Capillary Rise Of Groundwater Research Articles

The Control of Plant and Soil Hydraulics on the Interannual Variability of Plant Carbon Uptake Over the Central US

AbstractThe interannual variability (IAV) of gross primary productivity (GPP) reflects the sensitivity of GPP to climate variations and contributes substantially to the variations and long‐term trend of the atmospheric CO2 growth rate. Analyses of three observation‐based GPP products indicate that their IAVs are consistently correlated to terrestrial water storage anomaly over the central US, where episodic droughts occur. A land surface model explicitly representing plant hydraulics and groundwater capillary rise with an adequate soil hydraulics well captures the observed GPP IAV. Our sensitivity experiments indicate that, without representations of plant hydraulics and groundwater capillary rise or using an alternative soil hydraulics, the land model substantially overestimates the GPP IAV and the GPP sensitivity to water in the central US. This study strongly suggests the use of the van Genuchten water retention model to replace the most commonly used Brooks–Corey model, which generally produces too strong matric suction of soil water especially in dry conditions, in land surface modeling. This study highlights the importance of plant and soil hydraulics and surface–groundwater interactions to Earth system modeling for projections of future climates that may experience more intense and frequent droughts.

Building Problems in Architectonic Heritage and Geotourism: Is there a Connection?

Architectonic heritage buildings attract millions of tourists for many reasons: their beauty, history, style, art, location, and so on. Presently, this list is being supplemented by the touristic exploration of the construction material, with particular emphasis on the natural stones. This material is the aim of urban geotourism because it can give precious information about its age, origin, paleo-environment, as well as its provenience, way of exploitation, transport, treatment and finally degradation by weathering, among others. Therefore, the study of the construction stones of heritage buildings constitutes a complement to the “classical” cultural items which are shown and presented during a visit. A particular segment in geotouristic activities may be the presentation of building problems to the visitors. There are many examples in this field, like moisture or cracks in the walls, unusual solutions in construction, disintegration of stones, and so on. These problems can have various causes: the capillary rise of groundwater in a wall, the lack of construction material, the heterogeneous composition of the substrate, the seismic activity, the weathering of material, to name but a few. For a visitor interested in science and technology, the knowledge of the problems, their origin and their solution (or, at least, the attempt of their solution) may be an unforgettable experience. The purpose of the work is to open a new point of view to architectonic heritage and its building problems, which can be used and explained in touristic activities. For this, mainly qualitative non-interventionist and participatory methodologies are applied. As a result, there will be the situation that the damage in one part leads to a profit in the other. This ambiguity may be resolved by considering that better knowledge about the state of the heritage building, which is made accessible to a larger public, will contribute to its preservation. So, the main conclusion is that geotourism applied to architectonic heritage and its problems is an important support to its maintenance because of the dissemination of the knowledge of what may happen with the construction material. Likewise, the knowledge acquired during a geotouristic visit may help to avoid similar problems in other buildings.

Enhancing the Noah‐MP Ecosystem Response to Droughts With an Explicit Representation of Plant Water Storage Supplied by Dynamic Root Water Uptake

AbstractPlants are able to adapt to changing environments and thus survive droughts. However, most land surface models produce unrealistically low ecosystem resiliency to droughts, degrading the credibility of the model‐predicted ecohydrological responses to climate change. We aim to enhance the Noah‐MP modeled ecosystem resilience to droughts with an explicit representation of plant water storage supplied by dynamic root water uptake through hydrotropic root growth to meet the transpiration demand. The new model represents plant stomatal water stress factor as a function of the plant water storage and relates the rate of root water uptake to the profile of model‐predicted root surface area. Through optimization of major leaf, root, and soil parameters, the new model improves the prediction of leaf area index, ecosystem productivity, evapotranspiration, and terrestrial water storage variations over most basins in the contiguous United States. Sensitivity experiments suggest that both dynamic root water uptake and groundwater capillary rise extend the plants' “memory” of antecedent rainfall. The modeled plants enhance their efficiency to use antecedent rain water stored in shallow soils mainly through more efficient root water uptake over the U.S. Southwest drylands while use that stored in deep soils and aquifers with the aid of groundwater capillary rise in the Central United States. Future plant hydraulic models should not ignore soil water retention model uncertainties and the soil macropore effects on soil water potential and infiltration.

Effect of cushion and cover on moisture distribution in clay embankments in southern China

To achieve durability of the embankment in southern China, a method to control the change of moisture content with the cushion and cover was proposed. A finite element model of cushion and cover considering different materials and thicknesses for a typical embankment was built, and 20 numerical analyses of transient seepage in the embankment were simulated. The results show that the sand cushion effectively blocks the effect of groundwater capillary rise and the minimum thickness of the sand cushion is 75 cm without considering the atmospheric environment. With the combination of sand cushion and clay cover, as the thickness of the clay cover increases, the duration time of the moisture content from the initial to relative equilibrium state increases, but the equilibrium moisture content is the same as that of the original embankment. Besides, with the combination of the sand cushion and sand cover, the moisture content inside the embankment remains the same, which is consistent with the optimum moisture content during construction. The combination of 75 cm sand cushion and 30 cm sand cover is a very effective method to block groundwater and atmospheric environment, and achieve the control of the humidity stability of the embankment in southern China.

Соотношение влаги и химических веществ при инфильтрации и испарении грунтовых вод в дерново- подзолистой суглинистой почве

The specificities of leaching (outflow) of chemicals from soddy-podzolic loamy deeply gleyed soil by infiltration and its return from groundwater during their evaporation are considered in the paper. In the annual cycle calcium is the element which is mostly washed out with amount of 89…106 kg/ha. It was shown that potassium (15…14), manganese (13,6…9,3), zinc (13,6…7,7), calcium (7,5…5,2) and magnesium (7,1…4,7) in percentage of the outflow return in the soil with the capillary rise of groundwater.
 It is shown that the ratio of infiltration (I) and evaporation of groundwater (K) in soddy-podzolic soil is within the range of 0,3…0,6 for medium arid, 2,6…2,9 for average long-term and 2,6…2,9 for humid conditions of atmospheric moistening. Thus, the lowest values of ratios for medium arid, and the highest ones – for medium humid conditions, which reflects the real specificities of the infiltration and evaporation of groundwater in natural conditions.

3DGPR for the Non-Destructive Monitoring of Subsurface Weathering of Sandstone Masonry

Remote sensing techniques, such as LiDAR and photogrammetry, are used by researchers exploring the spatial distribution of weathering features in historic masonry. These well-established tools provide users with a perspective of the processes affecting the surface of masonry blocks; however, they cannot provide information on the alteration occurring subsurface. Geophysical tools are being explored as a potential approach to observe the variation in material properties beneath masonry block surfaces and to examine the patterns of deterioration across wall sections. Applying such techniques inform the development of conceptual models of weathering at the block to building wall scale. In this study, ground-penetrating radar (GPR) was selected to inspect the subsurface condition of the wall section of an historic church wall, where areas of granular disintegration and flaking can be observed. 3DGPR was selected for this task, as its use of regular grids during data collection make it better suited for detecting features within an area. Three high-frequency antennas, 1.2 Ghz, 1.6 Ghz and 2.3 Ghz, were run across the study area in a series of 80 cm by 80 cm grids. The data were collated within GIS, where observed features were annotated onto a schematic of the wall surface. The 3DGPR outputs identified anomalies within this structure that could not have been as easily interpreted using a 2DGPR transect. However, as 3DGPR relies upon interpolative techniques to estimate the returns between observation transects, the validity of features detected in these locations need to be tested. The results of this application of 3DGPR identified variable weathering response across the wall section, relative to elevation. These observations were used to develop a conceptual model linking these findings to seasonal variation in the capillary rise of groundwater, upward from the base of the church wall. Through these findings it is possible to see how GPR can assist in developing our understanding of the processes threatening heritage buildings.

Modelling percolation and lateral seepage in a paddy field-bund landscape with a shallow groundwater table

Percolation in farmland increasingly is needed to be quantified to improve water use efficiency and mitigate accompanying nutrient loss. Experiments were conducted to measure the soil properties and moisture in a consolidated paddy field-bund landscape during the rice growing season in 2014–2015. The HYDRUS-2D model simulated soil water movement in the landscape with an excellent performance. In the study, the soil properties of the bund were similar to those of the paddy field after land consolidation. Modelling results showed that most percolation in the paddy field occurred along with water input (rainfall and irrigation). Groundwater capillary rise was detected in the coupled conditions of low soil moisture in the root zone and the shallow groundwater table. Percolation accounted for 23.2%–31.3% of water input, and groundwater capillary rise contributed 26.1%–31.2% to rice evapotranspiration. The variation of the soil water content of the bund indicated that lateral infiltration from the paddy field to the bund primarily occurred in the upper bund adjacent to the field, while the lateral seepage was only found in the lower bund below the groundwater level. Vertical percolation and lateral seepage accounted for 10.5%–14.8% of water input lost through the bund, in which the lateral seepage contributed 77.6%–88.4%. Scenario simulation with the calibrated model investigated the impacts of saturated hydraulic conductivity (Ks) and the irrigation amount on the percolation and lateral seepage in the landscape. The results implied that percolation increased with the increasing Ks of soil. The percolation in the paddy-bund landscape and lateral seepage were most influenced by the illuvial horizon layer of the paddy field. Furthermore, a higher irrigation amount decreased the groundwater capillary rise and aggravated percolation linearly, while it had few effects on lateral seepage. The research suggests a potential adjustment in making irrigation schedules and conducting land consolidation in the rice-planting areas with shallow groundwater depths.

Shallow groundwater plays an important role in enhancing irrigation water productivity in an arid area: The perspective from a regional agricultural hydrology simulation

Agricultural water productivity (WP) is an important indicator to evaluate the implementation of agricultural water saving in arid regions. However, the role of groundwater capillary rise to crop water use and WP is unclear at the regional scale, as the soil texture, irrigation amount, planting pattern and groundwater depth is various for different fields. Based on the calibrated Agricultural Water Productivity Management for Shallow Groundwater (AWPM-SG) model, a five-year regional WP and water budgets assessment was performed. The results showed that the groundwater contribution to crop evapotranspiration (ET) would be up to 65% with a groundwater depth of 1.0–1.5 m, but the agricultural productivity would be relatively low resulting from a waterlogged root zone. Additionally, deep groundwater could result in a reduced WP due to less capillary rise, while WP would be 2.02 and 1.98 kg/m3 with groundwater depth of 2.5–3.0 m and 3.0–4.5 m under irrigation amount of 100–300 mm. Furthermore, limited irrigation can enhance the contribution of groundwater to WP and irrigation water productivity (IWP), which is significant with groundwater depth increasing. While the average IWP were 5.83, 3.62, 2.54 and 1.77 kg/m3, respectively for irrigation amount of 100–300, 300–500, 500–700 and 700–900 mm and the average IWP decreased from 4.79 m to 3.18 kg/m3 with groundwater depth increasing 0.5–1.0 m to 3.0–4.5 m. However, irrigation effective utilization (Cieu) was affected by groundwater depth weakly with irrigation water increasing. Furthermore, the optimal groundwater depth of 2.5–3.0 m was obtained by the impact of groundwater on irrigation water productivity (IWP) and Cieu. Thus at the regional scale, the spatial distribution of groundwater levels needs to be considered for making irrigation decisions.

Model of resalinization by capillary rise in reclaimed land

Large areas of reclaimed land have recently been required to be developed as environmentally friendly centers of vegetation, such as dryland fields for cultivation of high-income crops and green fields. However, reclaimed lands in coastal areas such as reclaimed tidal flats have a setback in this regard: The capillary rise of groundwater from deeper levels causes resalinization, resulting in concentration of salt at the surface. The existing studies conducted on resalinization of soils in reclaimed lands are either insufficient or employ complex experimental and analytical methods. In this study, resalinization testing equipment was developed, and a laboratory model test on reclaimed-land soil was carried out. We identified the relationship between the capillary rise rate and initial volumetric water content and proposed a simple experimental model. The proposed model was verified by a comparison with experiment results and measured data of the field and could more accurately predict the resalinization according to the volumetric water content. In addition, proposed model can be applied in the field as the predicted results showed a similar trend to that of the measurements of the field.

Assessing water productivity in the Hetao Irrigation District in Inner Mongolia by an agro-hydrological model

The Hetao Irrigation District (HID) is an important food production area, where irrigation is essential for agriculture. Because of water shortages, it is crucial to optimize the irrigation schedule and cropping structure to preserve the water resource and maintain sustainable crop production. In this study, a distributed Soil-Water-Atmosphere-Plant WOrld FOod STudies model was calibrated and validated, and then used to simulate yield and water productivity (WP) during 2000–2010 in the HID. Then, the suggested irrigation schedules and the cropping structure were analyzed by comparisons of yield and WP. The results showed that, compared with the basic scenario, the annual average yields of spring wheat, spring maize, and sunflower were improved by 17.3, 1.2 and 10.5%, respectively, and the crop WPs were increased by 9.5, 3.7 and 16.5%, respectively, after division in the suggested irrigation scenario. The corresponding multiyear (2000–2010) average field irrigation amount (irrigation amount × cultivated areas) that would be saved was 4.89 × 108 m3. Although the capillary rise of groundwater was larger, the groundwater depth could not sustainably decline during 2000–2010. Therefore, the irrigation schedules and the cropping structure suggested in this study could contribute to more sustainable food production and reduced irrigation water usage in the HID.

Evaluation of the Impact of Different Soil Salinization Processes on Organic and Mineral Soils

Soil salinization is a worldwide problem of which secondary salinization is increasingly more frequent, threatening agricultural production. Salt accumulation affects not only plants but also the physio-chemical characteristics of the soil, limiting its potential use. Climate change will further increase the rate of salinization of soil and groundwater as it leads to increased evaporation, promotes capillary rise of saline groundwater as well as increased irrigation with brackish water. Episodic seawater inundation of coastal areas is likely to increase in frequency as well. This work analyzed three types of salinization: seawater inundation (by irrigating soils with a 54 dS m−1 NaCl solution), saline groundwater capillary rise (soil contact with a 27 dS m−1 NaCl solution), and irrigation with two types of brackish water with different residual sodium carbonate (RSC). Two soils were used: a mineral soil (7.0 % clay; 0.7 % organic matter) and an organic soil (2.7 % clay; 7.4 % organic matter). The tested soils had different resilience to salinization: The mineral soil had higher sodium adsorption ratio (SAR) due to low levels of calcium + magnesium but had higher leaching efficiency and more limited effects of RSC. The organic soil however was more prone to capillary rise but seemingly more structurally stable. Our results suggest that short-term inundation with seawater can be mitigated by leaching although soil structure may be affected and that capillary rise of brackish groundwater should be carefully monitored. Also, the impact of irrigation with brackish water with high RSC can be inferior in soils with higher exchangeable acidity.

Simulating soil water regime in lowland paddy fields under different water managements using HYDRUS-1D

The widely adopted alternate wetting and drying (AWD) irrigation for rice production in lowland paddy fields with shallow groundwater table is increasingly needed to quantify the soil water regime for irrigation schedule design. Field experiments were conducted to compare the soil water flow between paddy fields under AWD and continuously flooded irrigation (CFI), during the rice growing season in 2010–2011. Model simulations using HYDRUS-1D were also conducted based on the measured pressure head distribution of soil profiles. Modeling results show that the pressure head derived from forward simulation using the point estimated soil hydraulic parameters did not agree well with the measured pressure head. However, from inverse modeling of saturated hydraulic conductivities of plow pan (mean of 0.68cmd−1 in AWD plots and 0.54cmd−1 in CFI plots), the HYDRUS-1D model can properly simulate the water flow in multi-layer paddy soil flow, where the plow pan plays an important role in determining the vertical pressure head distribution. The measured pressure head and simulated pressure head derived from inverse modeling agreed well (NSE of 0.93–0.98) during the whole rice growing season. Measurement and simulation results indicated that the practice of AWD decreased the percolation 38.2–40.3% in 2010 and 23.3–27.2% in 2011, compared to that of CFI. It is also found that groundwater capillary rise amounted to 26.1–27.4% in AWD plots, and 10.2–18.1% in CFI plots of respective water input (irrigation and rainfall).

Improvement of Salt-affected Soils by Deep Tillage: Part 2: Large-scale Field Tests in a Sodic Soil (Solonetz) Region

A deep tillage method was tested for soil improvement of salt-affected soils. Capillary rise of groundwater was cut off by the deep tillage, which made a coarse layer in the subsoil. This paper deals with large-scale field tests constructed by a four-stage subsoil plough in a sodic soil (solonetz) region. The results showed that the deep tillage down to the subsoil proved positive for the improvement of the solonetz soil. In the deeply tilled field, the grass height and density of cultivated natural pasture were much greater than those in the conventional (subsoiled) field. In the subsoiled field, the grasses were growing at the areas on the subsoiler channels, but their grass height was much shorter than in the deeply tilled field. At the undisturbed areas between the subsoiler channels, the grasses could not survive at all.

Modeling irrigated cotton with shallow groundwater in the Aral Sea Basin of Uzbekistan: I. Water dynamics

In Khorezm, a region located in the Aral Sea basin of Uzbekistan, water use for irrigation of predominantly cotton is high whereas water use efficiency is low. To quantify the seasonal water and salt balance, water application, crop growth, soil water, and groundwater dynamics were studied on a sandy, sandy loam and loamy cotton field in the years 2003 and 2005. To simulate and quantify improved management strategies and update irrigation standards, the soil water model Hydrus-1D was applied. Results showed that shallow groundwater contributed a substantial share (up to 399 mm) to actual evapotranspiration of cotton (estimated at 488–727 mm), which alleviated water stress in response to suboptimal quantities of water applied for irrigation, but enhanced concurrently secondary soil salinization. Thus, pre-season salt leaching becomes a necessity. Nevertheless, as long as farmers face high uncertainty in irrigation water supply, maintaining shallow groundwater tables can be considered as a safety-net against unreliable water delivery. Simulations showed that in 2003 around 200 mm would have been sufficient during pre-season leaching, whereas up to 300 mm of water was applied in reality amounting to an overuse of almost 33%. Using some of this water during the irrigation season would have alleviated season crop-water stress such as in June 2003. Management strategy analyses revealed that crop water uptake would only marginally benefit from a permanent crop residue layer, often recommended as part of conservation agriculture. Such a mulch layer, however, would substantially reduce soil evaporation, capillary rise of groundwater, and consequently secondary soil salinization. The simulations furthermore demonstrated that not relying on the contribution of shallow groundwater to satisfy crop water demand is possible by implementing timely and soil-specific irrigation scheduling. Water use would then not be higher than the current Uzbek irrigation standards. It is argued that if furrow irrigation is to be continued, pure sandy soils, which constitute <5% of the agricultural soils in Khorezm, are best to be taken out of annual cotton production.

Control of surface soil chemistry in early-successional floodplain soils along the Tanana River, interior Alaska

Surface soils on recently deposited alluvium along the Tanana River, Alaska, have an elevated pH and are high in salts such as calcium carbonate and calcium sulfate. With advancing plant succession surface soil chemistry changes, and when the alder–balsam poplar stage is reached these salt deposits are absent. To test the hypothesis that soil surface salt (salt crust) accumulates as a result of the combined action of capillary rise of groundwater and surface evaporation, a treated plot experiment was undertaken in the early open willow stage on the floodplain where the soil surface was devoid of litter. Treatments, applied in early summer, were salt crust removed, leaf litter added on the surface (evaporation barrier), and polyethylene sheeting installed at a depth of 30 cm (capillary rise barrier). Surface 5 cm soil samples, collected in September, showed significant reductions from salt crust removal and surface litter application in electrical conductance and amounts of bicarbonate, sulfate, calcium, magnesium, potassium, and sodium. In clearings within dense alder–balsam poplar stands on the first terrace, forest floor removal resulted in significantly increased amounts of surface soil sodium, sulfate, calcium, and magnesium. However, this treatment did not result in re-establishment of the salt crust, probably because of a higher ground surface elevation at this terrace and consequent deeper water table. On lower, early-successional terraces salt crusts may form in a period of only several weeks if precipitation is low. The advent of a complete litter layer has great significance in the successional sequence on these soils not only because of nutrient cycling as a result of decomposition processes but also because of the probable physical effect of severely decreasing rates of evaporation from the mineral soil surface. In the latter case, although we did not directly measure mineral soil surface evaporation rates with and without litter layers, movement of salt solution injected at 25 cm in the soil profile to the surface was restricted by application of a surface litter layer.

Effects of salinity and waterlogging on the vegetation of Lake Toolibin, Western Australia

AbstractIncreased rates of tree senescence and mortality in and adjacent to an ephemeral lake in the Western Australian wheatbelt have been attributed to increased levels of soil salinity and inundation following agricultural clearing. Winter lake salinities approximate freshwater lake values, but during periods when the lake is dry, capillary rise of groundwater is thought to increase surface soil salinity. An undescribed species of Melaleuca and Casuarina obesa dominated the seasonally inundated regions of the lake bed. Aeolian deposits of higher elevation were dominated by Eucalyptus loxophleba, Allocasuarina huegeliana or species of Banksia. Woodland of E. oleosa var. longicornis and E. salmonophloia occurred predominantly on upland fluviatile deposits of sand and sandy clays. Measurements of soil salinity and the calculation of percentage inundation from tree elevations and observations of tree vigour and xylem pressure potential response indicated that tree deaths in Melaleuca sp. and C. obesa were due to increased levels of salinity. Deaths and low vigours in E. rudis were attributed to both increasing salinities and prolonged inundation. We believe control of ground water levels should be a major consideration in the preservation of this ephemeral lake and the water fowl populations it supports.

INFLUENCE OF RAIN ON THE GROUND WATER LEVEL

It is true that the rainfall causes to rise the level of ground water, but the rate of rising is dependent on the characteristics of rainfall, antecedent rain and evapotranspiration etc. The author carried out an investigation on the rainfall effects which influenced the change in the ground water level on the basis of rainfall characteristics and the nature of soil layer of the sand dune in natural condition. In selecting an observation well, the author examined several conditions such as the depth to ground water table, the effect of lateral ground water flow and the effect of tide. The southern part of Kashima (Fig. 1) was selected as the study field where no appreciable influences mentioned above were found. To obtain basic data, precipitation was measured by a self-recording gauge, water table level by a self-recording water level gauge, infiltration by an infiltration gauge (made by myself) and soil moisture by the oven-dry method (Fig. 3). The investigation was made during three months from June 27 th to November 25th in 1967 (Fig. 4). The results obtained were summarized as follow: (1) Soil moisture increase caused by a single rain amounting to 155.0mm depth was calculated to be 132.7mm, while 22.3mm was lost by evapotranspiration. (2) Deficit of soil moisture before rainfall is an important factor influencing the rate of rising of ground water level. (3) The following point was made clear by measuring the effective porosity of the shallower (sand) and the deeper part (clayey sand under 80cm from the surface) of the soil column at the observation site that the smaller effective porosity in the deeper part was caused by capillary rise of ground water.

Environmental Impact Assessment On The PorousStone Masonries Of The Rethymnon Fortress

The weathering of monuments, considered as interaction between building materials and environmental factors, presents specific interest in the case of the marine environment in the mild climatic conditions of the Mediterranean. An extended monument, like the Fortress of Rethymnon could well serve as an example. It is constructed by a susceptible to salt decay biocalcareous porous stone and suffers mainly from salt crystallization and hard carbonate crust formation. The research program develops on various masonry surfaces, as far as position and exposure orientation to various environmental factors are concerned mainly regarding humidity sources like groundwater's capillary rise and marine salt spray. Stone specimens from various positions along the Fortress, characteristic of the various decay patterns, underwent mineralogical and microstructural examination. Digital image processing is performed on characteristic surface images from the Fortifications, acquired from photograms and restituted in false colors, in order to assess and evaluate the environmental impact to the masonries according to the physicochemical criteria employed for the weathering classification (microstructure, texture and composition). Digital image processing is proved to be a reliable automatic mapping method for environmental impact assessment on extended masonry surfaces, when the conversion of the varying surface energy contents renders and distinguishes the microstructural and textural characteristics of weathered stones. Hence, a sound basis for interdisciplinary scientific conservation planning is provided.