Abstract Commonly, the topographic influence on soil hydrology is calculated as a Topographic Wetness Index (TWI), which often correlates with surface soil properties, such as carbon and nitrogen, across broad spatial scales. However, traditional TWI methods can be ineffective at capturing finer scale variations when depression filling approaches are used and they do not incorporate localized soil texture controls on infiltration. We developed a new Dynamic Wetness Index (DWI) that attempts to account for the persistence of soil moisture over time at the microtopographic scale (~1 m2) by including inputs of measured soil texture, and information from the Dhara modeling framework that incorporates canopy process and surface-subsurface hydrologic models. DWI and TWI values were correlated with measured soil geochemical properties across six study sites (four agricultural sites, one restored prairie, and one forest site) within the Upper Sangamon River Basin, in central Illinois, USA. Relative to TWI, DWI improved correlations with certain measured soil surface geochemistry (pH R = −0.53), δ13C R = 0.13, δ15N R = 0.44) and certain lignin phenols (vanillyl, cinnamyl/vanillyl, syringyl-vanillyl-cinnamyl/substituted fatty acids). DWI positively correlated with indicators of lignin oxidation, indicating that wetter soils have higher potential for lignin decomposition. In this small dataset, relative to TWI the data show DWI increased significance and decreased the range of correlations with soil moisture and certain surface soil geochemistry parameters driving plant chemistry decay and nitrogen cycling.

中文翻译：

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一种新的动态湿度指数 (DWI) 可预测土壤水分持久性并与表层土壤地球化学的关键指标相关联

摘要 通常，地形对土壤水文的影响被计算为地形湿度指数 (TWI)，该指数通常与广泛空间尺度上的表层土壤特性（如碳和氮）相关。然而，当使用凹陷填充方法时，传统的 TWI 方法在捕捉更精细的尺度变化方面可能无效，并且它们没有结合对渗透的局部土壤质地控制。我们开发了一个新的动态湿度指数 (DWI)，试图通过包括测量的土壤质地的输入以及来自包含冠层过程的 Dhara 建模框架的信息来解释土壤水分在微地形尺度（~1 平方米）上随时间的持久性和地表-地下水文模型。DWI 和 TWI 值与美国伊利诺伊州中部桑加蒙河流域上游六个研究地点（四个农业地点、一个恢复草原和一个森林地点）的土壤地球化学特性相关。相对于 TWI，DWI 改善了与某些测量的土壤表面地球化学（pH R = -0.53）、δ13C R = 0.13、δ15N R = 0.44）和某些木质素酚（香草基、肉桂基/香草基、丁香基-香草基-肉桂基/取代脂肪酸）。DWI 与木质素氧化指标呈正相关，表明较潮湿的土壤具有较高的木质素分解潜力。在这个小数据集中，