Department of Geography, Yarmouk University, Irbid, 21163, Jordan.
Department of Geography, University of Jordan, Amman, Jordan.
Environ Monit Assess. 2019 Jan 23;191(2):96. doi: 10.1007/s10661-019-7230-9.
In this study, soil water balance model was implemented to estimation moisture in two sub-humid areas located in north-western part of Jordan namely Irbid and Ras Muneef. In addition, in situ observations of soil moisture were collected from 16 randomly distributed sampling locations and used for monitoring the spatiotemporal variability of soil moisture in the study area. Sampling was performed during the growing season in the study area with a total of seven sampling occasions from 11 March to 12 April 2017. The results showed that the estimated soil moisture in Ras Muneef was slightly higher than Irbid. This might be referred to variations of, for instance, Ras Muneef receiving higher precipitation and lower temperature values comparing to Irbid. Also, we noticed that the spatiotemporal variability of the observed soil moisture is directly linked with the precipitation in our study area. The coefficients of the spatial and temporal variabilities were in the range 3 to 40% and 8 to 15%, respectively. Due to the high Spearman's rank correlation values which range from 0.42 to 0.73, soil moisture is temporarily stable. Strong and positive relationship was found between the estimated and observed soil moisture with determination coefficients (r) and root mean square error (RMSE) around 0.7 and 0.41, respectively, whereas negative relationship between evapotranspiration and observed soil moisture was shown with R3and RMSE are 0.34 and 0.24 respectively. This indicates that actual soil moisture can be predicted from soil water balance model.
在这项研究中，我们实施了土壤水平衡模型，以估计位于约旦西北部的两个次湿润地区（即伊尔比德和拉斯穆尼夫）的土壤水分。此外，我们还从 16 个随机分布的采样点收集了土壤湿度的实地观测数据，用于监测研究区域土壤湿度的时空变化。采样在研究区域的生长季节进行，总共有 7 次采样，时间从 2017 年 3 月 11 日至 4 月 12 日。结果表明，拉斯穆尼夫的估算土壤湿度略高于伊尔比德。这可能是由于例如，拉斯穆尼夫接收的降水较高，温度值较低，与伊尔比德相比。此外，我们注意到观测到的土壤湿度的时空变化与我们研究区域的降水直接相关。空间和时间变化的系数分别在 3%到 40%和 8%到 15%之间。由于斯皮尔曼等级相关系数的范围在 0.42 到 0.73 之间，土壤湿度暂时稳定。估算和观测到的土壤湿度之间存在很强的正相关关系，决定系数（r）和均方根误差（RMSE）分别约为 0.7 和 0.41，而蒸散量与观测到的土壤湿度之间存在负相关关系，相关系数（R3）和 RMSE 分别为 0.34 和 0.24。这表明可以从土壤水平衡模型预测实际的土壤湿度。
