of discussions in the academic and policy arenas. These events severely disrupted the supply of irrigation water for agriculture in paddy field areas and posed a substantial threat to farmers’ livelihoods. Within a broader context of accessing farmers’ resilience to agricultural drought, this paper focuses on the response mechanisms and adaptive strategies adopted by farming households in three types of areas (Plain, Hill, Mountain) in Dingcheng, Hunan Province. With the increasing drought frequency and the pressure from the demand for livelihood improvement, farmers’ response mechanisms have evolved, expanding from short-term adjustments to long-term adaptations, and switching focus from securing reliable water sources to improving irrigation efficiency and diversifying both on- and off- farm productions. The three types of geographic units have different resilience profiles and have developed diverse patterns of adaptive processes that update the conceptual model of Disaster Resilience of “Loss-Response” of Location. It presents a temporal dimension to the study of resilience, which is largely missing from the current literature and provides insights into how to enhance farmers’ response capacities in the face of agricultural drought in southern China.     

Spatial–temporal differences in disaster perception and response among new media users and the influence factors: a case study of the Shouguang Flood in Shandong province

Natural Hazards - When human beings cannot avoid extreme climate disasters, it is widely accepted to take measures to address climate change. Research on ordinary people’s perception of...     

Temporal–spatial variability of soil fertility in karst region: a case study of Xiaojiang watershed Yunnan

By sampling in the field and analyzing the soil samples in the laboratory in 1982 and 2005 the soil fertility data were obtained. Through application of geo-statistics combined with GIS, the temporal–spatial variability of the pH, organic matter, total nitrogen, total phosphorus and total potassium in soil of Xiaojiang watershed from 1982 to 2005 were analyzed. Results showed that: (1) the pH value and total potassium in soil showed an increasing trend, but the organic matter, total nitrogen and the total phosphorus in soil declined in the past 20 years in Xiaojiang watershed, (2) the parameters fitted by semivariogram models for fertility indices changed significantly in the past 20 years and (3) the result estimated by ordinary Kriging indicated the spatial pattern of the soil fertility indices changed significantly in the past 20 years. The soil pH increased in the east and southeast, but decreased in the middle of the watershed. The organic content of the soil matter decreased in the east, southeast and southwest, but increased in the northeast and middle of the watershed. The total nitrogen content of the soil decreased in the east, but increased in the middle of watershed. The total phosphorus content of the soil decreased in the whole watershed. The total potassium content of the soil increased in the southwest and southeast, but decreased in the middle of the watershed and (4) the change of land use and soil management measures was the main driving force of variability of soil properties.     

Mantle and crustal sources of Archean anorthosite: a combined in situ isotopic study of Pb–Pb in plagioclase and Lu–Hf in zircon

Isotopic analyses of ancient mantle-derived magmatic rocks are used to trace the geochemical evolution of the Earth’s mantle, but it is often difficult to determine their primary, initial isotope ratios due to the detrimental effects of metamorphism and secondary alteration. We present in situ analyses by LA-MC-ICPMS for the Pb isotopic compositions of igneous plagioclase (An_75–89) megacrysts and the Hf isotopic compositions of BSE-imaged domains of zircon grains from two mantle-derived anorthosite complexes from south West Greenland, Fiskenæsset and Nunataarsuk, which represent two of the best-preserved Archean anorthosites in the world. In situ LA-ICPMS U–Pb geochronology of the zircon grains suggests that the minimum crystallization age of the Fiskenæsset complex is 2,936 ± 13 Ma (2σ, MSWD = 1.5) and the Nunataarsuk complex is 2,914 ± 6.9 Ma (2σ, MSWD = 2.0). Initial Hf isotopic compositions of zircon grains from both anorthosite complexes fall between depleted mantle and a less radiogenic crustal source with a total range up to 5 ε_Hf units. In terms of Pb isotopic compositions of plagioclase, both anorthosite complexes share a depleted mantle end member yet their Pb isotopic compositions diverge in opposite directions from this point: Fiskenæsset toward a high-μ, more radiogenic Pb, crustal composition and Nunataarsuk toward low-μ, less radiogenic Pb, crustal composition. By using Hf isotopes in zircon in conjunction with Pb isotopes in plagioclase, we are able to constrain both the timing of mantle extraction of the crustal end member and its composition. At Fiskenæsset, the depleted mantle melt interacted with an Eoarchean (~3,700 Ma) mafic crust with a maximum ¹⁷⁶Lu/¹⁷⁷Hf ~0.028. At Nunataarsuk, the depleted mantle melt interacted with a Hadean (~4,200 Ma) mafic crust with a maximum ¹⁷⁶Lu/¹⁷⁷Hf ~0.0315. Evidence from both anorthosite complexes provides support for the long-term survival of ancient mafic crusts that, although unidentified at the surface to date, could still be present within the Fiskenæsset and Nunataarsuk regions.     

Assessing the vulnerability of social–environmental system from the perspective of hazard,sensitivity, and resilience: a case study of Beijing,China

Despite a recent increase in the number of vulnerability analyses there has been relatively little discussion of vulnerability assessment of social–environment system, especially when they face multiple hazards. In this study, we developed an applicable and convenient method to assess vulnerability of social–environment system at a regional scale. Vulnerability is quantified by measuring three critical elements (i.e. hazards, sensitivity, and resilience) through some key variables. The results showed that vulnerability is high in Miaofeng Mountain in Mengtougou District, the hills of Pinggu County and the riparian zones of the lower courses of the Beiyun and Yongding Rivers; but low in the city of Beijing and the southwestern part of the Fangshan District. Areas of very high, high, medium, and low-vulnerability account for 6.19, 25.48, 33.06, and 35.27% of the total area, respectively. The degree of vulnerability decreases in a northwest direction in mountainous areas and declines from watercourses to riparian zones along a lateral direction in the plain. Some adaptive strategies are also proposed.     

Pullout behavior of biocement–geosynthetic reinforcement system: a parametric study

Acta Geotechnica - In the biocement–geosynthetic system, biocement is combined with geosynthetic to increase the pullout resistance of the geosynthetic and thereby the stability of reinforced...     

Landslide hazard and risk assessment: a?case study from the Hlohovec–Sered’ landslide area in south-west Slovakia

Landslide hazard or susceptibility assessment is based on the selection of relevant factors which play a role on the slope instability, and it is assumed that landslides will occur at similar conditions to those in the past. The selected statistical method compares parametric maps with the landslide inventory map, and results are then extrapolated to the entire evaluated territory with a final product of landslide hazard or susceptibility map. Elements at risk are defined and analyzed in relation with landslide hazard, and their vulnerability is thus established. The landslide risk map presents risk scenarios and expected financial losses caused by landslides, and it utilizes prognoses and analyses arising from the landslide hazard map. However, especially the risk scenarios for future in a selected area have a significant importance, the literature generally consists of the landslide susceptibility assessment and papers which attempt to assess and construct the map of the landslide risk are not prevail. In the paper presented herein, landslide hazard and risk assessment using bivariate statistical analysis was applied in the landslide area between Hlohovec and Sered?? cities in the south-western Slovakia, and methodology for the risk assessment was explained in detail.     

Quantification of groundwater–seawater interaction in a coastal sandy aquifer system: a study from Panama,Sri Lanka

The Panama coastal aquifer system is an important water resource in the southeast coast of Sri Lanka that provides adequate supplies of water for agriculture and domestic uses. One of the biggest threats to these fragile aquifers is the sea water intrusion. In this study, recharging mechanism and geochemical evaluation of groundwater in the coastal sandy aquifer of Panama were evaluated using chemical and stable isotope techniques. Thirty groundwater samples were collected and analyzed for their major ion concentrations and stable isotope ratios of oxygen (¹⁸O/¹⁶O) and hydrogen (D/H). All studied samples showed a ranking of major anions in the order Cl^? > HCO ₃ ^?  > SO ₄ ^2?  > N-NO₃ ^? while cations showed a decreasing order of abundance with Na⁺ > Ca²⁺ > Mg²⁺ > K⁺. Dominant groundwater hydrogeochemical types were Na–Cl and mixed Ca–Mg–Cl. Results of saturation index calculations indicate that the investigated groundwater body was mostly saturated with respect to calcite, dolomite and gypsum. In addition, stable isotope and geochemical data suggest that fresh groundwater in the aquifer is recharged mainly by local precipitation with slight modification from evaporation and saline water intrusions. Isotope data suggest that mixing of salt water with freshwater occurs in aquifers which are located towards the lagoon. Since the communities in the study area depend entirely on groundwater, an understanding of the hydrogeochemical characteristics of the aquifer system is extremely important for the better water resource management in the region.     

The role of water resources in the evolution of the Israeli–Lebanese border

The current location of the border between Lebanon and Palestine, today's Israel, is a product of various competing forces. The Zionist Organization aspired to include the entire Galilee region up to the lower reaches of the Litani River (also known as the Kassimiyah River) within Palestine. The river itself was the desired northern border of the country. The Zionists supported their position by employing instrumental arguments that were largely related to the availability of water resources. On the other hand, residents of the upper Galilee, today's southern Lebanon, demanded that they be included with Lebanon. They used their trade links with Beirut, and cultural and familial ties with other parts of Lebanon to support their position. These instrumental and expressive arguments appear to have assisted in the demarcation of the border between Lebanon and Palestine. Currently, access to the water resources, not necessarily control over them, is likely to influence negotiations between Israel and Lebanon over the future of the Israeli-occupied security zone in southern Lebanon.     

Identifying urban–rural differences in social vulnerability to natural hazards: a case study of China

Identifying and analyzing the urban–rural differences of social vulnerability to natural hazards is imperative to ensure that urbanization develops in a way that lessens the impacts of disasters and generate building resilient livelihoods in China. Using data from the 2000 and 2010 population censuses, this study conducted an assessment of the social vulnerability index (SVI) by applying the projection pursuit cluster model. The temporal and spatial changes of social vulnerability in urban and rural areas were then examined during China’s rapid urbanization period. An index of urban–rural differences in social vulnerability (SVI_D) was derived, and the global and local Moran’s I of the SVI_D were calculated to assess the spatial variation and association between the urban and rural SVI. In order to fully determine the impacts of urbanization in relation to social vulnerability, a spatial autoregressive model and Bivariate Moran’s I between urbanization and SVI were both calculated. The urban and rural SVI both displayed a steadily decreasing trend from 2000 to 2010, although the urban SVI was always larger than the rural SVI in the same year. In 17.5% of the prefectures, the rural SVI was larger than the urban SVI in 2000, but was smaller than the urban SVI in 2010. About 12.6% of the urban areas in the prefectures became less vulnerable than rural areas over the study period, while in more than 51.73% of the prefectures the urban–rural SVI gap decreased over the same period. The SVI_D values in all prefectures had a significantly positive spatial autocorrelation and spatial clusters were apparent. Over time, social vulnerability to natural hazards at the prefecture-level displayed a gathering–scattering pattern across China. Though a regional variation of social vulnerability developed during China’s rapid urbanization, the overall trend was for a steady reduction in social vulnerability in both urban and rural areas.

     

Geostatistical analysis of spatiotemporal variability of groundwater level fluctuations in Amman–Zarqa basin,Jordan: a case study

The main objective of this study was to assess the spatial and temporal variability of groundwater level fluctuations in the Amman–Zarqa basin, during the period 2001–2005. In the year 2003, as a consequence of war, there was a sudden increase in the population in this basin. Knowing that the basin is already heavily populated and witnesses most of the human and industrial activities in Jordan, this study was prompted to help make wise water resources management decisions to cope with the new situation. Data from 31 fairly distributed wells in the upper aquifer of the basin were subjected to geostatistical treatment. Kriging interpolation techniques have indicated that the groundwater flow directions remained almost constant over the years. The two main directions are SW–NE and E–W. Kriging mapped fluctuations have also showed that drop and rise events are localized in the basin. Forecasting possibilities for management purposes were tackled using autocorrelation analysis. The constructed autocorrelograms indicated, in general, the temporal dependence of seasonal water level fluctuations, and that forecasting can be carried out within a period of 3–21 months. Several suggestions were made to mitigate the drop and rise hazards in the detected sites.     

Origin of epithermal Ag–Au–Cu–Pb–Zn mineralization in Guanajuato, Mexico

The Guanajuato epithermal district is one of the largest silver producers in Mexico. Mineralization occurs along three main vein systems trending dominantly northwest–southeast: the central Veta Madre, the La Luz system to the northwest, and the Sierra system to the east. Mineralization consists dominantly of silver sulfides and sulfosalts, base metal sulfides (mostly chalcopyrite, galena, sphalerite, and pyrite), and electrum. There is a broad zonation of metal distribution, with up to 10 % Cu+Pb+Zn in the deeper mines along the northern and central portions of the Veta Madre. Ore occurs in banded veins and breccias and as stockworks, with gangue composed dominantly of quartz and calcite. Host rocks are Mesozoic sedimentary and intrusive igneous rocks and Tertiary volcanic rocks. Most fluid inclusion homogenization temperatures are between 200 and 300 °C, with salinities below 4 wt.% NaCl equivalent. Fluid temperature and salinity decreased with time, from 290 to 240 °C and from 2.5 to 1.1 wt.% NaCl equivalent. Relatively constant fluid inclusion liquid-to-vapor ratios and a trend of decreasing salinity with decreasing temperature and with increasing time suggest dilution of the hydrothermal solutions. However, evidence of boiling (such as quartz and calcite textures and the presence of adularia) is noted along the Veta Madre, particularly at higher elevations. Fluid inclusion and mineralogical evidence for boiling of metal-bearing solutions is found in gold-rich portions of the eastern Sierra system; this part of the system is interpreted as the least eroded part of the district. Oxygen, carbon, and sulfur isotope analysis of host rocks, ore, and gangue minerals and fluid inclusion contents indicate a hydrothermal fluid, with an initial magmatic component that mixed over time with infiltrating meteoric water and underwent exchange with host rocks. Mineral deposition was a result of decreasing activities of sulfur and oxygen, decreasing temperature, increasing pH, and, in places, boiling.     

Trends and relationships in victims’ recovery perceptions: a case study of the recovery process following the Great East Japan Earthquake

Natural Hazards - In the aftermath of a disaster, the recovery process has long-term, multi-dimensional, and interactive aspects. To clarify the recovery conditions and victims’ perceptions...     

Water quality and risk assessment of dug wells: a case study for a poor community in the city of São Paulo, Brazil

Sparsely populated areas, or peripheral communities commonly lack access to a public water supply and sewerage systems. The inhabitants of these areas must make use of excavated wells to provide their water needs, and cesspits for domestic wastewater disposal. These on-site sanitation systems can release pathogens and nutrients into shallow groundwater. These poor communities urgently require cheap and efficient techniques for the detection of sanitary conditions, in order to prevent contamination of the water resources supplied by dug wells. The sanitary risk assessment methodology, applied in an irregular settlement south of the city of São Paulo, was based on a questionnaire with yes/no questions (risk factors), which allowed the identification of problems related to the well construction and operation, and the presence of potential contamination sources in its vicinity. These risk factors were compared against nitrate and bacterial analysis using the clustering statistical method, to verify the relationship between contamination and certain aspects surveyed in the questionnaire. Questions that were more related to contaminated wells were those concerning the presence of cover and its integrity; gaps between mouth and cover; the surrounding pavement and presence of ground irregularities; infiltration in the well casing; water-suspended materials; and proximity to contamination sources. Contamination models based on variograms allowed to observe that bacterial contamination presented a strong localized component, which was associated frequently with the way residents handled the wells, whereas nitrate contamination was related more to a regional (spatial) component; that is, the distance between wells and cesspits.     

An evaluation of residents’ perceptions of the creation of a geopark: a case study on the geopark in Mt. Huaying Grand Canyon, Sichuan Province, China

In recent years, geoparks (a geoheritage effort to protect geological features) have been vigorously promoted in China and abroad. The evaluation of a geopark is important for geopark development. However, current evaluation methods focus on geoheritage and their values, and often ignore residents’ situations, even though community participation is essential to the sustainable development of geoparks. In this paper, the Mt. Huaying Grand Canyon Geological Park was selected as a study area to evaluate resident’s perceptions of the park. Perception impact factors were selected from the perspective of the park residents. Quantitative evaluation models, based on data from questionnaires, were created using the hierarchy process model and expert evaluation method. The results showed that the following factors influenced residents’ perceptions, listed from the most significant to the least: residents’ understanding of geoheritage, participation level in commercial activities, participation level in planning decisions, satisfaction level regarding benefit distribution and level of participation willingness. It was found that residents’ level of understanding of geoheritage and their participation level in planning decisions were the main reasons for poorer perceptions of geoheritage. The keys to improving residents’ perceptions of geoheritage are to change the management system, implement people-centered policies and to establish a government-led management mode that encourages community participation and involves private business contracts.     

Power,perception, and adaptation: Exploring gender and social–environmental risk perception in northern Guanajuato,Mexico

This paper examines how gender relations within rural communities in north-central Mexico affect women’s perceptions of and responses to environmental and social risks. Several studies currently exist which suggest various reasons as to how people especially vulnerable to the effects of climate change perceive their risks, and how this influences their responses. In this paper, I take a feminist approach to questions of social–environmental risks and adaptation to argue that risk perception is tightly linked to knowledge production, and knowledge production is a power-laden process involving the constant negotiation of resources, responsibilities and knowledge. I base this argument on the results of fieldwork conducted from September 2009 to May 2010 with women residents of two ejidos in northern Guanajuato, Mexico. In drawing from feminist political ecology studies, I intend to show how gender, environmental knowledge, risk perception and thus, adaptation are constituted by and embedded in social relations of power.     

An overview of US state drought plans: crisis or risk management?

Natural Hazards - Recent severe drought events across the nation have raised our concerns over society’s changing and increasing vulnerability to droughts. All levels of governments have...     

Spatial equity in urban facility versus residents’ satisfaction: challenge for the unplanned cities—a case study of Barasat city,India

Spatial equity in urban facilities or service distribution is considered as a critical determinant of the quality of urbanization. Spatial equity simply means the presence of adequate facilities and equal proximity. Many initiatives have mostly focused on one type of facility, obviating the holistic understanding of the equity of distribution of all basic facilities in cities. Moreover, the perceptions of the citizens in the process of planning are hardly considered. In this paper, an integrated facility-satisfaction index is presented to evaluate the balance between the distribution of facilities and the level of residents' satisfaction derived from those facilities. This method has taken all possible urban facilities and categorized them as educational, health, financial, recreation, and others. The per capita facility availability is calculated by incorporating the spatial distribution of urban facilities, the service range of facilities, population distribution, and weight. The proper weights have been given by employing the analytical hierarchy process (AHP). The satisfaction index has been derived from the citizens’ perception of each facility, marked on a 5-point Likert scale during the field survey. The paired-sample t-test demonstrated that there is a significant difference between the facility availability and satisfaction index at the significance level of 0.05. The application of the method is demonstrated in fast urbanizing Barasat city, West Bengal, India. Based on the degree of facility-satisfaction differences or correspondences, the entire region has been categorized into four zones viz. satisfied people with favorable facility availability, unsatisfied people with poor facility availability, unsatisfied people with relatively high facility availability, and satisfied people with relatively low facility availability. The pattern has been validated by identifying spatial clusters and spatial outliers of facility availability and satisfaction using local Moran’s I. This approach can help a city to distribute the facilities to satisfy the citizens of all corners which will help to overcome the constant problems of policy decisions without adequate and reliable information about the actual demand of the residents.

     

Mobility of rare earth elements in the system soils–plants–groundwaters: a case study of an arid area (Oman)

Groundwater samples from six wells and various species of plants from soils developed on ophiolites were collected from an arid area (AlKhod area, Oman) and analyzed for trace elements including rare earth elements (REEs). The distribution patterns of REEs in plants indicated an enrichment in middle REEs (MREEs?=?Sm to Dy) and heavy REEs (HREEs?=?Ho to Lu), when they are normalized to the REE composition of the Post Archean Australian Shale (PAAS), with a significant negative anomaly in Ce and a positive anomaly in Eu. Compared to Oman ophiolites, the REEs in different species of plants are depleted in Ce and enriched in MREEs and slightly enriched in light REE (LREE?=?from La to Nd). Relative to PAAS, the distribution of REEs in groundwaters revealed similar patterns to the REE distribution in plants. The distribution patterns of REEs in plants relative to those in waters are nearly flat. These patterns suggest that the transfer of REEs from soil solutions to the groundwaters in Oman occurs without any significant fractionation.