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ANALYSIS OF ESTIMATED RAINFALL DATA USING SPATIAL INTERPOLATION. Preethi Raj GEOG 5650 (Environmental Applications of GIS). INTRODUCTION. Current research in Hydrology emphasizes on ability to forecast hydrologic parameters. Precipitation. Evapo-transipiration. Infiltration. Stream flow.
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ANALYSIS OF ESTIMATED RAINFALL DATA USING SPATIAL INTERPOLATION. Preethi Raj GEOG 5650 (Environmental Applications of GIS)
INTRODUCTION • Current research in Hydrology emphasizes on ability to forecast hydrologic parameters. Precipitation Evapo-transipiration Infiltration Stream flow Hydrologic Cycle Environmental Application of GIS Spring 06
PROBLEMS • Precipitation plays an important role in Hydrologic cycle. • Need for precipitation data to have a better understanding of Hydrologic cycle. • Due to practical difficulties not possible to have rain gauges all over the world. • Need for an alternative to estimate precipitation data. Environmental Application of GIS Spring 06
STUDY AREA - USA • Total number of stations = 6322 Environmental Application of GIS Spring 06
STUDY AREA - USA • Number of stations selected = 1904 Environmental Application of GIS Spring 06
PROCESSES SPATIAL INTERPOLATION • Kriging Interpolation • Inverse Distance Weighted interpolation Environmental Application of GIS Spring 06
KRIGING Environmental Application of GIS Spring 06
KRIGING • PREDICTION STANDARD ERROR MAP Environmental Application of GIS Spring 06
INVERSE DISTANCE WEIGHTED IDW POWER - 3 IDW POWER- 2 IDW POWER - 4 IDW POWER - 5 Environmental Application of GIS Spring 06
ANALYSIS • TENNESSEE • ALABAMA SELECTED STATIONS = 62 UNSELECTED STATIONS = 148 = SELECTED STATION = UNSELECTED STATION Environmental Application of GIS Spring 06
RESULTS Environmental Application of GIS Spring 06
RESULTS Environmental Application of GIS Spring 06
CONCLUSIONS • Values obtained using Kriging, IDW- Power 2 & 3 gives similar values and closer to actual precipitation value. • Difference in values obtained using IDW –Power 5 is high. Environmental Application of GIS Spring 06
ANY QUESTIONS ? THANK YOU Environmental Application of GIS Spring 06