Vulnerability assessment of coastal aquifer system for irrigation suitability — A classical approach from southern India

The vulnerability of the shallow aquifer system for saline water intrusion has been evaluated using the classical tools at a coastal area, southern India. Groundwater samples (N=144) from Quaternary aquifer system within 25 km² area in pre- and post-monsoon seasons were analyzed for major ion chemistry including Electrical Conductivity (EC). The hydrochemical parameters are examined applying classical irrigation suitability tools. Based on their weight percentages (ratios in meq/l) the dominance of cations and anions was established as Na-Cl and Ca-SO₄ type. Results show that high hydraulic conductivity (10_?2 to 1 cm/s) of the sandy aquifer enhanced the vertical recharge leading to major spatial distribution suitable for irrigation use in post-monsoon. The overexploitation of groundwater resources has generated reversal of hydraulic gradient enhancing salinity intrusion from marine sources in pre-monsoon. Further, the Differential Global Positioning System (DGPS) survey and water level measurements are assessed to demarcate the study area into zones of water table ‘above mean sea level (amsl)’ and ‘below mean sea level (bmsl)’. It was deduced that, the industrial effluent and seawater were the prime sources of groundwater salinity of water table ‘amsl’ and ‘bmsl’ zones, respectively. The area up to 600 m from marine source is found vulnerable which is falling under ‘Unsuitable’ category of irrigation classifications. The remedial measures are also framed to protect further extension of aquifer vulnerability for sustainable agriculture.     

Hydrochemical characterization and suitability assessment of groundwater in Baga–Calangute stretch of Goa,India

The present study is the first attempt to determine the suitability of groundwater for drinking and irrigation in the Baga–Calangute stretch of Goa. The suitability of groundwater for potable use was assessed by comparing observed values against standards prescribed by the Bureau of Indian Standards, and the quality was classified based on the Weighted Arithmetic Water Quality Index. Most of the groundwater samples (90%) were found to be suitable for drinking except for hardness, chlorides, and nitrates. The percent sodium (%Na), residual sodium carbonate, soluble sodium percentage, sodium adsorption ratio, Kelly’s ratio, and Permeability Index were found to be within the prescribed limits for irrigation purposes. The major mechanism controlling groundwater chemistry, i.e., rock–water interaction, was also studied, and it was found that silicate weathering plays a major role in the dissolution of minerals. Based on the hydrochemical characterization, the water was observed to be of the Ca–Na–SO₄ composition type except for one sample which was of the Na–Cl composition type. Classification of the meteoric genesis suggested that the groundwater in surficial aquifers in the region had a deep meteoric percolation, and its chemistry is regulated by rock–water interaction.     

Satellite-based assessment of large-scale land cover change in Asian arid regions in the period of 2001–2009

Arid regions in Asia are commonly characterized by rapidly growing populations with limited land resources and varying rainfall frequencies under climatic change. Despite being one of the most important environmental challenges in Asia, the changing aridity in this region, particularly due to large-scale land cover change, has not been well documented. In this study, we used rainfall data and a new land heterogeneity index to identify recent trend in land cover changes in the Asian arid regions. The result indicates a significant decreasing trend of barren lands and an increasing trend of vegetated lands. Although the potential land cover change is commonly believed to be strongly sensitive to rainfall change, such sensitivity has not been observed during the nine-year period (2001–2009) analyzed. Through the analyses of two separate periods (2001–2005 and 2005–2009), the sensitivity of rainfall to land cover change in arid regions is found to be dependent on the initial spatial heterogeneity of vegetated land cover. The approach used and the findings in this study represent an important step toward better understanding of large-scale land cover change in the Asian arid regions, and have the potential to predict future land cover change under various climate change scenarios.     

Development and application of Shannon’s entropy integrated information value model for landslide susceptibility assessment and zonation in Sikkim Himalayas in India

Natural Hazards - The state of Sikkim in India has many steep slopes and has been susceptible to landslides. Since 1968 there have been innumerable losses of lives and properties due to landslides....     

Approaches for tsunami risk assessment and application to the city of Cádiz, Spain

Tsunamis can represent a significant risk to the population and cause huge economic damage in many costal regions. In order to be able to identify risk hot spots and implement targeted risk reduction measures, decision makers need to have a clear picture of the risk situation in their countries or regions. This work reviews existing approaches for tsunami risk assessment and recommends a five-step process for assessing tsunami risk. As a case study, a qualitative risk assessment for a worst-case tsunami scenario was carried out to understand the tsunami risk to the population in Cádiz. Moreover, a sensitivity analysis of the tsunami hazard input parameters was performed as a strong influence of the variability of the input parameters on the resultant tsunami hazard and risk zonation maps was observed. The study shows that regardless of the assumptions made a non-negligible tsunami risk to Cádiz exists.     

Regional vulnerability assessment for debris flows in China—a CWS approach

Based on former conceptual models of vulnerability, this paper aims to improve the quantitative model for regional vulnerability assessment by analyzing in-depth the relation between vulnerability, exposure, coping capacity, and resilience. Taking the mountain settlements in the upper reaches of Min River, China, as a case study, the method of Contributing Weight Superposition (CWS) is applied in establishing both a model and a system for the vulnerability assessment of elements at risk. The CWS approach consists of 13 index factors including population, economic and road densities, building and farmland coverage, hazard-affected areas, urbanization rate, and GDP per capita. Accordingly, a debris flow hazard vulnerability zoning map was obtained and the assessment results show that the distribution of high and comparatively high vulnerability zones, where economic activities are considerably high, has a close correlation to the topography of the catchment and population characteristics. The results thus may serve as a pertinent guidance for settlement relocation, population distribution readjustment, and management to prevent and reduce hazards in the upper reaches of Min River and beyond.     

Regionalisation of the “intensity-duration-frequency” curves in Northern Algeria

The flood events observed during last years in the urban areas are subject of main interest for quantification of the hydro-climatic risks and climatic change to the regional scales. The establishment of a statistical relationship between the intensities of intense rains and the recurrence of these events allows us to determine the dimensions of the works according to a previously defined level of risk. They constitute today a leading tool for various users. This work concerns the study of the maximum annual rains, recorded at 49 stations in the northern Algeria. The objectives of this work are to determine the estimators who are the “intensity-duration-frequency” curves and to extract from these whole of information the b Montana climatic parameter to be regionalized for the calculating the river flow and for the dimensioning of the networks of cleansing in the event of insufficiency of data. Different durations going from 15 min to 24 h are studied. We utilised the collocated co-kriging as multivariate estimation method for interpolation in order to yield the space distribution maps of b Montana climatic parameter, with the benefit of using spatially correlated secondary variables, such as the digital elevation model and the distance from the coastline that are known at any localisation. All features led to choose the digital elevation model as covariate for interpolating b Montana values, yielding a better regionalisation of the studied climatic parameter. The geostatistical handling of b Montana values strictly related to auxiliary variables that constitute physical factors overcomes the data shortage in planning, managing and preventing the rain flood risk.     

Samovar: a thermomechanical code for modeling of geodynamic processes in the lithosphere—application to basin evolution

We present a new 2D finite difference code, Samovar, for high-resolution numerical modeling of complex geodynamic processes. Examples are collision of lithospheric plates (including mountain building and subduction) and lithosphere extension (including formation of sedimentary basins, regions of extended crust, and rift zones). The code models deformation of the lithosphere with viscoelastoplastic rheology, including erosion/sedimentation processes and formation of shear zones in areas of high stresses. It also models steady-state and transient conductive and advective thermal processes including partial melting and magma transport in the lithosphere. The thermal and mechanical parts of the code are tested for a series of physical problems with analytical solutions. We apply the code to geodynamic modeling by examining numerically the processes of lithosphere extension and basin formation. The results are directly applicable to the Basin and Range province, western USA, and demonstrate the roles of crust–mantle coupling, preexisting weakness zones, and erosion rate on the evolutionary trends of extending continental regions. Modeling of basin evolution indicates a critical role of syn-rift sedimentation on the basin depth and a governing role of Peierls deformation in cold lithospheric mantle. While the former may increase basin depth by 50%, the latter limits the depth of rift basins by preventing faulting in the subcrustal lithosphere.     

Imageries of the contested concepts “land grabbing” and “land transactions”: Implications for biofuels investments in Ghana

In Ghana, the contested concepts of “land grabbing” and “land transaction” are strategically applied by proponents of critical and win–win discourses respectively to describe outcomes of land deals. Using case study methods and discourse analysis, this paper explores four cases of biofuels investments in Ghana and the implications of the choice of concepts used to represent them. Proponents of the critical discourse use the “land grabbing” concept to invoke imageries of “illegality”, “theft” and “food insecurity” when describing land deals. Consequently, some biofuels investments have been hampered in their potential to generate profit and local employment. The biofuel investors in this study, whose projects have been labeled “land grabbing”, therefore switched to food production to downplay public scepticism. Proponents of the win–win discourse portray biofuels investments as “pro-poor” projects and use the “land transaction” concept to pre-empt possible public criticisms in the media and elsewhere. Such representations of these biofuels investments are therefore mainly intended to pre-empt criticisms or attract public praise. Some projects with potentially promising outcomes have thus been terminated, while others with problematic outcomes have continued to be promoted. In contexts characterized by weak land regulations and ambivalence towards large-scale agriculture, the trajectory and outcomes of biofuels investments are often influenced by land deal representations drawn from global discourses and how they interact with pre-existing local discourses.     

Research achievements and application in anaerobic treatment of organic solid wastes—— A review

1 IntroductionSolid wastes (SW) refer to all the wastes derivedfrom human and animal activities, which are normallysolid and are discarded as useless or unwanted (Juha-Heikki Tanskanen, 2000 ). Generally, the organicfraction accounts for more than 50% -60…     

Groundwater quality assessment and its suitability in Çeltikçi plain (Burdur/Turkey)

The Çeltikçi (Burdur) plain is located in the southwest of Turkey and is a semi-closed basin. Groundwater is densely used as drinking, irrigation and domestic water in the plain. Hydrogeochemical processes controlling groundwater chemistry and geochemical assessment of groundwater were investigated in the Çeltikçi (Burdur/Turkey) plain. In this study, groundwater samples for two seasons were analyzed and major ion chemistry of groundwater was researched to understand the groundwater geochemistry. Two major hydrochemical facies (Ca–HCO₃ and Ca–Mg–HCO₃) were determined in the area. Various graphical plots and multivariate statistical analysis were used for identifying the occurrence of different geochemical processes. In the study area, weathering is one of the key geochemical processes which controlled the solute concentration in groundwater. Chemical indexes such as sodium adsorption ratio, %Na, residual sodium carbonate, magnesium hazard and permeability index were calculated and results show that groundwater is suitable for irrigation purpose except for permeability index values. Concentrations of Mn, NO₃ and total hardness exceed the prescribed limits of WHO and are the major limiting parameters of groundwater use for potable and domestic purposes.     

Spatiotemporal relation of RADAR-derived land subsidence with groundwater and seismicity in Semnan—Iran

Natural Hazards - Due to excessive harvesting of underground water resources in many important aquifers inside Iran, ground subsidence is occurring at different speeds. In present study, InSAR...     

Development and application of diffusive gradients in thin films for determining inorganic arsenic concentrations in natural waters

In environmental systems arsenic exists in both inorganic and organic forms. These forms differ substantially with respect to their toxicity as inorganic forms of arsenic are generally more toxic than organic forms. A novel method for in-situ inorganic ar…     

A prototype system for space–time assessment of rainfall-induced shallow landslides in Italy

In the last decades, physically based distributed models turned out rather promising to achieve the space–time assessment of shallow landslides at large spatial scale. This technical note deals with the application of a physically based stability model named Shallow Landslides Instability Prediction (SLIP), which has been adopted by the Department of National Civil Protection of Italy as a prototype early warning system for rainfall-induced shallow landslides on national scale. The model is used as a main methodology to create space–time shallow landslide susceptibility maps based on a simple deterministic slope-stability approach, combined with high-resolution rainfall information and geographic information system-based geospatial datasets. The safety factor as an index to measure slope instability is modeled as function of topographic, geologic, geotechnical and hydrologic variables. Although the main aim of this work was to prove the operational viability of such model on a nationwide domain and some simplification are adopted at this stage, hind cast tests on some relevant case histories of shallow landslides occurred between October 2009 and October 2011 showed that the model has skill in representing both timing and location of those shallow landslides.     

Sobol’ sensitivity analysis of parameters in the common land model for simulation of water and energy fluxes

The water and energy transfer of land surface is complex due to its large spatial and temporal variability. The modeling and simulation is an important means to study land water and energy transfer, but most selection and analysis of model parameters are empirical and qualitative. This paper has proposed a method of quantitatively identifying the most influential parameters of Common Land Model through Sobol?? sensitivity analysis. Considering sensible heat flux as the model output, the first order and total sensitivity indices of 25 model input parameters are estimated using an improved Sobol?? method. The simulated results are resampled using a bootstrapping method and the corresponding sensitivity indices are calculated. Confidence intervals for the bootstrapping sensitivity indices are estimated by using a percentile method. The results show that the parameters phi0 and porsl are the most important parameters, followed by ref(2,1), tran(2,1) and bsw. Five out of 25 parameters need to have an accurate evaluation, while the other parameters are fixed to a certain value. The sensitivity indices of parameters phi0 and porsl are decreasing after precipitation, while the sensitivity indices of parameters tran(2, 1) and ref(2, 1) are increasing after precipitation.     

Ecological risk assessment for heavy metal contamination of a new consideration—Agricultural soils

The contamination of soils has a direct impact on human health. The ecological risk assessment for heavy metal contamination of agricultural soils (ERAHMCA) is of vital importance. Although the overall concentrations of PTEs in the soils are usually taken into consideration a important factor of assessment for PTEs contamination, this study, by taking it into consideration that the main-path for ecological risk of heavy metal contamination of agricultural soil is soil-vegetation-man, intr…     

Energetic and spatial characterization of seismicity in the Algeria–Morocco region

We estimate the energetic and spatial characteristics of seismicity in the Algeria–Morocco region using a variety of seismic and statistical parameters, as a first step in a detailed investigation of regional seismic hazard. We divide the region into five seismotectonic regions, comprising the most important tectonic domains in the studied area: the Moroccan Meseta, the Rif, the Tell, the High Plateau, and the Atlas. Characteristic seismic hazard parameters, including the Gutenberg–Richter b-value, mean seismic activity rate, and maximum possible earthquake magnitude, were computed using an extension of the Aki–Utsu procedure for incomplete earthquake catalogs for each domain, based on recent earthquake catalogs compiled for northern Morocco and northern Algeria. Gutenberg–Richter b-values for each zone were initially estimated using the approach of Weichert (Bull Seismol Soc Am 70:1337–1346, 1980): the estimated b-values are 1.04 ± 0.04, 0.93 ± 0.10, 0.72 ± 0.03, 0.87 ± 0.02, and 0.77 ± 0.02 for the Atlas, Meseta, High Plateau, Rif, and Tell seismogenic zones, respectively. The fractal dimension D ₂ was also estimated for each zone. From the ratio D ₂/b, it appears that the Tell and Rif zones, with ratios of 2.09 and 2.12, respectively, have the highest potential earthquake hazard in the region. The Gutenberg–Richter relationship analysis allows us to derive that in the Tell and Rif, the number of earthquake with magnitude above Mw 4.0, since 1925 normalized to decade and to square cell with 100-km sides is equal to 2.6 and 1.91, respectively. This study provides the first detailed information about the potential seismicity of these large domains, including maximum regional magnitudes, characteristics of spatial clustering, and distribution of seismic energy release.     

Energetic and spatial characterization of seismicity in the Algeria–Morocco region

We estimate the energetic and spatial characteristics of seismicity in the Algeria–Morocco region using a variety of seismic and statistical parameters, as a first step in a detailed investigation of regional seismic hazard. We divide the region into five seismotectonic regions, comprising the most important tectonic domains in the studied area: the Moroccan Meseta, the Rif, the Tell, the High Plateau, and the Atlas. Characteristic seismic hazard parameters, including the Gutenberg–Richter b-value, mean seismic activity rate, and maximum possible earthquake magnitude, were computed using an extension of the Aki–Utsu procedure for incomplete earthquake catalogs for each domain, based on recent earthquake catalogs compiled for northern Morocco and northern Algeria. Gutenberg–Richter b-values for each zone were initially estimated using the approach of Weichert (Bull Seismol Soc Am 70:1337–1346, 1980): the estimated b-values are 1.04 ± 0.04, 0.93 ± 0.10, 0.72 ± 0.03, 0.87 ± 0.02, and 0.77 ± 0.02 for the Atlas, Meseta, High Plateau, Rif, and Tell seismogenic zones, respectively. The fractal dimension D ₂ was also estimated for each zone. From the ratio D ₂/b, it appears that the Tell and Rif zones, with ratios of 2.09 and 2.12, respectively, have the highest potential earthquake hazard in the region. The Gutenberg–Richter relationship analysis allows us to derive that in the Tell and Rif, the number of earthquake with magnitude above Mw 4.0, since 1925 normalized to decade and to square cell with 100-km sides is equal to 2.6 and 1.91, respectively. This study provides the first detailed information about the potential seismicity of these large domains, including maximum regional magnitudes, characteristics of spatial clustering, and distribution of seismic energy release.