With the increasing temporal resolution of medium spatial resolution data, seasonal features are becoming more readily available for land cover characterization. However, in the tropical regions, images can be severely contaminated by clouds during the rainy season and fires during the dry season, with possible effects to seasonal features. In this study, we evaluated the performance of seasonal features based on an annual Landsat time series (LTS) of 35 images for land cover characterization in West Sudanian savanna woodlands. First, the burnt areas were detected and removed. Second, the reflectance seasonality was modelled using a harmonic model, and model parameters were used as inputs for land cover classification and tree crown cover prediction using the random forest algorithm. Furthermore, to study the sensitivity of the approach to the burnt areas, we repeated the analyses without the first step. Our results showed that seasonal features improved classification accuracy significantly from 68.7% and 66.1% to 76.2%, and decreased root mean square error (RMSE) of tree crown cover predictions from 11.7% and 11.4% to 10.4%, in comparison to the dry and rainy season single date images, respectively. The burnt areas biased the seasonal parameters in near-infrared and shortwave infrared bands, and decreased the accuracy of classification and tree crown cover prediction, suggesting that burnt areas should be removed before fitting the harmonic model. We conclude that seasonal features from annual LTS improved land cover characterization performance, and the harmonic model, provided a simple method for computing annual seasonal features with burnt area removal. © 2016 by the authors.
Tag: fire
Quantifying off-site effects of land use change: filters, flows and fallacies
Many external effects of land use change are based on modifications of lateral flows of soil, water, air, fire or organisms. Lateral flows can be intercepted by filters and thus the severity and spatial range of external effects of land use change is under the influence of filter effects. Wherever lateral flows are involved, research results cannot be simply scaled on an area basis, and overall impact does not follow simple linear causal relationships. This complexity has consequences for relationships amongst the primary agents who initiate or exacerbate external effects, other stakeholders who are affected by them and policymakers who attempt to mitigate problems that reach sufficient visibility in society. In this paper we review how the relative importance of lateral flows and filter effects differs among a number of externalities, and the implications this has for research methods. If flows and filters are incompletely understood, policies may be based on fallacies. Whereas ‘fire-breaks’ act as filters in the lateral flow of the high temperature pulse of a fire, smoke from land-based fires can be intercepted only by rainfall acting as a filter and the external impact of smoke is determined by the atmospheric conditions governing lateral flow and chemical transformations along the pathway. Causal relations in smoke and haze problems are relatively simple and may form a basis for designing policy interventions to reduce downwind damage. For biodiversity issues, landscape connectivity, the absence of filters restricting dispersal and movement of organisms, is increasingly recognised as an influence on the dynamics of species richness and its scaling relations. Biodiversity research methods can extend beyond the current descriptive stage into clarifying causal relations with a lateral flow perspective. The question whether connectivity is in fact desired, however, depends on stakeholder interests and situation. Forest functions in watershed protection, presumably leading to a continuous flow of clean water in the dry season through the subsoil instead of a rapid surface transfer, have been generally attributed to the trees rather than the forest, with its rough surface structure, swamps and infiltration sites. A new synthesis of site-specific hydrological knowledge and tree water balance studies may be needed to separate myth from reality, and avoid wasting public funds on tree planting under the heading of reforestation, without restoring the hydrological regime of a real forest. Soil movement can be intercepted at a range of scales and in as far as soil transport entails movement of soil fertility, filter zones can be very productive elements of a landscape. To achieve ‘integrated natural resource management’ all external effects of land use will somehow have to be taken into account in farmer decision making about the use of natural resources on and off farm. Farmers’ ecological knowledge may include concepts of lateral flows and should be further explored as an integral part of a new landscape ecological approach.
Lessons on Community-Based Fire Prevention and Peatland Restoration
Ideas, narratives and arguments on preventing natural disasters and restoring ecosystems focus on raising awareness and fostering participation from all parties. Conventional research helps in understanding socioecological systems and their interactions, but governments, communities and donors want research that makes a difference. There is an urgent need for tangible change. Research conducted with full participation and an action-oriented approach is the solution. Participatory Action Research (PAR) is designed to bring real change on the ground. PAR is transdisciplinary in nature; it integrates approaches from various disciplines and draws on both local and global wisdom. This book aims to provide an understanding of the concepts, philosophical foundations and steps involved in implementing PAR, and is complemented by examples of fire prevention and community-based peatland restoration efforts implemented in Riau Province, Indonesia. We hope it can serve as a valuable resource for researchers, private sector operators, communities, NGOs, governments and practitioners involved in natural disaster prevention and ecosystem restoration.
The Effect of Fire and Rewetting on the Groundwater Level in Tropical Peatlands
Hydrological system strongly influences the sustainability of peatlands. The drainage system in peatlands that is not designed appropriately will result in the drop of groundwater level (GWL), and thus, peat will be dried and become susceptible to fire. Efforts to restore peatlands have been carried out, one of which is peat rewetting through canal blocking. This study assessed the non-burnt and burnt peatland areas as well as an area with canal blocking to determine the effect of fire and canal blocking on the GWL for the foregoing variables. In each area, dipwells were established at a distance of 1 m (representing the canal water level), 10, 50, 100, 250, and 350 m from the canal. The study clearly showed a significant correlation between the average GWL and fire, and canal blocking as well as the distance from the canal. Fire resulted to an increase of the average GWL, from 61 cm to 50 cm below the ground. There were significant impacts on land use relevant to the average GWL. Canal blocking demonstrated its role in increasing GWL on drained peat areas by mimicking the average GWL on the reference site. This study concluded that constructing more canal blockings and planting more fire-resistant plants are critical to reduce the fire risks.
Wildfire effects on forest structure of Pinus merkusii in Sumatra, Indonesia
Pinus merkusii (Jungh. & de Vriese), the only pine species native to Indonesia, is threatened by land-use change, resource extraction, and fire. P. merkusii forests in Sumatra are subject to mixed-severity wildfires that can change forest structure over time. This project is only the second study to quantify differences between burned and unburned P. merkusii forests in Sumatra. We measured six burned-unburned paired sites for forest characteristics, regeneration, forest floor and woody debris, and effects of resin tapping. Fires killed more than 60% of P. merkusii trees and reduced tree biomass and carbon by about 40%. Fire killed trees of all sizes up to 60 cm diameter at breast height (DBH), but preferentially killed small trees with DBH less than 10 cm. Seedling regeneration of P. merkusii in the burned forest was higher on average than in the unburned forest, but the difference was not statistically significantly different and P. merkusii regeneration was low overall. Unlike continental Asian P. merkusii forests, the insular populations did not have a seedling grass stage or evidence of fire-stimulated germination. Forest floor and woody debris values were relatively low by the standards of global pine forests but comparable data do not exist for Indonesia. Recent tapping of trees for P. merkusii resin affected most trees over 20 cm DBH and was associated with high mortality in fires, suggesting that the interaction between resin tapping and fire could be lethal. Further research is needed to evaluate longer-term forest dynamics, especially for regeneration and the effects of resin tapping.
New Approach Evaluating Peatland Fires in Indonesian Factors
Until 2018, the El Niño–Southern Oscillation (ENSO) was used as an explanation for fires in Indonesia’s peatlands. However, when the 2019 fires occurred independently of El Niño, more suitable indicators and methods were required to (a) analyze, (b) evaluate and (c) forecast peatland fires. In this study, we introduced the OLR–MC index—one of the rain-related indices derived from OLR (outgoing longwave radiation) in MC (maritime continent) area in Indonesia. This index showed stronger correlation with active peatland fires than the conventional ENSO index, and is likely to be able to respond to heat and dry weather supposed to be under climate-change conditions. We then analyzed peatland fires in the top six fire years from 2002 to 2018 and showed that peatland fires occurred in three stages—surface fire, shallow peatland fire and deep peatland fire. To explain each stage, we proposed a one-dimensional groundwater level (GWL) prediction model (named as MODEL-0). MODEL-0 predicts GWL from daily rainfall. Analysis using MODEL-0 showed the GWL thresholds for the three fire stages were between -300 mm and -500 mm; peatland fire activities during the three fire stages were dependent on these GWL values. The validity of MODEL-0 was shown by comparison with the measured values of GWL in the top three fire years.
Out of fire disaster: dynamics of livelihood strategies of rural community on peatland use and management
Rural community in peatland is less concerned actor during the recurrent fire disaster. This disaster has already diminished the source of livelihoods. There is limited information about the dynamics of the livelihoods related to the use of fire in peatland. This paper examines the dynamics of rural livelihoods and the adaptation livelihoods strategies in degraded peatland. Data are collected by field survey, in-depth interview, focus group discussion in three villages at Riau Province and they are analyzed descriptively. Peatland is the only remaining important resource for the rural people after fire disaster. They will select prospective commodities based on their capabilities and access to market. Rural community are more intensive in using the resource of peatland for their livelihoods with the growing interest to several commodities. Recent community livelihoods depend on some certain commodities (palm oil, areca nut, rubber) and tend to conduct expansive and monoculture land use strategy rather than polyculture strategy. Diversification livelihood with adaptive and valuable commodities through trainings, continuous coaching and building business.
Impact of trainings on knowledge, skill, behaviour and income of farmers living around peatlands: case study in Riau Province
Peatlands in Indonesia have been objected to draining, burning and converting into agriculture lands causing huge greenhouse gas emissions and triggering climate change. To reduce emissions on peatland but still keep maintaining community livelihoods, farmers need to be trained with best practices on peatland uses and management. Under the Haze Free Sustainable Livelihoods Project, three trainings have been conducted, namely training on nursery and land preparation without burning, training on post harvests processing of fish and corn, and training on honeybee cultivation. The training participants are community who live in and around the Peatland Hydrological Unit of Kampar-Indragiri Rivers, Riau. An impact assessment of the completed trainings has been conducted which employe four-level evaluation model as proposed by Kirkpatrick (1994). The results indicatesthat all of the trainings improve participants’ knowledge and skill. Moreover, the honeybee cultivation training has also transformed participants’ behaviour to be more preserve and maintain nectarpollen and resin producing trees, pollen and sap. The trainings, however, are yet to affect household income although an increase of profit has been recorded on some champion participants.
Tropical Dry Forest Resilience to Fire Depends on Fire Frequency and Climate
Wildfires are becoming increasingly frequent and devastating in many tropical forests. Although seasonally dry tropical forests (SDTF) are among the most fire-threatened ecosystems, their long-term response to frequent wildfires remains largely unknown. This study is among the first to investigate the resilience in response to fire of the Chiquitano SDTF in Bolivia, a large ecoregion that has seen an unprecedented increase in fire intensity and frequency in recent years. We used remote sensing data to assess at a large regional and temporal scale (two decades) how fire frequency and environmental factors determine the resilience of the vegetation to fire disturbance. Resilience was measured as the resistance to fire damage and post-fire recovery. Both parameters were monitored for forested areas that burned once (F1), twice (F2), and three times (F3) between 2000 and 2010 and compared to unburned forests. Resistance and recovery were analyzed using time series of the Normalized Burn Ratio (NBR) index derived from Landsat satellite imagery, and climatic, topographic, and a human development-related variable used to evaluate their influence on resilience. The overall resilience was lowest in forests that burned twice and was higher in forests that burned three times, indicating a possible transition state in fire resilience, probably because forests become increasingly adapted during recurrent fires. Climatic variables, particularly rainfall, were most influential in determining resilience. Our results indicate that the Chiquitano dry forest is relatively resilient to recurring fires, has the capacity to recover and adapt, and that climatic differences are the main determinants of the spatial variation observed in resilience. Nevertheless, further research is needed to understand the effect of the higher frequency and intensity of fires expected in the future due to climate change and land use change, which may pose a greater threat to forest resilience.
Sustainable land preparation for farmer-managed lowland agriculture in Indonesia
In almost all forms of agriculture and farming practice, land clearing is the initial step. In Indonesia, in general, the most cost effective means of clearing land is through the use of fire. However, this use of fire often results in uncontrolled outbreaks, particularly in lowland areas especially and during prolonged dry seasons. In recent years, these uncontrolled fire outbreaks have had a catastrophic environmental, social and economic impact. The Indonesian government has expressed a strong commitment to controlling these outbreaks, as demonstrated by a broad set of laws, regulations, decrees, guidelines, and directives to control and manage land and forest fire. However, despite these measures, the occurrence of widespread, high-intensity fire outbreaks is still unacceptably high. This study assessed land-clearing techniques associated with a low risk of fire outbreaks, comparing the costs associated with a range of these techniques. It then analyzed intervention options that would involve the adoption of these techniques by farmers. These low-risk techniques included: (i) zero-burning practices involving traditional machinery and farmer groups; (ii) zero-burning involving modern machinery and partnerships with government agencies/private enterprises; (iii) controlled burning; and (iv) the chemical removal of biomass using herbicides. The study finds that the costs for all four of these options are higher than with land-clearing techniques that use fire alone. However, it also showed that the cost implications for farmers could be mitigated by taking a more holistic view of farming practices as a system, rather than focusing only on land-clearing practices in isolation. It found that when land-clearing practices that involve low risks of fire outbreak are combined with good agricultural practices (GAP), farmers could still achieve higher levels of profitability and productivity than under a business as usual (BAU) scenario. The study produced scenarios involving BAU practices; land clearing without fire and with BAU practices; and land clearing without fire and with good agricultural practices (GAP) for four agricultural commodities (oil palm, cocoa, rubber, and paddy). It found that the return on land (NPV) in the case of the scenario involving land clearing without fire and with GAP was still higher than under the BAU scenario, except in the case of rubber, with which the NPV was higher in the scenario with modern machinery and GAP. The study concludes that a systems approach is necessary to effectively control fire outbreaks. Government programs should be designed and implemented on the basis of this systems approach with the involvement of a wide range of stakeholders, including through partnerships with the private sector operators, to effectively control the risk of fire outbreaks while at the same time supporting farmers’ livelihoods by ensuring that they are enabled to generate higher levels of productivity and profitability from their land.