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鄱阳湖流域水文过程是区域研究的热点问题,但相对于其它水文要素而言,土壤水分的时空分布特征及其影响因素尚缺乏系统研究,成为流域水文过程研究不确定性的主要来源之一。采用AMSR-E土壤水分数据,从流域、子流域及地表覆被等不同的空间尺度,阐明了鄱阳湖流域2003~2009年土壤水分的年际与年内变化特征,并分析其影响因素。研究表明:在流域尺度上,土壤水分总体呈现中心低、周边高的“漏斗式”空间分布形态,但夏、秋季节空间差异性减弱,年际土壤水分呈现较强的下降趋势,其中以湖区下降速度最大;在地表覆被尺度上,林地土壤水分最高、年际下降速度最低,表明其在年际尺度上对干旱具有较强的调节作用,不同地表覆被类型的土壤水分年内差异较明显,但在6、7及10月差异较小,地表覆被对土壤水分的调节作用减弱;在影响因素方面,降水是土壤水分的主要影响因素,气温、灌溉等则一定程度上影响了土壤水分的变化特征。研究结果不仅有利于加强对流域水文过程的理解与认识,同时可为水资源管理及防旱抗旱等提供科学的辅助依据。
However, compared with other hydrological elements, the temporal and spatial distribution of soil moisture and its influencing factors are still lack of systematic study, which has become one of the main sources of uncertainty in the hydrological process of the basin. Using AMSR-E soil moisture data, the spatial and temporal variations of soil moisture in the Poyang Lake Basin from 2003 to 2009 were clarified from different spatial scales, such as watersheds, sub-basins and land cover, and the influencing factors were analyzed. The results show that: on the scale of the basin, the soil moisture shows a low center and a high “hopper” spatial distribution, but the spatial variability of summer and autumn is weakened, and the annual soil moisture shows a strong downward trend, of which In the lake area, the rate of decline was the highest. On the scale of land cover, the soil moisture of the forest land was the highest and the lowest was the declination rate in the interannual period, indicating that it had strong regulation on the interannual scale. The annual differences of soil moisture in different land cover types However, the differences were less significant in June, July and October, and the effect of surface cover on soil moisture was weakened. Precipitation was the main influencing factor of soil moisture in terms of influencing factors, and temperature and irrigation affected to some extent Characteristics of Soil Moisture Changes. The results not only help to strengthen understanding and understanding of hydrological processes in the river basin, but also provide scientific support for water resources management and drought control and drought relief.