Floodplain Soils Research Articles

Reactive Iron, Not Fungal Community, Drives Organic Carbon Oxidation Potential in Floodplain Soils

Reactive Iron, Not Fungal Community, Drives Organic Carbon Oxidation Potential in Floodplain Soils

Geotechnical Characteristic Assessments of Floodplain Soils Using SCPTU Data in Nanjing, China

In order to improve the understanding of such floodplain sediments and determining the validity of the tests, an extensive series of multifunctional seismic piezocone tests with pore pressure dissipation phase have been performed and supplemented with conventional borings, standard penetration, laboratory testing, and so forth. Sounding results from SCPTU were used to determine the stratigraphic profiles and the soil characteristics of two anchorage sites. A comparison of the boring and laboratory results with the CPTU profiles showed that the CPTU provided excellent information on soil stratigraphy and good guidance for determination of behavior and engineering implications of recent Yangtze River floodplain. At an area where local correlations based on modern SCPTU do not exist, methods for estimating coefficient of earth pressure at rest (K0), hydraulic permeability (kh), and equivalent stiffness (G0) associated with bridge foundation design are presented, compared, and verified. Results also illustrate the complexity and variability of the floodplain stratigraphy and soil properties, which means that the suggestions in this study should be updated when more local experience is obtained. This case study suggests that such enhanced seismic piezocone test should be considered as a potential tool and the instrument of first choice in site characterization programs for design of bridges founded on complicated soils in China.

CHARACTERIZATION AND CLASSIFICATION OF SELECTED FLOODPLAIN SOILS FOR ARABLE CROP PRODUCTION IN ABAKALIKI SOUTHEASTERN NIGERIA

The study investigated soils of Abakaliki floodplains to characterize and classify them for sustainable use and management. Two profile pits each were dug in Mgbo-Abaja, Inyimagu and Nkwagu sites. Twenty-seven soil samples were collected from genetic horizons and sent to the laboratory for analysis. Results showed that soils were well drained except in Mgbo-Abaja 002 which was poorly drained. Colour varied from brown (10YR 5/3) to weak red (2.5YR 5/2), brown (10YR 4/3) to red (2.5YR 5/6) and dark yellowish brown (10YR 4/6) to reddish yellow (5YR 7/8) in Mgbo-Abaja, Inyimagu and Nkwagu respectively. Mottles were observed in MgboAbaja and Inyimagu profiles as a result of redoximorphism. Soils were sandy and ranged from 526 – 764 mg/kg. The pH was moderately acidic (5.80 – 6.07); mean values of base saturation (%) was moderate (21.03 – 45.31 %), electrical conductivity was low (< 4.0 dSm-1 ) and exchangeable sodium percent (ESP) was < 15 % except in Nkwagu profile 006. The soils were classified (USDA / WRB) as Typic Kandiaquults / Ferralic Gleysols (Mgbo-Abaja 001), Typic Kandiaquults / Cambic Gleysols (Mgbo-Abaja 002), Typic Kandiaquults / Ferralic Gleysols (Inyimagu 003), Grossarenic Kandiaqualfs / Ferralic Gleysols (Inyimagu 004), Typic Kandiaquults / Ferralic Acrisols (Nkwagu 005) and Grossarenic Kandiaqualfs / Ferralic Acrisols (Nkwagu 006). It is recommended that there should be creation of drainage channels to reduce water logging of sites, employ some management practices like liming, application of biochar technique, organic manure and inorganic fertilizer, which will boost the condition of soils and improve their fertility for arable crop production.

Integrated Nutrient Management Improves Productivity and Quality of Sugarcane (Saccharum Officinarum L.)

Sugarcane is one of the major important sugar yielding crops in Bangladesh. As an exhaustive crop, sugarcane removes a huge amount of plant nutrients from the soil. However, the combined use of organic and inorganic fertilizers can be a good approach to deal with nutrient depletion and promote sustainable crop production as well as improve soil health. Therefore, an attempt was made to identify the most fruitful and profitable integrated nutrient management on the aspects of growth, yield and quality of sugarcane in two consecutive growing seasons. Seven treatments: T1 = Control, T2 = 165:55:120:30:10:2.5:4 kg N:P:K:S:Mg:Zn:B ha−1, T3 = Poultry Litter (PL) at 5 t ha−1 + 95:51:87:9:10:2.5:4 kg N:P:K:S:Mg:Zn:B ha−1, T4 = Cow Dung (CD) at 15 t ha−1 + 36:52:60:17:10:2.5:4 kg N:P:K:S:Mg:Zn:B ha−1, T5 = Press Mud (PM) at 15 t ha−1 + 10:50:43:0:10:2.5:4 kg N:P:K:S:Mg:Zn:B ha−1, T6 = Mustard Oil Cake (MOC) at 0.5 t ha−1 + 140:54:115:25:10:2.5:4 kg N:P:K:S:Mg:Zn:B ha−1 and T7 = GM (Green Manure) at 5 t ha−1 + 140:53:100:28:10:2.5:4 kg N:P:K:S:Mg:Zn:B ha−1 were used in this experiment. Two years data showed that treatment T3 produced the maximum amount of tillers, total dry matter yield, millable sugarcane, cane yield and sugar yield, followed by the T4 treatment. The highest stalk heights were recorded in the T3 treatment, which was statistically similar to all other treatments except T1 and T2. The juice quality parameters viz., brix and pol in cane were found significant in treatment T3 while the highest purity was obtained in the T7 treatment. All the data of Jaggery (goor) quality parameters, the highest sucrose content, color transmittance, Jaggery (goor) recovery and the lowest ash content of Jaggery (goor) were observed in the T3 treatment, which was statistically similar to the T4 treatment in both seasons. The highest cost of production was obtained from the T6 treatment while the highest gross return, net return and BCR were recorded in the T3 treatment. No significant changes were found in one cycle of sugarcane in initial and post-harvest soil characteristics viz., pH, organic carbon, total N, and available P, K and S contents due to integrated use of different fertilizer packages. From the experimental findings, it was concluded that treatment T3 followed by T4 treatment would be the better productive and profitable integrated nutrient management technology for ensuring higher yields and quality of sugarcane without soil fertility degradation in the High Ganges River Floodplain soils.

The Response of Lentil (Lens culinaris Medik.) to Variety and Water Management under Old Brahmaputra Floodplain Soil of Bangladesh

The Response of Lentil (Lens culinaris Medik.) to Variety and Water Management under Old Brahmaputra Floodplain Soil of Bangladesh

Determination of Critical Limit of Zinc for Rice (Oryza sativa L.) and Potato (Solanum tuberosum L.) Cultivation in Floodplain Soils of Bangladesh

The critical limit for zinc (Zn) varies from 0.38 to 2 µg/g soil depending on the crop and soil type. However, the critical limit for Zn was not explored recently for rice and potato cultivation in the floodplain soils of Bangladesh. A pot experiment was conducted to determine the critical limits of Zn in soil and plants for rice and potato cultivation in two agro-ecological zones (AEZs) of Bangladesh. The soil samples were collected from 20 different locations of Old Brahmaputra and Active Ganges Floodplains with low (<0.9 µg/g), medium (0.91–1.80 µg/g) and high (>1.80 µg/g) Zn status. The experiment was laid out in a factorial and completely randomized design with two levels of Zn (Zn0 and Zn1 (0 and 4.87 kg/ha as Zn sulphate)) applied to 20 different soil samples for rice and potato cultivation using three replications. The critical limit of Zn was determined through a graphical and statistical approach and crops were harvested at the stem elongation (for rice) and tuber filling (for potato) stage. The critical limit of Zn in soil for rice was found to be 0.8 and 0.85 µg/g by graphical and statistical methods, respectively, and both methods revealed the same value (0.73 µg/g) for potato. The critical limit of Zn in rice plants was 23.9 and 24.32 µg/g, whereas in potato plants it was 27.1 and 26.61 µg/g, determined by graphical and statistical methods, respectively. The added Zn supply in soil significantly increased the dry matter accumulation in rice (by 5.6%) and potato (by 10%) compared to no Zn supply. Therefore, a significant positive response to added Zn could be observed on crop growth and yield when the Zn concentration remained below the mentioned critical level for rice and potato cultivation in floodplain soils of Bangladesh.

A comparison of activated carbon remediation success in floodplain soils contaminated with DDT and its metabolites using ex situ and in situ experimentation

Remediation of hydrophobic organic contaminants using activated carbon is an effective means by which to clean up contaminated areas. Predicting remediation success using laboratory experimentation with soil, however, is unclear. Current remediation efforts involving activated carbon addition to floodplain soils downstream of the Velsicol Chemical Corporation Superfund Site (VCCSS) have offered the opportunity to directly compare in situ activated carbon remediation with laboratory experimentation. The objective of the current study was to compare bioaccumulation of DDT, DDD, and DDE (DDX) residues by earthworms (Eisenia fetida) exposed to laboratory-aged (LA) or field-aged (FA) soils from four locations. Samples were evaluated at 0-, 3-, and 9-months post-remediation to determine the ability of laboratory studies to predict in situ remediation. Floodplain soils downstream from the VCCSS were amended with 2% by weight activated carbon in the field and the laboratory, and then aged for 3- or 9-months. At 0-, 3-, and 9-months bioaccumulation assays were conducted with LA and FA soils and tissue concentrations were compared within study sites. In both LA and FA soils, activated carbon caused significant reductions (37.01–92.94%) in bioaccumulated DDX in earthworms. Field-collected worms showed a similar trend in reduction of bioaccumulated DDX, suggesting activated carbon remediation was successful in reducing bioavailable DDX for native organisms within the floodplain soils. The rate of reduction in bioavailable DDX, however, was significantly faster in LA soils (β = −0.189, p < 0.0001) compared to FA soils (β = −0.054, p < 0.0038). Differences in temperature and methods of activated carbon incorporation between LA and FA soils may account for the differences in remediation rate, suggesting laboratory experiments may overpredict the extent or speed in which remediation occurs in the field. Therefore, use of laboratory studies in predicting success of activated carbon remediation may be most effective when conditions mimic field remediation as closely as possible.

Typology of rice-based cropping systems for improved soil carbon management: Capturing smallholder farming opportunities and constraints in Dinajpur, Bangladesh

Characterization of smallholder land resource endowment and cropping practice can assist in the implementation of a more tailored approach to Soil Carbon Management (SCM). Land resource and cropping practice data, stratified by soil physiography, was collected through a survey involving 83 farmers in four upazila of Dinajpur district, Bangladesh. The aim was to determine a farming system typology based on smallholder land resource endowment and cropping practices, and to consider the likelihood of soil carbon improvement under the typology. A Cluster Analysis was performed using data on seven variables that combined land resource (physiography, land type, landholding, farm size) and cropping practice (cropping system, cropping intensity, crop rotation) characteristics to determine a farming system typology. The resulting typology, referred to as Soil Carbon Improvement Likelihood (SCIL), identified three different farming system types. These were then assessed with regard to their potential for improving soil carbon in these systems. The most prevalent SCIL, Medium SCIL (Type 1, 42%) consists of the maize-rice, wheat-rice and veg.-rice cropping systems in the HL areas of the Piedmont plain, Floodplain and Terrace. It is managed with high fertilization, low crop rotation and low to medium crop residue retention. The next most prevalent SCIL, Low SCIL (Type 3, 30%) consists of a rice-rice cropping system in the HL and MHL areas of the Piedmont plain, Floodplain and Terrace, and is managed with medium fertilization, no crop rotation and limited residue retention. The least prevalent farming system type, the High SCIL (Type 2, 28%) consists of crop-diversified and mustard-rice cropping systems in the MHL areas of the Floodplain and Terrace, which is managed with high fertilization, crop rotation and high crop residue retention. This study showed that cropping systems with higher crop intensification and high retention of crop residue, on the Floodplain soil physiography and MHL land inundation type, provide the greatest opportunity for improved SCM, but were represented by less than one-third of the farmers (n = 20) in this survey. These farmers were also mainly private landholders. The typology presented here can potentially serve as a practical framework for delineating cropping systems and management under particular land resource settings to undertake more targeted innovations and SCM priorities in Rice-based Cropping Systems.

The Assessment of Heavy Metal Contamination of the Cultivated Soils in the Odra River Floodplain

Abstract The aim of the study was to assess the contamination of selected heavy metals in cultivated soils of the Odra river floodplain. The heavy metals Mn, Fe, Cu, Zn, Ni, Cd and Pb were determined in soil samples collected in the autumn of 2020 - after the vegetation period of plants from designated measurement points. Concentrations of the analytes were measured using an atomic absorption spectrometer (F-ASA). A comparison was made between concentrations of heavy metals in soil samples collected from areas flooded in 1997 and from areas flooded as a result of rainfall, snowmelt and winter floods. The results of the studies were compared with the data for soils taken from non-flooded areas. The studies confirmed enrichment of soils subjected to precipitation, snowmelt and winter floods in heavy metals. Also samples taken from two measurement points located on floodplains of the Odra river were characterised by high concentrations of Zn, Cd and Pb.

Biomass efficiency and productivity of soybean inoculated with Trichoderma / Eficiência de biomassa e produtividade de soja inoculada com Trichoderma

This work aimed to evaluate the efficiency of the product TrichoPlus (Trichoderma asperellum) as a plant growth promoter in soybean and the productive performance at the field in a floodplain in the municipality of Formoso do Araguaia, Tocantins, Brazil. Four treatments with different doses of the TrichoPlus product (2, 4, 6 and 8 g per kg of seeds) were used in the experiment, plus two treatments being a positive control with a commercial product based on Trichoderma asperellum and an absolute control (without inoculation). Biomass, stand and productivity data were evaluated. For the treatment with the TrichoPlus product, a powder formulation was used, with active ingredient based on Trichoderma asperellum 201, formulated with a minimum concentration of 2 x108 UFC g-1, having graphite in the composition as inert, being applied directly to the seeds before planting, aiming better adherence and protection of the Trichoderma in direct contact with the seed and protection right after planting. Significant results were observed for the treatments with different doses of TrichoPlus in the characteristics of biomass, stand maintenance and productivity. The best dose for productivity was achieved in 5.1 g kg-1 of seed, with gains 12.6 and 6.0% higher compared with the absolute control and positive control treatments, proving its effectiveness in promoting plant growth and, consequently, in the productivity, in the cultivation in floodplain soil.

Deposition and in-situ translocation of microplastics in floodplain soils

The microplastic (MP) contamination of oceans, freshwaters, and soils has become one of the major challenges within the Anthropocene. MP is transported in large quantities through river systems from land to sea and is deposited in river sediments and floodplains. As part of the river system, floodplains and their soils are known for their sink function with respect to sediments, nutrients, and pollutants. However, the questions remain: To what extend does this deposition occur in floodplain soils? Which spatial distribution of MP accumulations, resulting from possible environmental drivers, can be found? The present study analyzes the spatial distribution of large (L-MP, 2000–1000 μm) and medium (M-MP, 1000–500 μm) MP particles in floodplain soils of the Lahn River (Germany). Based on a geospatial sampling concept, the MP contents in floodplain soils are investigated down to a depth of 2 m through a combined method approach, including MP analyses, soil surveys, properties, and sediment dating. The analysis of the plastic particles was carried out by density separation, visual fluorescence identification, and ATR-FTIR analysis. In addition, grain-size analyses and 210Pb and 137Cs dating were performed to reconstruct the MP deposition conditions. The results prove a more frequent accumulation of MP in upper floodplain soils (0–50 cm) deposited by flood dynamics since the 1960s than in subsoils. The first MP detection to a depth of 2 m and below recent (>1960) sediment accumulation indicates in-situ vertical transfer of mobile MP particles through natural processes (e.g., preferential flow, bioturbation). Furthermore, the role of MP as a potential marker of the Anthropocene is assessed. This study advances our understanding of the deposition and relocation of MP at the aquatic-terrestrial interface.

Heavy metal concentrations in floodplain soils of the Innerste River and in leaves of wild blackberries (Rubus fruticosus L. agg.) growing within and outside the floodplain: the legacy of historical mining activities in the Harz Mountains (Germany)

We studied heavy metal levels in floodplain soils of the Innerste River in northern Germany and in the leaves of wild blackberries (Rubus fruticosus L. agg.) growing within and in adjacent areas outside the river floodplain. Heavy metal contamination of the Innerste floodplain is a legacy of historical metal ore mining, processing, and smelting in the Harz Mountains. The heavy metal (Cd, Pb, Zn, Cu, Ni, and Cr) contents of previously studied soil samples from eleven floodplain sites along the Innerste River were re-analyzed statistically, and the levels of these metals in blackberry leaves were determined at five sites. Mean concentrations in the floodplain soils were elevated by factors of 4.59 to 28.5 for Cd, 13.03 to 158.21 for Pb, 5.66 to 45.83 for Zn, and 1.1–14.81 for Cu relative to the precautionary limits for soils stipulated by the German Federal Soil Protection and Contaminated Sites Ordinance. Cadmium, Pb, Zn, Cu, and Ni levels in floodplain soils decreased markedly downstream, as did the concentrations of Cd, Zn, and Ni in the leaves of blackberries from within the floodplain. Levels of Cd, Pb, and Zn in leaves of blackberries from within the floodplain significantly exceeded those of specimens from outside the floodplain. The findings of our study highlight the potential of wild blackberry as a biomonitor of soil pollution by Cd, Pb, and Zn and corroborate the massive heavy metal contamination of floodplain soils along the Innerste River observed in previous studies.

Spatio‐temporal effects of inundation and climate on vegetation greenness dynamics in dryland floodplains

AbstractMonitoring floodplain vegetation response to water availability is essential for sustainable water resource management. However, the interpretation of these responses through space and time has been challenging due to the limitation of satellite‐derived inundation extent, which is restricted by the return period of imagery and prevalence of clouds affected images during high flow events. We address this issue by utilising a predictive inundation model capable of reporting inundation at daily temporal resolution. Spatio‐temporal patterns in vegetation greenness of four floodplain vegetation communities (Eucalyptus camaldulensis, Eucalyptus largiflorens, Eucalyptus coolabah and Duma florulenta) were quantified using Landsat‐derived vegetation index and a combination of time series of floodplain inundation pattern, rainfall and soil moisture for the years 1989–2016. The results show that vegetation dynamics were highly variable between years and are closely associated with irregular rainfall patterns and overbank flooding. Linear mixed‐effect models explained between 38% and 67% of the variability in vegetation productivity, with all involved variables being significant predictors (p &lt; 0.05). The effects of rainfall, soil moisture and inundation were diverse and depended on vegetation type. Higher inundation frequency and low interflood period often corresponded to lower vegetation responses, which may relate to a mixed surface water and vegetation signal, or a short‐term inhibitive effect of surface water on growth. These results highlight the importance of groundwater and lagged effects of rainfall and flow in explaining patterns of vegetation condition in semi‐arid floodplains and should be considered in the design of environmental water monitoring programmes.

Focused Microbiome Shifts in Reconstructed Wetlands Correlated with Elevated Copper Concentrations Originating from Micronized Copper Azole-Treated Wood.

Micronized copper (Cu) azole (MCA) wood preservative formulations include Cu in nano form, and relatively little is known about longer term effects of Cu leached from MCA into wetland ecosystems. We tested the hypothesis that changes in soil microbiomes within reconstructed freshwater wetlands will be associated with exposure to elevated Cu concentrations originating from immersed MCA-treated wood stakes. Eight replicate communities were assembled with Willamette Valley (OR, USA) flood plain soil and clonally propagated wetland plants within mesocosms. Inundated communities were equilibrated for 5 months before installation of MCA or control southern yellow pine stakes (n = 4 communities/experimental group). Soil samples were collected for 16S and internal transcribed spacer amplicon sequencing to quantify responses in prokaryotes and eukaryotes, respectively, at 15 time points, spanning two simulated seasonal dry downs, for up to 678 days. Physiochemical properties of water and soil were monitored at 20 and 12 time points respectively, over the same period. For both taxonomic groups of organisms, phylogenetic diversity increased and was positively correlated with elapsed days. Furthermore, there was significant divergence among eukaryotes during the second year based on experimental group. Although the composition of taxa underwent succession over time, there was significantly reduced relative abundance of sequence variants from Gomphonema diatoms and Scutellinia fungi in communities where MCA wood stakes were present compared with the controls. These focused microbiome shifts were positively correlated with surface water Cu and soil Cu concentrations, which were significantly elevated in treated communities. The reconstructed communities were effective systems for assessing potential impacts to wetland microbiomes after exposure to released copper. The results further inform postcommercialization risk assessments on MCA-treated wood. Environ Toxicol Chem 2021;40:3351-3368.Published 2021. This article is a U.S. Government work and is in the public domain in the USA.

Fertility Status of Some Selected Floodplain Soils and the Management Recommendations on the Maximun Yield of Tomato (Lycopersicum Esculentum) in Kebbi State, Nigeria

The study was under taken to assess the fertility status of the flood plain soils of some selected local government areas of Kebbi State and recommend management practices to be provided for the maximum yield of tomatoes in Kebbi State. Soil samples were analyzed for the various physical and chemical properties following the standard procedures. The study revealed that the soils were predominantly sandy loam in texture with the mean particles composition of 715.71 gkg-1, 87.42 kg-1 and 196.87 kg-1 for sand, silt and clay, respectively. The soils contained low organic carbon of 6.0 gkg-1 and high concentration of nitrogen (0.8 gkg-1) which might be due to frequent addition of nitrogenous fertilizers on the soil. The low available phosphorus of 0.64 mgkg-1 was observed which might be due to acidity level of the soils (pH 5.6). On the basis of exchangeable bases, the soils were discovered to be low in Ca (1.51cmolkg-1), but high in Mg content (1.78 cmolkg-1). The soils contained high Na value of 0.59cmolkg-1 an indication ofsodicity hazard. The K content of 0.64 cmolkg-1 was also high in the soils of the study area. Based on the obtained values of the above parameters, the soils could be considered as medium in fertility. Based on the concentration of EC (0.55 dsm-1) ESP (6.04%) and pH 5.6, the soils could be considered to be free from salinity and sodicity at least for now, but has

Soils of mountain floodplains in the zone of tectonic joints of Mongol-Okhotsk Orogenic Belt (Mongolia)

New data on the soils of mountain floodplains in the tectonic joints zone of the Mongol-Okhotsk Orogenic Belt on the example of the Upper Kerulen Basin are presented. Soil diversity is mostly determined by sedimentation conditions and drainage of the parent rocks. There are alluvial–humus (Fluvisol (Humic)), mucky–humus (Folic Fluvisol), dark–humus (Fluvisol (Mollic)), dark–humus gley (Gleyic Fluvisol) and dark–humus saline soils (Sodic Gleyic Fluvisol (Mollic)) were diagnosed. Tectonic movements of the earth’s crust lead to the appearance of shaftlike linear dams, blocking river flow through the valley. So, the Kerulen river changed the direction of the channel and go beyond the depression, embedding into its mountain frame. Current seismicity impact on soils appears locally at tectonically active positions of epigenetic areas, close to outputs of saline underground deep waters, in the form of surface soil salinity and hydrometamorphism.

Polycyclic aromatic hydrocarbons and organochlorine pesticides in floodplain soils: A case study of Onuku River in Okitipupa, Nigeria

We report on the sources, distribution, and toxicity of sixteen polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs) in floodplain soils of the Onuku River in Okitipupa, Nigeria. Gas chromatography was used to quantify the compounds. Five PAHs with an average trace concentration of 0.25 (benzo(a)pyrene)-21.3 µg/kg (benzo(g,h,i)perylene) were identified, while the OCPs residues ranged from 0.116 (aldrin)-2.18 µg/kg (p,p’-DDT). High spatial distribution of OCPs was mostly recorded among the sampling sites, whereas chlorothalonil, δ-BHC, and p,p’-DDT were the most predominant. High distribution of high molecular weight PAHs (HMW-PAHs) with 6-ring (75.6%) as the most predominant compositions in the study area. The diagnostic ratio of specific PAH compounds revealed pyrogenic origin. Furthermore, the toxic equivalency factors (TEFs) evinced that the carcinogenic potency of benzo(a)pyrene and the equivalent concentration (BaPeq) of PAHs load were relatively low. Hence, regular monitoring of HMW-PAHs is required in the site.

Field observations to establish the impact of fluvial flooding on potentially toxic element (PTE) mobility in floodplain soils

Inundation of river water during flooding deposits contaminated sediments onto floodplain topsoil. Historically, floodplains were considered an important sink for potentially toxic elements (PTEs). With increasing flood frequency and duration, due to climate change and land use change, it is important to understand the impact that further flooding may have on this legacy contamination. In this study a field-based approach was taken, extracting soil pore waters by centrifugation of soils sampled on multiple occasions from multiple locations across a floodplain site, which lies adjacent to the River Loddon in southeast England. Flooding generally decreased pore water PTE concentrations and significantly lower pore water concentrations of Cd, Cu, and Cr were found post-flood compared to pre-flood. The dominant process responsible for this observation was precipitation with sulphides resulting in PTE removal from the pore water post-flood. The changes in pH were found to be associated with the decreased pore water concentration of Cu, which suggests the pH rise may have aided adsorption mechanisms or precipitation with phosphates. The impact of flooding on the release and retention of PTEs in floodplain soils is the net effect of several key processes occurring concurrently. It is important to understand the dominant processes that drive mobility of individual PTEs on specific floodplains so that site-specific predictions can determine the impact of future floods on the environmental fate of legacy contaminants.

Floodplain soils on the soil map of the Russian Federation, scale 1 : 2.5 M, 1988, in the Russian soil classification

The development of the digital model of the soil map of Russia derived of the map of the Soviet Russian Federation, 1988, compiled in Dokuchaev Soil Science Institute, comprises the transfer of soil names in the initial legend to those in the new classification system of Russian soils (2004). Floodplain soils (only native) are represented by seven legend units (out of 205) that were named in terms of soil classification of USSR, 1977, and part of their names indicated ‘landscapes’ rather than soils, which disagrees with the principles of the new classification system. Basing on numerous publications and following the rules of the new system, soils were renamed. Most of them were referred to alluvial soil types within the synlithogenic trunk (Fluvisols), and their new names indicate both their properties and their zonal attachment. In order to obtain more adequate patterns of soils in river valleys additional soils were introduced including stratified-alluvial soils in the trunk of primary pedogenesis (Regosols). Simultaneously, the composition of polygons in the database was revised in accordance with regional data; human-modified soils were introduced (agro-soils and urbo-soils).

The anthropocene landscape and ecosystem services in the closure of sand mining: Paraíba do Sul River basin – Brazil

Geodiversity is a determinant of mining patterns, because its nature defines the interaction with humans, type of exploitation, and, consequently, ecosystem services (ES) of the final landscape. The environmental recovery obligations defined in the legislation serve as a good guidance, but sand mining companies are not always able to finalize their activity entirely and to comply with the laws. To take this into account, the present study was developed with an objective of analyzing the changes observed in the ES after 70 years of sand exploitation in the Paraíba do Sul River Valley, Brazil. The services of the floodplain soil formation and associated components, such as the quality and quantity of water and refuges provided by the riparian forest, are highlighted in this study. To evaluate the different ESs modified by mining, socio-environmental variables were studied, and the analytic hierarchy process (AHP) method was applied to assign significance to each variable in the phase of closing activities, thus creating a compound index for ES evaluation at mine closure. The closure conditions were analyzed against the UN Sustainable Development Goals (SDGs) 6, 8, 9, and 11. The results showed that the companies are small, that they met the legislation in equal criteria of environmental rehabilitation, and that they were induced to a closure standard, reflecting the reforestation with native forest variable, related to the ES of provisioning of habitat to wild fauna. However, the mine facilities variable, associated with the cultural ES of recreation, predominated, because the buildings and access roads were preserved, even though the movable assets were demobilized quickly. It was concluded from the analysis that the scenario of the ES at mine closure is generally linked to geodiversity, company size, and compliance with legal duties.