This dataset consist of three products including: (1) Lake ice thickness of 11 large lakes measured by satellite altimeters for 2002-2019; (2) Lake ice thickness and lake surface snow depth of 1260 lakes with an area > 50 km2 in the Northern Hemisphere modeled by a one-dimensional remote sensing lake ice model for 2003-2018; (3) Future lake ice thickness and surface snow depth for 2091-2099 modeled by the lake ice model with a modified ice growth module. This daily lake ice and snow thickness dataset could provide a benchmark for the estimation of global lake ice and snow mass, thereby improving our understanding of the ecological and economical significance of fresh water ice as well as its response to climate change.
Abstract The scarcity of groundwater storage change data at the global scale hinders our ability to monitor groundwater resources effectively. In this study, we assimilate a state‐of‐the‐art terrestrial water storage product derived from Gravity Recovery and Climate Experiment (GRACE) satellite observations into NASA's Catchment land surface model (CLSM) at the global scale, with the goal of generating groundwater storage time series that are useful for drought monitoring and other applications. Evaluation using in situ data from nearly 4,000 wells shows that GRACE data assimilation improves the simulation of groundwater, with estimation errors reduced by 36% and 10% and correlation improved by 16% and 22% at the regional and point scales, respectively. The biggest improvements are observed in regions with large interannual variability in precipitation, where simulated groundwater responds too strongly to changes in atmospheric forcing. The positive impacts of GRACE data assimilation are further demonstrated using observed low‐flow data. CLSM and GRACE data assimilation performance is also examined across different permeability categories. The evaluation reveals that GRACE data assimilation fails to compensate for the lack of a groundwater withdrawal scheme in CLSM when it comes to simulating realistic groundwater variations in regions with intensive groundwater abstraction. CLSM‐simulated groundwater correlates strongly with 12‐month precipitation anomalies in low‐latitude and midlatitude areas. A groundwater drought indicator based on GRACE data assimilation generally agrees with other regional‐scale drought indicators, with discrepancies mainly in their estimated drought severity.
Abstract: The Haihe River Basin (HRB) in North China, characterized by a warm and humid environment, has witnessed a transformation in agricultural water supply patterns, influenced by both climatic changes and groundwater withdrawal restrictions. Despite the impact of these changes on irrigation activities, comprehensive monitoring of irrigation water use (IWU) is lacking, with existing studies predominantly focusing on the influence of irrigation on climatic factors and crop yield. Few studies address the effects of warming and humidification on IWU, and the impacts of human activities associated with groundwater withdrawal restrictions remain underexplored. This study introduces a novel IWU estimation method and examines changes in IWU across the HRB from 2003 to 2022. By quantifying the contribution of irrigation water to different destinations (evapotranspiration consumption, root zone soil water increment, and groundwater recharge), key drivers of IWU change are revealed. The accuracy of IWU estimates proves high, effectively reflecting spatiotemporal changes in irrigation activities. Results demonstrate declining trends in irrigation water intensity and the proportion of irrigation area, with changes in irrigation water intensity dominating overall IWU variations. Shifts in cropping patterns, such as the southward relocation of winter wheat planting and increased drought-tolerant corn cultivation after 2012, explain regional disparities in IWU values. The proportion of irrigation water consumed by evapotranspiration and root zone water increment was 0.58 and 0.39, respectively. Utilizing the least partial square regression method, cropping pattern changes emerge as common drivers for irrigation water intensity in the three main administrative regions (Hebei Province, Beijing, and Tianjin). Irrigation management factors prevail in Hebei Province and Tianjin, while climate factors, particularly in Beijing, play a significant role. Increased water supply and a wetter climate over the past 20 years contributed to decreased irrigation water intensity, particularly in Hebei Province and Beijing. Additionally, optimization of cropping patterns and the adoption of water-saving agriculture further reduced irrigation water intensity in the HRB. This study provides a thorough understanding of the evolving irrigation landscape and associated mechanisms in the HRB over the past two decades. The findings offer insights into combatting climate change and groundwater depletion, informing strategies for sustainable water resource management. Keywords: Irrigation water use; drivers; cropping patterns; North China Plain
This data archive includes the boundary of the North China and Tibetan Plateau (NCTP), three sub-regions, and respective province, the CLCD landcover in 2020, annual PM ET in 1982, and trends in projected water yield and leaf area index by the end of the 21st century (up to 2100). The boundary of the NCTP, three sub-regions, and respective province is in the shapefile (.shp) format, and other processed data are in the geotiff (.tif) or in the mat format. For calculation details please see the publication.
Abstract Precipitation is one of the most important components in the water and energy cycles. Radars are considered the best available technology for observing the spatial distribution of precipitation either from the ground since the 1980s or from space since 1998. This study, for the first time ever, compares and evaluates the only three existing spaceborne precipitation radars, i.e., the Ku‐band precipitation radar (PR), the W‐band Cloud Profiling Radar (CPR), and the Ku/Ka‐band Dual‐frequency Precipitation Radar (DPR). The three radars are matched up globally and intercompared in the only period which they coexist: 2014–2015. In addition, for the first time ever, TRMM PR and GPM DPR are evaluated against hourly rain gauge data in Mainland China. Results show that DPR and PR agree with each other and correlate very well with gauges in Mainland China. However, both show limited performance in the Tibetan Plateau (TP) known as the Earth's third pole. DPR improves light precipitation detectability, when compared with PR, whereas CPR performs best for light precipitation and snowfall. DPR snowfall has the advantage of higher sampling rates than CPR; however, its accuracy needs to be improved further. The future development of spaceborne radars is also discussed in two complementary categories: (1) multifrequency radar instruments on a single platform and (2) constellations of many small cube radar satellites, for improving global precipitation estimation. This comprehensive intercomparison of PR, CPR, and DPR sheds light on spaceborne radar precipitation retrieval and future radar design.
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