scholarly journals Two soil hydrology formulations of ORCHIDEE (version Trunk.rev1311) tested for the Amazon basin

2014 ◽  
Vol 7 (1) ◽  
pp. 73-129
Author(s):  
M. Guimberteau ◽  
P. Ciais ◽  
A. Ducharne ◽  
J. P. Boisier ◽  
S. Peng ◽  
...  

Abstract. This study analyzes the impact of the two soil model parameterizations of the Land Surface Model ORCHIDEE on their estimates of Amazonian hydrology and phenology for five major sub-basins (Xingu, Tapajós, Madeira, Solimões and Negro), during the 29 yr period 1980–2008. The two soil models are a simple 2 layer soil scheme with a bucket topped by an evaporative layer vs. an 11 layer soil diffusion scheme. The soil models were coupled with a river routing module and a process model of plant physiology, phenology and carbon dynamics. The simulated water budget and vegetation functioning components were compared with several datasets at sub-basin scale. The use of the 11 layer soil diffusion scheme did not significantly change the Amazonian water budget simulation when compared to the 2 layer soil scheme (+3.1 and −3.0% in evapotranspiration and river discharge, respectively). However, the higher water holding capacity of the soil and the physically based representation of runoff and drainage in the 11 layer soil diffusion, resulted in higher dynamics of soil water storage variation and improved simulation of the total terrestrial water storage when compared to GRACE satellite estimates. The greater soil water storage within the 11 layer soil diffusion scheme resulted in increased dry-season evapotranspiration (+0.5 mm d−1, +17%) and river discharge in the southeastern sub-basins such as the Xingu. Evapotranspiration over this sub-basin was sustained during the whole dry season with the 11 layer soil diffusion model, whereas the 2 layer soil scheme limited it at the end of the dry season. Lower plant water stress simulated by the 11 layer soil diffusion scheme, led to better simulation of the seasonal cycle of photosynthesis (GPP) when compared to a GPP data-driven model based upon eddy-covariance and satellite greenness measurements. Simulated LAI was consequently higher with the 11LAY (up to +0.4) but exhibited too low a variation when compared to a satellite-based dataset. The dry-season length between 4 and 7 months over the entire Amazon basin was found to be critical in distinguishing differences in hydrological feedbacks between the soil and the vegetation cover simulated by the two soil models. Overall, the 11 layer soil diffusion scheme provided little improvement in simulated hydrology on average over the wet tropical Amazonian sub-basins but a more significant improvement over the drier sub-basins. However, the use of the 11 layer soil diffusion scheme might become critical for assessments of future hydrological changes, especially in southern regions of the Amazon basin where longer dry season and more severe droughts are expected in the next century.

2014 ◽  
Vol 7 (3) ◽  
pp. 1115-1136 ◽  
Author(s):  
M. Guimberteau ◽  
A. Ducharne ◽  
P. Ciais ◽  
J. P. Boisier ◽  
S. Peng ◽  
...  

Abstract. This study analyzes the performance of the two soil hydrology schemes of the land surface model ORCHIDEE in estimating Amazonian hydrology and phenology for five major sub-basins (Xingu, Tapajós, Madeira, Solimões and Negro), during the 29-year period 1980–2008. A simple 2-layer scheme with a bucket topped by an evaporative layer is compared to an 11-layer diffusion scheme. The soil schemes are coupled with a river routing module and a process model of plant physiology, phenology and carbon dynamics. The simulated water budget and vegetation functioning components are compared with several data sets at sub-basin scale. The use of the 11-layer soil diffusion scheme does not significantly change the Amazonian water budget simulation when compared to the 2-layer soil scheme (+3.1 and −3.0% in evapotranspiration and river discharge, respectively). However, the higher water-holding capacity of the soil and the physically based representation of runoff and drainage in the 11-layer soil diffusion scheme result in more dynamic soil water storage variation and improved simulation of the total terrestrial water storage when compared to GRACE satellite estimates. The greater soil water storage within the 11-layer scheme also results in increased dry-season evapotranspiration (+0.5 mm d−1, +17%) and improves river discharge simulation in the southeastern sub-basins such as the Xingu. Evapotranspiration over this sub-basin is sustained during the whole dry season with the 11-layer soil diffusion scheme, whereas the 2-layer scheme limits it after only 2 dry months. Lower plant drought stress simulated by the 11-layer soil diffusion scheme leads to better simulation of the seasonal cycle of photosynthesis (GPP) when compared to a GPP data-driven model based on eddy covariance and satellite greenness measurements. A dry-season length between 4 and 7 months over the entire Amazon Basin is found to be critical in distinguishing differences in hydrological feedbacks between the soil and the vegetation cover simulated by the two soil schemes. On average, the multilayer soil diffusion scheme provides little improvement in simulated hydrology over the wet tropical Amazonian sub-basins, but a more significant improvement is found over the drier sub-basins. The use of a multilayer soil diffusion scheme might become critical for assessments of future hydrological changes, especially in southern regions of the Amazon Basin where longer dry seasons and more severe droughts are expected in the next century.


2009 ◽  
Vol 60 (8) ◽  
pp. 730 ◽  
Author(s):  
P. R. Ward ◽  
K. Whisson ◽  
S. F. Micin ◽  
D. Zeelenberg ◽  
S. P. Milroy

In Mediterranean-type climates, dryland soil water storage and evaporation during the hot and dry summer are poorly understood, particularly for sandy-textured soils. Continued evaporation during summer, and any effects of crop stubble management, could have a significant impact on annual components of the water balance and crop yield. In this research, the effect of wheat stubble management on summer evaporation and soil water storage was investigated for a sandy soil in south-western Australia, during the summers of 2005–06 and 2006–07. Treatments comprised: retained standing stubble; retained flattened stubble; removed stubble; and removed stubble followed by burying the crowns with topsoil from an adjacent area. Under ‘dry’ conditions, evaporation continued at ~0.2 mm/day. In contrast to previous results for finer textured soil types, stubble retention did not decrease the rate of evaporation, but marginally (10–30%) increased evaporation on 7 out of 14 days when measurements were taken. Significant differences due to stubble management were observed in two successive summers, but only for relatively dry soil conditions. There were no significant differences observed for several days after irrigation or rainfall. Under dry conditions in the absence of rainfall, total decrease in water storage during a 90-day summer period could be ~20 mm, but differences attributable to stubble management are likely to be a few mm.


2016 ◽  
Vol 24 (2) ◽  
pp. 31-40
Author(s):  
Miroslava Jarabicová ◽  
Peter Minarič

Abstract The main objective of this paper is to evaluate the impact of climate change on the soil-water regime of the Záhorská lowlands. The consequences of climate change on soil-water storage were analyzed for two crops: spring barley and maize. We analyzed the consequences of climate change on soil-water storage for two crops: spring barley and maize. The soil-water storage was simulated with the GLOBAL mathematical model. The data entered into the model as upper boundary conditions were established by the SRES A2 and SRES B1 climate scenarios and the KNMI regional climate model for the years from 2071 to 2100 (in the text called the time horizon 2085 which is in the middle this period). For the reference period the data from the years 1961-1990 was used. The results of this paper predict soil-water storage until the end of this century for the crops evaluated, as well as a comparison of the soil-water storage predictions with the course of the soil-water storage during the reference period.


Geosciences ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 344
Author(s):  
Marco Delle Rose ◽  
Corrado Fidelibus ◽  
Paolo Martano

In this note, the Water Budget Method (WBM) is applied to estimate local values of the specific yield of the deep karst aquifer of Salento peninsula. A selection in a period of two years of relevant short precipitation events has been considered and the related localized recharges have been compared to the water table fluctuations measured at two selected wells. The recharge amounts have been corrected by using data of evapotranspiration and soil water storage available from a micrometeorological base. The results are very similar for both the wells and more consistent when the corrections are applied. A discussion involving frequency and apertures of the fractures in the rock mass of the aquifer suggests the effect of the karst dissolution to be dominant in determining these values of the specific yield.


1997 ◽  
Vol 1 (2) ◽  
pp. 265-277 ◽  
Author(s):  
M. G. Hodnett ◽  
I. Vendrame ◽  
A. De O. Marques Filho ◽  
M. D. Oyama ◽  
J. Tomasella

Abstract. Soil water storage was monitored in three landscape elements in the forest (plateau, slope and valley floor) over a 3 year period to identify differences in sub-surface hydrological response. Under the plateau and slope, the changes of storage were very similar and there was no indication of surface runoff on the slope. The mean maximum seasonal storage change was 156 mm in the 2 m profile but it was clear that, in the dry season, the forest was able to take up water from below 3.6 m. Soil water availability was low. Soil water storage changes in the valley were dominated by the behaviour of a shallow water table which, in normal years, varied between 0.1 m below the surface at the end of the wet season and 0.8 m at the end of the dry season. Soil water storage changes were small because root uptake was largely replenished by groundwater flow towards the stream. The groundwater behaviour is controlled mainly by the deep drainage from beneath the plateau and slope areas. The groundwater gradient beneath the slope indicated that recharge beneath the plateau and slope commences only after the soil water deficits from the previous dry season have been replenished. Following a wet season with little recharge, the water table fell, ceasing to influence the valley soil water storage, and the stream dried up. The plateau and slope, a zone of very high porosity between 0.4 and 1.1 m, underlain by a less conductive layer, is a probable route for interflow during, and for a few hours after, heavy and prolonged rainfall.


2010 ◽  
Vol 67 (1) ◽  
pp. 87-95 ◽  
Author(s):  
Durval Dourado-Neto ◽  
Quirijn de Jong van Lier ◽  
Klaas Metselaar ◽  
Klaus Reichardt ◽  
Donald R. Nielsen

The original Thornthwaite and Mather method, proposed in 1955 to calculate a climatic monthly cyclic soil water balance, is frequently used as an iterative procedure due to its low input requirements and coherent estimates of water balance components. Using long term data sets to establish a characteristic water balance of a location, the initial soil water storage is generally assumed to be at field capacity at the end of the last month of the wet season, unless the climate is (semi-) arid when the soil water storage is lower than the soil water holding capacity. To close the water balance, several iterations might be necessary, which can be troublesome in many situations. For (semi-) arid climates with one dry season, Mendonça derived in 1958 an equation to quantify the soil water storage monthly at the end of the last month of the wet season, which avoids iteration procedures and closes the balance in one calculation. The cyclic daily water balance application is needed to obtain more accurate water balance output estimates. In this note, an equation to express the water storage for the case of the occurrence of more than one dry season per year is presented as a generalization of Mendonça's equation, also avoiding iteration procedures.


2013 ◽  
Vol 21 (1) ◽  
pp. 1-8
Author(s):  
Mária Pásztorová

Abstract Climate change is one of the largest threats to the modern world. It is primarily experienced via changes and extreme weather events, including air temperature changes, the uneven distribution of precipitation and an increase in the alteration of torrential short-term precipitation and longer non-precipitation periods. However climate change is not only a change in the weather; it also has a much larger impact on an ecosystem. As a result of expected climate change, a lack of either surface water or groundwater could occur within wetlands; thus, the existence of wetlands and their flora and fauna could be threatened. This submitted work analyses the impact of climate change on the wetland ecosystems of Poiplie, which is situated in the south of Slovakia in the Ipeľ river basin. The area is an important wetland biotope with rare plant and animal species, which mainly live in open water areas, marshes, wet meadows and alluvial forests. To evaluate any climate change, the CGCM 3.1 model, two emission scenarios, the A2 emission scenario (pessimistic) and the B1 emission scenario (optimistic), were used within the regionalization. For simulating the soil water storage, which is one of the components of a soil water regime, the GLOBAL mathematical model was used.


2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Mandana Rahgozar ◽  
Nirjhar Shah ◽  
Mark Ross

Simultaneous measurements of soil moisture profiles and water table heads, along a flow path, were used to determine evapotranspiration (ET) along with other components of the water budget. The study was conducted at a small-scale (~0.8 Km2) hydrologic monitoring field site in Hillsborough County, Florida, from January 2002 to June 2004. Frequency Domain Reflectometry soil moisture probes, installed in close proximity to water table monitoring wells were used to derive changes in the soil water storage. A one-dimensional transect model was developed; changes in the soil water storage and water table observations served as input to determine all vertical and lateral boundary fluxes along the shallow water table flow plane. Two distinct land cover environments, grassland and an alluvial wetland forest, were investigated in this particular study. The analysis provided temporally variable ET estimates for the two land covers with annual totals averaging 850 mm for grassland, to 1100 mm for the alluvial wetland forest. Quantitative estimates of other components of a water budget, for example, infiltration, interception capture, total rainfall excess, and runoff were also made on a quarterly and annual basis. Novelty of this approach includes ability to resolve ET components and other water budget fluxes that provide useful parameterization and calibration potential for predictive simulation models.


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