摘要:
本研究联合1948—2014年GLDAS_2.0数据和2000—2021年GLDAS_2.1数据,构建河南省1948—2021年逐月土壤含水量数据集。利用M-K趋势分析和突变检验、小波分析、互相关分析,揭示河南省土壤含水量的时空分布特征及主要影响因素。结果表明: 重构的2000—2014年逐月土壤含水量与GLDAS_2.1提供的月度土壤含水量的平均偏差为2.09 mm,平均绝对误差为13.01 mm,均方根误差为18.26 mm,数据是可信的。基于该构建的土壤含水量数据,1948—2021年土壤含水量则以0.301 0 mm/a的速度减少,其中,春季河南省土壤含水量的变化率为-0.236 8 mm/a,夏季土壤含水量的变化率为-0.085 5 mm/a,秋季土壤含水量的变化率为-0.380 5 mm/a,冬季土壤含水量的变化率为-0.240 3 mm/a。空间上,土壤含水量变化整体上由南向北递减,与降水和蒸散发具有明显的一致性。垂向上,单位深度土壤含水量为2.63 mm/cm。小波分析与互相关分析表明降水是影响土壤含水量的主要因素。本研究不仅揭示了河南省长时间序列的土壤含水量及其时空分布特征,还可为河南省地表水资源科学管理提供依据。
Abstract:
This study constructed a monthly soil moisture content dataset of Henan Province during 1948—2021 by combining 1948—2014 GLDAS_2.0 data and 2000—2021 GLDAS_2.1 data. Through the Mann-Kendall (M-K) trend analysis, mutation test, wavelet analysis, and cross-correlation analysis, this study revealed the spatio-temporal distribution and critical influencing factors of soil moisture content in Henan Province. The results show that compared with the monthly soil moisture content data provided by GLDAS_2.1, the reconstructed monthly soil moisture content data during 2000—2014 showed an average deviation, average absolute error, and root mean square error of 2.09 mm, 13.01 mm, and 18.26 mm, respectively, indicating reliable data. According to the constructed soil moisture content data, the soil moisture content decreased at a rate of 0.301 0 mm/a during 1948—2021, with change rates of -0.236 8 mm/a in spring, -0.085 5 mm/a in summer, -0.380 5 mm/a in autumn, and -0.240 3 mm/a in winter in Henan Province. Spatially, the soil moisture content decreased from south to north, highly consistent with precipitation and evapotranspiration. The soil moisture content was 2.63 mm/cm in the vertical direction. The wavelet and cross-correlation analyses show that precipitation is a critical factor influencing soil moisture content. This study revealed the long-time-series spatio-temporal distribution of soil moisture content in Henan Province, providing a basis for the scientific management of surface water resources in Henan Province.
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