Long-term monitoring to inform the geophysical detection of archaeological ditch anomalies in different climatic conditions
Long-term monitoring to inform the geophysical detection of archaeological ditch anomalies in different climatic conditions
复制标题
长期监测为不同气候条件下考古沟渠异常的地球物理检测提供信息
DOI：
10.1002/arp.1902
复制
发表时间：
2023
影响因子：
1.8
通讯作者：
Boddice D
中科院分区：
文献类型：
--
作者：
Boddice D
目标地物与周围土壤的电磁特性对比对于探地雷达探测考古地物具有重要意义。这些变化是由于气候条件和土壤类型的变化而变化的，目前人们对此知之甚少。通过长期现场监测不同土壤类型(一种粘土和一种自由排水)上两条考古沟渠的表观相对介电常数、整体电导率和土壤温度，以了解这些特性随时间变化的探测动态和过程。结果与考古沟渠填方和周围自然土壤基质的土壤岩土性质以及之前得出的水分、温度和地球物理性质之间的实验室关系相关联，以找到最佳地球物理对比的时机和原因。监测包括两个不同的相对稳定的时期：一个是潮湿的，一个是干燥的。与以往认为沟渠和周围自然土壤的入渗速度有显著差异的看法相反，时滞相关分析表明，入渗速度没有显著差异。考古土壤和自然土壤之间的主要区别是饱和状态下的持水量、不同土壤的干燥速度和温度。因此，调查的最佳时间是在持续几天的炎热(>；15°C)天气之后，这会加剧水分和温度的反差。然而，在土壤质地和自然土壤之间存在较大差异的自由排水地点，时机并不那么关键。
Contrasts in electromagnetic properties between the target feature and surrounding soil are of importance for detection of archaeological features with Ground Penetrating Radar. These vary because of changing climatic conditions and soil type and are currently poorly understood. Long‐term in situ monitoring of apparent relative dielectric permittivity, bulk electrical conductivity and soil temperature over two archaeological ditch features on sites with different soil types (one clay and one free draining) was employed to understand the detection dynamics and processes by which these properties change over time. Results were correlated with geotechnical properties of the soil for both archaeological ditchfills and the surrounding natural soil matrix and previously derived laboratory relationships between water content, temperature and geophysical properties to find the timing and reasons for the optimum geophysical contrasts. Monitoring included two distinct, relatively stable periods: one wet and one dry. In contrast to previous perception that there are significant differences in infiltration between the ditch and surrounding natural soil, time‐lagged correlation analysis showed no significant differences in infiltration speed. The key differences between archaeological and natural soils were the amount of water held in a saturated state, the rates at which the different soils dried and the temperature. Thus, the optimum time for surveys was after a sustained period of several days of hot (>15°C) weather, which accentuates both water content and temperature contrasts. However, on freely draining sites that had a greater difference in the soil texture and therefore water holding capacity between the archaeological and natural soils, the timing is less critical.