长江流域陆地水储量与多源水文数据对比分析

A comparison of terrestrial water storage data and multiple hydrological data in the Yangtze River basin

  • 摘要: 从趋势性、滞后性及相关性三方面,对2002—2013年间GRACE重力卫星反演的长江上游与中游陆地水储量与模型模拟土壤含水量、实测降水和实测径流数据进行了对比分析,并从干旱强度及发展时间两方面评估了标准化陆地水储量指数SWSI、标准化降水指数SPI、标准化径流指数SRI和标准化土壤含水量指数SSMI对区域性干旱的表征能力.结果表明:长江上游地区陆地水储量与降水、径流和土壤水蓄量均无显著变化,而中游地区陆地水储量则与水库蓄量同样具有显著性增加,反映人类活动对中游地区陆地水储量变化有很大影响;各指标指示的各等级干旱月份数量基本相当,但各指标反映的特旱具体月份有较大差别,基于GRACE数据构建的SWSI指标对特大干旱的指示性不好;对比各指标对上游与中游地区干旱事件发展时间,体现出水文干旱、农业干旱对气象干旱存在一定的迟滞关系.

     

    Abstract: The monthly GRACE-based terrestrial water storage (TWS) data in upper and middle Yangtze River basin during 2002—2013 are compared with measured precipitation and discharge, and model simulated soil moisture from the aspects of temporal trend, correlation, and time lag. Four drought indices, including Standardized Water Storage Index (SWSI), Standardized Precipitation Index (SPI), Standardized Runoff Index (SRI) and Standardized Soil Moisture Index (SSMI), are used to assess the intensity and timing of drought events in the upper and middle Yangtze River basin. The results show that: TWS exhibits similar temporal variation as precipitation, discharge and soil moisture in the upper Yangtze River basin, exhibiting no significant trends, whereas TWS has the same significant upward trend as annual reservoir water storage in the middle Yangtze River basin, indicating significant impacts of human activities on TWS in the middle Yangtze River basin; the number of months with drought at various levels indicated by different drought indicators are close to each other, although not equal; the GRACE-based SWSI has poor capability to capture extreme droughts; the comparison of the timing of drought events indicated by different drought indicators shows lags between meteorological drought and hydrological drought and agricultural drought.

     

/

返回文章
返回