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1.
山区降水较集中,但降水测站多位于山谷或人口密集区,代表性差。遥感和再分析降水产品能提供时空分布连续的数据,不受地形条件限制。柴达木盆地中心属干旱荒漠区,水是制约该区开发的首要条件,其四周属高寒山区,降水相对较多,但降水监测十分薄弱。为获取该区相对精确的降水时空分布信息,本文评估了4套高分辨率降水产品(CMADS、TRMM、GPM和MSWEP)的适用性。首先基于地面站点数据评估它们在不同时空尺度上的精度,并分析它们在柴达木盆地的空间分布和年内分配特征。然后,以盆地东南隅的无测站山区香日德河流域为研究区,利用降水产品驱动SWAT模型来评估它们的分布式水文模拟适用性。结果表明:① MSWEP在年、月尺度上与站点降水的吻合程度最高(R ≥ 0.79,PBIAS = 0.5%),其次是GPM和TRMM,CMADS精度最低(R ≥ 0.64,PBIAS = 5.8%);② 从降水精度与站点高程的关系来看,降水产品在相对低海拔区容易高估站点降水,而在相对高海拔区常低估实际降水;③ 在香日德河流域,MSWEP(NSE = 0.64)在基准期(2009—2012年)的径流模拟表现明显好于其它降水产品(NSE = 0.36~0.59),变化期(2013—2016年)表现最好的是CMADS(NSE = 0.75,其余产品NSE = 0.53~0.68)。本研究可为缺资料干旱山区获取精确的降水时空信息和后续水资源的科学管理与规划提供重要支撑。  相似文献   

2.
遥感降水产品在中国不同气候区的适用性研究   总被引:1,自引:0,他引:1  
遥感降水产品相对于气象站观测数据能够更好地反映降水的空间分布特征,对其进行不同气候区上的差异性评价对数据产品选择和遥感降水反演算法改进均有重大意义。本文选择中国典型气候区(干旱区、过渡区、湿润区和青藏高原地区),以649个经偏差矫正后的气象站降水数据为标准,评估了5种国际常用的遥感降水产品 (CHIRPS v2.0, CMORPH v1.0, MSWEP v2.0, PERSIANN-CDR, TRMM 3B42v7) 在中国典型气候区的适用性。研究发现,各产品的性能存在空间差异性。MSWEP在各气候区的相关系数(CC),Kling-Gupta efficiency(KGE),均方根误差(RMSE)等基本统计性能指标均优于其他4种产品。相对偏差(BIAS)方面,在干旱区、湿润区、青藏高原、过渡区表现较优越的产品分别为MSWEP、CHIRPS、PERSIANN、TRMM。在评估遥感降水产品对降水事件发生概率的估算能力方面,选择了误报率(FAR,降水事件预报错误的比例)、命中率(POD,降水事件预报正确的比例)、关键成功指数(CSI,降水事件正确预报综合性能)、精度指数(ACC,等级预报综合性能)和降水等级概率分布(PDF)5个指标作为评估依据,结果表明,就POD,CSI和ACC而言,在各气候区MSWEP表现明显优于其他产品;对于FAR,TRMM和CMORPH产品在湿润区表现优越,其余气候区仍以MSWEP表现较为优越;就PDF而言,PERSIANN和MSWEP产品对1~20 mm的日降水量的估算偏高,特别是MSWEP在青藏高原和湿润区对小雨的估算频率明显偏高, MSWEP有待在该区提高频率预报的能力。综合而言,多源数据融合的MSWEP在各气候区的基本统计性能和降水等级性能较好,可作为可靠的降水数据源用于中国水文气象研究,同时也表明多源数据融合产品具有良好的应用前景。  相似文献   

3.
高精度曲面建模方法(High Accuracy Surface Modeling, HASM),从理论上解决了传统方法在插值过程中峰值削平和边界震荡等问题。其模拟精度相对于经典插值方法有很大提高,已成功应用于人口密度、土壤属性,以及气候要素等领域的空间制图。然而,由于地面气象站点数量和分布的限制,使得HASM仅依靠站点数据难以得到高精度的空间降水估计数据,因此,本文以地貌与气候类型复杂多样的我国中西部地区2010年年降水量空间分布模拟为例,采用混合插值法进行HASM区域降水模拟。结果表明,TRMM作为背景场的HASM模拟的年降水量精度,在全局和局部明显优于IDW、Spline和Kriging等经典插值方法的结果,作为背景场的HASM模拟精度,MAE和RMSE分别为125.15 mm和155.80 mm,其他方法最好的模拟结果比其误差值分别高出53.6%和54.5%;其模拟误差在不同子区域都较小;各种方法在平原的精度都高于山区的精度。  相似文献   

4.
降水数据的准确性和时空分辨率成为水文过程模拟的关键。卫星遥感降水资料的日益丰富为资料缺乏区的水文模拟带来了新的突破。本研究拟在资料缺乏、下垫面复杂,观测难、建模难的柴达木盆地高寒内陆河流域—巴音河中上游,基于近5年的TMPA 3B42、GPM IMERG V5及GPM IMERG V6逐日降水数据和气象站点观测数据建立SWAT模型,采用流域出口径流数据及不同的参数化方案分别率定4个模型,比较和探究不同数据在巴音河流域的适用性。结果表明:① 在月、年尺度上,实测降水数据及TMPA 3B42 V07对应的SWAT模型径流模拟效果较好,前者模拟精度较后者仅高6%~12%,且二者对于流域水量平衡的刻画均较准确。说明TMPA 3B42数据对应的径流模拟结果误差相对较小,可直接用于高寒内陆河流域水文模拟;② GPMIMERG V5数据对应的那什系数NSE值为0.13(月)、-1.58(年),误差百分数PBIAS值为41.2%(月、年),均方根误差与标准误差比率RSR值为0.93(月)、1.61(年),其径流模拟误差较大,模拟效果不可信,说明GPMIMERG V5数据集并不适用于巴音河流域水文模拟;③ GPMIMERG V6-F对应的月径流模拟结果明显优于GPMIMERG V5-F,前者模拟精度较后者提高4倍,但其模拟的年径流对应的NSE值为-0.12,RSR值为1.09。该研究可为资料缺乏的高寒内陆河流域生态水文过程模拟提供参考。  相似文献   

5.
海河流域降水空间插值方法的选取   总被引:27,自引:2,他引:25  
在水资源承载力模型的研究中,空间插值可以提供每个计算栅格的气象要素资料。在众多的气象要素空间插值方法中,并没有一种适合每一个气象要素的最佳插值方法,因此在不同的区域进行气象插值时,宜采用不同的方法进行比较,从而得到最佳的插值方法。本文以京津冀地区43个站1961-2000年降水资料为数据源,选用了距离平方反比法(IDS)、梯度距离平方比和普通克里格法。交叉验证结果表明:在海河流域进行降水插值分析时由于各月份降水与高程之间的相关系数较弱,不宜采用GIDS方法;在本研究区内大部分月份降水数据进行对数变换后进行插值,插值精度得到了提升;对于月降水的插值Kriging方法比IDW方法更加优越。  相似文献   

6.
Floods are one of the most common natural hazards occurring all around the world. However, the knowledge of the origins of a food and its possible magnitude in a given region remains unclear yet. This lack of understanding is particularly acute in mountainous regions with large degrees in Sichuan Province, China, where runoff is seldom measured. The nature of streamflow in a region is related to the time and spatial distribution of rainfall quantity and watershed geomorphology. The geomorphologic characteristics are the channel network and surrounding landscape which transform the rainfall input into an output hydrograph at the outlet of the watershed. With the given geomorphologic properties of the watershed, theoretically the hydrological response function can be determined hydraulically without using any recorded data of past rainfall or runoff events. In this study, a kinematic-wave-based geomorphologic instantaneous unit hydrograph (KW-GIUH) model was adopted and verified to estimate runoff in ungauged areas. Two mountain watersheds, the Yingjing River watershed and Tianquan River watershed in Sichuan were selected as study sites. The geomorphologic factors of the two watersheds were obtained by using a digital elevation model (DEM) based on the topographic database obtained from the Shuttle Radar Topography Mission of US’s NASA. The tests of the model on the two watersheds were performed both at gauged and ungauged sites. Comparison between the simulated and observed hydrographs for a number of rainstorms at the gauged sites indicated the potential of the KW-GIUH model as a useful tool for runoff analysis in these regions. Moreover, to simulate possible concentrated rainstorms that could result in serious flooding in these areas, synthetic rainfall hyetographs were adopted as input to the KW-GIUH model to obtain the flow hydrographs at two ungauged sites for different return period conditions. Hydroeconomic analysis can be performed in the future to select the optimum design return period for determining the flood control work.  相似文献   

7.
基于TRMM数据的福建省降水时空格局BME插值分析   总被引:1,自引:0,他引:1  
传统空间插值方法可获得福建省区域内降水的总体分布,但该地区气象站点较稀疏且分布不均,导致该区域内降水的空间插值结果误差较大。为提高插值精度,本文利用TRMM卫星数据以弥补站点数据的不足,尝试将TRMM数据作为"软数据"、台站数据作为"硬数据",两者相结合后采用贝叶斯最大熵(Bayesian Maximum Entropy,BME)方法对福建省降水的时空格局进行分析。以2000-2012年近13年20个气象站点的年降水量和月降水量为基础数据,分别利用普通克里格法(Ordinary Kriging,OK)和TRMM为"软数据"的BME插值法,分析福建省多年降水的时空分布格局,并对2种方法的插值结果进行比较。结果表明:在时空分布上,以TRMM数据为辅助变量的贝叶斯最大熵插值结果能更好地体现降水的局部差异特征;在误差评价上,以TRMM数据为辅助变量的贝叶斯最大熵插值结果的MAE和RMSE较小,表明TRMM数据作为"软数据"参与插值的BME方法可以在一定程度上弥补站点数据的不足,有效降低预测结果的绝对误差。通过对福建省降水插值的时空分布格局分析和误差评价可看出,BME插值法通过对基础台站数据,以及TRMM卫星产品数据的利用,使降水的时空分析结果更加真实客观,同时,为TRMM卫星降水数据的应用提供了一个新思路。  相似文献   

8.
基于ArcView GIS平台,利用流域水资源规划管理软件工具MIKE BASIN,以西藏达孜县为试验区,采用50×50m格网DEM数据,开展拉萨河流域内的地表水的产汇计算,并进行流域水资源合理配置研究。本文建立了流域供需水的空间分析网络,对各汇流区进行流域模拟分析,研究结果以直观的专题图表显示,为本区的流域水资源管理提供了可视化的研究框架。  相似文献   

9.
潜在蒸发作为研究蒸发及区域水循环的重要因素之一,其模拟结果对相关领域的研究应用具有重要影响。利用 2000-2009年“黑河流域每日四次常规气象观测数据集”所提供的12个气象站点的潜在蒸发数据,对黑河流域潜在蒸发量进行模拟。首先针对潜在蒸发的特点,分析影响研究区域潜在蒸发的气象因素、地理及地形因素,使用多项式回归和逐步回归的方法对研究区域潜在蒸发进行了背景趋势模拟,选出影响潜在蒸发的最优影响因素组合,在此基础上采用高精度曲面建模(HASM)方法,结合站点实测数据,对去掉趋势后的残差进行精度修正。本文使用kriging法、IDW法和Spline法插值所得潜在蒸发数据,以及“黑河流域1980-2010年3 km 6 h模拟气象强迫数据”作为对照,比较验证模拟精度。模拟结果表明:HASM方法模拟精度最高,模拟结果分布合理,表明该方法在潜在蒸发模拟中具有应用前景。该方法所得到的潜在蒸发数据可作为基础地理数据供相关研究应用。  相似文献   

10.
土地利用和气候变化对海河流域蒸散发时空变化的影响   总被引:1,自引:0,他引:1  
蒸散发(ET)是水文能量循环和气候系统的关键环节,研究ET的时空变化特征及其响应土地利用和气候变化的驱动机制对于理清流域水资源和气候变化的关系具有重要的意义。本文基于MOD16/ET数据集定量分析了海河流域2000-2014年ET的时空变化特征,并结合时序气温降水数据和土地利用数据,采用相关分析方法定量探索了ET与气候因子的驱动力关系。结果表明:① 海河流域2000-2014年ET表现为较为显著的空间分布格局,呈现出北部和南部高、西北部和中东部低的分布特性。不同土地利用类型的多年ET呈林地>草地>耕地>其他类型的特征;② 2000-2014年海河流域年均ET波动范围为371.96~441.29 mm/a,多年ET的均值为398.69 mm/a,平均相对变化率为-0.41%,整体呈下降趋势;③ 多年月ET与气温和降水均呈单峰型周期性变化趋势,年内月ET呈单峰变化趋势;④ 春秋两季的ET与降水和气温的相关性明显高于其他季节,ET与气温和降水的平均相关系数是-0.17和0.37,表明降水对于ET的响应程度强于气温;⑤ 驱动分区结果表明海河流域ET受气候因子驱动的主要类型是降水驱动型和降水、气温共同驱动型;⑥ 海河流域耕地ET变化气候因子驱动模式主要是降水、气温共同驱动型;林地、草地的驱动模式主要气温驱动型和降水驱动型,其他土地利用类型的驱动模式主要是受其他因素驱动。该研究将对海河流域水资源开发管理和区域气候调节起到科学指导作用。  相似文献   

11.
Evapotranspiration (ET) is a critical component of the global hydrological cycle, and it has a large impact on water resource management as it affects the availability of freshwater resources. It is important to understand the hydrological cycle for the water resources planning and management. This study used Moderate Resolution Imaging Spectroradiometer (MODIS) satellite derived ET, and potential evapotranspiration (PET) and Tropical Rainfall Measuring Mission (TRMM) satellite derived precipitation datasets to assess the spatial and temporal distributions of ET, PET, and precipitation during the study period at Three Gorges Reservoir (TGR) region. Based on the topographic variations and land-use/land-cover distributions, the study region which includes five counties of Hubei Province and nineteen counties of Chongqing Municipality was divided into four study zones. The ET and precipitation data were evaluated using in situ observations. The ET, PET, and precipitation data were compared to analyze the spatial and long-term (2001-2016) temporal distributions of average annual ET, PET, and precipitation, and to understand the relationships between them in the study region. The results showed that each selected zone had highest ET at the counties with the Yangtze River passing through whereas lowest at the counties which were located away from the river. Results also showed increasing trends in ET and PET from south-west to north-east in the study region. Analysis showed TGR had a significant impact on spatial and temporal distributions of ET and PET in the study region. Therefore, this study helps to understand the impact of TGR on spatial and temporal distributions of ET and PET during and after the construction.  相似文献   

12.
Land use changes such as deforestation,increase in cropping or grazing areas and built-up land, likely modify the water balance and land surface behavior in the Himalayan watersheds.An integrated approach of hydrological and hydraulic modeling was adopted for comparative analysis of hydrological pattern in three Himalayan watersheds i.e.Khanpur,Rawal and Simly situated in the Northern territory of Pakistan.The rainfall-runoff model SWAT- Soil and water assessment tool and Hydro CAD were calibrated for the selected watersheds.The correlation analysis of the precipitation data of two climate stations i.e.Murree and Islamabad, with the discharge data of three rivers was utilized to select best suitable input precipitation data for Hydro CAD rainfall-runoff modeling.The peak flood hydrograph were generated using Hydro CAD runoff to optimize the basin parameters like CN, runoff volume, peak flows of the three watersheds.The hydrological response of the Rawal watershed was studied as a case study to different scenarios of land use change using SWAT model.The scenario of high deforestation indicated a decline of about 6.3% in the groundwater recharge tostream while increase of 7.1% in the surface runoff has been observed under the scenario of growth in urbanization in the recent decades.The integrated modeling approach proved helpful in investigating the hydrological behavior under changing environment at watershed level in the Himalayan region.  相似文献   

13.
基于TRMM降水数据的空间降尺度模拟   总被引:1,自引:0,他引:1  
本研究以黑河流域为例,通过在不同空间尺度上建立降水与影响因素的关系并选择最优尺度以此进行降尺度,建立了基于地理加权回归(GWR)与高精度曲面建模方法(HASM)相结合的跨尺度统计降尺度方法,对TRMM降水数据进行了降尺度模拟。最后,结合站点观测数据采用交叉验证法对降尺度结果进行了验证。结果表明,与传统的降尺度方法相比,考虑最优尺度的降尺度方法在一定程度上提高了降尺度结果的精度,同时表明对跨尺度过程中产生的误差进行修正可进一步提高结果精度。本研究所提出的方法可用于粗分辨率降水数据的降尺度模拟,可为站点稀疏地区或地形复杂地区高分辨率高精度降水数据的获取提供方法上的支持。  相似文献   

14.
The poor distribution of meteorological stations results in a limited understanding of the precipitation pattern in the Tianshan Mountains. The spatial patterns of precipitation over the mid Tianshan Mountains were characterized based on the TRMM 3B43 monthly precipitation data. By comparing satellite estimates with observed data, it shows that TRMM 3B43 data underestimate the precipitation in mountain region. Regression models were developed to improve the TRMM 3B43 data, using geographic location and topographic variables extracted from DEM using GIS technology. The explained variance in observed precipitation was improved from 64% (from TRMM 3B43 products alone) to over 82% and the bias reduced by over 30% when location and topographic variables were added. We recalculated all the TRMM 3B43 monthly precipitation grids for the period 1998 to 2009 using the best regression models, and then studied the variation patterns of precipitation over the mid Tianshan Mountains. The results are well explained by a general understanding of the patterns of precipitation and orographic effects. This indicated that the Tianshan Mountains strongly influences the amount and distribution of precipitation in the region. This is highlighted by the confinement of the precipitation maxima to the windward (northern slope). And complex vertical changes in the provenance and distribution of precipitation, like that a negative increasing rate of precipitation in the vertical direction exists in the north but does not in south. The results have also revealed large gradients and different patterns in seasonal precipitation that are not simply related to elevation, the distribution of precipitation may also be affected by other seasonal factors such as the sources of moist air, wind direction and temperature.  相似文献   

15.
The Jinsha River Basin is an important basin for hydropower in China and it is also the main runoff and sediment source area for the Yangtze River,which greatly influence the runoff and sediment in the Three Gorges Reservoir.This study aims to characterize the spatial distribution,inter-annual variation of runoff and sediment load in the Jinsha River Basin,and to analyze the contribution of rainfall and human activities to the runoff and sediment load changes.The monitoring data on runoff,sediment load and precipitation were collected from 11hydrological stations in the Jinsha River Basin from1966 to 2016.The data observed at the outlet of the basin showed that 71.4%of the runoff is from the upper reaches of the Jinsha River Basin and the Yalong River,while 63.3%of the sediment is from the lower reaches(excluding the Yalong River).There is no significant increase in runoff on temporal scale in the Jinsha River Basin,while it has an abrupt change in runoff in both upstream and midstream in 1985,and an abrupt change in downstream in 1980 and2013.The sediment load demonstrated a significantincreasing trend in the upstream,no significant reducing trend in the midstream,but significant reducing trend in the downstream.The sediment load in upstream showed abrupt change in 1987,in midstream in 1978 and 2014,in downstream in 2012.Rainfall dominated runoff variation,contributing more than 59.0%of the total variation,while human activity,including reservoirs construction,the implementation of soil and water conservation projects,is the major factor to sediment load variation,contributing more than 87.0%of the total variation.  相似文献   

16.
As an important indicator of the structural and functional stability of wetland landscapes, hydrological connectivity plays an important role in maintaining the stability of wetland ecosystems. Large-scale human activities have led to significant changes in the hydrological connectivity pattern of wetlands in Naoli River Basin since 1950 s. Combined with the availability of wetland habitat and the spreading capacity of aquatic birds, hydrological connectivity indices of marsh wetlands were calculated in the studied area, and the temporal and spatial changes were analyzed from 1950 s to 2015. The results indicate that:(1) the hydrological connectivity index of the marsh wetlands shows a growth trend with increasing distance threshold. All patches of marsh wetlands linked together when the distance threshold reached 35--40 km;(2) the optimal distance of hydrological connectivity is about 10 km for marsh wetlands of whole Naoli River Basin;(3) the total hydrological connectivity of marsh wetlands decreased in the Naoli River Basin from 1950 s to 2015. Although the hydrological connectivity index increased after 2005, the fragmentation of the landscape has not been improved. The analysis of the wetland hydrological connectivity can provide a scientific basis for the ecological restoration and protection of the wetland in the Naoli River Basin.  相似文献   

17.
水汽输送及降水模式对流域水文模型及水资源研究具有重要意义。汉江流域水资源对南水北调以及下游生态环境有重要影响,研究汉江流域水汽输送和降水的时空分布特征是水文模拟和水资源环境管理的基础。本文利用NCEP/NCAR再分析资料和汉江流域19个气象站点的降水资料,以及GIS数据库和分析工具,分析了汉江流域的水汽通量、可降水量、实测降水量和降水转换率的计算方法;以汉江流域1998年7月的气候再分析资料和降水资料为例,计算并分析了汉江流域1998年7月可降水量与实测降水量的空间分布特征,以及降水转化率的分布特征;探讨了水汽输送、可降水量、实测降水量,以及降水转化率的相关性和空间分布特征。通过分析汉江流域1981-2010年的可降水量和实际降水量的分布表明,汉江流域可降水量与降水量变化趋势基本相同,降水转换率近年有所增加。  相似文献   

18.
利用东北地区2000-2010年93个气象站点观测数据作为“真实值”,对TRMM降水数据进行精度验证,发现研究区TRMM降水数据与观测数据之间具有明显的线性相关性,且TRMM降水数据数值偏大于观测值,表明TRMM降水数据在东北地区具有一定的可信度。对东北地区多年平均、2001、2010年的TRMM数据,进行GWR模型降尺度研究,得到1 km的新降水数据,并与全局OLS回归模型进行对比。结果表明:(1)相比全局OLS回归模型,GWR模型的降尺度结果可获得更好的RRMSE,说明GWR模型更适用于东北地区TRMM数据的降尺度研究;(2)东北地区GWR模型的降尺度分析结果与观测数据之间的相关系数在0.44-0.97之间,且分布较分散;(3)经过降尺度的TRMM降水数据,在空间分辨率上有较大提高,能更真实地反映研究区的降水特征,为该数据小尺度的应用研究奠定基础。  相似文献   

19.
人口增长、气候变化、制度变迁、城市化等均会导致土地利用/覆被的变化,进而引起流域水文过程(截留、入渗、蒸散发和地下水补给等)和水循环过程的改变。当前,由于逐年土地利用/覆被数据获取困难、水文模型本身计算缺陷等问题,所有在流域尺度上开展的借助水文模型进行的土地利用/覆被变化影响下的水文模拟研究都存在一个共同缺点,就是采用的水文模型并不能逐年调用土地利用/覆被数据,即水文模型无法真实体现或模拟土地利用/覆被的时空变化。SWAT作为一个广泛应用的分布式水文模型,在其模拟期内,不能逐年调用土地利用/覆被数据,即在进行水文模拟时忽略了土地利用/覆被时间上的变化,这可能会影响其在土地利用/覆被变化剧烈地区(如黑河中游)的应用。黑河流域是典型的内陆河流域,也是中国西北地区第二大内陆河流域。黑河中游是黑河流域的径流耗散区。本文针对SWAT模型在考虑土地利用/覆被变化时的缺点,对其进行了改进并开发出能够逐年调用土地利用/覆被数据的LU-SWAT模型。在土地利用/覆被变化剧烈的黑河中游对SWAT和LU-SWAT模型的径流模拟效果进行比较,发现LU-SWAT模型更适用于黑河中游水循环模拟。  相似文献   

20.
The performance of spectral nudging in an investigation of the 2010 East Asia summer monsoon was assessed using the Weather Research and Forecasting (WRF) model, forced by 1-degree NCEP Global Final Analysis (FNL). Two pairs of experiments were made, spectral nudging (SP) and non-spectral nudging (NOSP), with five members in each group. The members were distinguished by different initial times, and the analysis was based on the ensemble mean of the two simulation pairs. The SP was able to constrain error growth in large-scale circulation in upper-level, during simulation, and generate realistic regional scale patterns. The main focus was the model ability to simulate precipitation. The Tropical Rainfall Measuring Mission (TRMM) 3B42 product was used for precipitation verification. Mean precipitation magnitude was generally overestimated by WRF. Nevertheless, SP simulations suppressed overestimation relative to the NOSP experiments. Compared to TRMM, SP also improved model simulation of precipitation in spatial and temporal distributions, with the ability to reproduce movement of rainbands. However, extreme precipitation events were suppressed in the SP simulations.  相似文献   

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