收藏设为首页 广告服务联系我们在线留言

干旱区地理 ›› 2026, Vol. 49 ›› Issue (6): 1203-1214.doi: 10.12118/j.issn.1000-6060.2025.390 cstr: 32274.14.ALG2025390

• 植被与土壤 • 上一篇    下一篇

SMAP升轨土壤水分产品在柴达木盆地的适用性和时空变化分析

李素雲1,2(), 祝存兄1,2,3(), 王镜4, 陈国茜1,2, 史飞飞1,2   

  1. 1 青海省防灾减灾重点实验室青海 西宁 810001
    2 青海省气象科学研究所青海 西宁 810001
    3 海东市平安区气象局青海 海东 810600
    4 西宁市气象局青海 西宁 810001
  • 收稿日期:2025-07-08 修回日期:2025-09-28 出版日期:2026-06-25 发布日期:2026-06-29
  • 通讯作者: 祝存兄(1990-),女,硕士,副高级工程师,主要从事生态气象服务应用等方面研究. E-mail: zhucunxiong_2008@126.com
  • 作者简介:李素雲(1992-),女,硕士,工程师,主要从事土壤水分遥感反演技术等方面研究. E-mail: lisuyun_qh@163.com
  • 基金资助:
    青海省气象局“揭榜挂帅”科技项目(QXGS2023-05);青海省防灾减灾重点实验室重点项目(QFZ-2024-Z02);国家自然科学基金项目(U22A20556);青海省科学技术协会“青海省科技工作者建言”项目资助

Applicability and spatiotemporal variation analysis of SMAP ascending products to soil moisture in Qaidam Basin

LI Suyun1,2(), ZHU Cunxiong1,2,3(), WANG Jing4, CHEN Guoqian1,2, SHI Feifei1,2   

  1. 1 Key Laboratory of Disaster Prevention and Mitigation of Qinghai Province, Xining 810001, Qinghai, China
    2 Qinghai Institute of Meteorological Sciences, Xining 810001, Qinghai, China
    3 Ping’an District Meteorological Bureau, Haidong City, Haidong 810600, Qinghai, China
    4 Xining Meteorological Bureau, Xining 810001, Qinghai, China
  • Received:2025-07-08 Revised:2025-09-28 Published:2026-06-25 Online:2026-06-29

摘要:

土壤水分是陆地生态系统水循环、能量交换和碳通量的关键参数,而在高原地区土壤水分观测存在站点分布不均、实测数据稀少等问题,土壤水分主被动卫星(SMAP)产品可为高原地区大范围监测提供重要的数据支持。研究采用多种精度评价指标分析了SMAP升轨土壤水分产品在柴达木盆地的适用性,采用Theil-Sen Median+Mann-Kendall趋势分析、重标极差分析以及变异系数等分析了2015—2024年柴达木盆地土壤水分的时空变化特征。结果表明:(1) SMAP土壤水分产品在柴达木盆地存在干区高估、湿区低估现象,与实测土壤含水量相关系数为0.6543,无偏均方根误差为0.0928 m3·m-3,在柴达木盆地未达到其预期精度,但仍具参考价值。(2) SMAP土壤水分产品在不同等级植被覆盖条件下表现各异,中覆盖度下表现最好,低覆盖度次之,高覆盖度最差。(3) SMAP土壤水分产品可以有效捕捉土壤水分激增,准确反映降水入渗、土壤水分累积以及消退的全过程。(4) 2015—2024年柴达木盆地草地生长季多年平均土壤含水量在空间上呈现由中部向四周先递减后增加的分布格局,趋势变化率在空间上呈现“东南增加、中部略减、西北略增”的分布格局,稳定性以比较稳定和不稳定为主,空间上呈现“过渡带广泛、极端区集中”的分布格局。预计未来柴达木盆地土壤水分总体以持续上升为主。

关键词: SMAP, 土壤水分, 适用性, 时空变化, 柴达木盆地

Abstract:

Soil moisture is a critical regulator of terrestrial water cycles, energy exchange, and carbon fluxes. However, soil moisture observations in plateau regions are constrained by challenges, such as uneven station distribution and sparse measured data. However, soil moisture active passive (SMAP) satellite products provide important data support for large-scale monitoring in these regions. The applicability of SMAP ascending soil moisture data was first evaluated using multiple accuracy-evaluation metrics, after which spatiotemporal soil moisture responses in Qaidam Basin were analyzed via Theil-Sen median+Mann-Kendall trend tests, rescaled range analysis, and coefficient of variation. Results show the following: (1) SMAP soil moisture products exhibit dry-overestimation and wet-underestimation biases in the Qaidam Basin. The correlation coefficient with the measured soil moisture content is 0.6543, with an unbiased root-mean-square error of 0.0928 m3·m-3. Although this does not meet the expected target accuracy, it remains a viable reference. (2) SMAP soil moisture products exhibit different performances across varying vegetation covers, peaking under medium coverage, followed by low coverage, and declining significantly under high coverage. (3) SMAP soil moisture products effectively capture moisture surges, accurately reflecting the entire process involving precipitation infiltration, soil moisture accumulation, and extinction. (4) From 2015 to 2024, Qaidam Basin grassland soil moisture shows a space distribution in the growing season: It first decreases, after which it increases from the basin center toward its four peripheries on average for many years, exhibiting a space distribution of the trend-change rate. Spatially, trend rates increase in the southeast, decrease slightly in the central region, and increase marginally in the northwest. The stability is dominated by medium and relatively low fluctuations. Additionally, the spatial distribution pattern shows a “wide transition zone and a concentrated extreme zone”. Projections indicate that Qaidam Basin soil moisture will generally maintain a persistent increasing trend.

Key words: SMAP, soil moisture, applicability, spatiotemporal variation, Qaidam Basin