准确估算区域降水对水文过程评价和水资源管理意义重大。为评估TRMM 3B42V7降水产品在海河流域南系的估算精度及其在土壤和水评估模型(Soil and Water Assessment Tool,SWAT)中的适用性,利用28个气象站降水观测数据(2007-2016年)和101个雨量站观测数据(2010-2016年)开展研究。研究表明:站点尺度上,3B42V7降水产品对月降水估算的均方根误差小于15 mm,平均误差小于8.5 mm;在湿润季节的估算精度更好。流域尺度上,日降水估算精度较差,相关系数小于0.6。分区尺度上,3B42V7能够很好地捕捉到不同等级降水强度,但对微量降雨有所低估;山区和平原的年降水量均出现高估现象,平原区较为突出;此外,3B42V7能够较好地捕捉到研究区内极端降水的时间和空间分布。分2种情景进行水文模拟,利用月平均流量对模型进行校准和验证,在情景Ⅰ中,验证期模拟结果较好,决定系数在0.56~0.96之间,纳什效率系数在-11.09~0.94之间。TRMM 3B42V7可为海河流域及其类似区域的水资源管理提供参考。 相似文献
Arbuscular mycorrhizal-like fungi (AM-like fungi) are crucial for ecosystem functioning and soil organic matter (SOM) is an indicator of soil quality. However, the spatial distribution of arbuscular mycorrhizal-like fungi, glomalin-related soil protein (GRSP) and SOM in a large scale is still unclear. The objectives of this study were to investigate the spatial distribution of SOM, arbuscular mycorrhizal-like fungi and GRSP, and reveal the potential relationship among them in a large scale across China.
Materials and methods
Soil samples (different in vegetation type, climate, and soil variables) were collected from 26 sites in a large scale across China. The soil properties including pH, total carbon (TC), total nitrogen (TN), and SOM were determined. Quantitative PCR amplification of the 18S rRNA gene was conducted to evaluate the abundance of arbuscular mycorrhizal-like fungi. The contents of easily extractable GRSP (EE-GRSP), difficultly extractable GRSP (DE-GRSP), and total GRSP (T-GRSP) were measured.
Results and discussion
Arbuscular mycorrhizal-like fungi abundance was significantly affected by the vegetation type and dramatically correlated with the soil TN and mean annual precipitation (MAP). EE-GRSP and DE-GRSP were more associated with the TC and TN content, respectively. The abundance of arbuscular mycorrhizal-like fungi significantly but weakly correlated with the T-GRSP and EE-GRSP. The SOM content positively correlated with the DE-GRSP and T-GRSP. Those results suggested that the arbuscular mycorrhizal-like fungi are a larger contributor to regulating the content of GRSP, which is an important indicator of the soil organic carbon pool.
Conclusions
Our results indicated that arbuscular mycorrhizal-like fungi abundance has a greater contribution to driving the distribution of soil C and N in a large scale by affecting the content of glomalin-related soil protein.
Journal of Soils and Sediments - Purple paddy soils cover about 66% of the paddy soils in Sichuan Basin. Complex interactions made the effects of potassium fertilizer application on NH4+ adsorption... 相似文献
Journal of Soils and Sediments - Soil bulk density and hydraulic conductivity are two of many key factors for vegetation establishment and the other way around. Variations in them may cause patchy... 相似文献