scholarly journals Analysis of the suitability of the German soil texture classification for the regional scale application of physical based hydrological model

2007 ◽  
Vol 11 ◽  
pp. 7-13 ◽  
Author(s):  
H. Bormann
Keyword(s):  
Water Balance ◽  
Soil Texture ◽  
Texture Classification ◽  
Regional Scale ◽  
Grid Cell ◽  
Grid Cells ◽  
Soil Columns ◽  
Transfer Scheme ◽  
Physically Based ◽  
Texture Class

Abstract. Regional scale hydrological simulations are mostly based on the use of standard data sets such as soil maps which are based on soil texture classification schemes. This paper analyses the suitability of the German soil texture classification for the application of a physically based soil-vegetation-atmosphere-transfer scheme. Theoretical soil columns are defined to be able to represent the entire soil texture triangle by a 1% grid of the three particle size classes: sand, clay and silt. These theoretical soil columns are characterized by a homogenous soil texture and consist of two layers of increasing bulk density and decreasing content of organic matter with depth. Soil hydraulic parameterisation is derived by applying a pedotransfer function. Continuous water balance calculations are carried out for a ten year period for all grid cells of the 1% grid. The results of the water balance calculations are compared to the simulation results of the centre of gravity of the respective soil texture class. Texture class specific mean deviations and root mean squared deviations are calculated from the differences between the 1% pixels and texture class representatives. The results reveal that the loam and silt texture classes show only small deviations from the centres of gravity. For a few sand texture classes and most of the clay texture classes deviations are considerably large. Assuming an equal distributed probability of occurrence of all realisations within a soil texture class, an uncertainty of more than 100 mm/a with respect to runoff and actual evapotranspiration is detected for four clay texture classes, two sand texture classes and one silt texture class. These results are confirmed by a sensitivity analysis investigating the model response for a grid cell compared to the neighboured grid cells. High sensitivities mainly appear for sandy and clayey soils while the sensitivity of the model for loam and silt soils is smaller. Resuming it can be stated that most of the texture classes of the German texture classification scheme are suitable for the application of a physically based model, on regional scale in particular. Clay texture classes can be expected to cause high simulation uncertainties.

Using digital soil hydraulic maps to simulate water balance at the regional scale (southern Portugal) - impact of spatial resolution and modelling approach

2021 ◽  
Author(s):  
Ana R. Oliveira ◽  
Ana Horta ◽  
Tiago Ramos
Keyword(s):  
Water Balance ◽  
Soil Water ◽  
Soil Texture ◽  
Regional Scale ◽  
Water Dynamics ◽  
Irrigation District ◽  
Geostatistical Simulation ◽  
Southern Portugal ◽  
Soil Hydraulic ◽  
Modelling Approaches

<p>Modelling of soil physical, chemical, and biological processes is critical to improve the understanding of soil functions, the effect of agricultural practices on soil degradation, and appropriate soil management strategies. However, the use of such tools at the regional scale is largely limited by the lack of accurate mapping of soil texture and soil hydraulic properties (SHP). To overcome this limitation, SHP digital maps were obtained using two modelling approaches. One used a national harmonized soil texture database and geostatistical simulation to create soil texture maps which were further used as input data to derive SHP maps using local pedotransfer functions (PTFs). The other approach used SHP maps produced by Tóth et al (2017) using soil texture from the product SoilsGrids (Hengl et al, 2017). The SHP maps from both approaches were produced at two spatial resolutions: 250 m and 1000 m. This study aims to evaluate the usefulness of such SHP maps to simulate soil water dynamics and biomass growth at the regional scale using the MOHID-Land model. This model describes the movement of water in the porous medium based on mass and momentum conservation equations that are computed in a 3D grid domain using a finite volume approach. Crop development is simulated using a modified version of the EPIC model. The SHP maps produced using the two modelling approaches and considering two spatial resolutions (250 and 1000 m) were used as inputs for the hydraulic characteristics of soils. Simulations were compared for an irrigation area (Roxo Irrigation District), located in southern Portugal. Results revealed the differences in the components of the soil water balance, with soil inputs from local data being able to better portray landscape heterogeneity.</p>

scholarly journals Modeling boreal forest evapotranspiration and water balance at stand and catchment scales: a spatial approach

2019 ◽  
Vol 23 (8) ◽  
pp. 3457-3480 ◽  
Author(s):  
Samuli Launiainen ◽  
Mingfu Guan ◽  
Aura Salmivaara ◽  
Antti-Jussi Kieloaho
Keyword(s):  
Stomatal Conductance ◽  
Water Balance ◽  
Grid Cell ◽  
Hydrological Processes ◽  
Distributed Model ◽  
Transfer Scheme ◽  
Area Index ◽  
Vegetation Heterogeneity ◽  
Gis Data ◽  
Open Gis

Abstract. Vegetation is known to have strong influence on evapotranspiration (ET), a major component of terrestrial water balance. Yet hydrological models often describe ET by methods unable to include the variability of vegetation characteristics in their predictions. To take advantage of the increasing availability of high-resolution open GIS data on land use, vegetation and soil characteristics in the boreal zone, a modular, spatially distributed model for predicting ET and other hydrological processes from grid cell to catchment level is presented and validated. An improved approach to upscale stomatal conductance to canopy scale using information on plant type (conifer/deciduous) and stand leaf-area index (LAI) is proposed by coupling a common leaf-scale stomatal conductance model with a simple canopy radiation transfer scheme. Further, a generic parametrization for vegetation-related hydrological processes for Nordic boreal forests is derived based on literature and data from a boreal FluxNet site. With the generic parametrization, the model was shown to reproduce daily ET measured using an eddy-covariance technique well at 10 conifer-dominated Nordic forests whose LAI ranged from 0.2 to 6.8 m2 m−2. Topography, soil and vegetation properties at 21 small boreal headwater catchments in Finland were derived from open GIS data at 16 m × 16 m grid size to upscale water balance from stand to catchment level. The predictions of annual ET and specific discharge were successful in all catchments, located from 60 to 68∘ N, and daily discharge was also reasonably well predicted by calibrating only one parameter against discharge measurements. The role of vegetation heterogeneity in soil moisture and partitioning of ET was demonstrated. The proposed framework can support, for example, forest trafficability forecasting and predicting impacts of climate change and forest management on stand and catchment water balance. With appropriate parametrization it can be generalized outside the boreal coniferous forests.

scholarly journals Compatibility of granulometric groups determined based on standard BN-78/9180-11 and granulometric groups according to PTG 2008 and USDA texture classes

2018 ◽  
Vol 69 (4) ◽  
pp. 223-233
Author(s):  
Michał Stępień ◽  
Elżbieta Bodecka ◽  
Dariusz Gozdowski ◽  
Magdalena Wijata ◽  
Joanna Groszyk ◽  
...  
Keyword(s):  
Soil Texture ◽  
Texture Classification ◽  
The United States ◽  
Agricultural Drought ◽  
United States Department ◽  
Department Of Agriculture ◽  
Great Probability ◽  
Soil Particles ◽  
Almost All ◽  
Texture Class

Abstract Two groups of soil texture classification, differing in limit diameters for particular soil fractions, are used in Poland. The older groups of classifications consider soil particles as < 1 mm and divide them into sand (1.0–0.1 mm), silt (0.1–0.02 mm) and fine or flowable particles (< 0.02 mm). These classifications are used, in a version which originated in 1956 and here denominated as PTG/Musierowicz 1956 in land quality assessment and elaboration of soil agricultural maps. Newer versions of these classifications – professional standard BN-78/9180-11 (1978) and division of soils in agronomic categories described in 1986 – are used in fertilizer recommendations and in agricultural drought monitoring. According to the new soil texture classification PTG 2008, the upper diameter limit for soil particles is 2 mm and these parts are divided into sand (2.0–0.05 mm), silt (0.05–0.002 mm) and clay (<0.002 mm). This classification is compatible with soil texture classification elaborated by the United States Department of Agriculture (USDA) and most frequently applied worldwide. In this paper, the results of analyses of 1087 soil samples representing almost all granulometric groups existing in older and newer Polish soil texture classifications were considered. On the base of the current and earlier studies, the table with probability of occurrence of granulometric group PTG 2008 or texture class USDA for particular granulometric groups BN-78/9180-11 was prepared. For majority of granulometric groups (pl, ps, psp, pgl, pgmp, gp, gpp, gl, glp, gc, gcp, ip, płi) determined on the base of BN-78/9180-11, it is possible to determine their granulometric group/texture class according to PTG 2008/USDA correctly and, frequently, unambiguously. For granulometric groups pglp, pgm, gs, gsp i and płg it is possible to propose with great probability more than one equivalent according to PTG 2008/USDA, and in other cases more studies are recommended.

scholarly journals Regional Analyses of Rainfall-Induced Landslide Initiation in Upper Gudbrandsdalen (South-Eastern Norway) Using TRIGRS Model

Geosciences ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 35
Author(s):  
Luca Schilirò ◽  
José Cepeda ◽  
Graziella Devoli ◽  
Luca Piciullo
Keyword(s):  
Numerical Simulations ◽  
Regional Scale ◽  
Shallow Landslides ◽  
South Eastern ◽  
Physically Based ◽  
Triggering Conditions ◽  
Cover Thickness ◽  
Regional Analyses ◽  
Factor Maps ◽  
Eastern Norway

In Norway, shallow landslides are generally triggered by intense rainfall and/or snowmelt events. However, the interaction of hydrometeorological processes (e.g., precipitation and snowmelt) acting at different time scales, and the local variations of the terrain conditions (e.g., thickness of the surficial cover) are complex and often unknown. With the aim of better defining the triggering conditions of shallow landslides at a regional scale we used the physically based model TRIGRS (Transient Rainfall Infiltration and Grid-based Regional Slope stability) in an area located in upper Gudbrandsdalen valley in South-Eastern Norway. We performed numerical simulations to reconstruct two scenarios that triggered many landslides in the study area on 10 June 2011 and 22 May 2013. A large part of the work was dedicated to the parameterization of the numerical model. The initial soil-hydraulic conditions and the spatial variation of the surficial cover thickness have been evaluated applying different methods. To fully evaluate the accuracy of the model, ROC (Receiver Operating Characteristic) curves have been obtained comparing the safety factor maps with the source areas in the two periods of analysis. The results of the numerical simulations show the high susceptibility of the study area to the occurrence of shallow landslides and emphasize the importance of a proper model calibration for improving the reliability.

scholarly journals A Novel Physically Based Distributed Model for Irrigation Districts’ Water Movement

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 692
Author(s):  
Boyu Mi ◽  
Haorui Chen ◽  
Shaoli Wang ◽  
Yinlong Jin ◽  
Jiangdong Jia ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Movement ◽  
Regional Scale ◽  
Irrigation District ◽  
Distributed Model ◽  
Efficiency Coefficient ◽  
Good Correspondence ◽  
Groundwater Movement ◽  
Irrigation Districts ◽  
Physically Based

The water movement research in irrigation districts is important for food production. Many hydrological models have been proposed to simulate the water movement on the regional scale, yet few of them have comprehensively considered processes in the irrigation districts. A novel physically based distributed model, the Irrigation Districts Model (IDM), was constructed in this study to address this problem. The model combined the 1D canal and ditch flow, the 1D soil water movement, the 2D groundwater movement, and the water interactions among these processes. It was calibrated and verified with two-year experimental data from Shahaoqu Sub-Irrigation Area in Hetao Irrigation District. The overall water balance error is 2.9% and 1.6% for the two years, respectively. The Nash–Sutcliffe efficiency coefficient (NSE) of water table depth and soil water content is 0.72 and 0.64 in the calibration year and 0.68 and 0.64 in the verification year. The results show good correspondence between the simulation and observation. It is practicable to apply the model in water movement research of irrigation districts.

scholarly journals Tiling soil textures for terrestrial ecosystem modelling via clustering analysis: a case study with CLASS-CTEM (version 2.1)

2017 ◽  
Author(s):  
Joe R. Melton ◽  
Reinel Sospedra-Alfonso ◽  
Kelly E. McCusker
Keyword(s):  
Soil Texture ◽  
Land Surface ◽  
Clustering Analysis ◽  
Clustering Algorithms ◽  
Terrestrial Ecosystem ◽  
Grid Cell ◽  
Moisture Stress ◽  
Ecosystem Model ◽  
Global Scale ◽  
Terrestrial Ecosystem Model

Abstract. We investigate the application of clustering algorithms to represent sub-grid scale variability in soil texture for use in a global-scale terrestrial ecosystem model. Our model, the coupled Canadian Land Surface Scheme – Canadian Terrestrial Ecosystem Model (CLASS-CTEM), is typically implemented at a coarse spatial resolution (ca. 2.8° × 2.8°) due to its use as the land surface component of the Canadian Earth System Model (CanESM). CLASS-CTEM can, however, be run with tiling of the land surface as a means to represent sub-grid heterogeneity. We first determined that the model was sensitive to tiling of the soil textures via an idealized test case before attempting to cluster soil textures globally. To cluster a high-resolution soil texture dataset onto our coarse model grid, we use two linked algorithms (OPTICS (Ankerst et al., 1999; Daszykowski et al., 2002) and Sander et al. (2003)) to provide tiles of representative soil textures for use as CLASS-CTEM inputs. The clustering process results in, on average, about three tiles per CLASS-CTEM grid cell with most cells having four or less tiles. Results from CLASS-CTEM simulations conducted with the tiled inputs (Cluster) versus those using a simple grid-mean soil texture (Gridmean) show CLASS-CTEM, at least on a global scale, is relatively insensitive to the tiled soil textures, however differences can be large in arid or peatland regions. The Cluster simulation has generally lower soil moisture and lower overall vegetation productivity than the Gridmean simulation except in arid regions where plant productivity increases. In these dry regions, the influence of the tiling is stronger due to the general state of vegetation moisture stress which allows a single tile, whose soil texture retains more plant available water, to yield much higher productivity. Although the use of clustering analysis appears promising as a means to represent sub-grid heterogeneity, soil textures appear to be reasonably represented for global scale simulations using a simple grid-mean value.

scholarly journals Description and Analysis of a 20-Year (1960-79) Digital Ice-Concentration Database for the Great Lakes of North America

1983 ◽  
Vol 4 ◽  
pp. 14-18 ◽  
Author(s):  
Raymond A. Assel
Keyword(s):  
North America ◽  
Great Lakes ◽  
Surface Area ◽  
Information Service ◽  
Grid Cell ◽  
Ice Cover ◽  
Unit Surface Area ◽  
Grid Cells ◽  
Data Set ◽  
Ice Concentration

A digital ice-concentration database spanning 20 years (1960 to 1979) was established for the Great Lakes of North America. Data on ice concentration, i.e. the percentage of a unit surface area of the lake that is ice-covered, were abstracted from over 2 800 historic ice charts produced by United States and Canadian government agencies. The database consists of ice concentrations ranging from zero to 100% in 10% increments for individual grid cells of size 5 × 5 km constituting the surface area of each Great Lake. The data set for each of the Great Lakes was divided into half-month periods for statistical analysis. Maxinium, minimum, median, mode, and average ice-concentrations statistics were calculated for each grid cell and half-month period. A lakewide average value was then calculated for each of the half-month ice-concentration statistics for all grid cells for a given lake. Ice-cover variability and the normal extent and progression of the ice cover is discussed within the context of the lakewide averaged value of the minimum and maximum ice concentrations and the lakewide averaged value of the median ice concentrations, respectively. Differences in ice-cover variability among the five Great Lakes are related to mean lake depth and accumulated freezing degree-days. A Great Lakes ice atlas presenting a series of ice charts which depict the maximum, minimum, and median icecover concentrations for each of the Great Lakes for nine half-monthly periods, starting the last half of December and continuing through the last half of April will be published in 1983 by the National Oceanic and Atmospheric Administration (NOAA). The database will be archived at the National Snow and Ice Data Center of the National Environmental Satellite Data and Information Service (NESDIS) in Boulder, Colorado, USA, also in 1983.

scholarly journals A new discrete multiplicative random cascade model for downscaling intermittent rainfall fields

2019 ◽  
Author(s):  
Marc Schleiss
Keyword(s):  
Classical Method ◽  
Mathematical Problem ◽  
Grid Cell ◽  
Cascade Model ◽  
Small Scale ◽  
Grid Cells ◽  
Cascade Generator ◽  
Cascade Models ◽  
First Results ◽  
Original Amount

Abstract. Spatial downscaling of rainfall fields is a challenging mathematical problem for which many different types of methods have been proposed. One popular solution consists in redistributing rainfall amounts over smaller and smaller scales by means of a discrete multiplicative random cascade (DMRC). This works well for slowly varying, homogeneous rainfall fields but often fails in the presence of intermittency (i.e., large amounts of zero rainfall values). The most common workaround in this case is to use two separate cascade models, one for the occurrence and another for the intensity. In this paper, a new and simpler approach based on the notion of equal-volume areas (EVAs) is proposed. Unlike classical cascades where rainfall amounts are redistributed over grid cells of equal size, the EVA cascade splits grid cells into areas of different sizes, each of them containing exactly half of the original amount of water. The relative areas of the sub-grid cells are determined by drawing random values from a logit-normal cascade generator model with scale and intensity dependent standard deviation. The process ends when the amount of water in each sub-grid cell is smaller than a fixed bucket capacity, at which point the output of the cascade can be re-sampled over a regular Cartesian mesh. The present paper describes the implementation of the EVA cascade model and gives some first results for 100 selected events in the Netherlands. Performance is assessed by comparing the outputs of the EVA model to bilinear interpolation and to a classical DMRC model based on fixed grid cell sizes. Results show that on average, the EVA cascade outperforms the classical method, producing fields with more realistic distributions, small-scale extremes and spatial structures. Improvements are mostly credited to the higher robustness of the EVA model to the presence of intermittency and to the lower variance of its generator. However, improvements are not systematic and both approaches have their advantages and weaknesses. For example, while the classical cascade tends to overestimate small-scale extremes and variability, the EVA model tends to produce fields that are slightly too smooth and blocky compared with observations.

scholarly journals The green, blue and grey water footprint of crops and derived crop products

2011 ◽  
Vol 8 (1) ◽  
pp. 763-809 ◽  
Author(s):  
M. M. Mekonnen ◽  
A. Y. Hoekstra
Keyword(s):  
Water Balance ◽  
River Basin ◽  
Crop Production ◽  
Water Footprint ◽  
Grid Cell ◽  
Blue Water ◽  
Total Water ◽  
Grey Water ◽  
Global Average ◽  
Average Water

Abstract. This study quantifies the green, blue and grey water footprint of global crop production in a spatially-explicit way for the period 1996–2005. The assessment is global and improves upon earlier research by taking a high-resolution approach, estimating the water footprint of 126 crops at a 5 by 5 arc min grid. We have used a grid-based dynamic water balance model to calculate crop water use over time, with a time step of one day. The model takes into account the daily soil water balance and climatic conditions for each grid cell. In addition, the water pollution associated with the use of nitrogen fertilizer in crop production is estimated for each grid cell. The crop evapotranspiration of additional 20 minor crops is calculated with the CROPWAT model. In addition, we have calculated the water footprint of more than two hundred derived crop products, including various flours, beverages, fibres and biofuels. We have used the water footprint assessment framework as in the guideline of the water footprint network. Considering the water footprints of primary crops, we see that global average water footprint per ton of crop increases from sugar crops (roughly 200 m3 ton−1), vegetables (300 m3 ton−1), roots and tubers (400 m3 ton−1), fruits (1000 m3 ton−1), cereals} (1600 m3 ton−1), oil crops (2400 m3 ton−1) to pulses (4000 m3 ton−1). The water footprint varies, however, across different crops per crop category and per production region as well. Besides, if one considers the water footprint per kcal, the picture changes as well. When considered per ton of product, commodities with relatively large water footprints are: coffee, tea, cocoa, tobacco, spices, nuts, rubber and fibres. The analysis of water footprints of different biofuels shows that bio-ethanol has a lower water footprint (in m3 GJ−1) than biodiesel, which supports earlier analyses. The crop used matters significantly as well: the global average water footprint of bio-ethanol based on sugar beet amounts to 51 m3 GJ−1, while this is 121 m3 GJ−1 for maize. The global water footprint related to crop production in the period 1996–2005 was 7404 billion cubic meters per year (78% green, 12% blue, 10% grey). A large total water footprint was calculated for wheat (1087 Gm3 yr−1), rice (992 Gm3 yr−1) and maize (770 Gm3 yr−1). Wheat and rice have the largest blue water footprints, together accounting for 45% of the global blue water footprint. At country level, the total water footprint was largest for India (1047 Gm3 yr−1), China (967 Gm3 yr−1) and the USA (826 Gm3 yr−1). A relatively large total blue water footprint as a result of crop production is observed in the Indus River Basin (117 Gm3 yr−1) and the Ganges River Basin (108 Gm3 yr−1). The two basins together account for 25% of the blue water footprint related to global crop production. Globally, rain-fed agriculture has a water footprint of 5173 Gm3 yr−1 (91% green, 9% grey); irrigated agriculture has a water footprint of 2230 Gm3 yr−1 (48% green, 40% blue, 12% grey).

scholarly journals Assessing the regional surface influence through Backward Lagrangian Dispersion Models for aircraft CO<sub>2</sub> vertical profiles observations in NE Spain

2010 ◽  
Vol 10 (3) ◽  
pp. 8103-8134
Author(s):  
A. Font ◽  
J.-A. Morguí ◽  
X. Rodó
Keyword(s):  
Regional Scale ◽  
Grid Cell ◽  
Particle Dispersion ◽  
Vertical Profiles ◽  
Lagrangian Particle ◽  
Mixing Ratios ◽  
Continental Scale ◽  
Lagrangian Dispersion ◽  
Threshold Criteria ◽  
Ne Spain

Abstract. A weekly climatology for 2006 composed of 96-h-backward Lagrangian Particle Dispersion simulations is presented for nine aircraft sites measuring vertical profiles of atmospheric CO2 mixing ratios along the 42° N parallel in NE Spain to assess the surface influence at a regional scale (102–103 km) at different altitudes in the vertical profile (600, 1200, 2500 and 4000 meters above the sea level, m a.s.l.). The Potential Surface Influence (PSI) area for the 96-h-backward simulations, defined as the air layer above ground with a thickness of 300 m, are reduced from the continental scale (~107 km2) to the watershed one (~104 km2), when a Residence Time Threshold Criteria (Rttc) greater than 500 s is imposed for each grid cell. In addition, this regional restricted information is confined during 50 h before the arrival for simulations centered at 600 and 1200 m a.s.l. At higher altitudes (2500 and 4000 m a.s.l.), the regional surface influence is only recovered during spring and summer months. For simulations centered at 600 and 1200 m a.s.l. sites separated by ~60 km may overlap 20–50% of the regional surface influences whereas sites separated by ~350 km as such do not overlap. The overlap for sites separated by ~60 km decreases to 8–40% at higher altitudes (2500 and 4000 m a.s.l.). A dense network of sampling sites below 2200 m a.s.l. (whether aircraft sites or tall tower ones) guarantees an appropriate regional coverage to properly assess the dynamics of the regional carbon cycle at a watershed scale (102–103 km length scale).

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