scholarly journals GLOBAL SIMULATION OF GROUNDWATER RECHARGE, WATER TABLE DEPTH, AND LOW FLOW USING A LAND SURFACE MODEL WITH GROUNDWATER REPRESENTATION

2012 ◽  
Vol 68 (4) ◽  
pp. I_211-I_216 ◽  
Author(s):  
Sujan KOIRALA ◽  
Hannah YAMADA ◽  
Pat YEH ◽  
Taikan OKI ◽  
Yukiko HIRABAYASHI ◽  
...  
Keyword(s):  
Groundwater Recharge ◽  
Water Table ◽  
Land Surface ◽  
Land Surface Model ◽  
Water Table Depth ◽  
Low Flow ◽  
Surface Model ◽  
Global Simulation

Evaluation of modelled methane emissions over high-latitude wetlands

2020 ◽  
Author(s):  
Yao Gao ◽  
Eleanor Burke ◽  
Sarah Chadburn ◽  
Maarit Raivonen ◽  
Timo Vesala ◽  
...  
Keyword(s):  
Soil Respiration ◽  
Soil Carbon ◽  
Water Table ◽  
High Latitude ◽  
Land Surface ◽  
Water Table Depth ◽  
Surface Model ◽  
Emission Model ◽  
Earth System ◽  
Positive Feedbacks

<p>Atmospheric emissions and concentrations of CH<sub>4</sub> are continuing to increase, making CH<sub>4</sub> the second most important human-influenced greenhouse gas in terms of climate forcing, after CO<sub>2</sub>. Previous studies indicated that wetland CH<sub>4</sub> emission is not only the single largest but also the most uncertain natural source in the global CH<sub>4</sub> budget. Furthermore, the strong sensitivity of wetland CH<sub>4</sub> emissions to environmental conditions has raised concerns on potential positive feedbacks to climate change. Therefore, evaluation of the process-based land surface models of earth system models (ESMs) in simulating CH<sub>4</sub> emission over wetlands is needed for more precise future predictions. In this work, a set of high-latitude wetland sites with various nutrient conditions are studied. The wetland CH<sub>4</sub> fluxes are simulated by the land surface model JULES of the UK Earth System model and the Helsinki peatland methane emission model (HIMMELI), which is developed at Finnish Meteorological Institute and Helsinki University. The differences between the modelled and observed CH<sub>4</sub> fluxes are analyzed, complemented with key environmental variables for interpretation (e.g. soil temperature and moisture, vegetation types, snow depth, NPP, soil carbon). In general, the simulated CH<sub>4</sub> fluxes by HIMMELI is closer to the observed CH<sub>4</sub> fluxes in magnitude and seasonality at sites than those by JULES. The inter-annual variability of simulated CH<sub>4</sub> fluxes by HIMMELI depends on the simulated anoxic soil respiration, which serves as the substrate of the CH<sub>4</sub> fluxes in HIMMELI. The anoxic soil respiration is calculated based on the simulated soil respiration and water table depth in JULES. More accurate simulation of soil carbon pool and water table depth in JULES will lead to improvement in the simulated anoxic soil respiration.</p>

scholarly journals Development of a Coupled Land Surface Hydrologic Model and Evaluation at a Critical Zone Observatory

2013 ◽  
Vol 14 (5) ◽  
pp. 1401-1420 ◽  
Author(s):  
Yuning Shi ◽  
Kenneth J. Davis ◽  
Christopher J. Duffy ◽  
Xuan Yu
Keyword(s):  
Latent Heat ◽  
Water Table ◽  
Land Surface ◽  
Hydrologic Model ◽  
Heat Fluxes ◽  
Water Table Depth ◽  
Surface Model ◽  
Land Surface Scheme ◽  
Model Predictions ◽  
Surface Scheme

Abstract A fully coupled land surface hydrologic model, Flux-PIHM, is developed by incorporating a land surface scheme into the Penn State Integrated Hydrologic Model (PIHM). The land surface scheme is adapted from the Noah land surface model. Because PIHM is capable of simulating lateral water flow and deep groundwater at spatial resolutions sufficient to resolve upland stream networks, Flux-PIHM is able to represent heterogeneities due to topography and soils at high resolution, including spatial structure in the link between groundwater and the surface energy balance (SEB). Flux-PIHM has been implemented at the Shale Hills watershed (0.08 km2) in central Pennsylvania. Multistate observations of discharge, water table depth, soil moisture, soil temperature, and sensible and latent heat fluxes in June and July 2009 are used to manually calibrate Flux-PIHM at hourly temporal resolution. Model predictions from 1 March to 1 December 2009 are evaluated. Both hydrologic predictions and SEB predictions show good agreement with observations. Comparisons of model predictions between Flux-PIHM and the original PIHM show that the inclusion of the complex SEB simulation only brings slight improvement in hourly model discharge predictions. Flux-PIHM adds the ability of simulating SEB to PIHM and does improve the prediction of hourly evapotranspiration, the prediction of total runoff (discharge), and the predictions of some peak discharge events, especially after extended dry periods. Model results reveal that annual average sensible and latent heat fluxes are strongly correlated with water table depth, and the correlation is especially strong for the model grids near the stream.

scholarly journals Climate model based consensus on the hydrologic impacts of climate change to the Rio Lempa basin of Central America

2008 ◽  
Vol 5 (6) ◽  
pp. 3099-3128 ◽  
Author(s):  
E. P. Maurer ◽  
J. C. Adam ◽  
A. W. Wood
Keyword(s):  
Central America ◽  
Land Surface ◽  
Climate Models ◽  
Climate Model ◽  
Land Surface Model ◽  
Low Flow ◽  
Surface Model ◽  
Temperature And Precipitation ◽  
Hydrologic Impacts ◽  
Emissions Scenarios

Abstract. Temperature and precipitation from 16 climate models each using two emissions scenarios (lower B1 and mid-high A2) were used to characterize the range of potential climate changes for the Rio Lempa basin of Central America during the middle (2040–2069) and end (2070–2099) of the 21st century. A land surface model was applied to investigate the hydrologic impacts of these changes, focusing on inflow to two major hydropower reservoirs. By 2070–2099 the median warming relative to 1961–1990 was 1.9°C and 3.4°C under B1 and A2 emissions, respectively. For the same periods, the models project median precipitation decreases of 5.0% (B1) and 10.4% (A2). Median changes by 2070–2099 in reservoir inflow were 13% (B1) and 24% (A2), with largest flow reductions during the rising limb of the seasonal hydrograph, from June through September. Frequency of low flow years increases, implying decreases in firm hydropower capacity of 33% to 53% by 2070–2099.

scholarly journals Ensemble Evaluation of Hydrologically Enhanced Noah-LSM: Partitioning of the Water Balance in High-Resolution Simulations over the Little Washita River Experimental Watershed

2011 ◽  
Vol 12 (1) ◽  
pp. 45-64 ◽  
Author(s):  
Enrique Rosero ◽  
Lindsey E. Gulden ◽  
Zong-Liang Yang ◽  
Luis G. De Goncalves ◽  
Guo-Yue Niu ◽  
...  
Keyword(s):  
Water Table ◽  
Land Surface ◽  
Water Cycle ◽  
Land Surface Model ◽  
Surface Model ◽  
Model Parameters ◽  
Shallow Water Table ◽  
Total Runoff ◽  
Physically Based ◽  
Subsurface Runoff

Abstract The ability of two versions of the Noah land surface model (LSM) to simulate the water cycle of the Little Washita River experimental watershed is evaluated. One version that uses the standard hydrological parameterizations of Noah 2.7 (STD) is compared another version that replaces STD’s subsurface hydrology with a simple aquifer model and topography-related surface and subsurface runoff parameterizations (GW). Simulations on a distributed grid at fine resolution are compared to the long-term distribution of observed daily-mean runoff, the spatial statistics of observed soil moisture, and locally observed latent heat flux. The evaluation targets the typical behavior of ensembles of models that use realistic, near-optimal sets of parameters important to runoff. STD and GW overestimate the ratio of runoff to evapotranspiration. In the subset of STD and GW runs that best reproduce the timing and the volume of streamflow, the surface-to-subsurface runoff ratio is overestimated and simulated streamflow is much flashier than observations. Both models’ soil columns wet and dry too quickly, implying that there are structural shortcomings in the formulation of STD that cannot be overcome by adding GW’s increased complexity to the model. In its current formulation, GW extremely underestimates baseflow’s contribution to total runoff and requires a shallow water table to function realistically. In the catchment (depth to water table >10 m), GW functions as a simple bucket model. Because model parameters are likely scale and site dependent, the need for even “physically based” models to be extensively calibrated for all domains on which they are applied is underscored.

scholarly journals Climate model based consensus on the hydrologic impacts of climate change to the Rio Lempa basin of Central America

2009 ◽  
Vol 13 (2) ◽  
pp. 183-194 ◽  
Author(s):  
E. P. Maurer ◽  
J. C. Adam ◽  
A. W. Wood
Keyword(s):  
Central America ◽  
Land Surface ◽  
Climate Models ◽  
Climate Model ◽  
Land Surface Model ◽  
Low Flow ◽  
Surface Model ◽  
Temperature And Precipitation ◽  
Hydrologic Impacts ◽  
Emissions Scenarios

Abstract. Temperature and precipitation from 16 climate models each using two emissions scenarios (lower B1 and mid-high A2) were used to characterize the range of potential climate changes for the Rio Lempa basin of Central America during the middle (2040–2069) and end (2070–2099) of the 21st century. A land surface model was applied to investigate the hydrologic impacts of these changes, focusing on inflow to two major hydropower reservoirs. By 2070–2099 the median warming relative to 1961–1990 was 1.9°C and 3.4°C under B1 and A2 emissions, respectively. For the same periods, the models project median precipitation decreases of 5.0% (B1) and 10.4% (A2). Median changes by 2070–2099 in reservoir inflow were 13% (B1) and 24% (A2), with largest flow reductions during the rising limb of the seasonal hydrograph, from June through September. Frequency of low flow years increases, implying decreases in firm hydropower capacity of 33% to 53% by 2070–2099.

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