Yin Xin Wei, Zheng Xin Jun, Li Yan, Hu Shun Jun, Guo Yong
State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China.
Fukang Station for Desert Ecosystem Observation and Experiment, Chinese Academy of Sciences, Fukang 831505, Xinjiang, China.
Ying Yong Sheng Tai Xue Bao. 2019 Jan 20;30(1):146-156. doi: 10.13287/j.1001-9332.201901.015.
To examine the effects of soil moisture dynamics on hydrological and ecological processes at the hillslope scale in the desert region, a hillslope-scale soil moisture dynamic stochastic model in arid sandy based on Rodriguez-Iturbe soil moisture dynamic stochastic model (RI model) was developed by modifying the input parameters of the model. Using the continuously monitored data of soil moisture in root zone during growing season from 2015 to 2016 and daily precipitation from 2000 to 2016 in a fixed dune at the southern edge of Gurbantunggut Desert, we analyzed soil moisture dynamics and probability density function of soil moisture on slopes in growing season and discussed the sensitivity of parameters of the stochastic model and its application feasibility. The results showed that the seasonal distribution of precipitation was irregular. The total number of annual precipitation was mainly derived from the precipitation of >10 mm. The precipitation frequency and interval were dominated by <5 mm and <10 d, respectively. The precipitation in the eastern slope was slightly larger than that in the western slope. The interannual variability of soil moisture in the eastern and western slopes in the growing season was basically consistent with the rainfall distribution. The soil moisture in the root zone in the western slope was slightly lower than that in the eas-tern slope, and the soil water content in different slope positions followed a normal distribution. The curve characteristics of the soil moisture probability density function (the curve peak value, the position of the peak, the confidence interval of 95%) in the root zone in the different slopes in growing season simulated by the hillslope-scale model were consistent with observed values, with the consistency measure (CM) being higher than 0.5. Such a result indicated that the hillslope-scale stochastic model could be used for simulating the soil moisture probability density function in diffe-rent slope positions in the study area, with a good applicability. This model could provide theoretical basis and scientific methods for vegetation survival or restoration and the implementation of ecological construction project of desertification control in arid sandy area.
为研究沙漠地区坡面尺度土壤水分动态对水文和生态过程的影响，在Rodriguez-Iturbe土壤水分动态随机模型（RI模型）基础上，通过修改模型输入参数，构建了干旱沙地坡面尺度土壤水分动态随机模型。利用2015—2016年生长季古尔班通古特沙漠南缘固定沙丘根区土壤水分连续监测数据以及2000—2016年日降水量数据，分析了生长季坡面土壤水分动态及土壤水分概率密度函数，探讨了随机模型参数敏感性及其应用可行性。结果表明，降水季节分布不均，年降水量主要集中在大于10 mm的降雨，降水频率和间隔分别以小于5 mm和小于10 d为主，东坡降水量略大于西坡。生长季东西坡面土壤水分年际变化基本与降雨分布一致，西坡根区土壤水分略低于东坡，不同坡面位置土壤含水量呈正态分布。坡面尺度模型模拟的生长季不同坡面根区土壤水分概率密度函数曲线特征（曲线峰值、峰值位置、95%置信区间）与实测值一致，一致性度量（CM）大于0.5，表明该坡面尺度随机模型可用于模拟研究区不同坡面位置土壤水分概率密度函数，适用性良好。该模型可为干旱沙地植被存活或恢复及荒漠化防治生态建设工程实施提供理论依据和科学方法。
