相关实验视频
Updated: Mar 12, 2026

08:20
In Situ Soil Moisture Sensors in Undisturbed Soils
Published on: November 18, 2022
7.7K
全球0.25度网格 雪水等价数据来源于机器学习,使用现场测量
Jungho Seo1,2, Mahdi Panahi1, JiHyun Kim3,4
1Department of Civil and Environmental Engineering, Yonsei University, Seoul, 03722, South Korea.
Scientific data
|March 11, 2026
概括
一个新的机器学习模型每天生成从1980年到2020年的全球雪水等价 (SWE) 数据. 这种强大的SWEML产品显示出高精度,即使在山区.
科学领域:
- 地球和环境科学 地球和环境科学
- 气候科学 气候科学
- 水文学的水文学
背景情况:
- 准确的雪水等价 (SWE) 数据对于水资源管理和气候研究至关重要.
- 现有的SWE数据集在空间覆盖,时间分辨率或准确性方面存在局限性.
研究的目的:
- 开发一个基于机器学习的,高分辨率的全球每日SWE产品 (SWEML),涵盖1980-2020年.
- 为了评估SWEML的性能与不同的参考数据集对比.
主要方法:
- 使用k-means集群,将现场SWE测量分为14个集群.
- 在11,687个网点上使用气象强迫和地形属性训练了一种随机森林模型.
- 将SWEML与十个不同的参考数据集进行比较,包括重新分析,雪模型和遥感产品.
主要成果:
- 获得了10.33毫米的整体根平均平方误差 (RMSE) 和7.13毫米的偏差.
- 在高海拔地区,如落基山脉 (RMSE = 7.30 mm,R = 0.98) 证明了高精度.
- 与北美空中SWE数据强烈一致,与安第斯山脉雪再分析类似.
结论:
- 开发的SWEML产品提供了强大而准确的每日全球SWE数据集.
- 在数据丰富的地区和数据稀缺的地区,SWEML的表现都很好,这突出了其广泛的适用性.
- 这一数据集可以显著提高水文建模,气候研究和水资源管理.
相关概念视频
Precipitation Gravimetry
15.9K
Precipitation gravimetry is based on converting an analyte into a sparingly soluble precipitate, which is separated by filtration and weighed. An ideal precipitate should be pure, insoluble, of known composition, and easily filtered from the reaction mixture.
In determining nickel by gravimetric analysis, a precipitant of ethanolic dimethylglyoxime is added to a hot nickel salt solution. This is quickly followed by the dropwise addition of dilute ammonia solution until precipitation occurs. A...
In determining nickel by gravimetric analysis, a precipitant of ethanolic dimethylglyoxime is added to a hot nickel salt solution. This is quickly followed by the dropwise addition of dilute ammonia solution until precipitation occurs. A...
15.9K
Precipitation and Co-precipitation
5.1K
Precipitation and coprecipitation methods can be used to separate a mixture of ions in a solution. In qualitative inorganic analysis, ions that form sparingly soluble precipitates with the same reagent are separated based on the differences in solubility products. For example, consider the separation of Cu(II) and Fe(II) ions by precipitation as insoluble sulfides. First, copper(II) sulfide is precipitated by the addition of acidic H2S, where the dissociation of H2S is suppressed. Adding H2S...
5.1K
Precipitation Processes
6.4K
The experimental conditions in a gravimetric analysis should be optimized to maximize the particle size and purity of the obtained precipitate. Ideally, the concentration of the precipitating reagent should be low with effective stirring to maintain low relative supersaturation for the growth of large crystals. In homogeneous precipitation, the precipitant is slowly generated by a chemical reaction in the solution to avoid local reagent excesses. For example, urea decomposes gradually to...
6.4K
Field Application of Global Positioning System
349
The Global Positioning System (GPS) has become an indispensable tool in fieldwork, offering unparalleled precision and efficiency for surveying, navigation, and infrastructure development. By harnessing signals from a constellation of satellites, GPS receivers determine the location of objects with remarkable speed and accuracy, often completing calculations within a second.Advantages of Modern GPS TechnologyContemporary GPS receivers are designed to meet the practical demands of field...
349
Geoid and Ellipsoid
931
The Earth's shape is best described as an ellipsoid, a slightly flattened sphere created by rotating an ellipse around its minor axis. This flattening results in the polar axis being about 21 kilometers shorter than the equatorial axis. In contrast, the geoid represents the Earth's gravitational shape and aligns with the mean sea level (MSL). The geoid is an irregular equipotential surface where gravity is perpendicular at every point. Variations in Earth's mass distribution cause geoid...
931
Selected Data About Geographic Locations
307
Geographic Information Systems (GIS) rely on two core types of data: spatial data and attribute data.Spatial DataSpatial data defines the physical location of features within a coordinate system, typically expressed in terms of latitude and longitude. It provides precise positioning for elements like roads, rivers, or buildings.Attribute DataAttribute data complements spatial data by adding descriptive information about these features. For example, a road's spatial data includes its start and...
307

