The interactive pedological-hydrological processes and environmental sensitivity of a tropical isolated wetland in the Brazilian Cerrado

AbstractIn seasonal flooding isolated wetlands, the degree of wetness suggests a close synergy between soil processes, landscape evolution and hydrology along space and time. Until now, that subject has received insufficient attention despite natural wetlands supply essential environmental services to society and are surrounded by intensive agriculture that uses agrochemicals and fertilizers in their management. The objectives of this study were to propose an infiltration architecture model based on local surface and subsurface water-fluxes in isolated wetland embedded in lateritic plateau covered by savanna and qualify the environmental sensitivity as an area of aquifer recharge. Grain size, soil bulk density, and hydraulic conductivity were determined in five profiles in a soil catena. Unmanned Aerial Vehicle high-resolution images were obtained to generate a digital elevation model and discriminate areas with different vegetation, water accumulation, and environmental sensitivity. Electrical tomography was performed to unveil the soil architecture and infiltration. The soils (Plinthosols) developed on aquic conditions determine the linkage between the surface–subsurface hydrodynamics with the soil's physical properties. We have identified vertical and lateral water-flows in the soil architecture. Vertical flow occurs exclusively at the center, where the wetland is characterized as a recharge zone. Lateral flow towards the borders characterizes a discharge zone. The recharge zone is a depression surrounded by crops; therefore, it is a point of high environmental sensitivity. This hydrodynamic model is essential to support studies related to the dispersion of contaminants since soybean agriculture dominates the whole area of well-drained soils in the Brazilian Cerrado.

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A Simple Modelling Framework for Shallow Subsurface Water Storage and Flow

Water ◽

10.3390/w11081725 ◽

2019 ◽

Vol 11 (8) ◽

pp. 1725

Author(s):

Lucile Verrot ◽

Josie Geris ◽

Lei Gao ◽

Xinhua Peng ◽

Joseph Oyesiku-Blakemore ◽

...

Keyword(s):

Steady State ◽

Water Storage ◽

Water Dynamics ◽

Subsurface Water ◽

Richards Equation ◽

Runoff Generation ◽

Catchment Scale ◽

Shallow Subsurface ◽

Modelling Framework ◽

Vegetation Water

Water storage and flow in shallow subsurface drives runoff generation, vegetation water use and nutrient cycling. Modelling these processes under non-steady state conditions is challenging, particularly in regions like the subtropics that experience extreme wet and dry periods. At the catchment-scale, physically-based equations (e.g., Richards equation) are impractical due to their complexity, while conceptual models typically rely on steady state assumptions not found in daily hydrological dynamics. We addressed this by developing a simple modelling framework for shallow subsurface water dynamics based on physical relationships and a proxy parameter for the fluxes induced by non-unit hydraulic gradients. We demonstrate its applicability for six generic soil textures and for an Acrisol in subtropical China. Results showed that our new approach represents top soil daily fluxes and storage better than, and as fast as, standard conceptual approaches. Moreover, it was less complex and up to two orders of magnitude faster than simulating Richards equation, making it easy to include in existing hydrological models.

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Quality index of an Oxisol under different management systems in the Brazilian Cerrado

Revista Brasileira de Engenharia Agrícola e Ambiental ◽

10.1590/1807-1929/agriambi.v25n5p319-324 ◽

2021 ◽

Vol 25 (5) ◽

pp. 319-324

Author(s):

Marla O. Fagundes ◽

Diony A. Reis ◽

Roberto B. Portella ◽

Fabiano J. Perina ◽

Julio C. Bogiani

Keyword(s):

Soil Quality ◽

Cover Crops ◽

Quality Index ◽

Soil Bulk Density ◽

Conventional Tillage ◽

Management Systems ◽

No Tillage ◽

Brazilian Cerrado ◽

Soil Quality Index ◽

Tillage System

ABSTRACT Assessing soil quality under different cover crops or different management systems is essential to its conservation. This study aimed to evaluate an Oxisol cultivated with corn and cotton, after different crop successions and under no-tillage system (NTS) and conventional tillage system (CT), through the soil quality index (SQI), using an area of native Cerrado as reference. The study was carried out in the municipality of Luís Eduardo Magalhães, Western Bahia, Brazil. Soil samples with the preserved and non-preserved structure were collected in the layers of 0-0.05 m, 0.05-0.10 m, and 0.10-0.20 m to determine the macroporosity, the soil bulk density, the available water, the levels of total organic carbon, the clay dispersed in water, and the degree of flocculation. The averages of the attributes measured in the treatments and the soil quality index, which was elaborated by the method of deviations of the values of the attributes measured in the treatments concerning the reference area, followed by normalization, were compared by the Duncan test (p ≤ 0.05). The soil under CT, in all treatments, had its quality reduced when compared to the NTS. Also, the SQI used was sensitive to detect the changes caused by the management systems and assign consistent scores to the evaluated soil quality.

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Physical Atributes of a Oxisol from the Brazilian Cerrado under Different Management Systems

Journal of Agricultural Science ◽

10.5539/jas.v10n1p361 ◽

2017 ◽

Vol 10 (1) ◽

pp. 361

Author(s):

Márcio Godofrêdo Rocha Lobato ◽

Fabrício Menezes Telo Sampaio ◽

Júlio César Azevedo Nóbrega ◽

Mozart Martins Ferreira ◽

Sammy Sidney Rocha Matias ◽

...

Keyword(s):

Physical Properties ◽

Particle Density ◽

Aggregate Stability ◽

Total Porosity ◽

Soil Bulk Density ◽

Management Systems ◽

Porous Space ◽

Brazilian Cerrado ◽

Tillage Systems ◽

No Till

The tillage systems induce changes in soil structure; modify the porous space, and influence soil water and air dynamics. In this sense, it is important to evaluate these impacts on soil physical quality according to different tillage system with distinct years of implementation. The physical properties of a Oxisol at the Brazilian Cerrado with distinct tillage conditions (conventional, no-till, and a native Cerrado) with different years were compared. The study was conducted at Novo Horizonte farm, at the Cerrado region of southwest Piauí. Soil samples were collected at 0.0-0.10, 0.10-0.20 and 0.20-0.30 m depth in different management systems: no-till with three and five years of implantation (NT3 and NT5, respectively); conventional till with five and nine years (CC5 and CC9, respectively); and a native cerrado area. Were analyzed the aggregate stability in water, soil bulk density, particle density, macro and microporosity, total porosity and total organic carbon. The years of implementation of the tillage systems caused changes in the soil physical properties, which were more evident in the surface layer. Although improved soil physical attributes were observed in no-till after five years of implantation, a longer evaluation time is required for the studied conditions.

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Nitrogen transformations along a shallow subterranean estuary

Biogeosciences ◽

10.5194/bg-14-3321-2017 ◽

2017 ◽

Vol 14 (13) ◽

pp. 3321-3336 ◽

Cited By ~ 17

Author(s):

Mathilde Couturier ◽

Gwendoline Tommi-Morin ◽

Maude Sirois ◽

Alexandra Rao ◽

Christian Nozais ◽

...

Keyword(s):

Chemical Constituents ◽

Flow Path ◽

Trophic Levels ◽

Discharge Zone ◽

Nutrient Concentrations ◽

Nutrient Loads ◽

Aquifer Recharge ◽

Nitrogen Transformations ◽

N Transformations ◽

Biogeochemical Transformations

Abstract. The transformations of chemical constituents in subterranean estuaries (STEs) control the delivery of nutrient loads from coastal aquifers to the ocean. It is important to determine the processes and sources that alter nutrient concentrations at a local scale in order to estimate accurate regional and global nutrient fluxes via submarine groundwater discharge (SGD), particularly in boreal environments, where data are still very scarce. Here, the biogeochemical transformations of nitrogen (N) species were examined within the STE of a boreal microtidal sandy beach located in the Magdalen Islands (Quebec, Canada). This study revealed the vertical and horizontal distribution of nitrate (NO3−), nitrite (NO2−), ammonia (NH4+), dissolved organic nitrogen (DON) and total dissolved nitrogen (TDN) measured in beach groundwater during four spring seasons (June 2011, 2012, 2013 and 2015) when aquifer recharge was maximal after snowmelt. Inland groundwater supplied high concentrations of NOx and DON to the STE, whereas inputs from seawater infiltration were very limited. Non-conservative behaviour was observed along the groundwater flow path, leading to low NOx and high NH4+ concentrations in the discharge zone. The long transit time of groundwater within the beach (∼ 166 days), coupled with oxygen-depleted conditions and high carbon concentrations, created a favourable environment for N transformations such as heterotrophic and autotrophic denitrification and ammonium production. Biogeochemical pathways led to a shift in nitrogen species along the flow path from NOx-rich to NOx-poor groundwater. An estimate of SGD fluxes of N was determined to account for biogeochemical transformations within the STE based on a N-species inventory and Darcy's flow. Fresh inland groundwater delivered 37 mol NOx yr−1 per metre of shoreline and 63 mol DON m−1 yr−1 to the STE, and NH4+ input was negligible. Near the discharge zone, the potential export of N species was estimated around 140, 1.5 and 33 mol yr−1 per metre of shoreline for NH4+, NOx and DON respectively. In contrast to the fresh inland groundwater, the N load of beach groundwater near the discharge zone was dominated by NH4+ and DON. Our study shows the importance of tidal sands in the biogeochemical transformation of the terrestrial N pool. This local export of bioavailable N probably supports benthic production and higher trophic levels leading to its rapid transformation in surface sediments and coastal waters.

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Potenciometria e fluxo subterrâneo no aqüífero aluvionar do baixo curso do Rio Macaé, município de Macaé-RJ

Anuário do Instituto de Geociências - UFRJ ◽

10.11137/2005_2_102-115 ◽

2005 ◽

Vol 28 (2) ◽

pp. 102-115

Author(s):

Giselle Ramalho Barbosa ◽

Gerson Cardoso da Silva Jr

Keyword(s):

River Mouth ◽

Northern Region ◽

River Channel ◽

Alluvial Aquifer ◽

Subsurface Water ◽

Aquifer Recharge ◽

Peripheral Population ◽

The Relationship ◽

The City ◽

Janeiro State

Macaé city is inserted in the coastal portion of the Northern region of Rio de Janeiro State, Brazil. The study accomplished in the alluvial aquifer of the Macaé river lower course, whose waters fulfill the domestic needs of a significant part of the rural and peripheral population of the city, comprised the neighborhoods of Córrego do Ouro, Fazenda Severina, Virgem Santa and Aterrado do Imburo. Results comprise the hydrodynamic studies that lead to the elaboration of a potentiometric map in that alluvial aquifer. The potentiometry shows the relationship between the surface and subsurface water. The Macaé River has an effluent character in the studied area. Aquifer recharge is associated to the topographical adjacent higher grounds and discharge is towards the Macaé river channel and river mouth. The hydrographs of water level temporal variation suggest a possible hydraulic connection among the monitored water points, evidencing a lateral continuity in the area.

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OFF-SEASON STRATEGIES TO IMPROVE SOIL PHYSICAL ATTRIBUTES IN A NO-TILL SYSTEM IN THE BRAZILIAN CERRADO

Revista Brasileira de Milho e Sorgo ◽

10.18512/rbms2020v19e1183 ◽

2020 ◽

Vol 19 ◽

pp. 13

Author(s):

RANIER VIEIRA FERREIRA ◽

ROSE LUIZA MORAES TAVARES ◽

SILVIO VASCONCELOS PAIVA FILLHO ◽

INDIAMARA MARASCA ◽

ALESSANDRO GUERRA SILVA

Keyword(s):

Dry Matter ◽

Block Design ◽

Soil Bulk Density ◽

No Tillage ◽

Brazilian Cerrado ◽

No Till ◽

Randomized Complete Block Design ◽

Tillage System ◽

Physical Attributes ◽

Resistance To Penetration

In the central region of Brazil, sorghum and maize are considered viable crop alternatives to be cultivated during off-season periods, mainly for the production of grains in succession to the cultivation of soybeans and intercropping with brachiaria grasses. This study aimed to evaluate the physical soil qualities of the soil from an area with different off-season management histories (monoculture or agricultural intercropping). Maize, sorghum and brachiaria crops have been cultivated under no-tillage system. The experiment was conducted using a randomized complete block design, with four replications. The treatments included: monoculture or intercropping between sorghum and brachiaria (first off-season strategy) or maize and brachiaria (second off-season strategy). The following physical properties of the soil were evaluated: soil bulk density, porosity, soil resistance to penetration, soil moisture and texture and the contents of organic carbon, which were analyzed at 0-20, 20-40 and 40-60 cm deep. In the off-season, the cultivation of single brachiaria promoted a greater amount of dry matter when compared with sorghum- brachiaria or maize-brachiaria intercropping. The topsoil presented better physical quality when compared with the adjacent layers under no-tillage system. The use of brachiaria combined with sorghum or maize tends to improve the macro and microporosity of the soil.

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Dynamics of water fluxes and storages in an Alpine karst catchment under current and potential future climate conditions

10.5194/hess-2017-216 ◽

2017 ◽

Cited By ~ 1

Author(s):

Zhao Chen ◽

Andreas Hartmann ◽

Thorsten Wagener ◽

Nico Goldscheider

Keyword(s):

Climate Change ◽

Karst Aquifer ◽

Future Climate ◽

Subsurface Water ◽

Water Fluxes ◽

Aquifer Recharge ◽

Climate Conditions ◽

Snow Storage ◽

Highly Sensitive ◽

Karst Catchment

Abstract. Climate change projections indicate significant changes to precipitation and temperature regimes in European karst regions. Alpine karst systems can be especially vulnerable under changing hydro-meteorological conditions since snowmelt in mountainous environments is an important controlling process for aquifer recharge, and is highly sensitive to varying climatic conditions. The current study presents an investigation of present and future water fluxes and storages at an Alpine karst catchment using a distributed numerical model. A delta approach combined with random sampling was used to assess the potential impacts of climate changes. The study site is characterized by high permeability (karstified) limestone formations and low permeability (non-karst) sedimentary flysch. The model simulation under current conditions demonstrates that a large proportion of precipitation infiltrates into the karst aquifer as autogenic recharge. Surface runoff in the adjacent non-karst areas partly infiltrates into the karst aquifer as allogenic point recharge. Moreover, the result shows that surface snow storage is dominant from November to April, while subsurface water storage in the karst aquifer dominates from May to October. The climate scenario runs demonstrate that varied climate conditions significantly affect the spatiotemporal distribution of water fluxes and storages: (1) the total catchment discharge decreases under all evaluated future climate conditions. (2) The spatiotemporal discharge pattern is strongly controlled by temperature variations, which can shift the seasonal snowmelt pattern, with snow storage in the cold season (December to April) decreasing significantly under all change scenarios. (3) Increased karst aquifer recharge in winter and spring, and decreased recharge in summer and autumn, partly offset each other. (4) Impacts on the karst springs are distinct; the permanent spring presents a robust discharge behavior, while the estavelle is highly sensitive to changing climate. This analysis effectively demonstrates that the impacts on subsurface flow dynamics are regulated by the characteristic dual flow and spatially heterogeneous distributed drainage structure of the karst aquifer. Overall, our study suggests that bespoke hydrological models tailored to the specific subsurface characteristics of an Alpine karst catchment are needed to understand climate change impact.

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Making Rainwater Harvesting a Key Solution for Water Management: The Universality of the Kilimanjaro Concept

Sustainability ◽

10.3390/su11205606 ◽

2019 ◽

Vol 11 (20) ◽

pp. 5606 ◽

Cited By ~ 2

Author(s):

Qinwen Qi ◽

Janeth Marwa ◽

Tulinave Burton Mwamila ◽

Willis Gwenzi ◽

Chicgoua Noubactep

Keyword(s):

Water Management ◽

Drinking Water ◽

Rainwater Harvesting ◽

Hydrological Cycle ◽

Free Water ◽

Water Source ◽

Subsurface Water ◽

Groundwater Depletion ◽

Drinking Water Source ◽

Aquifer Recharge

Rainwater is conventionally perceived as an alternative drinking water source, mostly needed to meet water demand under particular circumstances, including under semi-arid conditions and on small islands. More recently, rainwater has been identified as a potential source of clean drinking water in cases where groundwater sources contain high concentrations of toxic geogenic contaminants. Specifically, this approach motivated the introduction of the Kilimanjaro Concept (KC) to supply fluoride-free water to the population of the East African Rift Valley (EARV). Clean harvested rainwater can either be used directly as a source of drinking water or blended with polluted natural water to meet drinking water guidelines. Current efforts towards the implementation of the KC in the EARV are demonstrating that harvesting rainwater is a potential universal solution to cover ever-increasing water demands while limiting adverse environmental impacts such as groundwater depletion and flooding. Indeed, all surface and subsurface water resources are replenished by precipitation (dew, hail, rain, and snow), with rainfall being the main source and major component of the hydrological cycle. Thus, rainwater harvesting systems entailing carefully harvesting, storing, and transporting rainwater are suitable solutions for water supply as long as rain falls on earth. Besides its direct use, rainwater can be infiltrating into the subsurface when and where it falls, thereby increasing aquifer recharge while minimizing soil erosion and limiting floods. The present paper presents an extension of the original KC by incorporating Chinese experience to demonstrate the universal applicability of the KC for water management, including the provision of clean water for decentralized communities.

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