Remote sensing of fire regimes in semi-arid Nusa Tenggara Timur, eastern Indonesia: current patterns, future prospects

2006 ◽  
Vol 15 (3) ◽  
pp. 307 ◽  
Author(s):  
Rohan Fisher ◽  
Wilfrida E. Bobanuba ◽  
Agus Rawambaku ◽  
Greg J. E. Hill ◽  
Jeremy Russell-Smith
Keyword(s):  
Remote Sensing ◽  
Prescribed Burning ◽  
Landsat Imagery ◽  
Great Majority ◽  
Fire Regimes ◽  
Dry Season ◽  
Hotspot Detection ◽  
Fire Policy ◽  
Eastern Indonesia ◽  
Semi Arid

Substantial areas of eastern Indonesia are semi-arid (with a pronounced dry season extending from April to November) with extensive areas of uncultivated vegetation dominated by savanna grasslands and woodlands. These are highly fire-prone, despite high population densities reliant on intensive subsistence agriculture and an official national fire policy that prohibits all burning. To date, no regional studies have been undertaken that reliably assess the seasonal extent and patterning of prescribed burning and wildfire. Focusing on two case studies in east Sumba (7000 km2) and central Flores (3000 km2) in the eastern Indonesian province of Nusa Tenggara Timur, the present paper addresses: (1) the efficacy of applying standard remote sensing and geographic information system tools as developed for monitoring fire patterns in savanna landscapes of adjacent northern Australia, for (2) describing the seasonal patterning of burning at village and broader regional scales in 2003 and 2004. Despite recurring cloudiness, which significantly affected daily fire detection of ‘hotspots’ from Advanced Very High Resolution Radiometer and Moderate Resolution Imaging Spectroradiometer sensors, fire mapping from Landsat imagery was undertaken successfully to reveal: (1) fires burnt an annual average of 29% of eastern Sumba (comprising mostly grassland savanna), and 11% of central Flores (with large forested areas); (2) most fire extent occurred in savanna grassland areas, and significantly also in cultivated lands and small remnant patches of forest; (3) most fire activity occurred under harsh, late dry season conditions; and (4) while the great majority of individual fires were less than 5 ha, some late dry season fires were hundreds of hectares in extent. The potential routine application of different image sensors for fire mapping and hotspot detection is considered in discussion.

scholarly journals The influence of prescribed fire on the extent of wildfire in savanna landscapes of western Arnhem Land, Australia

2012 ◽  
Vol 21 (3) ◽  
pp. 297 ◽  
Author(s):  
Owen F. Price ◽  
Jeremy Russell-Smith ◽  
Felicity Watt
Keyword(s):  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Prescribed Fire ◽  
Fire History ◽  
Prescribed Burning ◽  
Landsat Imagery ◽  
Fire Regimes ◽  
Dry Season ◽  
Gas Emissions ◽  
Arnhem Land

Fire regimes in many north Australian savanna regions are today characterised by frequent wildfires occurring in the latter part of the 7-month dry season. A fire management program instigated from 2005 over 24 000 km2 of biodiversity-rich Western Arnhem Land aims to reduce the area and severity of late dry-season fires, and associated greenhouse gas emissions, through targeted early dry-season prescribed burning. This study used fire history mapping derived mostly from Landsat imagery over the period 1990–2009 and statistical modelling to quantify the mitigation of late dry-season wildfire through prescribed burning. From 2005, there has been a reduction in mean annual total proportion burnt (from 38 to 30%), and particularly of late dry-season fires (from 29 to 12.5%). The slope of the relationship between the proportion of early-season prescribed fire and subsequent late dry-season wildfire was ~–1. This means that imposing prescribed early dry-season burning can substantially reduce late dry-season fire area, by direct one-to-one replacement. There is some evidence that the spatially strategic program has achieved even better mitigation than this. The observed reduction in late dry-season fire without concomitant increase in overall area burnt has important ecological and greenhouse gas emissions implications. This efficient mitigation of wildfire contrasts markedly with observations reported from temperate fire-prone forested systems.

scholarly journals A reconstruction of the recent fire regimes of Majete Wildlife Reserve, Malawi, using remote sensing

Fire Ecology ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Willem A. Nieman ◽  
Brian W. van Wilgen ◽  
Alison J. Leslie
Keyword(s):  
Remote Sensing ◽  
Fire Management ◽  
Fire Regime ◽  
Fire Regimes ◽  
Dry Season ◽  
Annual Rainfall ◽  
Vegetation Types ◽  
Local Evidence ◽  
Hot Dry Season ◽  
Wildlife Reserve

Abstract Background Fire is an important process that shapes the structure and functioning of African savanna ecosystems, and managers of savanna protected areas use fire to achieve ecosystem goals. Developing appropriate fire management policies should be based on an understanding of the determinants, features, and effects of prevailing fire regimes, but this information is rarely available. In this study, we report on the use of remote sensing to develop a spatially explicit dataset on past fire regimes in Majete Wildlife Reserve, Malawi, between 2001 and 2019. Moderate Resolution Imaging Spectroradiometer (MODIS) images were used to evaluate the recent fire regime for two distinct vegetation types in Majete Wildlife Reserve, namely savanna and miombo. Additionally, a comparison was made between MODIS and Visible Infrared Imager Radiometer Suite (VIIRS) images by separately evaluating selected aspects of the fire regime between 2012 and 2019. Results Mean fire return intervals were four and six years for miombo and savanna vegetation, respectively, but the distribution of fire return intervals was skewed, with a large proportion of the area burning annually or biennially, and a smaller proportion experiencing much longer fire return intervals. Variation in inter-annual rainfall also resulted in longer fire return intervals during cycles of below-average rainfall. Fires were concentrated in the hot-dry season despite a management intent to restrict burning to the cool-dry season. Mean fire intensities were generally low, but many individual fires had intensities of 14 to 18 times higher than the mean, especially in the hot-dry season. The VIIRS sensors detected many fires that were overlooked by the MODIS sensors, as images were collected at a finer scale. Conclusions Remote sensing has provided a useful basis for reconstructing the recent fire regime of Majete Wildlife Reserve, and has highlighted a current mismatch between intended fire management goals and actual trends. Managers should re-evaluate fire policies based on our findings, setting clearly defined targets for the different vegetation types and introducing flexibility to accommodate natural variation in rainfall cycles. Local evidence of the links between fires and ecological outcomes will require further research to improve fire planning.

Fire regimes and their correlates in the Darwin region of northern Australia

2007 ◽  
Vol 13 (3) ◽  
pp. 177 ◽  
Author(s):  
Owen Price ◽  
Bryan Baker
Keyword(s):  
Fire History ◽  
Ad Hoc ◽  
Fire Regime ◽  
Negative Impact ◽  
Fire Suppression ◽  
Landsat Imagery ◽  
Fire Regimes ◽  
Fire Frequency ◽  
Dry Season ◽  
Generalized Linear Modelling

A nine year fire history for the Darwin region was created from Landsat imagery, and examined to describe the fire regime across the region. 43% of the region burned each year, and approximately one quarter of the fires occur in the late dry season, which is lower than most other studied areas. Freehold land, which covers 35% of the greater Darwin region, has 20% long-unburnt land. In contrast, most publicly owned and Aboriginal owned land has very high fire frequency (60-70% per year), and only 5% long unburnt. It seems that much of the Freehold land is managed for fire suppression, while the common land is burnt either to protect the Freehold or by pyromaniacs. Generalized Linear Modelling among a random sample of points revealed that fire frequency is higher among large blocks of savannah vegetation, and at greater distances from mangrove vegetation and roads. This suggests that various kinds of fire break can be used to manage fire in the region. The overall fire frequency in the Darwin region is probably too high and is having a negative impact on wildlife. However, the relatively low proportion of late dry season fires means the regime is probably not as bad as in some other regions. The management of fire is ad-hoc and strongly influenced by tenure. There needs to be a clear statement of regional fire targets and a strategy to achieve these. Continuation of the fire mapping is an essential component of achieving the targets.

The contradictory role of fire from the nature conservation perspective

2020 ◽  
Author(s):  
Orsolya Valkó
Keyword(s):  
Nature Conservation ◽  
Land Surface ◽  
Fire History ◽  
Prescribed Burning ◽  
Fire Regime ◽  
Fire Regimes ◽  
Fire Effects ◽  
Negative Effects ◽  
Fire Policy

<p>Fire is a globally relevant natural or anthropogenic phenomenon with a rapidly increasing importance in the era of the climate change. In each year, approximately 4% of the global land surface burns. For effective ecosystem conservation, we need to understand fire regimes, identify potential threats, and also the possibilities in the application of prescribed burning for maintaining ecosystems.</p><p>Here I provide an overview on the contradictory role of fire in nature conservation from two continents with contrasting fire histories, focusing on European and North-American grasslands. I show that the ecological effects of fire depend on the fire regime, fire history, ecosystem properties and the socio-economic environment. Catastrophic wildfires, arson, too frequent or improperly planned human-induced fire often lead to the degradation of the ecosystems, the disappearance of rare plant and animal species, and to the encroachment of weed and invasive species. I illustrate with examples that these negative fire effects act synergistically with the human-induced changes in land use systems.</p><p>I also underline with case studies that in both regions, properly designed and controlled prescribed burning regimes can aid the understanding and managing disturbance-dependent ecosystems. Conservation in these dynamic and complex ecosystems is far more than fencing and hoping to exclude disturbance; but the contrary: disturbance is needed for ecosystem functioning. Therefore, the conservation of dynamic, diverse and functioning ecosystems often require drastic interventions and an unconventional conservation attitude. However, the expanding urban-wildlife interface makes the application of prescribed burning challenging worldwide. A major message for the future is about fire policy: it is crucial to moderate the negative effects of fire, however, properly designed prescribed burning should be used as a tool for managing and conserving disturbance-dependent ecosystems.</p>

Enhancing food security in semi-arid eastern Indonesia through permanent raised-bed cropping: a review

1999 ◽  
Vol 39 (8) ◽  
pp. 1035 ◽  
Author(s):  
D. E. Van Cooten ◽  
A. K. Borrell
Keyword(s):  
Water Supply ◽  
Food Production ◽  
Crop Production ◽  
Ground Cover ◽  
Dry Season ◽  
Wet Season ◽  
Additional Food ◽  
Eastern Indonesia ◽  
Raised Bed ◽  
Semi Arid

Summary. Much of south-eastern Indonesia is mountainous and characterised by a semi-arid tropical environment. Soil erosion is a significant environmental problem facing the region, affecting both productivity of the land and water quality. The challenge for the region is to secure year-round food production in such a fragile environment. More than 90% of rain falls in a distinct wet season between November and April. Therefore, cropping in this region is dependent on matching crop growth with water supply. In particular, crop production depends on the efficient use of rainfall during the wet season, including avoidance of waterlogging, and efficient use of stored soil water during the dry season. This paper summarises the results of a series of experiments undertaken in West Timor, Indonesia, between 1993 and 1999 aimed at developing a raised-bed cropping system. The objective of these studies was to better utilise the more fertile alluvial soils that are often susceptible to waterlogging during the wet season, allowing a range of crops to be grown in addition to rice. Raised beds of height 0.2 m and width 1.5 m were constructed either manually or with an 8.5 hp two-wheeled hand tractor. A range of crops including soybeans, sorghum, maize, pigeon pea, yam bean and cassava were successfully grown on raised beds in the wet season in addition to rice, indicating that raised-bed technology overcomes the constraints of waterlogging in the wet season. Soybeans grew particularly well on raised beds, with December-sown crops producing almost twice the yield of January-sown crops (2.6 v. 1.4 t/ha). For rice and soybeans, early sown crops were better able to match growth with water supply, thereby avoiding end-of-season drought. Early sowing and harvesting of wet season crops enables a drought-resistant crop such as sorghum to be planted in lateMarch or early April, utilising the stored soil moisture for grain production and also maintaining ground cover in the dry season. It is argued that cropping systems based on permanent raised beds can reduce erosion in 2 ways. First, raised beds are a permanent structure and, with the inter-cropping and relay-cropping proposed, crops can provide all-year ground cover in lowland areas. Second, if sufficient food and cash crops are grown on raised beds to meet the basic needs of subsistence farmers, then upland cropping on steep slopes can be replaced by a variety of tree species, providing additional food, fodder, firewood and medicines. Together, these strategies have the capacity to enhance food production and security in the semi-arid areas of eastern Indonesia.

Contemporary fire regime risks to key ecological assets and processes in north Australian savannas

2015 ◽  
Vol 24 (6) ◽  
pp. 857 ◽  
Author(s):  
Andrew Edwards ◽  
Jeremy Russell-Smith ◽  
Mick Meyer
Keyword(s):  
Climate Change ◽  
Prescribed Burning ◽  
Fire Management ◽  
Fire Regime ◽  
Ghg Emissions ◽  
Fire Regimes ◽  
Dry Season ◽  
Suspended Sediment Transport ◽  
Change Models ◽  
Positive Effects

Despite the intact appearance of relatively unmodified north Australian savannas, mounting evidence indicates that contemporary fire regimes characterised by frequent, extensive and severe late dry season wildfires are having deleterious effects on a range of regional water, soil erosion, biodiversity conservation and greenhouse gas (GHG) emissions values. For the high rainfall (>1000 mm year–1) savannas (426 000 km2), we assessed the spatial effects of contemporary fire regimes within the context of ecosystem response models and three plausible alternative fire management scenarios on ecosystem attributes. Over the 2008–12 assessment period, mean annual fire frequency (0.53) comprised mostly late dry season fires. Although spatially variable, contemporary fire regimes resulted in substantial GHG emissions, hill slope erosion and suspended sediment transport, a slight decline in carbon biomass and slight positive effects on fire-vulnerable vegetation. Based on available climate change models and strategic fire management practice, we show that, relative to business-as-usual, improved fire management involving strategic prescribed burning results in substantial benefits to most ecosystem attributes, including under enhanced climate change conditions, whereas in the absence of improved fire management, climate change results in substantially worse outcomes.

Confronting complexity: fire policy choices in South African savanna parks

2003 ◽  
Vol 12 (4) ◽  
pp. 381 ◽  
Author(s):  
William J. Bond ◽  
Sally Archibald
Keyword(s):  
South African ◽  
Prescribed Burning ◽  
Fire Regimes ◽  
Lessons Learned ◽  
Conservation Areas ◽  
Fire Policy ◽  
African Savanna ◽  
Policy Alternatives ◽  
Ecological Criteria ◽  
Fire Intervals

Changes in ecological concepts and a new focus on biodiversity as a central objective have led to changes in fire policies in South African savanna parks. Prescribed burning using fixed fire intervals is being replaced by systems that promote more variable fire regimes and greater management flexibility. Three policy alternatives have been proposed for Kruger National Park: a lightning fire policy, patch mosaic burning, and burning based on ecological criteria. There is no agreement as yet on which policy to adopt. However there is growing consensus on the use of a management system using 'thresholds of potential concern' to evaluate the outcome of different policies. These thresholds have been established for numerous indicators, help focus monitoring activities, and guide managers on the need for active intervention. We discuss the applicability of the policy alternatives for preventing successional change from savanna to forest and promoting grazing lawns and their associated grazers. We conclude that none of the current policies is universally applicable. A prescriptive program of frequent, high intensity burns will be required in mesic savannas to prevent succession to forests. In arid savannas, fire regimes designed to promote variable fire frequencies and fire sizes would be preferred to maintain greater diversity of grassland swards and grazer communities. The lessons learned from fire policy debates in South African savannas are of wider relevance for managing conservation areas elsewhere.

scholarly journals Comparison of blue and green water fluxes for different land use classes in a semi-arid cultivated catchment using remote sensing

2021 ◽  
Vol 36 ◽  
pp. 100860
Author(s):  
Anna Msigwa ◽  
Hans C. Komakech ◽  
Elga Salvadore ◽  
Solomon Seyoum ◽  
Marloes L. Mul ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Land Use ◽  
Green Water ◽  
Water Fluxes ◽  
Semi Arid

scholarly journals Multispectral Remote Sensing of Wetlands in Semi-Arid and Arid Areas: A Review on Applications, Challenges and Possible Future Research Directions

2020 ◽  
Vol 12 (24) ◽  
pp. 4190
Author(s):  
Siyamthanda Gxokwe ◽  
Timothy Dube ◽  
Dominic Mazvimavi
Keyword(s):  
Remote Sensing ◽  
Arid Regions ◽  
Remote Sensing Data ◽  
Sub Saharan Africa ◽  
Future Research ◽  
Multispectral Imagery ◽  
Aquatic Life ◽  
Sensing Data ◽  
Spatial Coverage ◽  
Semi Arid

Wetlands are ranked as very diverse ecosystems, covering about 4–6% of the global land surface. They occupy the transition zones between aquatic and terrestrial environments, and share characteristics of both zones. Wetlands play critical roles in the hydrological cycle, sustaining livelihoods and aquatic life, and biodiversity. Poor management of wetlands results in the loss of critical ecosystems goods and services. Globally, wetlands are degrading at a fast rate due to global environmental change and anthropogenic activities. This requires holistic monitoring, assessment, and management of wetlands to prevent further degradation and losses. Remote-sensing data offer an opportunity to assess changes in the status of wetlands including their spatial coverage. So far, a number of studies have been conducted using remotely sensed data to assess and monitor wetland status in semi-arid and arid regions. A literature search shows a significant increase in the number of papers published during the 2000–2020 period, with most of these studies being in semi-arid regions in Australia and China, and few in the sub-Saharan Africa. This paper reviews progress made in the use of remote sensing in detecting and monitoring of the semi-arid and arid wetlands, and focuses particularly on new insights in detection and monitoring of wetlands using freely available multispectral sensors. The paper firstly describes important characteristics of wetlands in semi-arid and arid regions that require monitoring in order to improve their management. Secondly, the use of freely available multispectral imagery for compiling wetland inventories is reviewed. Thirdly, the challenges of using freely available multispectral imagery in mapping and monitoring wetlands dynamics like inundation, vegetation cover and extent, are examined. Lastly, algorithms for image classification as well as challenges associated with their uses and possible future research are summarised. However, there are concerns regarding whether the spatial and temporal resolutions of some of the remote-sensing data enable accurate monitoring of wetlands of varying sizes. Furthermore, it was noted that there were challenges associated with the both spatial and spectral resolutions of data used when mapping and monitoring wetlands. However, advancements in remote-sensing and data analytics provides new opportunities for further research on wetland monitoring and assessment across various scales.

scholarly journals Suitability Evaluation of Typical Drought Index in Soil Moisture Retrieval and Monitoring Based on Optical Images

2020 ◽  
Vol 12 (16) ◽  
pp. 2587
Author(s):  
Yan Nie ◽  
Ying Tan ◽  
Yuqin Deng ◽  
Jing Yu
Keyword(s):  
Remote Sensing ◽  
Soil Moisture ◽  
Arid Regions ◽  
Drought Index ◽  
Dynamic Monitoring ◽  
Landsat 8 ◽  
Landsat 8 Oli ◽  
Rapid Acquisition ◽  
Semi Arid ◽  
Soil Moisture Inversion

As a basic agricultural parameter in the formation, transformation, and consumption of surface water resources, soil moisture has a very important influence on the vegetation growth, agricultural production, and healthy operation of regional ecosystems. The Aksu river basin is a typical semi-arid agricultural area which seasonally suffers from water shortage. Due to the lack of knowledge on soil moisture change, the water management and decision-making processes have been a difficult issue for local government. Therefore, soil moisture monitoring by remote sensing became a reasonable way to schedule crop irrigation and evaluate the irrigation efficiency. Compared to in situ measurements, the use of remote sensing for the monitoring of soil water content is convenient and can be repetitively applied over a large area. To verify the applicability of the typical drought index to the rapid acquisition of soil moisture in arid and semi-arid regions, this study simulated, compared, and validated the effectiveness of soil moisture inversion. GF-1 WFV images, Landsat 8 OLI images, and the measured soil moisture data were used to determine the Perpendicular Drought Index (PDI), the Modified Perpendicular Drought Index (MPDI), and the Vegetation Adjusted Perpendicular Drought Index (VAPDI). First, the determination coefficients of the correlation analyses on the PDI, MPDI, VAPDI, and measured soil moisture in the 0–10, 10–20, and 20–30 cm depth layers based on the GF-1 WFV and Landsat 8 OLI images were good. Notably, in the 0–10 cm depth layers, the average determination coefficient was 0.68; all models met the accuracy requirements of soil moisture inversion. Both indicated that the drought indices based on the Near Infrared (NIR)-Red spectral space derived from the optical remote sensing images are more sensitive to soil moisture near the surface layer; however, the accuracy of retrieving the soil moisture in deep layers was slightly lower in the study area. Second, in areas of vegetation coverage, MPDI and VAPDI had a higher inversion accuracy than PDI. To a certain extent, they overcame the influence of mixed pixels on the soil moisture spectral information. VAPDI modified by Perpendicular Vegetation Index (PVI) was not susceptible to vegetation saturation and, thus, had a higher inversion accuracy, which makes it performs better than MPDI’s in vegetated areas. Third, the spatial heterogeneity of the soil moisture retrieved by the GF-1 WFV and Landsat 8 OLI image were similar. However, the GF-1 WFV images were more sensitive to changes in the soil moisture, which reflected the actual soil moisture level covered by different vegetation. These results provide a practical reference for the dynamic monitoring of surface soil moisture, obtaining agricultural information and agricultural condition parameters in arid and semi-arid regions.

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