| Since the21st century, the global water environment is facing a huge crisis,shortage of water resources is growing and flood disasters are occurring in China. Asa moisture flux, precipitation connects atmosphere to land surface, is an essential partof hydrologic cycle and one of the important sources of water, has importantsignificance of meteorology, climatology and hydrology. Spatio-temporal variation ofprecipitation affects the hydrological process in the land. Especially the area onlydepends on agricultural production, precipitation is significant particularly. Unlikeother hydro-meteorological parameters, it is influenced by season, latitude andgeographical factors. Its variable ratio is so big, has obvious inter-annual and the yearscharacteristics changed, often show the non-normal distribution, so it is one of thehardest to measure atmospheric variables. Affected by terrain, latitude and longitude,stations are often uneven in distribution and short in number, so it creates tremendousinconvenience for estimation. With the development of RS, using in meteorologicalsatellite speculated that regional precipitation make up for the deficiency ofspace-time distribution greatly, it has been focus on more and more researchers.The area of this article is selected the Yellow River delta efficient ecologicaleconomic zone that located in northern of Shandong Province and has more plain andhills. Its development is based on environmental capacity and premise of ecologicalprotection. The water environment is greatly influenced by precipitation, has richreserves about agriculture, so spatio-temporal variation of precipitation has greatsignificance in agriculture and economic.The tropical rainfall measuring (TRMM) satellite acquired3b43data between2001and20013monthly precipitation is been used in this article. Firstly, it has beenread data, spatial correction, image masking, central pixel extraction and so on, andprecipitation value with the measured data under the same time is been achieved, andset up linear regression equation between values of central pixels extracted and themeasured data in different time scales, inspect reliability and precision level of thevalue of central pixels extracted; Secondly, Validate the spatial distribution of themetadata for normal distribution, select the optimal interpolation method from avariety of interpolation methods, get the high resolution of regional precipitation,calibrate the regression of regional precipitation combining with the meteorological data; Used optimal interpolation method and regression analysis model, get regionalprecipitation after the correction under different time scales, and analysis the changesof time and space of the Yellow River delta economic zone of precipitation since2000in the allocation proportion, spatial distribution and precipitation anomaly; Finally,combining with MODIS images data and meteorological data, analysis the changes ofprecipitation with meteorological parameters and terrestrial parameters.It shows that using satellite measurement can make up for water data acquisitionunder a lack of the stations with spatial interpolation method. It can be used to studythe spatial variation of precipitation in the region; Correlation detection of spatial datacan be understood the distribution characteristics of the data, optimized interpolationmethod. The radial basis function results with higher accuracy and been used in thispaper as the greatest method; Under different time scale, spatial distribution are morefrom northwest to southeast, inter-annual variability has increasing trend; Thisprecipitation factors in water vapor, monsoon, ocean currents, synthetically, Therelationship between precipitation and meteorological elements,such as pressure,temperature, humidity, shows obvious positive correlation or negative correlationsignificantly; Although underground is single, it still positively correlated betweenNDVI and precipitation, in addition to human activities could impact on precipitationby changing the land surface. |
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