evaluating satellite precipitation error propagation in runoff simulations of mountainous basins
TRANSCRIPT
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 BasinsYiwen Mei
1, Efthymios I. Nikolopoulos
2, Emmanouil N. Anagnostou
1and Marco Borga
2
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
-Au
gS
ep-N
ov
3B42 CMORPH PERSIANN 3B42 CMORPH PERSIANN
Mean Basin Elevation (m a.s.l.)
MR
E i
n F
low
MR
E i
n R
ain
fall
MRE
Ab
ove
90
th
Per
cen
tile
Bel
ow
90
th
Per
cen
tile
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.