Title: On the Dominant Factor Controlling Seasonal Hydrological Forecast Skill in China

Abstract

Initial conditions (ICs) and climate forecasts (CFs) are the two primary sources of seasonal hydrological forecast skill. However, their relative contribution to predictive skill remains unclear in China. In this study, we investigate the relative roles of ICs and CFs in cumulative runoff (CR) and soil moisture (SM) forecasts using 31-year (1980–2010) ensemble streamflow prediction (ESP) and reverse-ESP (revESP) simulations with the Variable Capacity Infiltration (VIC) hydrologic model. The results show that the relative importance of ICs and CFs largely depends on climate regimes. The influence of ICs is stronger in a dry or wet-to-dry climate regime that covers the northern and western interior regions during the late fall to early summer. In particular, ICs may dominate the forecast skill for up to three months or even six months during late fall and winter months, probably due to the low precipitation value and variability in the dry period. In contrast, CFs become more important for most of southern China or during summer months. The impact of ICs on SM forecasts tends to cover larger domains than on CR forecasts. These findings will greatly benefit future work that will target efforts towards improving current forecast levels for the particular regions andmore » forecast periods.« less

Authors:

Zhang, Xuejun ^[1]; Tang, Qiuhong ^[2]; Leng, Guoyong ^[3]; Liu, Xingcai ^[1]; Li, Zhe ^[1]; Huang, Zhongwei ^[2]

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+ Show Author Affiliations

1. Chinese Academy of Sciences (CAS), Beijing (China)
2. Chinese Academy of Sciences (CAS), Beijing (China); Univ. of Chinese Academy of Sciences, Beijing (China)
3. Pacific Northwest National Lab. (PNNL), College Park, MD (United States). Joint Global Change Research Inst.

Publication Date:

Mon Nov 20 00:00:00 EST 2017

Research Org.:

Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

Sponsoring Org.:

USDOE

OSTI Identifier:

1430451

Report Number(s):

PNNL-SA-130911
Journal ID: ISSN 2073-4441; WATEGH; KP1703030

Grant/Contract Number:  

AC05-76RL01830

Resource Type:

Accepted Manuscript

Journal Name:

Water (Basel)

Additional Journal Information:

Journal Name: Water (Basel); Journal Volume: 9; Journal Issue: 11; Journal ID: ISSN 2073-4441

Publisher:

MDPI

Country of Publication:

United States

Language:

English

Subject:

54 ENVIRONMENTAL SCIENCES; climate forecasts; China; cumulative runoff; drought; flood; hurricanes