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目前区域降雨型滑坡预测主要依赖降雨阈值开展,然而从降雨诱发滑坡机理可知,除降雨入渗导致的土壤含水量变化外,降雨入渗前的土壤含水量也是影响边坡失稳的重要因素,无法考虑降雨入渗前的土壤湿度情况,被认为是降雨阈值在滑坡预测中表现差的主要原因。针对这一问题,本文以四川省都江堰地区作为试验区域,提出考虑前期土壤湿度的区域降雨型滑坡预测思路,通过统计分析历史滑坡数据,构建了基于前期土壤湿度和近期降雨情况的水文-气象阈值模型,其中前期土壤湿度情况由改进的前期有效降雨指数刻画,近期降雨情况由最近的累积降雨量表示。试验结果表明:在试验区域的降雨型滑坡预测中,水文-气象阈值模型表现出较好的命中率和较低的误报率。本文构建的水文-气象阈值模型,可同时考虑前期土壤湿度和近期降雨对滑坡发生的影响,模型所需数据少、所用方法简单易操作且预测性能较优,适合在区域降雨型滑坡预测中推广应用。 相似文献
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GPS-IR（GPS-interferometric reflectometry）本质上是一种基于GPS辐射源的双基地雷达技术,利用大地测量型接收机记录的信噪比（signal-to-noise ratio,SNR）数据可用于反演土壤含水量。针对GPS-IR获取土壤含水量的参数估计问题,提出了一种改进的反射信号参数估计方法,并研究了土壤含水量反演模型的建立过程。实验结果表明,利用改进的反射信号参数估计方法可获得更加准确可靠的结果,反射信号相位与土壤含水量间存在显著的线性相关,可建立土壤含水量的线性反演模型,但在连续降雨条件下会存在较大误差。 相似文献
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付杨康 《测绘与空间地理信息》2023,(11):132-135
针对城市内涝问题,提出一种改进的局部等体积地表径流汇流模型。首先基于SCS模型获取地表产流;其次通过结合形态学重构方法对分水岭分割算法进行改进,获得相应的子汇水区,提升局部等体积汇流模型的精度;最后以武汉市中心城区为研究区,对模拟结果进行评价。结果显示：1)10 a、50 a重现期下的内涝模拟精度分别为78.1%和78.6%,模拟精度良好;2)最大积水深度、总积水面积、严重积水面积和总积水水量均与重现期呈正相关,并在降雨峰值处,各参数增长趋势均为最大;3)武汉城区2 h短历时降雨过程中,1 a重现期为城市内涝是否严重的分水岭;4)武汉城区暴雨内涝主要集中在江汉区和江岸区。 相似文献
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基于作物缺水指数的土壤含水量估算方法 总被引：1，自引：0，他引：1
为研究江苏省徐州市的土壤水分时空分布及动态变化,基于MODIS数据和站点气象数据,利用蒸散发双层模型和考虑土壤水分可供率的改进双层模型分别计算实际蒸散发量,利用Penman-Monteith模型计算区域潜在蒸散发量,计算获得作物缺水指数(crop water stress index,CWSI),并与2010年7月和11月的土壤相对含水量实测数据分别进行回归分析建模,得到了土壤含水量分布图。结果表明:基于蒸散发双层模型的土壤含水量估算结果与实测值的决定系数分别为0.53和0.72,平均相对误差分别为5.89%和9.6%;对双层模型进行改进后,土壤含水量估算结果与实测值的决定系数都为0.84,平均相对误差分别为3.47%和6.03%,利用改进后的双层模型对土壤相对含水量进行估算效果更好。 相似文献
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改进的表观热惯量法反演土壤含水量 总被引：4，自引：0，他引：4
提出一种改进的表观热惯量计算模型,以中科院栾城农业生态系统试验站为基地,通过实测的模型参数,利用提出的表观热惯量模型计算不同植被覆盖下、不同实验区土壤含水量的热惯量值,并与土壤含水量进行相关性分析,以找到热惯量方法可以用来反演土壤含水量的适用条件(归一化植被指数NDVI的阈值).实验结果表明,该模型监测土壤含水量是可行的,在植被覆盖度较低的情况下(NDVI≤O.35)具有较高的精度,在植被覆盖度较高(NDVI＞0.35)时,热惯量模型失效,因此用热惯量方法反演土壤含水量植被覆盖时将NDVI阈值的最大值设为0.35.将该方法应用到MODIS数据中,以河北省栾城县、赵县、藁城市3市县为研究区,分别反演该区土壤含水量,反演结果与实际情况相符合.实地取点人工监测土壤含水量为25.1％,栾城站模型计算结果为22.4％,匹配性较好,该方法在遥感数据中得到了很好的应用. 相似文献
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长期水文影响评价模型（Long-termHydrologicalImpactAssessment。L-THIA）是研究人类活动对流域非点源影响的重要评价模型之一。本文深入阐明了L—THIA模型的原理．探讨了SCSCN方法和污染物负荷的具体计算方法。在此基础上,提出了L-THIA模型存在的不足和改进方向,并以ArcMap为平台,对该模型进行了二次开发,二次开发后的模型主要包括六个模块．分别为土地利用分类模块、：￡壤分类模块、CN值计算模块、径流深度计算模块、径流最计算模块和污染物负荷计算模块。基于ArcMap平台的L-THIA模型利于用户方便处理数据,且提高了模型模拟的准确度,实现了模型本地化。 相似文献
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山洪是汛期多发地质灾害之一。受地形和气候的影响,西南地区高速公路沿线易受山洪威胁。为了更好地防范山洪灾害,保障交通安全,基于SCS模型推导了流域产生径流的临界雨量模型。以四川省高速公路沿线小流域为研究区,利用土地利用类型数据、土壤属性数据及降水数据等资料,计算得到了四川省高速公路沿线小流域发生山洪灾害的临界雨量。计算结果显示,四川省高速公路沿线流域的临界雨量在14—26 mm之间。与山洪灾害历史数据对比结果表明,模型预测效果良好。 相似文献
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《现代测绘》2015,(5)
在前人已有的土地利用/覆盖变化研究的基础上,应用美国农业部水土保持局研制的SCS(Soil Conservation Service)模型,对海河流域1980和2008年正常土壤湿度下的地表径流进行模拟计算,分析了近29年来海河流域城镇化对地表径流的影响,同时也验证了SCS模型应用于较大流域进行地表径流模拟计算的可行性。研究结果表明,海河流域城市扩张基本上都是建立在占用耕地基础上的。因城市扩张导致城市建筑用地大面积增加、耕地大面积减少而引起的流域不透水面积增多是致使流域地表径流深度增加的直接原因。城市地表径流增加与城市扩张变化是有直接关系的:城市扩张速度越快的地区地表径流深度增长也相对较快。同时,植树造林对强降雨条件下地表径流增加具有一定抑制作用。 相似文献
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三维GIS的城市暴雨积涝灾害模拟 总被引：2，自引：0，他引：2
针对传统基于二维GIS进行城市暴雨积涝模拟分析不能立体地展现积涝灾害动态演进过程、地物受灾情况的问题,该文提出了基于三维GIS进行城市暴雨积涝灾害模拟分析。该方法综合应用精细化建模与地物拉伸建模技术,通过区域DEM构建、地表路面建模、建筑物建模、地形匹配构建研究区三维模型;以改进的D8算法进行汇水区划分,应用径流系数法进行汇水区产流计算。研究结果表明,该方法能够有效实现三维场景中暴雨积涝积水深度、积水范围计算以及积水深度、受灾房屋、受灾道路可视化表达,为城市暴雨积涝灾害防灾减灾提供技术支撑。 相似文献
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Rainfall-runoff and soil erosion modeling using Remote Sensing and GIS technique — a case study of tons watershed 总被引：1，自引：0，他引：1
A S Jasrotia S D Dhiman S P Aggarwal 《Journal of the Indian Society of Remote Sensing》2002,30(3):167-180
In the present study, the rainfall-runoff relationship is determined using USDA Soil Conservation Service (SCS) method. The coefficient of determination (R2) is 0.99, which indicates a high correlation between rainfall and runoff. The runoff potential map was prepared by assigning individual class weight and scores input map. Annual spatial soil loss estimation was computed using Morgan, Morgan and Finney mathematical model in conjunction with remote sensing and GIS techniques. Higher soil erosion was found to occur in the northern part of the Tons watershed. The soil texture in the affected area is coarse loamy to loamy skeletal and soil detachment is higher. Moreover the land use has open forests, which does not reduce the impact of rainfall. The average soil loss for all the four sub-watersheds was calculated, and it was found that the maximum average soil loss of 24.1 t/ha occurred in the sub-watershed 1. 相似文献
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Dilip G. Durbude B. K. Purandara Arun Sharma 《Journal of the Indian Society of Remote Sensing》2001,29(1-2):47-58
An accurate assessment of run-off through aerial rainfall is a basic concept in most of the rainfall-runoff models, particularly conceptual models which emphasis a complete water balance. The run-off measurements by gauging can only be regarded as an index of rainfall and restrict our ability to successfully model the rainfall-runoff process. To overcome some of these problems, remote sensing satellite data are of immense use, particularly in mountainous and desert areas. Therefore in the present study, a typical watershed from a drought hit Banswara district of Rajasthan has been analysed using IRS-1B-LISS II satellite imagery for estimating the run-off potential under different geomorphic set-up. The run-off potential was estimated using SCS method based on the satellite data in conjunction with ground truth information collected during field visit. The results indicated that the soil and water conservation measures in the watershed would improve the existing water potential and storage capacity of the study area. Based on the study eight check dams and five lift irrigation schemes are proposed. 相似文献
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本文以新疆焉耆盆地为研究区,首先利用实测数据和Landsat 8 OLI遥感数据获取土壤调查植被指数（MSAVI）和地表温度（Ts）,构建Ts-MSAVI特征空间,拟合特征空间的干湿方程;然后利用该特征空间计算温度植被干旱指数（TVDIm）,反演9-11月的土壤湿度,探讨土壤湿度时空分布特征。试验结果表明：①遥感影像反演的TVDI与实地考察的土壤湿度显著相关（a=0.05）;不同土层中,TVDIm与10~20 cm土层湿度相关性最高（R=0.588）;②焉耆盆地湿度总体以半干旱为主（0.60.8）;土壤湿度空间分布上,焉耆盆地南侧为干旱区,西部和北部地区偏干旱,中部为湿润区域,对于该地区滨湖湿地和博斯腾湖附近小湖土壤湿度最高,博斯腾湖南部的沙地区土壤湿度最低,Ts与土壤湿度呈负相关;③10月湿地的TVDIm值最低,9月沙地的TVDIm值最高。TVDI模型应用于焉耆盆地取得较好的结果,可用于正确地估算土壤湿度,研究结果可为焉耆盆地生态环境和水资源提供重要的参数。 相似文献
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Nowadays watershed management plays a vital role in water resources engineering. Watershed based on water resources management
is necessary to plan and conserve the available resources. Remote Sensing (RS) and Geographic Information System (GIS) techniques
can be effectively used to manage spatial and non spatial database that represent the hydrologic characteristics of the watershed
use as realistically as possible. The present study area is Malattar subwatershed (4C2B2) lies in the region Gudiyattam Block,
Vellore District, Tamil Nadu. The daily rainfall data of Gudiyattam rain gauge station (1971–2007) was collected and used
to predict the daily runoff from the watershed using Soil Conservation Service — Curve Number (SCS — CN) method (USDA, 1972)
and GIS. Monthly and annual runoff have been calculated from the monthly rainfall data for the years of 1971 to 2007 in the
watershed area. The average minimum and maximum rainfall for the years of 1971 to 2007 is 35.30 mm and 111.61 mm respectively
and average runoff for the year of 1971 to 2007 is 31.87 mm3 and 47.04 mm3 respectively. The developed rainfall-runoff model is used to understand the watershed and its runoff flow characteristics. 相似文献
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R. K. Somashekar P. Ravikumar S. V. Sowmya Mubhashir Aziz Dar A. S. Ravikumar 《Journal of the Indian Society of Remote Sensing》2011,39(1):95-106
The study area, Hesaraghatta watershed is located between 77° 20′ to 77° 42′ E longitude and 13° 10′ to 13° 24′ N latitude
with an area of 600.01 km2. Thematic layers such as Land Use/Land Cover, drainage, soil and hydrological soil group were generated from IRS–1D LISS
III satellite data (FCC). An attempt was made to estimate runoff using Soil Conservation Service (SCS) curve number model
and it was estimated to be 1960, 2066, 1870 and 1810 mm for sub-watersheds 1, 2, 3 and 4 respectively. Quantitative morphometric
analysis was carried out for the entire watershed and the four sub-watersheds independently by estimating their (a) linear
aspects like stream order, stream length, stream length ratio, bifurcation ratio, length of overland flow, drainage pattern
(b) aerial aspects like shape factor, circulatory ratio, elongation ratio and drainage density and (c) relief aspects like
basin relief, relief ratio, relative relief and ruggedness number. Drainage density was estimated to be 1.23 km/km2 designating the study area as a very coarse textured watershed. 相似文献
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小流域已经成为水土流失治理、生态系统修复等研究工作的重要地理单元。本文以贵州省赤水河流域为研究对象,探索我国西南典型喀斯特与非喀斯特地貌混合分布区小流域划分方法及小流域分布特征,基于DEM提取小流域边界,利用1∶5万地形图进行修正,并结合野外调查和地质、水文数据验证,最终将贵州省赤水河流域划定了753个小流域。其中,喀斯特地貌区小流域个数358个,喀斯特+非喀斯特地貌区小流域个数182个,非喀斯特地貌区213个;就不同流域类型小流域划分结果看,完整型小流域530个,区间型小流域180个,坡面型小流域43个;这些小流域中面积小于3km2的有9个,面积在3～10km2的有310个,面积在10～30km2的有348个,面积在30～50km2的有86个。贵州省赤水河流域小流域划分研究可为小流域治理工作提供依据,为区域制定水土保持方案和生态建设措施提供辅助决策,促进喀斯特地区水土保持与生态环境建设。 相似文献
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Availability of reliable, timely and accurate rainfall data is constraining the establishment of flood forecasting and early warning systems in many parts of Africa. We evaluated the potential of satellite and weather forecast data as input to a parsimonious flood forecasting model to provide information for flood early warning in the central part of Nigeria. We calibrated the HEC-HMS rainfall-runoff model using rainfall data from post real time Tropical Rainfall Measuring Mission (TRMM) Multi satellite Precipitation Analysis product (TMPA). Real time TMPA satellite rainfall estimates and European Centre for Medium-Range Weather Forecasts (ECMWF) rainfall products were tested for flood forecasting. The implication of removing the systematic errors of the satellite rainfall estimates (SREs) was explored. Performance of the rainfall-runoff model was assessed using visual inspection of simulated and observed hydrographs and a set of performance indicators. The forecast skill was assessed for 1–6 days lead time using categorical verification statistics such as Probability Of Detection (POD), Frequency Of Hit (FOH) and Frequency Of Miss (FOM). The model performance satisfactorily reproduced the pattern and volume of the observed stream flow hydrograph of Benue River. Overall, our results show that SREs and rainfall forecasts from weather models have great potential to serve as model inputs for real-time flood forecasting in data scarce areas. For these data to receive application in African transboundary basins, we suggest (i) removing their systematic error to further improve flood forecast skill; (ii) improving rainfall forecasts; and (iii) improving data sharing between riparian countries. 相似文献