17 Strengthening Flood and Drought Risk Management Tools …
391
This chapter describes the development of the CHADFDM and its main features,
including the online interface, and provides an overview of the validation of the
system outputs. It concludes by discussing the potential use of the system in decisionmaking and policy development, and future plans for enhancing and further refining
the system.
2 Overview of the Lake Chad System
2.1 Rationale and Background
The CHADFDM is an outgrowth of various continental systems that have been developed since about 2010: the Africa Flood and Drought Monitor (AFDM) (Sheffield
et al. 2014), the Latin America Flood and Drought Monitor (LACFDM 2019) and
the US Flood and Drought Monitor (USFDM) (Sheffield et al. 2012). In general,
these systems leverage the coverage of satellite remote sensing, the consistency of
hydrological modelling and the power of climate forecasts, combined with available
on-the-ground information, to estimate water availability (primarily flood potential and drought conditions), historically, in near-real time and as forecasts. The
CHADFDM draws from the long legacy of operational and experimental systems
developed for the U.S. by the Terrestrial Hydrology Group at Princeton University
(Luo and Wood 2007), part of the North American Land Data Assimilation System
Phase 2 (NLDAS-2; Xia et al. 2012) and the Climate Forecast System (NCEP)
Climate Test Bed Program.
2.2 Main Components of the System
The CHADFDM consists of four parts (Fig. 1): 1. A historic, multi-decadal reconstruction of the terrestrial water cycle is generated by forcing a land surface hydrological model (Variable Infiltration Capacity (VIC)) (Liang et al. 1994 and Hamman
et al. 2018) with a merged reanalysis/satellite/observation dataset of precipitation
and other meteorological variables. This forms the climatology against which current
conditions are compared. Then the real-time monitoring system (2018–present) is
driven by a merged precipitation dataset and atmospheric analysis data that tracks
flood and drought conditions in real time. 2. The simulated outputs are augmented
by satellite remote sensing of soil moisture and vegetation indices. 3. A 7-day forecasting component provides hydrological forecasting of floods and water availability,
and 4. A seasonal forecast component provides hydrological predictions and derived
drought products out to 6 months, based on bias-corrected and downscaled climate
model forecasts that are used to drive the hydrologic and potentially other impact.
391
This chapter describes the development of the CHADFDM and its main features,
including the online interface, and provides an overview of the validation of the
system outputs. It concludes by discussing the potential use of the system in decisionmaking and policy development, and future plans for enhancing and further refining
the system.
2 Overview of the Lake Chad System
2.1 Rationale and Background
The CHADFDM is an outgrowth of various continental systems that have been developed since about 2010: the Africa Flood and Drought Monitor (AFDM) (Sheffield
et al. 2014), the Latin America Flood and Drought Monitor (LACFDM 2019) and
the US Flood and Drought Monitor (USFDM) (Sheffield et al. 2012). In general,
these systems leverage the coverage of satellite remote sensing, the consistency of
hydrological modelling and the power of climate forecasts, combined with available
on-the-ground information, to estimate water availability (primarily flood potential and drought conditions), historically, in near-real time and as forecasts. The
CHADFDM draws from the long legacy of operational and experimental systems
developed for the U.S. by the Terrestrial Hydrology Group at Princeton University
(Luo and Wood 2007), part of the North American Land Data Assimilation System
Phase 2 (NLDAS-2; Xia et al. 2012) and the Climate Forecast System (NCEP)
Climate Test Bed Program.
2.2 Main Components of the System
The CHADFDM consists of four parts (Fig. 1): 1. A historic, multi-decadal reconstruction of the terrestrial water cycle is generated by forcing a land surface hydrological model (Variable Infiltration Capacity (VIC)) (Liang et al. 1994 and Hamman
et al. 2018) with a merged reanalysis/satellite/observation dataset of precipitation
and other meteorological variables. This forms the climatology against which current
conditions are compared. Then the real-time monitoring system (2018–present) is
driven by a merged precipitation dataset and atmospheric analysis data that tracks
flood and drought conditions in real time. 2. The simulated outputs are augmented
by satellite remote sensing of soil moisture and vegetation indices. 3. A 7-day forecasting component provides hydrological forecasting of floods and water availability,
and 4. A seasonal forecast component provides hydrological predictions and derived
drought products out to 6 months, based on bias-corrected and downscaled climate
model forecasts that are used to drive the hydrologic and potentially other impact.