主动源与被动源地震数据插值及联合数据成像

本文提出了两种情况下主动源数据和被动源数据的插值方法,并研究了两种数据在偏移成像中的互补效果.基于互相关法被动源数据重构原理,本文提出了结合多域迭代去噪技术的重构方法.提出了两种时间域主动源和被动源数据的插值方法,分别是共炮点域能量匹配插值和共检波点域最小平方匹配插值.然后对获得的主动源和被动源联合地震数据进行叠前深度偏移成像.在被动源活跃度不是很高的地区进行被动源地震勘探时,少量的主动源地震数据可以有效控制和补充被动源数据的成像效果.在稀疏炮点的主动源勘探中,有效利用被动源的信息能够在成像中增加更多的细节信息,提高成像质量.     

基于稀疏约束和多源激发的地震数据高效采集方法

地震勘探目标日趋复杂化和精细化,"两宽一高"等采集技术获得了广泛应用,从而导致当前地震数据采集周期越来越长、成本越来越高,如何解决日益增长的勘探成本问题成为当前地震采集领域的研究热点之一.针对上述问题,本文首先开展了基于稀疏性的地震数据高效采集方法理论研究,对地震数据稀疏性基本理论、稀疏约束下随机采样及其数据重建方法进行了深入探讨,提出使用改进的分段随机采样方法灵活地进行实际地震采集测网设计;详细阐述了多源地震激发方法,对多源地震数据分离方法开展了深入研究,提出了基于小窗口中值滤波与稀疏约束联合随机去噪的多源数据分离方法,并在数据分离处理中取得了较好的效果;将上述两种地震数据采集方案有机结合,提出了1)规则多源、随机检波点(DmsRg)、2)随机多源、规则检波点(RmsDg)和3)随机多源、随机检波点(RmsRg)等三种高效采集方案及相应的数据重建方案,满足了后续常规化数据处理的要求,并讨论了多源激发对数据成像的影响.基于Marmousi模型数据的数值试验表明,本文构建的基于稀疏约束和多源激发的高效采集方法理论对于提高地震数据采集效率、降低勘探成本具有重要的应用价值,建立的数据重建方法流程可以取得和常规数据接近的成像结果.本文方法虽然在数值试验中取得了较为理想的效果,但还需要得到野外实际数据采集的进一步检验.     

多层等效源曲面磁异常转换方法

在磁异常数据处理中,利用等效源技术重构磁异常场具有较好的稳定性和较高的计算精度,因而被广泛应用.传统方法是采用设置在近地表的单层等效源拟合实测磁异常数据,尽管拟合精度很高,但向上延拓之后往往会出现较大的拟合误差,即可能存在磁异常信号的"泄漏",尤其在原始数据中存在背景场时更容易出现此种误差.本文提出一种多层等效源技术方案,应用分布于不同深度范围内的等效源模拟实测数据,减少了等效源参数设置的盲目性.理论模型试验表明,采用多层等效源方法重构的磁异常及其梯度与分量,较单层等效源方法具有更高精度,可以吸收更完整的实测磁异常信息.论文详细地讨论了如何优化多层等效源设置、等效源参数选择以及计算方法,通过二维和三维理论模型试验,验证了在复杂条件下多层等效源方法的可行性和适应性,并且将该方法应用于广西某地的实测磁异常数据转换之中,取得了较好的应用效果.     

基于泊松小波径向基函数融合多源数据的局部重力场建模

融合多源数据的高精度、高分辨率的局部重力场建模是物理大地测量学的前沿和热点问题.本文研究了基于径向基函数融合多源数据的局部重力场建模方法,利用Monte-Carlo方差分量估计实现了不同类型的观测数据的合理定权,引入了最小标准差法确定基函数的适宜网络,分析了地形因素对于基函数网络确定及局部重力场建模精度的影响.以泊松小波基函数为构造基函数,结合残差地形模型,融合实测的陆地重力异常、船载重力异常及航空重力扰动数据构建了局部区域陆海统一的似大地水准面模型.研究结果表明:引入残差地形模型平滑了地形质量引入的高频扰动信号,简化了基函数的网络设计;并提高了重力似大地水准面的精度,平原地区其精度提高了4mm,地形起伏较大的山区其精度提高了约5cm.总体而言,基于"三步法"构建的局部重力似大地水准面在荷兰、比利时及德国相关区域,其精度分别达到1.12cm、2.80cm以及2.92cm.     

基于CMIP5模式鄱阳湖流域未来参考作物蒸散量预估

预测未来气候情境下鄱阳湖流域参考作物蒸散量(Reference crop Evapotranspiration,ET0)的时空分布可为流域水资源的优化管理,为科学应对气候变化对农业生产的影响提供基础数据支撑.利用鄱阳湖流域14个气象站点1961-2014年逐日气象数据,采用Penman-Monteith公式计算出历史ET0;基于同期美国环境中心(NCEP)再分析数据及2006-2100年CMIP5中CNRM-CM5模式在RCP4. 5和RCP8. 5情景下的预测数据,经统计降尺度模型(statistical downscaling model,SDSM)模拟和偏差校正,预测流域未来ET0;通过Mann-Kendall检验、普通克里金插值和空间自相关法分析了流域1961-2100年ET0的时空演变特征.结果表明:NCEP再分析资料与流域ET0建立的逐步回归降尺度模型模拟效果较好,CNRMCM5模式降尺度模拟结果经偏差校正后,精度明显提高,适宜流域未来ET0的预估.鄱阳湖流域在基准期1961-2010年ET0整体上呈减小趋势,空间分布上呈南北高、中间低的特点,表现出明显的空间差异性.RCP4.5、RCP8.5情景下未来3个时期鄱阳湖流域ET0较基准期均呈不同程度的增加趋势,其空间分布整体表现为东高西低、局地略有突出;无论是在基准期或是未来情景下的3个时期,ET0均具有较强的空间自相关性.在RCP8.5情景下,鄱阳湖1961-2100年干旱指数呈现出较为明显的上升趋势,流域的干旱状况随时间加剧,2011-2100年间流域绝大部分地区由湿润区转为半湿润区,干旱指数自南向北递减,赣江流域将是鄱阳湖流域未来干旱风险的重点防范区.     

不同尺度流域地表径流氮、磷浓度比较

选择太湖上游为研究对象,采集了1-400 km2不同尺度小流域产出径流TN、TP浓度实测数据,结合前期开展的地表坡面流人工暴雨实验监测结果,开展不同尺度流域水质监测对水体面源污染产出浓度估算影响的比较研究,探讨流域尺度之间入渗、汇流以及伴随的流域生态系统营养盐调节机制的差异．结果表明,流域监测尺度对土地利用面源污染产出浓度估算有较大影响．地表坡面流由于未经过流域汇流过程伴随的下渗滤过与吸附等过程,产出径流TN、TP浓度一般高于小流域．小流域林地生态系统具有较强的入渗机制、接近自然的生态沟谷汇流网络,对面源污染TN、TP有较强的削减作用．农业生态系统较弱的入渗机制、人工沟渠汇流网络对面源污染TN、TP的削减作用较弱．现代农业造成流域面源污染增加不仅仅是因为人类农业活动对流域局部土体及养分的改变,农业生态系统改变流域自然生态系统整体水文过程及营养盐调节机制也是面源污染增加的重要因素之一,恢复小尺度的生态沟谷网络系统对削减流域面源污染具有重要的意义．     

基于多源地球物理数据的机器学习方法在地质体分类中的应用——以黑龙江多宝山矿集区为例

为适应多源地球物理大数据地质解释的需要,同时也为了在地质体物性存在交叠情况下快速有效地实现多源地球物理数据的地质解释,本文提出应用机器学习的支持向量机方法对多源地球物理数据进行地质解释的新思路,并给出了利用物性三体(密度、磁化率、电阻率)进行地质体圈定与分类方法.阐明了参数归一化、参数寻优对模型训练与学习及分类结果的影响与作用.本文将黑龙江多宝山矿集区物性三体与矿集区的区域地质、矿床地质及钻井资料相结合,利用所提出的方法对地下地质体进行了圈定与分类,对分类结果经过交叉检验,正确率达81.6%,表明了训练模型具有较高的可信度.经对预测模型填充已知物性参数正演的重磁异常与实测重磁异常对比,证明两者在整体和细节上均有高度的相似性,间接说明对地质体圈定与分类结果的可靠性,进一步表明利用多源地球物理数据,采用支持向量机方法圈定地质体及对地质体进行岩性识别方面的合理性与有效性.多源地球物理数据机器学习的支持向量机方法在多宝山矿集区地质体圈定与分类所取得较好的应用效果,为多源综合地球物理的地质解释提供了可借鉴的成功经验,也提供了多源地球物理资料地质解释的一种新型的技术手段,开辟了应用人工智能方法进行...     

基于储层骨架的多点地质统计学方法

建立弯曲、连续的河道形态是河流相储层建模的重点和难点.在分析了不同随机建模方法优缺点基础上,提出了一种针对河流储层新的建模方法,即基于储层骨架的多点地质统计学方法(SMPS).它综合利用了基于目标建模的优点以及多点地质统计学方法的长处.根据基于目标方法建模思路,预测河道骨架(即河道中线)分布,提出采用搜索窗预测河道骨架.随后,利用河道骨架对多点地质统计学中的数据事件选择进行约束,从而有效提高数据事件选择的合理性,达到更准确建立河道地质模型的目的.概念模型和实际储层建模对比研究表明,SMPS相比较于已有的序贯指示建模、Snesim和Simpat,确实能够更有效的建立起河道储层地质模型.这一新方法的提出对推动储层随机建模方法研究具有重要理论意义,对油田生产建立高精度储层地质模型也具有重要现实意义.     

黑河流域胡杨适宜生境分布模拟

胡杨(Populus euphratica)是中国干旱区内陆河流域河岸林的主要树种,是干旱内陆河流域绿洲生存和发展的天然屏障.胡杨潜在分布信息对于内陆河流域绿洲环境保护与恢复起关键作用,但是目前很少有研究尝试利用精确可靠的物种分布模型(Species distribution model, SDM)预测胡杨地在此类地区的潜在空间分布.文章基于胡杨的分布点位数据及29个环境因子并利用MaxEnt模型预测胡杨在黑河流域的潜在地理分布.结果表明:在黑河流域,胡杨潜在的适宜生境面积为820km2,主要集中在流域下游的河岸带地区.同时,为了证明本研究中使用方法的优越性,我们分别构建了其他两组对照模型,包括基于不同的环境因子的MaxEnt模型及基于相同的胡杨点位分布数据和29种环境因子数据构建的其他8种不同算法的胡杨分布模型.结果表明:在文章构建的所有模型中,基于29种环境因子的MaxEnt模型建模效果最好,该模型能够精确地描绘胡杨林在黑河流域的基本分布特征.同时,模型比较结果表明:在充足可靠的环境因子数据的基础上, MaxEnt模型能够更加合理地模拟极端干旱区的物种分布.本研究结果表明,黑河流域胡杨的适宜生境面积远大于现有分布区面积,因此对胡杨的生态保护及管理应优先考虑其适宜生境分布区.本研究可以为不断退化的胡杨河岸森林带的保护和管理提供参考.     

基于GRACE RL06数据监测和分析南极冰盖27个流域质量变化

本文基于CSR最新公布的GRACE RL06版本数据,采用Slepian空域反演法估算了南极冰盖27个流域的质量变化.Slepian空域反演法结合了Slepian空间谱集中法和空域反演法的技术优势,能够有效降低GRACE在小区域反演时信号出现的严重泄漏和衰减,进而精确获得南极冰盖在每个流域的质量变化.相对于GRACE RL05版本数据,RL06在条带误差的控制上要更加优化,获得的南极冰盖质量变化时间序列也更加平滑,但在趋势估算上差别并不明显(小于10Gt/a).本文的估算结果显示:在2002年4月至2016年8月期间,整个南极冰盖质量变化速率为-118.6±16.3Gt/a,其中西南极为-142.4±10.5Gt/a,南极半岛为-29.2±2.1Gt/a,东南极则为52.9±8.6Gt/a.南极冰盖损失最大的区域集中在西南极Amundsen Sea Embayment(流域20-23),该地区质量变化速率为-203.5±4.1Gt/a,其次为南极半岛(流域24-27)以及东南极Victoria-Wilkes Land (流域13-15),质量变化速率分别为-29.2±2.1Gt/a和-19.0±4.7Gt/a,其中Amundsen Sea Embayment和南极半岛南部两个地区的冰排放呈现加速状态.南极冰盖质量显著增加的区域主要有西南极的Ellsworth Land(流域1)和Siple Coast(流域18和19)以及东南极的Coats-Queen Maud-Enderby Land (流域3-8),三个地区质量变化速率分别为17.2±2.4Gt/a、43.9±1.9Gt/a和62.7±3.8Gt/a,质量增加大多来自降雪累积,比如:Coats-Queen Maud-Enderby Land在2009年和2011年发生的大规模降雪事件,但也有来自冰川的增厚,如:Siple Coast地区Kamb冰流的持续加厚.此外,对GRACE估算的南极冰盖质量变化年际信号进行初步分析发现,GRACE年际信号与气候模型估算的冰盖表面质量平衡年际信号存在显著的线性相关关系,但与主要影响南极气候年际变化的气候事件之间却不存在线性相关关系,这说明南极冰盖质量变化的年际信号主要受冰盖表面质量平衡的支配,而气候事件对冰盖表面质量平衡的影响可能是复杂的非线性耦合过程.     

利用重力卫星GRACE监测亚马逊流域2002-2010年的陆地水变化

本文利用GRACE (Gravity Recovery and Climate Experiment) 卫星重力资料研究了亚马逊流域2002-2010年的陆地水变化,并与水文模式和降雨资料进行了比较分析.在年际尺度上,GRACE结果表明:2002-2003年和2005年,亚马逊流域发生明显的干旱现象;2007年至2009年,陆地水呈逐年增加的趋势,并在2009年6月变化值达到最大,为772±181 km³;自2009年6月至2010年12月,陆地水总量又急剧减少了1139±262 km³,这相当于全球海平面上升3.2±0.7 mm所需的水量.水文模式得到的亚马逊流域陆地水在2010年也表现出明显的减少.降雨资料与GRACE观测资料有很好的一致性.在2005年和2010年的干旱期,亚马逊流域的降雨显著减少,说明降雨是亚马逊流域陆地水变化的重要因素.此外,本文采用的尺度因子的方法有效地降低了GRACE后处理误差的影响.     

基于Forward-Modeling方法的黑河流域水储量变化特征研究

黑河流域陆地水储量变化对流域下游等周边区域水资源的合理利用以及经济和社会发展等有着重要的意义.本文利用2003年1月至2013年12月的GRACE RL05数据反演了黑河流域陆地水储量长时间序列的变化,并针对重力场模型和数据处理中产生的信号泄漏问题,采用Forward-Modeling方法进行了改正并恢复泄漏信号;将GRACE获得的泄漏信号恢复前后的黑河流域水储量变化结果与全球水文模型GLDAS和CPC进行比较分析,结果表明泄漏信号改正后的结果与水文模型结果的时间序列相关性均有明显提高,从其空间分布结果可以看出Forward-Modeling方法有效地恢复初始信号、增强被湮没的信号,泄漏信号误差减小;通过分析黑河流域水储量变化的长时间序列结果,发现其具有明显的阶段性变化特征,即2003—2006年呈明显下降趋势,约为-0.86cm·a-1,在2007—2010年趋于平衡状态,而2011—2013年则呈现缓慢上升趋势约为0.14cm·a-1;联合GRACE数据和GLDAS数据反演了黑河流域地下水储量变化,并与全球降雨数据GPCC进行了比较分析,两者相关性可达到0.88以上.     

Large-Scale Total Water Storage and Water Flux Changes over the Arid and Semiarid Parts of the Middle East from GRACE and Reanalysis Products

Previous studies indicate that water storage over a large part of the Middle East has been decreased over the last decade. Variability in the total (hydrological) water flux (TWF, i.e., precipitation minus evapotranspiration minus runoff) and water storage changes of the Tigris–Euphrates river basin and Iran’s six major basins (Khazar, Persian, Urmia, Markazi, Hamun, and Sarakhs) over 2003–2013 is assessed in this study. Our investigation is performed based on the TWF that are estimated as temporal derivatives of terrestrial water storage (TWS) changes from the Gravity Recovery and Climate Experiment (GRACE) products and those from the reanalysis products of ERA-Interim and MERRA-Land. An inversion approach is applied to consistently estimate the spatio-temporal changes of soil moisture and groundwater storage compartments of the seven basins during the study period from GRACE TWS, altimetry, and land surface model products. The influence of TWF trends on separated water storage compartments is then explored. Our results, estimated as basin averages, indicate negative trends in the maximums of TWF peaks that reach up to ?5.2 and ?2.6 (mm/month/year) over 2003–2013, respectively, for the Urmia and Tigris–Euphrates basins, which are most likely due to the reported meteorological drought. Maximum amplitudes of the soil moisture compartment exhibit negative trends of ?11.1, ?6.6, ?6.1, ?4.8, ?4.7, ?3.8, and ?1.2 (mm/year) for Urmia, Tigris–Euphrates, Khazar, Persian, Markazi, Sarakhs, and Hamun basins, respectively. Strong groundwater storage decrease is found, respectively, within the Khazar ?8.6 (mm/year) and Sarakhs ?7.0 (mm/year) basins. The magnitude of water storage decline in the Urmia and Tigris–Euphrates basins is found to be bigger than the decrease in the monthly accumulated TWF indicating a contribution of human water use, as well as surface and groundwater flow to the storage decline over the study area.     

利用广义三角帽方法评估GRACE反演中国大陆地区水储量变化的不确定性

在无真实观测值的情况下,本文利用广义三角帽方法评估了五种GRACE时变重力场模型（CSR、GFZ、GRGS、HUST发布的球谐系数解和JPL发布的Mascon解）反演中国大陆地区2003-2013年水储量变化的不确定性.研究结果表明,CSR、GFZ、JPL、HUST和GRGS反演月水储量变化不确定性的区域平均RMS分别为14.4 mm、26.3 mm、25.3 mm、26.6 mm和56.1 mm,其中GRGS的结果未恢复泄漏信号;在季和年尺度上,模型的不确定性均小于月尺度;扣除周期和趋势信号后,各模型反演结果更为一致.除长江流域外,CSR在13个流域的不确定性均小于其他模型,GRGS反演各流域水储量变化的不确定性通常较大,且可能高估了温带大陆性气候地区水储量的波动;CSR和JPL的不确定性受流域周边水文特征、气候类型、流域面积和形状的影响相对较小,不确定性变化范围分别为2.3~17.1 mm和5.6~22.5 mm,GFZ和HUST受影响较大,不确定性变化范围分别为5.5~35.1 mm和4.0~40.6 mm.本文的研究结果为GRACE产品不确定性评估提供了新的途径,为GRACE时变重力场模型的选取提供参考.     

Seasonal Water Storage Variations as Impacted by Water Abstractions: Comparing the Output of a Global Hydrological Model with GRACE and GPS Observations

Better quantification of continental water storage variations is expected to improve our understanding of water flows, including evapotranspiration, runoff and river discharge as well as human water abstractions. For the first time, total water storage (TWS) on the land area of the globe as computed by the global water model WaterGAP (Water Global Assessment and Prognosis) was compared to both gravity recovery and climate experiment (GRACE) and global positioning system (GPS) observations. The GRACE satellites sense the effect of TWS on the dynamic gravity field of the Earth. GPS reference points are displaced due to crustal deformation caused by time-varying TWS. Unfortunately, the worldwide coverage of the GPS tracking network is irregular, while GRACE provides global coverage albeit with low spatial resolution. Detrended TWS time series were analyzed by determining scaling factors for mean annual amplitude (f _GRACE) and time series of monthly TWS (f _GPS). Both GRACE and GPS indicate that WaterGAP underestimates seasonal variations of TWS on most of the land area of the globe. In addition, seasonal maximum TWS occurs 1 month earlier according to WaterGAP than according to GRACE on most land areas. While WaterGAP TWS is sensitive to the applied climate input data, none of the two data sets result in a clearly better fit to the observations. Due to the low number of GPS sites, GPS observations are less useful for validating global hydrological models than GRACE observations, but they serve to support the validity of GRACE TWS as observational target for hydrological modeling. For unknown reasons, WaterGAP appears to fit better to GPS than to GRACE. Both GPS and GRACE data, however, are rather uncertain due to a number of reasons, in particular in dry regions. It is not possible to benefit from either GPS or GRACE observations to monitor and quantify human water abstractions if only detrended (seasonal) TWS variations are considered. Regarding GRACE, this is mainly caused by the attenuation of the TWS differences between water abstraction variants due to the filtering required for GRACE TWS. Regarding GPS, station density is too low. Only if water abstractions lead to long-term changes in TWS by depletion or restoration of water storage in groundwater or large surface water bodies, GRACE may be used to support the quantification of human water abstractions.     

Global Terrestrial Water Storage Changes and Connections to ENSO Events

Improved data quality of extended record of the Gravity Recovery and Climate Experiment (GRACE) satellite gravity solutions enables better understanding of terrestrial water storage (TWS) variations. Connections of TWS and climate change are critical to investigate regional and global water cycles. In this study, we provide a comprehensive analysis of global connections between interannual TWS changes and El Niño Southern Oscillation (ENSO) events, using multiple sources of data, including GRACE measurements, land surface model (LSM) predictions and precipitation observations. We use cross-correlation and coherence spectrum analysis to examine global connections between interannual TWS changes and the Niño 3.4 index, and select four river basins (Amazon, Orinoco, Colorado, and Lena) for more detailed analysis. The results indicate that interannual TWS changes are strongly correlated with ENSO over much of the globe, with maximum cross-correlation coefficients up to ~0.70, well above the 95% significance level (~0.29) derived by the Monte Carlo experiments. The strongest correlations are found in tropical and subtropical regions, especially in the Amazon, Orinoco, and La Plata basins. While both GRACE and LSM TWS estimates show reasonably good correlations with ENSO and generally consistent spatial correlation patterns, notably higher correlations are found between GRACE TWS and ENSO. The existence of significant correlations in middle–high latitudes shows the large-scale impact of ENSO on the global water cycle.     

Satellite based estimates of terrestrial water storage variations in Turkey

In recent years, the Gravity Recovery and Climate Experiment (GRACE) has provided a new tool to study terrestrial water storage variations (TWS) at medium and large spatial scales, providing quantitative measures of TWS change. Linear trends in TWS variations in Turkey were estimated using GRACE observations for the period March 2003 to March 2009. GRACE showed a significant decrease in TWS in the southern part of the central Anatolian region up to a rate of 4 cm/year. The Global Land Data Assimilation System (GLDAS) model also captured this TWS decrease event but with underestimated trend values. The GLDAS model represents only a part of the total TWS variations, the sum of soil moisture (2 m column depth) and snow water equivalent, ignoring groundwater variations. Therefore, GLDAS model derived TWS variations were subtracted from GRACE derived TWS variations to estimate groundwater storage variations. Results revealed that decreasing trends of TWS observed by GRACE in the southern part of central Anatolia were largely explained by the decreasing trends of groundwater variations which were confirmed by the limited available well groundwater level data in the region.     

Quantifying temporal variations in water resources of a vulnerable middle eastern transboundary aquifer system

Freshwater resources in the arid Arabian Peninsula, especially transboundary aquifers shared by Saudi Arabia, Jordan, and Iraq, are of critical environmental and geopolitical significance. Monthly Gravity Recovery and Climate Experiment (GRACE) satellite‐derived gravity field solutions acquired over the expansive Saq transboundary aquifer system were analysed and spatiotemporally correlated with relevant land surface model outputs, remote sensing observations, and field data to quantify temporal variations in regional water resources and to identify the controlling factors affecting these resources. Our results show substantial GRACE‐derived terrestrial water storage (TWS) and groundwater storage (GWS) depletion rates of ?9.05 ± 0.25 mm/year (?4.84 ± 0.13 km³/year) and ?6.52 ± 0.29 mm/year (?3.49 ± 0.15 km³/year), respectively. The rapid decline is attributed to both climatic and anthropogenic factors; observed TWS depletion is partially related to a decline in regional rainfall, while GWS depletions are highly correlated with increasing groundwater extraction for irrigation and observed water level declines in regional supply wells.     

Integration of GRACE mass variations into a global hydrological model

Time-variable gravity data of the GRACE (Gravity Recovery And Climate Experiment) satellite mission provide global information on temporal variations of continental water storage. In this study, we incorporate GRACE data for the first time directly into the tuning process of a global hydrological model to improve simulations of the continental water cycle. For the WaterGAP Global Hydrology Model (WGHM), we adopt a multi-objective calibration framework to constrain model predictions by both measured river discharge and water storage variations from GRACE and illustrate it on the example of three large river basins: Amazon, Mississippi and Congo. The approach leads to improved simulation results with regard to both objectives. In case of monthly total water storage variations we obtained a RMSE reduction of about 25 mm for the Amazon, 6 mm for the Mississippi and 1 mm for the Congo river basin. The results highlight the valuable nature of GRACE data when merged into large-scale hydrological modeling. Furthermore, they reveal the utility of the multi-objective calibration framework for the integration of remote sensing data into hydrological models.     

Consistency of precipitation products over the Arabian Peninsula and interactions with soil moisture and water storage

The regional-scale consistency between four precipitation products from the GPCC, TRMM, WM, and CMORPH datasets over the Arabian Peninsula was assessed. Their macroscale relationships were inter-compared with soil moisture and total water storage (TWS) estimates from AMSR-E and GRACE. The consistency analysis was studied with multivariate statistical hypothesis testing and Pearson correlation metrics for the period from January 2000 to December 2010. The products and GRACE estimates were assessed over a representative sub-domain (United Arab Emirates) with available in situ well observations. Next, geographically temporally weighted regression (GTWR) was employed to examine the interdependencies among the peninsula’s hydrological components. The results showed GPCC-TRMM recording the highest correlation (0.85) with insignificant mean differences over more than 90% of the peninsula. The highest GTWR predictive performance of TWS (R² = 0.84) was achieved with TRMM forcing, which indicates its potential to monitor changes in TWS over the arid peninsular region.