Seasonal forecasting of fire over Kalimantan, Indonesia

A C Spessa,J W Kaiser,S Englhart,F Pappenberger,A Langner,T Stockdale,F Siegert,R D Field,J Moore,U Weber

doi:10.5194/nhess-15-429-2015

Abstract

Abstract. Large-scale fires occur frequently across Indonesia, particularly in the southern region of Kalimantan and eastern Sumatra. They have considerable impacts on carbon emissions, haze production, biodiversity, health, and economic activities. In this study, we demonstrate that severe fire and haze events in Indonesia can generally be predicted months in advance using predictions of seasonal rainfall from the ECMWF System 4 coupled ocean–atmosphere model. Based on analyses of long, up-to-date series observations on burnt area, rainfall, and tree cover, we demonstrate that fire activity is negatively correlated with rainfall and is positively associated with deforestation in Indonesia. There is a contrast between the southern region of Kalimantan (high fire activity, high tree cover loss, and strong non-linear correlation between observed rainfall and fire) and the central region of Kalimantan (low fire activity, low tree cover loss, and weak, non-linear correlation between observed rainfall and fire). The ECMWF seasonal forecast provides skilled forecasts of burnt and fire-affected area with several months lead time explaining at least 70% of the variance between rainfall and burnt and fire-affected area. Results are strongly influenced by El Niño years which show a consistent positive bias. Overall, our findings point to a high potential for using a more physical-based method for predicting fires with several months lead time in the tropics rather than one based on indexes only. We argue that seasonal precipitation forecasts should be central to Indonesia's evolving fire management policy.

Highlights

The rainforests of equatorial Southeast (SE) Asia comprise some of the largest, oldest, most biodiverse forests on the planet (Page et al, 2011)
Seasonal mean Global Fire and Emissions Database version 4 (GFED4) area burnt in the south was, on the average, 27.1 times higher than in the central region (Table 1); seasonal mean Remote Sensing Solutions (RSS) fire-affected area in southern region was, on the average, 4.2 times higher than in the central region (Table 1)
Seasonal mean RSS fire-affected area and seasonal mean GFED4 burnt area was highly correlated in the southern region (R2 = 0.96) and the central region (R2 = 0.88)

Summary

Introduction

The rainforests of equatorial Southeast (SE) Asia comprise some of the largest, oldest, most biodiverse forests on the planet (Page et al, 2011). The El Niño Southern Oscillation (ENSO) is the major driver of rainfall variability in the equatorial Pacific region, and occurs irregularly on a 2–7 year intervals lasting about one year but with varying strengths (Aldrian and Dwi Susanto, 2003; Dobles-Reyes et al, 2013). Large-scale rainfall patterns in the region are affected by other major weather systems such as the Indian Ocean Dipole (IOD) and the Madden Julian Oscillation (MJO), but their interactions with ENSO are highly complex (Field et al, 2009; Reid et al, 2012; Dobles-Reyes et al, 2013). Land rainfall in the maritime continent is affected by a complex of biophysical effects including land–sea distribution, orography, land cover, and local SSTs (Aldrian and Dwi Susanto, 2003)

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Discussion

Conclusion