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| 气候变暖下土壤孔隙渗透率对碳通量的影响及误差修正 |
| Impacts of Soil Porosity Permeability on Carbon Fluxes under Climate Warming and Error Correction |
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| DOI： |
| 中文关键词: undefined |
| 英文关键词: undefined |
| 基金项目:国家自然科学基金资助项目（32371668，31971493） |
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| 摘要点击次数: 95 |
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| 中文摘要: |
| 采用梯度温控（5 ℃～20 ℃）实验方法，结合土壤碳通量测量系统和自主研发的碳通量校准装置，定量分析4种典型土壤基质（黄土、沙土、石英砂和碎石）中CO2传输的物理调控机制。结果表明：孔隙率（＞45%）与渗透率（＞1×10-9 m2）的协同作用是触发热对流（瑞利数Ra≥271）的临界条件；在高Ra条件下，传统扩散模型因忽略对流通量项而系统性低估CO2通量；对流〖CD*2〗扩散耦合模型（CDM）引入Ra阈值和温度依赖的流速项，将通量测量相对误差降至3%以内，显著提升了高温情景下的碳通量估算精度。 |
| 英文摘要: |
| A gradient temperature controlled experiment（5 ℃～20 ℃） was conducted using a soil carbon flux measurement system and a self developed carbon flux calibration device to quantitatively analyze the physical regulatory mechanisms of CO2 transport in four typical soil matrices（loess， sand， quartz sand， and gravel）. The results showed that the synergistic effect of porosity（＞45%） and permeability（＞1×10-9 m2） constituted the critical condition for triggering thermal convection， with a Rayleigh number threshold of Ra≥271. Under high Ra conditions， the conventional diffusion model systematically underestimated CO2 fluxes by neglecting 〖JP3〗the convective flux term. The coupled convection diffusion model（CDM）， which incorporated the Ra threshold and a temperature dependent flow velocity term， 〖GK!87mm〗reduced the relative error in flux measurements to within 3% significantly improving the estimation accuracy of carbon fluxes under high temperature conditions. |
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