Local Rainwater Research Articles

Development of a water resources utilization model and optimization of the patterns of rice genotypes with system dynamics approach

The system dynamics approach was conducted to optimize genotype patterns in various climatic and water availability scenarios, to address the water productivity improvement of the Sefidrood irrigation network. The studied cropping pattern scenarios were SD1 (the continuation of current trends), SD2 (the reduction in the cultivated area), SD3 (replacing modified crops on an annual basis), and SD4 (increasing the annual cultivated area of Hashemi type rice). Moreover, the impacts of irrigation efficiency improvements and water resources management strategies on the physical and economic water productivity indices were studied. The results indicated that the SD3 scenario has the most positive impact on water productivity with 0.45 kg/m3 increases. However, a questionnaire survey revealed that this scenario that belongs to the increase in the modified genotype area cannot be recommended due to cooking quality and low prices. The Hashemi genotype was the favorite rice among farmers and experts. Also, analyzing the irrigation efficiency improvement scenario showed that this strategy has a limited impact on the physical and economic water productivity. Increasing the capacity of local rainwater storage pools, Ab-bandans, and increasing the drainage water reuse had the highest water productivity in the condition of river water reduction and uncertain water availability.

Population tracing analysis and overwintering of Bactrocera dorsalis (Hendel) in newly occurring areas in China

AbstractBactrocera dorsalis (Hendel), a very destructive insect pest of many fruits and vegetables, is widespread in the tropical and subtropical zones of Asia. However, the northward extension of B. dorsalis has been reported in China recently. It is crucial to determine the origin of new populations and to investigate the invasive potential of the species. Here, we investigated B. dorsalis in Nanyang, Henan Province and Heze, Shandong Province using a combined methodological approach. We first detected the hydrogen stable isotope ratios (δ2H) of B. dorsalis samples. The results showed that the δ2H values for B. dorsalis from Nanyang were consistent with those of the local rainwater. In contrast, the samples from Heze were inconsistent with those of the rainwater in Heze. We then sequenced the complete mitochondrial cytochrome oxidase I (mtDNA COI) from the same fruit fly samples for haplotype diversity and phylogenetic analyses. We found a close genetic relationship between the Heze population and Nanyang, Hefei, Sanya, Fuyang and Wuhan populations. Besides, we surveyed the fruit's origin in the wholesale market, and concluded that B. dorsalis trapped in Heze might have come from Hainan and Zhejiang in China. Finally, overwintering potential experiments showed that a small number of pupae could survive during the test periods in Nanyang, whereas no pupae could survive in Heze. Overall, this study reveals that the Nanyang population of B. dorsalis were resident, whereas the Heze population did not colonize and were repeated entries from other areas every spring.

Quality of Harvested Rainwater from a Green and a Bitumen Roof in an Air Polluted Region

A one-year study was conducted to evaluate the impact of air pollution and roof coating on runoff quality. An existing 440 sq meter bitumen roof of a single-story building was coated with an extensive green roof layer on one half. Rainfall and runoff samples from both roofs were collected during 11 rainfall events after the separation of the first flush. The study monitored several key parameters, including pH, electrical conductivity (EC), turbidity, chemical oxygen demand (COD), ammonium nitrogen, nitrate nitrogen, and phosphates. The study revealed that both types of roofs altered the rainfall quality, but the changes caused by the green roof were more substantial. Although the retention of runoff from green roofs has a widely acknowledged positive impact on collecting systems, our study shows that green roofs also result in a 7.5-fold increase in COD concentrations, a 5.4-fold increase in the sum of ammonium and nitrate nitrogen, and a 2.3-fold increase in phosphates compared to bitumen roofs. A clear link between the quality of rainwater/runoff and air pollution was not established. The study's findings will aid in the development and management of local rainwater harvesting systems and enhance global understanding of the primary quality parameters of various roof types, particularly in regions with air pollution. Doi: 10.28991/CEJ-2024-010-05-015 Full Text: PDF

Groundwater-surface water interactions in a semi-arid irrigated agricultural valley: A hydrometric and tracer-aided approach

The purpose of this study was to assess hydrological controls (e.g., rainfall, irrigation practices, river discharge, dam operation, evaporation) on surface (SW)- ground water (GW) interactions in an irrigated valley within semi-arid Patagonia Argentina (−65.49 W, −43.29 S). We combined different sampling designs (watershed/sub-watershed scales, longitudinal and monthly samplings) from 2015 to 2019 to investigate the temporal and spatial variation of hydrometrics, electrical conductivity (EC) and stable isotope composition of surface and ground water. Results showed that plant transpiration in the upper basin, evaporation in the middle basin and the reservoir dynamics modified water salinity and left an imprint in stable isotopes. Water tables in the irrigated valley were high (0.5–2 m level from soil surface) and presented higher salinity than river water. Groundwater salinity, temporal variation of water table levels and stable isotopes suggested that groundwater is subjected to evaporation, is recharged from field seepage and, at a lesser extent, from local rainwater. River salinity increased downstream of the irrigated valley during the whole study period (3 years), showing the effects of agriculture and urbanization. EC also responded to the opening and closing of irrigation channels. EC and daily discharge statistical analysis revealed that groundwater recharge the stream below a threshold discharge of 26 m.s−1; with river salinity increasing linearly as daily discharge decrease. This study illustrates the deep modifications that agricultural systems, mainly surface irrigation, produce on semiarid watersheds. Given that SW and GW components are currently not isolated and flow regulation and irrigation practices are playing a critical role in soil quality and river chemistry at low flow conditions, a conjunctive water management strategy must be implemented in order to prevent further land and water quality degradation.

The financial aspect of local rainwater management on a wind farm

The financial aspect of local rainwater management on a wind farm

MONSOON RAINWATER CHEMISTRY AND ITS POTABLE STATUS: A CASE STUDY FROM SOUTH-EAST COASTAL BELT OF BANGLADESH

Major ion chemistry of rain water from a selected area has been determined. The rainwater is slightly acidic as in the case with rain waters globally. All major cations and anions are present in delectable amount. HCO3- is the dominant anion in the study area and its concentration generally decreases subsequent showers. Such decrease in concentration also is noticed in case of other cations and anions. The influence of seawater in the chemistry of rain water is quite significant in the present study. Although at the beginning of the first rainfall event, bicarbonate ion predominates, its concentration gradually diminishes with the passage of time, but sometimes erratic values are noticed and even in the last fraction of a continuous rainfall. Most of the other cations and anions behave similarly to that of bicarbonate ion. Concentrations of various chemical constituents are not constant in local rainwater and it varies from rainfall event to event. It is also dependent on the various local meteorological parameters. Different calculated weight ratios such as SO42-/Na+ etc. are compared with seawater. The results indicate the influence of southern seawater to a great extent. Moreover, non-marine origin from the onshore such as dust particles, automobile exhaust, smoke etc. also contribute significant amount of the dissolved constituents in the rainwater. A household survey was conducted to know about the water using pattern of the study area. However the calculated major cations and anions are below the potability status of DoE standard which is not viable for human health.

Phytic acid functionalized magnetic adsorbents for facile enrichment of trace rare earth elements in environmental water, digested atmospheric particulates and the extracts followed by inductively coupled plasma mass spectrometry detection

Phytic acid (PA) functionalized magnetic adsorbents was synthesized through simple process. The functionalized sorbents are featured with core-shell structure, good magnetism, chemical stability, selectivity, and fast adsorption/desorption dynamics for the preconcentration of trace rare earth elements (REEs). With the aid of inductively coupled plasma mass spectrometry detection, the prepared Fe3O4@SiO2@PA sorbents were employed for the separation and enrichment of 15 REEs from environmental water and atmospheric particulates with different sizes. Under the optimal conditions, the method presented an enrichment factor of 300-fold and low detection limits (0.002–1.1 ng/L) for 15 REEs, with the relative standard deviations of 1.4–4.4%. Environmental water samples were analyzed by the proposed method, and 15 REEs of 0.08–5.80 ng/L were found in local rainwater and river water. The REEs concentration in locally collected fine particulate matter was 0.01–0.93 ng/m3, 0.03–1.70 ng/m3 and 0.03–2.47 ng/m3 of REEs were found in inhalable particulate matter and total suspended particulate samples, respectively. The bioaccessibility of REEs in PM2.5 was evaluated by using Gamble's solution extraction, which was calculated to be 0.73–5.46%.

Groundwater Recharge Area Based on Hydrochemical and Environmental Isotopes Analysis in the South Bandung Volcanic Area

The determination of recharge areas needs to support the groundwater conservation in the southern volcanic Bandung area. This study aims to determine the recharge area based on environmental isotopes and hydrochemical. A sampling of 26 groundwater was carried out at springs, dug wells, and drilling wells. The variation in groundwater chemistry principally is controlled by a combination of ion exchange, silicate weathering, calcite, and dolomite dissolution of minerals. The hydrochemical facies were CaCl, CaMgCl, CaMgHCO3, CaHCO3, and NaKHCO3. The CaHCO3 facies describe moderate groundwater flows. The NaKHCO3 facies shows the mixing of shallow and deep groundwater. The recharge area in the central, proximal, and medial facies zone consists of 3 groups. Group I is considered water originating from local rainwater infiltration; Group II is considered the infiltration elevation which ranges from 980–1230 m asl; Group III estimated to be derived from the recharge elevation between 750–970 m asl, Group IV are more likely to show symptoms of evaporation or interaction with surface water. The discharge area is characterized by less active groundwater circulation, with dominant HCO3– and TDS value in the distal facies zone. Hydrochemical variation helped the identification of recharge areas in the volcanic facies.

Controls on the 36Cl/Cl input ratio of paleo-groundwater in arid environments: New evidence from 81Kr/Kr data

Measurements of the long-lived 81Kr and 36Cl radioisotopes in groundwater from the Negev Desert (Israel) were used to assess the 36Cl/Cl input ratios and Cl− contents for paleorecharge into the Nubian Sandstone Aquifer (NSA). The reconstructed Cl− content of the recharge flux was on the order of 300–400 mg/L. An initial 36Cl/Cl ratio of 50 × 10−15 was assessed for the groundwater replenishment in the Negev Desert since the late Pleistocene, in agreement with the 36Cl/Cl ratios in recent local rainwater. This is despite possible changes in the climatic conditions and the 36Cl production rates in the atmosphere over this timeframe. This similarity in values is explained by the major role played by the erosion and weathering of near-surface materials in the desert environment that dominate the hydrochemistry of rains, floods, and the consequent groundwater recharge. Spatial variation in the reconstructed initial 36Cl/Cl ratio is accounted for by the differences in the mineral aerosol sources for specific recharge areas of the NSA. Accordingly, regional variations in the 36Cl/Cl input in groundwater reservoirs surrounding the Mediterranean Sea indicate various processes that govern the 36Cl/Cl system. Finally, the results of this study highlight the great advantage of integrating 81Kr age information in evaluating the initial 36Cl/Cl and Cl− input, which is essential for the calibration of 36Cl radioisotope as an available long-term dating tool for a given basin.

Hydrochemical and environmental isotopes analysis for characterizing a complex karst hydrogeological system of Watuputih area, Rembang, Central Java, Indonesia

The karst hydrogeology systems of the Watuputih Hills region of Central Java, Indonesia, have many springs with varying discharge and are composed of formations with complex geological structures. This work characterized the karst hydrogeology by studying 50 hydrogeological features (caves, springs and wells) and by analyzing the chemical-physical properties of groundwater in the field (pH, temperature, EC, HCO3−, 222Rn) and the major ions and stable isotopes of the groundwater samples in the laboratory, along with the stable isotope content of rainwater sampled over 1 year. Hierarchical cluster analysis of the water samples identified three hydrochemical groups: groundwater flowing through carbonate rocks (groups C2 and C3), through quartz sandstones and volcanic rocks (group C4), and through carbonate rocks and the siliciclastic rocks (quartz sandstones) underneath them (group C1). Springs with large discharge, typified as artesian fault-guided springs, were categorized into group C1. These springs are Sumbersemen, Brubulan Tahunan, and Brubulan Pesucen, with mean discharges of 1,516, 165, and 95 L/s, respectively. Based on the results of the stable isotope analysis, the d-excess calculation and the 222Rn concentrations, groups C2, C3, and C4 associate with shallow groundwater systems that dominantly flow through pores, whereas group C1 associates with a deep groundwater system controlled by geological structure. The geological structure also determines the groundwater flow in the cave streams. The shallow groundwater system is sourced by local rainwater, while the deep groundwater system displays a relationship with the groundwater in the northern hills at an elevation >375 m above sea level.

Fog Interception Maintains a Major Waterfall Landscape in Southwest China Revealed by Isotopic Signatures

AbstractFog water intercepted by the forest canopy can be an important extra water input for the near‐surface ecosystems in some tropical montane or coastal Mediterranean zones. However, the significance of fog interception on groundwater systems needs to be further studied. An inland subtropical cloud forest in the southwest of China is covered by frequent fog/mist and has thousands of waterfalls with significant flow. To verify the role of fog interception to the local hydrological budget, field investigations and sampling campaigns were carried out over different temporal and spatial scales. Compared with local rainwater, surface water and spring water in the forest were more enriched in 2H and 18O isotopes and had much higher d‐excess, indicating that fog water produced by inland evapotranspiration is a key water supplier. During the dry period, waterfalls are sustained by baseflow, of which a considerable fraction comes from fog interception recharge. The waterfall landscape maintained by fog drip water in this study area represents an example of the important contribution of fog water to some subtropical montane groundwater systems.

Groundwater recharge sites and pollution sources in the wine-producing Guadalupe Valley (Mexico): Restrictions and mixing prior to transfer of reclaimed water from the US-México border

Rapid depletion of aquifers in semiarid and arid regions threatens water security. This holds true especially in emerging countries where insufficient knowledge about aquifer systems precludes the implementation of advanced management measures, such as managed aquifer recharge. This study deals with the generation of baseline knowledge for the assessment of aquifers in arid and semiarid regions where artificial recharge with reclaimed water gains increasing impetus. The Guadalupe aquifer in Baja California provides water to 57% of the Mexican wine industry. Recent plans foresee a partial replenishment of its depleted groundwater reserves by transferring treated waste water from the Mexico-USA border for irrigation. The aquifer demonstrated to have a rapid response by rising the water table of about +20 m in relation to natural recharge under an intense rainfall period of 236 mm. Two predominant recharge sources were identified based on a geochemical multi-tracer approach: (a) water of modern age (<5 yr, >1.8 TU) and mixed water of recent-submodern age (3H 0.8–1.8 TU), and (b) sub-modern waters that were recharged before 1952 (3H < 0.5 TU). Water of the first type originate in the main Guadalupe stream, which has a more depleted average δ18O isotope value (−7.8‰) than average local rainwater (−2.0‰). The stream water initially has a Na-HCO3 composition and recharges the entire Calafia zone and most groundwater along the riverbed across the valley. Water of the second type is mostly derived from hill-slope groundwater that has a stable isotope composition of mixed local rainwater and a NaCl composition. High total dissolved solids >2 g l−1 together with enriched NO3− and Se concentrations characterize groundwater in the downstream the Porvenir zone. The geochemical age of this older, hill-slope groundwater suggests that its replenishment takes at least several decades when it becomes exhausted.

Identification of groundwater origin using environmental isotopes (18O and 2H) in the upper catchment of Ikopa, district Antananarivo

The upper catchment of Ikopa has great potential for surface or sub-surface water resources. The Ikopa River plays an important role in the water supply of the plain of Antananarivo. Knowing that surface water is abundant but exposed to the high risk of pollution, and groundwater remains less exploited because of the insufficiency of the study concerning the recharge and the sources of their mineralization. The objective of this research is to use the isotope method to characterize groundwater to determine their origin and recharge process. The results of chemical analysis show three different facies type of groundwater which dominated by the sodium, nitrate and chloride ions. The isotopic compositions of the waters sampled vary respectively from -7.25‰ to 5-.09‰ for δ18O and from -46.9‰ to -24.7‰ for δ2H. water form the lakes are more enriched compared to those rivers and groundwater. The diagram δ18O- δ2H shows that groundwater is recharged from local rainwater but undergoes low evaporation before infiltration. However, the results obtained from the parameters measured in situ show that a lateral recharge of groundwater from the streams feeds the neighboring aquifers. Lakes are fed by run-off during the rainy season.

Chemical weathering rates of clastic sedimentary rocks from the Paraná Basin in the Paulista Peripheral Depression, Brazil

The chemical weathering plays an important role in the processes of surface geochemistry, which is fundamental to understand the landscape evolution. The Paraná Basin is an intracratonic sedimentary basin developed on the South American platform from Paleozoic to Cenozoic, with area of 1.5 × 106 km2 and 5000 km3 of clastic sediments and igneous rocks. The main clastic sedimentary rocks in the Paraná Basin are sandstones and mudstones. Surprisingly, there are no studies assessing the chemical weathering rates of clastic sedimentary rocks from the Paraná Basin under tropical climate conditions in Brazil or in South America. Thus, two small watersheds were chosen to assess the chemical weathering rates of clastic sedimentary rocks from the Paraná Basin in the Paulista Peripheral Depression (São Paulo State, Brazil), i.e. the Monjolo Grande and Jacutinga stream basins. The chemical composition of rain and surface waters, as well as the chemical and mineralogical composition of the fresh rocks (sandstones and mudstones) and soil (horizon C) were characterized. The instantaneous daily flux indicates that ca. 60% of the dissolved solids loads are carried from October to March in both watersheds. The natural fluxes due to chemical weathering (Fw) were ca. 4.5 t km−2 yr−1, with a mixed of local rainwater and chemical weathering of sandstones and mudstones controlling the surface waters composition. The possible chemical weathering processes of sandstones and mudstones occur by quartz dissolution and partial hydrolysis (monossialitization) of albite, microcline and illite, respectively. The chemical weathering rates were of 0.3 and 0.8 m Myr−1 for the Monjolo Grande and Jacutinga Streams basin, respectively, confirming the lower chemical weathering rates for clastic sedimentary rocks in relation to basalts (Paraná CFB) of the Paraná Basin and for the igneous and metamorphic rocks of the Ribeira Belt, other important geological units in the São Paulo State. In addition, these chemical weathering rates are also lower than the suggested for other rock types elsewhere, i.e., carbonates, basalts, granites, schist, gneisses or alkaline rocks. Finally, the effect of climate on [SiO2] was demonstrated, also described in basaltic and granitic watersheds, suggesting that the chemical weathering of sandstones and mudstones are more effective in the wet season.

Quantification of ZnO nanoparticles and other Zn containing colloids in natural waters using a high sensitivity single particle ICP-MS

Inductively coupled plasma mass spectrometry in single particle mode (SP-ICP-MS) is becoming a powerful tool of choice for the quantification and characterization of metallic nanoparticles (NP) at very low concentrations. Nonetheless, this technique has relatively high size detection limits for highly soluble nanoparticles (e.g. ZnO, CuO) or NP that are measured in the presence of high background concentrations of dissolved metal. In order to evaluate whether SP-ICP-MS could be used to measure a soluble NP under environmentally relevant conditions, an ion-exchange column (IEC) was coupled to a highly-sensitive sector-field ICP-MS (IEC-SP-ICP-MS) and then used to detect both spiked ZnO NP and natural Zn containing colloids in natural waters. The use of an ion exchange column, short dwell times (50 µs) and a high sensitivity instrument gave size detection limits for the measurement of ZnO NP of ca. 8.2 nm in pure water, 14.3 nm in a river water and 17.7 nm in a rainwater. IEC-SP-ICP-MS measured ca. 4.4 × 105 mL−1 zinc containing particles in a river water sample and ca. 1.0 × 105 mL−1 particles in a local rainwater.

Natural Isotopes Identify Changes in Groundwater Flows Affecting Wetland Vegetation in the Drentsche Aa Brook Valley, The Netherlands

This study uses groundwater isotopes and ion composition to verify model simulations and ecohydrological studies in the Drentsche Aa nature reserve in The Netherlands, which is representative for the northwestern wetland areas in the Ice Marginal Landscape zone. At eight field sites, a total of 24 samples were analysed for their 13 C, 14 C, 2 H, and 18 O isotopes and ionic composition. The isotopes indicate that most of the fen peatlands in the area depend on the exfiltration of sub-regional groundwater flows, which confirmed the previous model simulations and ecohydrological studies. At three sites, isotopes and ionic composition indicate that the groundwater from the sub-regional system has been replaced by local infiltrated rainwater, due to nearby groundwater abstractions for drinking water, which influenced the success rates of the restoration measures. Furthermore, the evidence from chloride and 14 C contents was found to indicate the presence of more saline groundwater, which are influenced by the groundwater flows near salt diapirs. Groundwater abstractions may enhance the upward flow of the saline groundwater to eventually exfiltrate at the wetlands, affecting the biodiversity of the nature reserve.

Hydrochemical processes, variability and natural background levels of Arsenic in groundwater of northeastern Mendoza, Argentina

Northeastern Mendoza is an arid area dominated by stabilized dunes and paleochannels. Groundwater is the main source of water for domestic and subsistence economy. Two types of wells are used for groundwater withdrawal. Wells operated by conventional windmills or pumps (Ws) and local traditional bucket wells operated manually (BWs). These wells are drugged a few cm below the water table, normally with a diameter of 1 m, remain always open and are located near corrals. The aim of this study was to evaluate the processes that control As in groundwater used As drinking water by rural communities. The study approach included an assessment of the natural as background levels and the use of environmental isotopes (δ18O and δ2H) to determine the origin of groundwater and improve the conceptual model for groundwater flow. Significant statistical differences were found between the chemical features of groundwater from Ws and BWs. The conceptual hydrogeologic model supported by isotopic data indicated that groundwater recharge was from the main Mendoza/Tunuyan Rivers in remote areas and that local rainwater recharge is negligible. The isotopic data suggests that a faster groundwater flow recharge could occur without any influence of a previous evaporation process. The natural As background level was 104 µg/L, with a range of between 8.6 and 394 µg/L. The average As concentration in Ws was 114 µg/L. Water from BWs showed higher average As concentration of 235 µg/L with a higher dispersion, high HCO3−, NO3− PO 4 −3 and Cl− concentrations, and the lowest concentrations of O2 with greater turbidity than groundwater from Ws. The increase in As concentrations in groundwater of NE Mendoza is not related to evaporation processes despite arid climatic conditions. According to the oxidizing environment in the aquifer, high pH and very fine sediments, adsorption–desorption processes from solid surfaces were the determining factors for the availability and spatial variability of As in groundwater. Spatial variability was related to type of well rather than to geomorphologic units or to flow direction. The design of bucket wells, near corrals, allows the input of windblown sediments and leachate from livestock units creating point sources of As contamination in water used for human consumption.

Seasonal characteristics of the chemical composition of rainwaters from Salta city, NW Argentina

Major ions, pH and electrical conductivity (EC) were analyzed in rainwater samples collected at Salta city (NW Argentina) during the summer seasons of years 2010–2011 and 2011–2012. Precipitations in the area are characterized by low total dissolved load and slightly acidic pH. The pH values are in agreement with low concentrations of anthropogenic acid species such as NO3− and SO42− and consistent with a low urban development. Data indicate that the high concentrations of dissolved Ca are probably associated with the existence of marble quarry mining in the valley. According to a below-cloud process, it is observed that during the dry season, dust particles and contaminants are concentrated in the lower troposphere and washed-out immediately after a rainfall occurred. This process is in part responsible for the chemical composition of the local rainwater. Apart from quarry mining activity, the area does not have significant extra atmospheric pollution linked to anthropogenic sources. The new data permit to establish the baseline of the chemical composition of the local rainwater.

Chemical and isotopic investigations (δ18O, δ2H, 3H, 87Sr/86Sr) to define groundwater processes occurring in a deep-seated landslide in flysch

Deep-seated landslides are complex systems. In many cases, multidisciplinary studies are necessary to unravel the key hydrological features that can influence their evolution in space and time. The deep-seated Berceto landslide, in the northern Apennines of Italy, has been investigated in order to define the origin and geochemical evolution of groundwater (GW), to identify the slope system hydrological boundary, and to highlight the GW flow paths, transit time and transfer modalities inside the landslide body. This research is based on a multidisciplinary approach that involves monitoring GW levels, obtaining analyses of water chemistry and stable and unstable isotopes (δ18O-δ2H, 3H, 87Sr/86Sr), performing soil leaching tests, geochemical modelling (PHREEQC), and principal component analysis (PCA). The results of δ18O-δ2H and 87Sr/86Sr analyses show that the source of GW recharge in the Berceto landslide is local rainwater, and external contributions from a local stream can be excluded. In the landslide body, two GW hydrotypes (Ca-HCO3 and Na-HCO3) are identified, and the results of PHREEQC and PCA confirm that the chemical features of the GW depend on water–rock interaction processes occurring inside the landslide. The 3H content suggests a recent origin for GW and appears to highlight mixing between shallow and deep GW aliquots. The 3H content and GW levels data confirm that shallow GW is mainly controlled by a mass transfer mechanism. The 3H analyses with GW levels also indicate that only deep GW is controlled by a pressure transfer mechanism, and this mechanism is likely the main influence on the landslide kinematics.

Wet precipitation in northern Argentina: chemical characterization of soluble components in the Lerma Valley, Salta.

Soluble components in rainwater were studied in Valle de Lerma (Salta-Argentina). The studied area is located in the central south area of Salta Province in the Cordillera Oriental region, Northwest Argentina. The largest urban area corresponds to Salta city, where sample collection and analysis of rainwater were performed between 2009 and 2012 periods. Conductivity and pH were measured on each sample, and major (Cl-, NO3-, SO42-, Na, Mg, K, Ca) and trace elements (Al, Mn, Co, Cu, Zn, As, Sb, Ba and Pb) were analyzed. Multivariate statistical calculation and enrichment factor were applied to the obtained data. Atmospheric dust collected on the same sampling stations were used as reference for enrichment factors calculations. The local rainwater presents significant enrichment in Ca, Cu, Zn, As, Sb and Pb while statistical analyses indicate a direct correlation between them. The association of elements in the rainwater is similar to those for the polymetallic ore deposits outcropping in the Puna-Altiplano region, which are located to west of the study area. Satellite images as well as previous research indicates transport of atmospheric dust from the Puna-Altiplano to the East, where Valle de Lerma is suited. We conclude that this phenomenon gives a particular print to the chemistry of the rainwater in this area. This work corresponds to the first study of the rainwater’s chemical composition in this region. As Salta city lacks of significant air pollution or major sources from anthropogenic activities, the data on this paper establish the background of the Valle de Lerma rainwater geochemistry.