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基于GIS & RS的长江流域区域地表水循环研究

Study on the Regional Surface Water Cycle of the Yangtze Basin (Baohe Basin) Based on the Technique GIS & RS

【作者】 薛根元

【导师】 孙照渤;

【作者基本信息】 南京信息工程大学 , 气象学, 2007, 博士

【摘要】 本文基于GIS与RS技术,应用VIC-3L模式对长江流域区域地表水循环进行研究,研究区域选在褒河流域,主要研究结论如下:(1)不同高度、纬度、坡度等都会造成气候变量空间分布的非均匀性,这时即使用多次订正误差的逐步插值法仍无法真实反映温度的小地形效应。本文提出先用高斯权重法作插值,再作逐步订正以获得温度空间分布,可明显提高空间插值精度;提出SIA方法与统计回归法结合的降水插值方案,与其他相关插值方法的对比分析表明,这一方法的插值精度较高。(2)应用ArcGIS技术提取水文模式参数。对比分析表明,这种由ArcGIS技术得到的流域内山地坡向、坡度,流域内河流流向、流速,流域边界与河网边界等与DEM计算结果相一致。(3)遥感的叶面指数较好地反映了实际叶面指数的季节变化,且遥感植被类型真实反映了地表覆盖,地表植被类型分布与遥感地表类型更为接近。应用遥感资料再次分别对地表水平衡进行了模拟研究,结果表明,模拟结果较不使用遥感资料时有明显改善,特别是入江口流量的模拟结果改善更为明显。(4)在地表水循环过程中,包括地表植被类型、土壤湿度、前期土壤湿度、地形和降水对地表径流都有可能对地表径流产生影响,进而影响到地表水循环。褒河流域1979-1984、1992-2001年地表水平衡各分量年平均值的空间分布的模拟结果表明,蒸发过程中植被蒸腾作用相对重要,地表土壤作用则相对较小。对于地表径流分布的模拟,土壤水分的空间差异不算太大,比较符合实际情况。对栅格时间序列的模拟结果表明,地表径流呈现出明显的年周期变化,这与气候与水文资料分析的结果一致的。(5)对褒河流域所进行的模拟试验,得到均匀性农田植被时流量的模拟误差达到21.82%,应用传统的植被类型资料模拟流量时的误差有下降,但有比实际流量偏少现象,达到-14.23%;应用非均匀性遥感地表类型模拟的流量为误差最小,平均误差只有1.43%。可见,地表非均匀性对于地表水循环的影响很大,这种影响进而又影响着河流的流量变化。

【Abstract】 Based on the technique GIS and RS, the paper studies the regional surface watercycle (SWC) of the Yangtze basin by model VIC-3L with focusing on Baohe basin.The main results are as followed:1) Different height, latitude, slope and other factors would lead to non-uniformspatial distribution of some climate variables. In fact, even step-to-step interpolationperformed multiple times for error correction could not truly reflect the littletemperature topographic effect. For this reason, Gaussian weighted method is adoptedfor interpolation before step-by-step correction for the space distribution oftemperatures to improve greatly the accuracy of spatial interpolation. SIA combinedwith statistical regression could decrease precipitation space interpolation error.2) ArcGIS is used to pick up the parameters of hydrological models. Thecomparison showes that what resulting from ArcGIS, such as slope aspect, slopegradient, flow direction, flow velocity in the river basin, river basin and river system’sborder, are consistent with the results from DEM.3) The remote sensing data of the leaf area index (LAI) could reflect the seasonalvariation of the real LAI, and the ground vegetation types acquired by remote sensingimaged the land cover, which has similarities with distribution of ground vegetationtypes. The simulation results are improved after adding the remote sensing data,particularly the flow into the estuary when the remote sensing data were applied in theresearch of simulation of surface water cycle (SWC).4) In the process of SWC, the ground vegetation types, soil humidity andprophase soil humidity, landscape and precipitation have effect on the surface runoff,even on the water surface cycle. The simulation of spatial distribution, which is aboutrespective average components of ground surface balance from 1979 to 1984 andfrom1992 to 2001 in Baohe basin, show that the transpiration of vegetation is moresignificant comparing with the earth’s surface soil during evaporation process. Thesimulation of ground runoffs distribution points out that the spatial difference of soilwater is in accordance with the real situation, and the simulation results of grid timeseries show that the surface runoff has an annual period oscillation, which iscoincident with the results from the climate and hydrological data.5) The simulations of Baohe basin regional SWC show that there are on error of21.82% of flow rate while using uniformity farmland vegetation and on error of-14.23% of flow rate while using traditional vegetation with less than actual flow rate,the lowest error is 1.43% when the non-uniformity farmland vegetation is applied inthe simulation. So the paper points out that the non-uniformity of land surface effectsSWC, which leads to the changes of river’s flow rate.

  • 【分类号】P339
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