Evaluating Satellite Precipitation Error Propagation in Runoff Simulations of Mountainous Basins
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This study evaluates the error characteristics of six satellite precipitation products and their impact on flood simulations in 16 mountainous basins in northeast Italy. It analyzes systematic and random errors across different basin scales, seasonal periods, and flow severities, finding gauge-adjusted products more effective than near-real-time counterparts. Results indicate that errors decrease with basin size and warm periods, with consistent performance in low to moderate flow rates compared to high flow rates.
Evaluating Satellite Precipitation Error Propagation in Runoff Simulations of Mountainous Basins
- 1. Classification • Basin scale: 9 medium and 7 large (less and greater than 1000 km2); • Seasonality: warm and cold period (May-Aug and Sep-Nov); • Severity: low to moderate and high flow rate (below and above the 90th percentile of gauge-simulated runoff). Evaluating Satellite Precipitation Error Propagation in Runoff Simulations of Mountainous Basins Yiwen Mei1, Efthymios I. Nikolopoulos2, Emmanouil N. Anagnostou1 and Marco Borga2 1 Civil and Environmental Engineering, University of Connecticut, Storrs, CT, USA 2 Department of Land, Environment, Agriculture and Forestry, University of Padova, Legnaro, Padova, Italy This study investigates the error characteristics of six quasi-global satellite precipitation products and associated error propagation in flow simulations for 16 mountainous basin scales (areas ranging from 255 to 6967 km2) and two different periods (May-Aug & Sep-Nov) in northeast Italy. The satellite products used in this study are 3B42-CCA, 3B42-V7, CMORPH and PERSIANN with their respect gauge-adjusted products. To evaluate the error propagation in flood simulations satellite precipitation datasets were used to force a gauge-calibrated hydrologic model to simulate runoff for the 16 basins, and comparing them to the gauge-driven simulated hydrographs for a range of moderate to high flood events spanning a nine- year period (2002 to 2009). Statistics describing the systematic and random error, the temporal similarity and error ratios between precipitation and runoff are presented. • Upper Adige River Basin (6967 km2); • 104 rain gauges and 143 temperature stations; • Integrated Catchment Hydrological Model (ICHYMOD): snow routine, soil moisture routine, flow routine Introduction Study Area Methods Error metrics • Mean Relative Error (MRE); • Centered Root Mean Square Error (CRMSE); • Correlation Coefficient (CC); • Ratio between Error Metric (γ). Role of elevation on systematic error Effects of basin scale, seasonality and flow severity Error Propagation May-AugSep-Nov 3B42 CMORPH PERSIANN 3B42 CMORPH PERSIANN Mean Basin Elevation (m a.s.l.) MREinFlow MREinRainfall MRE Above90th Percentile Below90th Percentile CRMSE CC γMRE γCRMSE γCC Satellite Precipitation Products Satellite Precipitation Products Conclusions • Systematic error ranged from underestimation to overestimation with the mean basin elevation; • Low to moderate flow rate group (below the 90th percentile threshold) yield higher consistency compared to the high flow rate one; • Random errors are reducing and converging with basin scale and from cold to warm period; • Gauge-adjusted products outperform their near-real- time counterparts; • Lower degree of variability from ratios of random error and temporal similarity metrics for larger basins and warm period cases; • Significant dampening effect in random error compared to the other metrics.