GIS | |
Higher fire incidences in apple-producing regions of Himachal Pradesh
Despite the frequent fire incidents, air pollution levels monitored through Sentinel 5P indicate does not present an alarming situation, yet it still deserves early attention |
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Burning apple twigs and horticultural residues after winter pruning in Himachal Pradesh raises environmental concerns, akin to the infamous Parali burning in North India, impacting air quality in parts of the apple-growing areas of Himachal Pradesh. Districtwise data from NASA/NOAA satellites highlight the human-made nature of the issue. Despite the frequent fire incidents, air pollution levels monitored through Sentinel 5P indicate does not present an alarming situation, yet it still deserves early attention.
Background
In the picturesque apple-growing regions of Himachal Pradesh, the practice of burning apple twigs and other horticultural residues after winter pruning sparks environmental concerns each passing year. Similar to the infamous Parali burning in the North Indian plains and this practice is tarnishing the otherwise pristine air quality of Himachal Pradesh, with traces of smoke blanketing the upper areas of apple belts in Shimla, Kullu, Mandi, Chamba, Kinnaur and other apple-growing areas during winter. In fact, apples are grown in all districts of Himachal Pradesh except for the lower districts such as Una, Hamirpur, and Bilaspur. This issue is particularly prevalent in upper Shimla, where 32 percent of fire incidents were recorded in the apple belt, followed by the Kullu region with 24 percent fire occurrences of the State. As winter approaches, farmers start burning dry leaves and twigs in orchards, lowering air pollution levels. District-wise data on fire incidents, captured by the Visible Infrared Imaging Radiometer Suite (VIIRS) 375m thermal sensor aboard the joint NASA/NOAA Suomi National Polarorbiting Partnership (Suomi NPP) and NOAA-20 satellites, indicate the burning of horticultural waste during winter. The district-wise breakdown of fire incidents as depicted in Graph-1 underscores the human-made nature of the issue in the upper regions.
As per the Economic Survey of Himachal Pradesh for the year 2022-23, horticulture crops hold substantial importance in the state’s agriculture, with fruits being a key component. Among these fruits, apples stand out as the predominant crop, contributing significantly to the horticulture sector, accounting for about three fourth share in the year 2021- 22. This underscores the pivotal role of apple cultivation in shaping the state’s economy and agricultural sector.
Forest fire or biomass burning?
Analysis of fire data from the Collection 6 Terra and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) revealed 240 fires detected in 2023, whereas over 2343 fire cases recorded by VIIRS sensor fire products in Himachal Pradesh. There seem to have some gaps in acquisition date of fire data making it difficult to arrive at exact percent of forest fires
Nevertheless, it can be vaguely suggested about 25-30 percent of fires originated in forest areas, occurred during summer.
MODIS Collection 6.1 incorporates advancements in calibration, correction algorithms, and data processing techniques, leading to enhanced data quality with minimized uncertainties and improved accuracy. Typically, MODIS land products offer spatial resolutions of 250 meters (bands 1-7) and 500 meters (bands 8-36) at nadir, with some products reaching 1-kilometer spatial resolution. The revisit time varies depending on the specific product and satellite platform (Terra or Aqua), ranging from once every 1 to 2 days for land products to multiple times per day for certain atmospheric products. Fire locations of MODIS have been superimposed on forest density map of Forest Survey of India, which depicts that three fourth of fires occur in non-forest lands remaining one fifth occurs in open and dense forests (Refer Graph-2). Three-fourths of fire incidents can be directly linked to the burning of agricultural and horticultural and other waste, a practice predominantly carried out by humans. Hence, the increased frequency of these fires during the winter season in the upper regions of Shimla, Kullu, Mandi, and other districts can unequivocally be attributed to the burning of horticultural waste.
Prominently winter fire
The analysis of MODIS data reveals a significant prevalence of winter fires across orchards. Graph-3 illustrates that approx. 70-75 percent of fires were recorded during the winter season, from November 2023 to March 2024, which is well illustrated by Graph-3.
This indicates that the majority of these fires are man-made, likely stemming from the burning of apple twigs or horticultural waste or other wastes. Furthermore, these fires are predominantly distributed in the upper regions of Shimla, Mandi, Kullu, and Chamba, aligning closely with the apple belt. Spatial dispersal map has been displayed at Map-1. Approximately 25 to 30 percent of fires can be attributed to the ignition of dry pine needles or forest fires.
The smoke emanating from the higher reaches of Himachal Pradesh is clearly visible in Image-1.
Dispersion of smoke
As winter pruning of apple plants intensifies, orchard fires are increasingly becoming a contributor to air pollution, with smoke billowing from several parts of the apple belt. Despite bans imposed by respective district administrations on burning pruning waste, the practice seems continuing. This situation mirrors the scenario in other apple producing areas, where individuals not only burn pruning waste but also set haystacks ablaze. From time to time, the administration has been urging farmers to refrain from burning twigs and instead encouraged their utilization in composting for the production of manure.
Past practices of burning of apple twigs
The burning of horticulture waste can be compared to the infamous stubble burning in the plains. However, due to the partial density of orchards compared to the continuous wheat fields of the plains, the magnitude and spread of smoke are localized. Furthermore, the State Pollution Control Board continually monitors the air quality of various activities and projects and has not reported alarming levels of air pollution in these areas. This practice reportedly originated in the 1980s when scab, a harmful fungal disease, emerged in the state for the first time. Growers were advised by experts to burn all waste to prevent the disease from recurring the following year. Initially, the environmental impact of this burning was minimal as the number of orchards was significantly lower compared to the present.
NGT References on waste/ biomass burning
In compliance with orders of Hon’ble National Green Tribunal (NGT), the H. P. State Pollution Control Board keep vigil on such occurrences and has submitted a draft fuel policy to the State Government to utilize such wastes particularly pine-based.
Draft policy stipulates “Biomass as fuel (like Pine Needles, Briquettes/Pellets of Pine Needles and other Biomass (including Lantana etc.): Cement Industries which are using Pet-Coke and Coal as a fuel will meet at least 0.1 % of their annual fuel consumption from forest-based biomass like Pine Needles, Briquettes/ Pellets of Pine Needles and other Biomass including Lantana etc. whether in briquette form or otherwise. This has also been stipulated in the Department of Environment, Science & Technology, Government of Himachal Pradesh Letter No. HPSPCB/EIA Notification (Consent Branch)/2018-14399-14433, dated-01-09-2018.”
Furthermore, some of the incidences of burning of household waste cannot be ruled out. Action plan for municipal solid waste management Himachal Pradesh prepared by Department of Urban Development also recommended enforcement of complete prohibition of open burning of waste of all types. In compliance ULBs were directed to take necessary steps to train their staff and educate people for not to burn the garbage in open in view of the NGT order dated 22nd Dec, 2016.
Satellite based fire monitoring
The Visible Infrared Imaging Radiometer Suite (VIIRS) 375 m thermal anomalies / active fire product provides data from the VIIRS sensor aboard the joint NASA/ NOAA Suomi National Polar-orbiting Partnership (Suomi NPP) and NOAA- 20 satellites. They both show good agreement in hotspot detection but the improved spatial resolution of the 375 m data provides a greater response over fires of relatively small areas and provides improved mapping of large fire perimeters.
The 375 m data also has improved night-time performance. Consequently, these data are well suited for use in support of fire management (e.g., near real-time alert systems), as well as other science applications requiring improved fire mapping fidelity.
This product provides data on actively burning fires globally, with a spatial resolution of 375 meters. It detects fires by observing the thermal radiation emitted by the fires in the mid-infrared spectrum.
Key details about the VIIRS 375 m Active Fire Product
1.Detection Method: The VIIRS instrument detects active fires by measuring the brightness temperature of the Earth’s surface in the mid-infrared spectrum. Pixels exhibiting temperatures higher than the background temperature are flagged as active fire detections.
2.Spatial Resolution: The VIIRS 375 m Active Fire Product provides fire detections at a spatial resolution of 375 meters, allowing for detailed mapping of fire locations and extents.
3.Temporal Resolution: The VIIRS instrument provides global coverage multiple times per day, allowing for near real-time monitoring of active fires on a global scale.
4.Applications: The data provided by the VIIRS 375 m Active Fire Product is used for a variety of applications, including wildfire monitoring and management, air quality assessment, carbon emissions estimation, and ecological research globally. It is valuable for both operational fire management agencies and scientific research institutions.
5. Data Accessibility: The VIIRS 375 m Active Fire Product data is freely accessible to the public through various data portals and platforms provided by NOAA, NASA, and other agencies. These platforms often offer tools for visualization, analysis, and download of the fire data. Overall, the VIIRS 375 m Active Fire Product plays a crucial role in global fire monitoring efforts, providing valuable information for understanding and managing wildfires and their impacts on the environment and society.
Environment and health implication
Forest fires and biomass/hortiwaste (apple twig) burning can have significant implications for air quality and environmental pollution. Burning such wastes release emissions, which are on rise:
1) Emission of Pollutants: Forest fires and biomass burning release a variety of pollutants into the atmosphere, including particulate matter (PM), carbon monoxide (CO), nitrogen oxides (NOx), volatile organic compounds (VOCs), and hazardous air pollutants (HAPs). These pollutants can have adverse effects on air quality and human health.
i) Particulate Matter: Smoke from forest fires contains high concentrations of fine particulate matter (PM2.5 and PM10), which can penetrate deep into the lungs and cause respiratory problems, cardiovascular issues, and exacerbate existing health conditions.
ii) Carbon Monoxide: Biomass burning emits carbon monoxide (CO), a colorless and odorless gas that is harmful when inhaled in high concentrations. CO can impair oxygen transport in the bloodstream, leading to symptoms such as headaches, dizziness, and even death in severe cases.
iii) Greenhouse Gas Emissions: Forest fires and biomass burning release large amounts of carbon dioxide (CO2) and other greenhouse gases into the atmosphere, contributing to climate change and global warming.
2) Air Quality Impacts: The pollutants emitted from forest fires and biomass burning can degrade air quality, leading to haze, reduced visibility, and smog formation. Prolonged exposure to poor air quality can have adverse effects on both human health and ecosystems.
3) Regional and Global Transport:
Smoke and pollutants from forest fires and biomass burning can be transported over long distances, affecting air quality and visibility in regions far from the source of the fire. Delhi is one such glaring example. This can have implications for air quality management and regulatory efforts on both regional and global scales.
4) Environmental Damage: In addition to air pollution, forest fires and biomass burning can cause extensive damage to ecosystems, including loss of biodiversity, soil degradation, and destruction of wildlife habitats.
Overall, forest fires and biomass burning are significant sources of air pollution and can have wide-ranging impacts on human health, the environment, and climate change. Effective management strategies, including fire prevention, early detection, and mitigation efforts, are essential for minimizing the adverse effects of these events. Additionally, monitoring and research efforts are crucial for understanding the complex interactions between forest fires, air quality, and environmental pollution.
Satellite based air quality assessment other than NASA
Sentinel-5P (Sentinel-5 Precursor) is a satellite mission developed by the European Space Agency (ESA) as part of the Copernicus program. Sentinel- 5P carries the Tropospheric Monitoring Instrument (TROPOMI), which is designed to monitor atmospheric composition with high spatial resolution and accuracy. Here’s how Sentinel-5P products help in the estimation of air pollution:
Measurement of Pollutants:
• TROPOMI onboard Sentinel-5P measures a range of atmospheric pollutants, including nitrogen dioxide (NO2), ozone (O3), sulfur dioxide (SO2), formaldehyde (HCHO), carbon monoxide (CO), methane (CH4), and aerosols. These pollutants are key indicators of air quality and are associated with various sources, including industrial activities, transportation, and biomass burning.
• Sentinel-5P provides high spatial resolution observations, allowing for detailed mapping of pollutant concentrations at a local and regional scale.
This spatial resolution is particularly useful for identifying hotspots of pollution and assessing the distribution of pollutants in urban areas and other densely populated regions.
• Sentinel-5P data can help identify sources of pollution and track the transport of pollutants across regions. By analyzing the spatial distribution and temporal evolution of pollutant concentrations, it is possible to attribute pollution events to specific sources, such as industrial emissions, traffic emissions, wildfires, or agricultural activities.
• In summary, Sentinel-5P products play a crucial role in the estimation of air pollution by providing detailed observations of atmospheric composition, high spatial resolution mapping of pollutant concentrations, and regular monitoring of air quality on a global scale.
• Air pollution of Himachal Pradesh has been mapped in Maps 3,4&5 indicating traces of such gases in Himachal Pradesh. However, the concentration is negligible or much lesser than plains of Punjab and Haryana.
Fire Incidences and NO2 Concentration
This Sentinel 5P dataset provides near real-time high-resolution imagery of NO2 concentrations. Nitrogen oxides (NO2 and NO) are important trace gases in the Earth’s atmosphere, present in both the troposphere and the stratosphere. They enter the atmosphere as a result of anthropogenic activities (notably fossil fuel combustion and biomass burning) and natural processes (wildfires, lightning, and microbiological processes in soils).
Here, NO2 is used to represent concentrations of collective nitrogen oxides because during daytime, i.e. in the presence of sunlight, a photochemical cycle involving ozone (O3) converts NO into NO2 and vice versa on a timescale of minutes.
Correlation between fire incidences and land-use & vegetation types
There is a discernible correlation between land use, vegetation types, and fire incidents. The maps and graphs illustrate that areas classified as scrubs, agricultural lands, orchards, pine vegetative areas and pine mixed recorded more fire incidences.
Thus, occurrence of forest fires excluding the summer may be attributed to forest fires. From google earth verification, scrubs seem to refer to areas containing orchards and various types of horticultural plants. While it wasn’t feasible to analyze apple areas at this scale, it’s reasonable to infer that many scrub areas correspond to the apple belt.
Pine forests are typically located in forest lands.
Upon closer examination of the Shimla and Kullu areas, it becomes apparent that cropped areas, citrus woodlands, open lands in forests, degraded forest lands, and areas with or without scrubs consistently recorded higher incidences of fire. The absence of an orchard database, which could have been combined with the fire dataset, hinders my ability to draw clear conclusions.
This emphatically underscores that the apple belt and higher elevations experienced heightened burning activities.
Summary
• In summary, fire incidences in Himachal Pradesh during the year 2023 are recorded very high. A significant share of fires are observed in the land use types (Map-10) of Pine Mixed indicating a huge contribution from forest fire. Nevertheless, forest fire and the burning of horticultural waste pose a significant challenge for environmental regulators and presents health risks to both the environment and people. The majority of these fires appear to be of human origin.
• Just as stubble burning is deemed unacceptable, so too is the burning of apple twigs. It is imperative to raise awareness and educate the public about this harmful practice, while also implementing measures to control it.
• It is important to understand that those engaged in this practice jeopardize their health for minimal financial gain, while the public bears the brunt of increased pollution levels.
• The burning of horticulture waste can partially be compared to the infamous stubble burning in the plains (Map-2). However, the intensity of pollution caused by this burning is significantly lower, more sporadic, and spread in pockets in Himachal Pradesh. Map -2 indicates the number of fire incidents (2023) in northwest India, with Himachal Pradesh showing a negligible number of incidents in comparison.
• The magnitude and spread of the smoke are localized, yet this still poses a serious challenge to regulators and decision-makers. The State Pollution Control Board frequently conducts awareness activities through various means to educate people about this issue. This matter requires continued attention from the concerned agencies.
• The above conclusion is supported by pollution levels assessed through Sentinel5P, which indicate that several parameters are well within limits. While this does not present an alarming situation, it still deserves early attention.
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