与传统光学遥感指标相比，微波遥感指标—植被光学厚度（VOD）具有对云和大气敏感性低和不易饱和的优势，可用于监测植被总含水量和生物量的变化。本文基于不同频率的VOD数据集（VODCA C-VOD、X-VOD、Ku-VOD和AMSRU X-VOD），利用趋势分析和残差分析等方法研究了2000—2018年中国不同地区以及不同植被类型VOD的时空动态变化，并在全国及区域尺度上定量评估了气候变化和人类活动的相对贡献。结果表明：① 中国植被VOD呈极显著增加趋势，AMSRU X-VOD增加速率最快（0.062/10a），尤其是华东地区，而VODCA C-VOD增加速率最低（0.013/10a），其中西南地区增速最高；不同植被类型中，草丛的增速最快，其次为针叶林和灌丛。② 降水和辐射的增加促进了华北和西北地区VOD的增加，气温的贡献主要分布在华南和沿海地区，辐射对表征植被冠层的Ku-VOD和X-VOD的贡献较高。③ 不同数据集均表明人类活动是植被VOD增加的主要因素，VODCA C-VOD、Ku-VOD、X-VOD和AMSRU X-VOD的人类活动贡献率分别为171%、48%、43%和30%，在黄土高原、西南地区和东北平原尤为突出。本文研究结果为生态工程成效评价提供新的数据支持，并为未来生态系统管理和碳增汇提供科学依据。

Compared to traditional optical remote sensing indicators, the microwave remote sensing indicator vegetation optical depth (VOD) is less sensitive to clouds and atmosphere, and also less susceptible to saturation. The VOD is capable of monitoring changes in the total water content and biomass of vegetation. In this study, we analyzed the spatio-temporal dynamics of VOD in different regions of China and different vegetation types from 2000 to 2018 based on multiple frequencies of VOD datasets (VODCA C-VOD, X-VOD, Ku-VOD, and AMSRU X-VOD) using trend analysis and residual analysis. Then, the relative contributions of climate change and human activities at national and regional scales were quantitatively assessed. Results showed the following. (1) All of the VOD increased significantly over this period. AMSRU X-VOD had the fastest growth rate (0.062/10a), especially in eastern China. VODCA C-VOD increased at the lowest rate (0.013/10a), which showed the highest increasing rate in southwestern China. The fastest increasing trend of VOD was observed in grasslands, followed by needleleaf forests and scrubs. (2) The rising precipitation and radiation promoted the increase of VOD in northern and northwestern China. The temperature was closely related to the VOD changes in southern China and coastal areas. The contribution of radiation on Ku-VOD and X-VOD representing vegetation canopy was higher than that of precipitation and temperature. (3) According to different datasets, human activities were the primary factor for the increase in VOD. The contribution of human activities to VODCA C-VOD, Ku-VOD, X-VOD, and AMSRU X-VOD was 171%, 48%, 43%, and 30%, respectively, especially in the Loess Plateau, southwestern China, and Northeast China Plain. The outcomes of this study shed new light on the efficiency evaluation of ecological projects, which will provide guidance for future ecosystems management and environment protection in China.

剖析百年尺度的城市变迁与气候要素变化对提升区域气候演变机理的认知具有重要意义。本文基于卫星遥感图像、社会经济数据和气象站点实测等数据，采用人机交互解译方法，刻画了1916—2020年北京城市扩展过程。利用滑动平均法和Mann-Kendall趋势检验方法，分析了关键气象要素的变化特征，从而揭示了百年尺度城市土地利用变化和社会经济发展与区域气候变化之间的关系。研究表明：1916—2020年北京城市土地面积增长了64.48倍，围绕中心地域呈圈层式蔓延扩展，呈现“缓慢—加速—减速”的扩展模式，城市扩展速度在2000—2010年达到峰值，为70.12 km²/a。1916—2020年北京的5 a滑动平均气温和年降水量分别为12.25 ℃和588.6 mm。随着城市发展，1916—2020年北京市5 a滑动平均气温以0.22 ℃/10a波动上升，1978年以来升温显著。年降水量则呈现波动下降趋势，速率为9.37 mm/10a。城市不透水面的加速扩张可能造成地表能量收支的改变，从而引发城市变暖。城市化率与气温升高具有协同关系，不同时段差异显著，1916—2020年北京城市化对区域升温的贡献为20.83%。另一方面，地表能量收支改变与空气污染物排放增加可能导致北京城市地区降水减少。本文结果可为提升北京城市变迁对区域气候演变影响过程和机制的认知提供科学参考。

Understanding the mechanisms of regional climate evolution requires extensive research on long-term urbanization and meteorological elements. The various data sources and an interactive interpretation method were utilized to reproduce the urban expansion in Beijing over the past century. The relationship between urban development and regional climate change was then determined by using the moving average method and the Mann-Kendall trend test. We found that the area of urban land in Beijing increased 64.48 times from 1916 to 2020, expanding in a circle around the central region. The rate of urban expansion peaked at 70.12 km²/a between 2000 and 2010. The average annual temperature and precipitation from 1916 to 2020 in Beijing were 12.25 ℃ and 588.6 mm, respectively. The 5-year moving average temperature fluctuated upward by 0.22 ℃/10a over the past century, with a notable warming trend since 1978. Precipitation trended downward at a rate of 9.37 mm/10a. The accelerated expansion of the impervious surface area in the city might lead to urban warming by altering the surface energy balance. The rate of urbanization and the regional temperature rise were positively correlated, with urbanization accounting for 20.83% of the regional warming in Beijing. Changes in the surface energy balance and an increase in air pollution emissions might result in a decline in precipitation. The results provide scientific resources for advancing knowledge of the processes and mechanisms by which urban development influences the regional climate change.

揭示降水不确定性在水文过程中的传递特征是气象水文耦合预报研究的关键环节，可为进一步加强流域水资源管理、提高农业灌溉保障能力提供有力支撑。利用TIGGE 资料中心CMA、CMC、ECMWF、NCEP和UKMO 5个模式降水集合预报（127个集合成员）驱动分布式新安江模型，生成2010-2013年涪江流域汛期径流集合预报。在此基础上，从精度和锐度两个方面，定量分析降水不确定性在水文过程的传递特征及其随预见期的变化规律。结果表明，降水预报经过水文过程后，其精度和锐度在不同年份、不同预见期均大幅提升。但随着预见期的延长，对精度的改进效果逐渐减小，而对锐度的改进效果则不断增大。

Revealing the propagation characteristics of precipitation uncertainty in hydrological process is the key element of hydro-meteorological forecasts, which can provides strong support for the improvements of watershed water resources management and agricultural irrigation. In this paper, the precipitation prediction from 5 different TIGGE center(CMA、CMC、ECMWF、NCEP and UKMO) were used to drive the distributed Xinanjiang model to generate the runoff ensemble forecast in flood season of The Fujiang River basin from 2010 to 2013.On this foundation, the propagation characteristics and temporal changes of precipitation uncertainty were analyzed quantitatively in accuracy and sharpness. The results indicated that both accuracy and sharpness of precipitation forecasts were significantly improved after hydrological process in different years and different prediction periods. However, with the prolongation of prediction period, the improvement effect on precision decreases gradually, while the improvement effect on sharpness increases continuously.

为了掌握泾河水沙变化的基本规律,运用EMD方法对泾河张家山水文站1958—2011年的年径流量及年输沙量序列分别进行了多时间尺度分解,依据实测年输沙量数据,应用时间序列分析方法建立了年输沙量模拟模型。泾河年径流和年输沙量的时间序列均可分解为3个不同波动周期的振荡分量和一个递减的趋势分量;年输沙量模型适用性较好,且模拟精度较高,可应用于年输沙量预测。泾河水沙多时间尺度变化的特征分析和输沙量预测可为泾河水资源规划提供科学依据。

In order to obtain the basic law of water and sediment variation in Jinghe River, we decompose series of annual runoff and sediment discharge into multiple temporal scales by EMD method, with Zhangjiashan station from 1956 to 2011 as an example. Firstly, we establish a simulation model of annual sediment discharge according to measured data and time series analysis. Then, the results show that both of the annual runoff and sediment series can be decomposed into 3 fluctuation components with different periods and a degressive tendency residual component. Furthermore, the model is of good suitability and high accuracy, and it can be used to predict annual sediment discharge. Finally, we can carry out characteristic analysis on multiple temporal scales of runoff and sediment and prediction of annual sediment discharge to provide a scientific basis for water resources planning in Jinghe River.

冰川径流是西北干旱区径流的主要组成部分，研究未来气候变化对冰川径流的影响对西北干旱区径流至关重要。以博尔塔拉河上游源流区为研究区，构建嵌入冰川模块的SWAT模型，模拟温泉水文站1972—2018年月径流过程，并在此基础上研究了气候变化情景下（RCP4.5和RCP8.5）未来（2020—2050年）气候变化对冰川径流的影响。结果表明：SWAT模型能够很好地模拟源流区径流变化过程，在整个模拟期间，径流数据的纳什系数（NSE）为0.82，偏差百分比（PBIAS）为-3.22%，均方根误差与实测值标准差的比值（RSR）为0.42，决定性系数（R²）为0.84，模型性能评定为优。根据CMIP5气候模式2种情景的模拟结果，2种情景模拟未来总径流都呈现出增加趋势，分别将以0.31×10⁸ m³·（10a）^-1和0.40×10⁸ m³·（10a）^-1的速度继续增加，冰川径流占比较历史时期的27.61%分别提升了4.84%和9.38%。冰川径流增加是径流量增加的主要原因。通过相关性分析发现，随着气温的升高，冰川消融时间提前，冰川消融加速，冰川积累时间减少，导致冰川面积进一步的缩减。研究结果可为博河地区水文资料历史变化、未来演变趋势和预防气候变化带来的潜在风险提供依据。