tri wahyuningsih - Academia.edu (original) (raw)
Papers by tri wahyuningsih
Hydrological Processes, 2020
The partitioning of rainfall into surface runoff and infiltration influences many other aspects o... more The partitioning of rainfall into surface runoff and infiltration influences many other aspects of the hydrologic cycle including evapotranspiration, deep drainage, and soil moisture. This partitioning is an instantaneous nonlinear process that is strongly dependent on rainfall rate, soil moisture, and soil hydraulic properties. Though all rainfall datasets involve some degree of spatial or temporal averaging, it is not understood how this averaging affects simulated partitioning and the land surface water balance across a wide range of soil and climate types. We used a one-dimensional physics-based model of the near-surface unsaturated zone to compare the effects of different rainfall discretization (5-minute point-scale; hourly point-scale; hourly 0.125° gridded) on the simulated partitioning of rainfall for many locations across the United States. Coarser temporal resolution rainfall data underpredicted seasonal surface runoff for all soil types except those with very high infiltration capacities (i.e., sand, loamy sand). Soils with intermediate infiltration capacities (i.e., loam, sandy loam) were the most affected, with less than half of the expected surface runoff produced in most soil types when the gridded rainfall dataset was used as input. The impact of averaging on the water balance was less extreme but non-negligible, with the hourly point-scale predictions exhibiting median evapotranspiration, drainage, and soil moisture values within 10% of those predicted using the higher-resolution 5-minute rainfall. Water balance impacts were greater using the gridded hourly dataset, with average underpredictions of ET up to 27% in fine-grained soils. The results suggest that "hyperresolution" modeling at continental to global
Soil Use and Management, 2018
Carbon sequestration in agricultural soils may help to reduce global greenhouse gas concentration... more Carbon sequestration in agricultural soils may help to reduce global greenhouse gas concentrations, but building up soil carbon levels requires accumulating organic matter faster than it is lost via heterotrophic respiration. Using field and laboratory studies, this study sought to elucidate how tillage, the below-ground incorporation of cover crop residue, and soil macroporosity affect soil respiration and residue decomposition rates. In the field, residue from a cover crop mixture of barley (Hordeum vulgare) and crimson clover (Trifolium incarnatum) was placed into litter bags that were left on the surface versus incorporated into the soil at three depths (4, 8 or 12 cm), while the laboratory study compared surfaceplaced versus incorporated litter (8 cm depth). To assess tillage effects on cover crop decomposition, the field study simulated no-till and conventional tillage treatments, while the laboratory and field studies both included treatments in which artificial soil macropores were created. The field study showed that conventional tillage and the presence of macropores enhanced soil respiration, while in the laboratory study, incorporating cover crop residue resulted in higher soil respiration and faster litter decomposition rates. Additionally, the laboratory measurements showed that macropores increased soil respiration in wet conditions, likely by enhancing oxygen diffusion. Thus, organic matter incorporation and macropores may represent important factors that affect soil respiration and carbon dynamics.
Hydrological Processes, 2020
The partitioning of rainfall into surface runoff and infiltration influences many other aspects o... more The partitioning of rainfall into surface runoff and infiltration influences many other aspects of the hydrologic cycle including evapotranspiration, deep drainage, and soil moisture. This partitioning is an instantaneous nonlinear process that is strongly dependent on rainfall rate, soil moisture, and soil hydraulic properties. Though all rainfall datasets involve some degree of spatial or temporal averaging, it is not understood how this averaging affects simulated partitioning and the land surface water balance across a wide range of soil and climate types. We used a one-dimensional physics-based model of the near-surface unsaturated zone to compare the effects of different rainfall discretization (5-minute point-scale; hourly point-scale; hourly 0.125° gridded) on the simulated partitioning of rainfall for many locations across the United States. Coarser temporal resolution rainfall data underpredicted seasonal surface runoff for all soil types except those with very high infiltration capacities (i.e., sand, loamy sand). Soils with intermediate infiltration capacities (i.e., loam, sandy loam) were the most affected, with less than half of the expected surface runoff produced in most soil types when the gridded rainfall dataset was used as input. The impact of averaging on the water balance was less extreme but non-negligible, with the hourly point-scale predictions exhibiting median evapotranspiration, drainage, and soil moisture values within 10% of those predicted using the higher-resolution 5-minute rainfall. Water balance impacts were greater using the gridded hourly dataset, with average underpredictions of ET up to 27% in fine-grained soils. The results suggest that "hyperresolution" modeling at continental to global
Soil Use and Management, 2018
Carbon sequestration in agricultural soils may help to reduce global greenhouse gas concentration... more Carbon sequestration in agricultural soils may help to reduce global greenhouse gas concentrations, but building up soil carbon levels requires accumulating organic matter faster than it is lost via heterotrophic respiration. Using field and laboratory studies, this study sought to elucidate how tillage, the below-ground incorporation of cover crop residue, and soil macroporosity affect soil respiration and residue decomposition rates. In the field, residue from a cover crop mixture of barley (Hordeum vulgare) and crimson clover (Trifolium incarnatum) was placed into litter bags that were left on the surface versus incorporated into the soil at three depths (4, 8 or 12 cm), while the laboratory study compared surfaceplaced versus incorporated litter (8 cm depth). To assess tillage effects on cover crop decomposition, the field study simulated no-till and conventional tillage treatments, while the laboratory and field studies both included treatments in which artificial soil macropores were created. The field study showed that conventional tillage and the presence of macropores enhanced soil respiration, while in the laboratory study, incorporating cover crop residue resulted in higher soil respiration and faster litter decomposition rates. Additionally, the laboratory measurements showed that macropores increased soil respiration in wet conditions, likely by enhancing oxygen diffusion. Thus, organic matter incorporation and macropores may represent important factors that affect soil respiration and carbon dynamics.