Mathew K Jacob

Abstract

Forest fires are potential threats to most of the wildlife sanctuaries in the world. Such areas for conservation of precious wildlife in parts of the Western Ghats in India are no exception. The present study area representing the Periyar Tiger Reserve forms a part of the Western Ghats, where during the past decade more than 200 wildfires have been recorded.

Objective: The present study is designed to demarcate the fire risk zones applying principles of geospatial techniques.

Materials and Methods: The technique integrates Remote Sensing and Geographic Information System. Parameters such as land cover type, surface slope, aspect, proximity to settlements, closeness to roads, and elevation have been considered. A Modified Fire Risk Index method has been used for preparing the risk zone map.

Results: The prepared map shows five fire risk zones such as very high, high, moderate, low, and very low. About 27.38% of the study area, according to this study falls within the high and very high risk zones. The final result of the study is validated with the MODIS active fire (hotspot) data, which shows very good reliability. Conclusion: This study based on geospatial technology is very useful to the local authorities for identifying in advance the fire risk zones for prevention and management of forest fires in future.

Abstract

In recent years, forest fires have become a major disaster in many countries of the world because of their impact on biodiversity, landscape, health, environment, ecology and economy. Forest fires are one of the major natural hazards occurring in the forests of the Western Ghats, a biodiversity hotspot in India. The present study aims to demarcate the risk zones of potential forest fire in Idukki Wildlife Sanctuary using integrated Remote Sensing (RS) and Geographic Information System (GIS) techniques.

Every year, during March-May months, the forests in this area are affected by severe fires. In order to generate the fire risk zone map of the study area, a thematic study was carried out on each of the influencing factors viz. land cover type, slope, distance from settlement, distance from road, and elevation. A Fire Risk Index method was used to prepare the risk zone map. The area of the final map was grouped into five different categories of risk zones, viz. very low, low, moderate, high, and very high.

Finally the risk zone map was validated with the fire incidence data for the last 10 years. Results of this study show that the most important factors which contribute to fire ignition are the human induced factors, also known as the anthropogenic factors. The resulting map of forest fire risk zone can be of great benefit for understanding the fire problem and will offer a more effective database for the preparation and control of forest fires.

Abstract

In recent years, forest fires have become a major disaster in many countries of the world because of their impact on biodiversity, landscape, health, environment, ecology and economy. Forest fires are one of the major natural hazards occurring in the forests of the Western Ghats, a biodiversity hotspot in India.

The present study aims to demarcate the risk zones of potential forest fire in Idukki Wildlife Sanctuary using integrated Remote Sensing (RS) and Geographic Information System (GIS) techniques. Every year, during March-May months, the forests in this area are affected by severe fires. In order to generate the fire risk zone map of the study area, a thematic study was carried out on each of the influencing factors viz. land cover type, slope, distance from settlement, distance from road, and elevation.

A Fire Risk Index method was used to prepare the risk zone map. The area of the final map was grouped into five different categories of risk zones, viz. very low, low, moderate, high, and very high. Finally the risk zone map was validated with the fire incidence data for the last 10 years.

Results of this study show that the most important factors which contribute to fire ignition are the human induced factors, also known as the anthropogenic factors. The resulting map of forest fire risk zone can be of great benefit for understanding the fire problem and will offer a more effective database for the preparation and control of forest fires.

Abstract

Wildfires bursting into forests are one of the major natural hazards in the Western Ghats region of Kerala. The aim of the present study is to demarcate the forest and wildfire risk zones in Nemmara Forest Division. This area frequently faces wild land and forest fire.

In this study a combination of Remote Sensing and GIS technology has been used to develop the Fire Risk Index model. The variables used for the present study were fuel type, slope, elevation, road density and settlement density. The selected variables were weighted based on their impact on the fire occurrence. ERDAS Imagine 9.2 and ArcGIS 9.3 software tools were used to prepare fire risk zone map.

The prepared forest fire risk map of Nemmara Forest Division has classified the area into five risk zones: very high, high, moderate, low and very low. To validate the prepared map, the result was compared with forest fire inventory points.

Abstract

Forest fires are of common occurrence in parts of Wayanad Wildlife Sanctuary in the central western slopes of Western Ghats, especially during the months from February to April. They pose great threat to forest vegetation, animal life and scattered human settlements. The present study aims to demarcate forest fire risk zones in Wayanad Wildlife Sanctuary in Kerala state using Remote Sensing (RS) and Geographic Information System (GIS) techniques.

This study considers human related factors as well as environmental factors. The factors selected for the study are land use/land cover, distance from settlement, distance from road, slope, and elevation. The thematic maps are prepared using ArcGIS 9.3 and ERDAS Imagine 9.2 software tools. A Fire Risk Index model is used to prepare the forest fire risk zone map. In the prepared map, the area has been classified into three categories viz., high, moderate, and low risk zones. Analyses of the primary data related to previous incidences of forest fires in this area have validated the reliability of the application of this methodology.

The GIS based forest fire risk prone area zonation therefore appears to be valid. Thus the present methodology can be used effectively in mitigation of forest fires, rehabilitation and restoration programs.

Abstract

In recent years, forest fires have become a major disaster in many countries of the world because of their impact on biodiversity, landscape, health, environment, ecology and economy. Forest fires are one of the major natural hazards occurring in the forests of the Western Ghats, a biodiversity hotspot in India.

The present study aims to demarcate the risk zones of potential forest fire in Idukki Wildlife Sanctuary using integrated Remote Sensing (RS) and Geographic Information System (GIS) techniques. Every year, during March-May months, the forests in this area are affected by severe fires. In order to generate the fire risk zone map of the study area, a thematic study was carried out on each of the influencing factors viz. land cover type, slope, distance from settlement, distance from road, and elevation. A Fire Risk Index method was used to prepare the risk zone map. The area of the final map was grouped into five different categories of risk zones, viz. very low, low, moderate, high, and very high.

Finally the risk zone map was validated with the fire incidence data for the last 10 years. Results of this study show that the most important factors which contribute to fire ignition are the human induced factors, also known as the anthropogenic factors. The resulting map of forest fire risk zone can be of great benefit for understanding the fire problem and will offer a more effective database for the preparation and control of forest fires.

Abstract

Forest fires represent one of the major natural disasters that are common in the tropical forests of India. The forests in Thenmala forest division are also prone to fires. The objective of this study is to demarcate the fire risk zones in Thenmala forest division using geospatial tools.

A Fire Risk Index model has been developed considering the land cover type, terrain geomorphology (slope and elevation), and anthropogenic factors (distance from settlement and distance from road). The area of the prepared forest fire risk zone map is classified into five risk zones viz. very low, low, moderate, high, and very high. The high and very high risk zones jointly constitute 51.57% area of the forest division. Most of the forest fires in this region have an anthropogenic origin.

The result of this study is validated by the fire incidence points for the years from 2004 to 2015. It shows very good reliability. This confirms the efficacy of the present methodology and can be used in any terrain of similar conditions. The prepared forest fire risk zone map is a valuable data for planners and decision makers for effective resource management and protection

Abstract

Forest fires are the most common natural disturbance occurring in the Western Ghats, especially during the summer season. The present study area is also prone to forest fires.

In this study, an attempt has been made to locate and map the potential fire risk zones in the Periyar Tiger Reserve using geospatial techniques. The factors selected in this study are land cover type, slope, distance from settlement, distance from road, and elevation. The forest fire risk zone map is generated using the developed Fire Risk Index model. In the prepared map, the area has been classified into five risk zones viz. very low, low, moderate, high, and very high.

The result has been validated with the fire incidence points for the past 10 years. The risk zone map of the Periyar Tiger Reserve is to be helpful for natural resource managers or planners in the management and environmental protection of resources.

Abstract

Forest fires are the most common natural disturbance occurring in the Western Ghats, especially during the summer season. The present study area is also prone to forest fires.

In this study, an attempt has been made to locate and map the potential fire risk zones in the Periyar Tiger Reserve using geospatial techniques. The factors selected in this study are land cover type, slope, distance from settlement, distance from road, and elevation. The forest fire risk zone map is generated using the developed Fire Risk Index model. In the prepared map, the area has been classified into five risk zones viz. very low, low, moderate, high, and very high.

The result has been validated with the fire incidence points for the past 10 years. The risk zone map of the Periyar Tiger Reserve is to be helpful for natural resource managers or planners in the management and environmental protection of resources.

Abstract

Tsunamis are caused by the displacement of a large volume of water, generally in an ocean or a sea. Submarine earthquakes, volcanic eruptions, underwater explosions, continental shelf landslides, glacier calvings, meteorite impacts, and other powerful submarine disturbances have the potential to generate a tsunami. Tsunami vulnerability zonation and mapping is very important to mitigate the impact due to tsunami disaster. The coastal areas of Kollam district, the present study area were seriously affected by the catastrophic Indian Ocean tsunami of December 26, 2004.

This study aims to demarcate tsunami vulnerable areas in Kollam district using Remote Sensing and GIS techniques. A multi criteria decision analysis has been carried out using five parameters, namely land use/land cover, slope, elevation, geomorphology, and distance from shoreline and based on thematic maps prepared with respect to them. The prepared vulnerability map area was classified into five zones: safe, rather safe, moderate, rather vulnerable, and vulnerable. The village boundary was overlaid on the vulnerability map in order to identify and highlight the vulnerable villages.

This study provides an interactive method to identify tsunami affected areas after a disaster in addition to mapping tsunami vulnerable areas before a disaster, in an effort to help manage future disasters.

Abstract

The Neogene succession, located along the southern coastal stretches of Kerala is represented by the sediments belonging to the Vaikom Formation, Quilon Formation, and the Warkalli Formation (Poulose and Narayanaswamy, 1968; Varadarajan and Madhavan Nair, 1978; Raha et al., 1983, Soman, 1997). These sediments apparently rest unconformably over the Archaean metamorphosed crystalline basement. While the older Vaikom and the younger Warkalli beds are unfossilliferous the Quilon limestone beds, sandwiched between them, are rich in marine macrofossils.

The present paper incorporates a systematic account of the macro invertebrate fossils recovered from the limestone beds that show dominance of Gastropoda followed by Bivalvia 26 (pelecypoda). The biostratigraphic correlation and palaeo-environmental conditions for the growth of these fauna have also been discussed.

Abstract

The kaolin deposits at Melthonnakkal and Pallipuram mines form part of the Warkalli Formation belonging to the Tertiary sequence in southern Kerala and occur at the boundary between the Tertiary sequence and Precambrian granulite facies metapelites (khondalites). The sedimentary clays are composed mainly of kaolinite, quartz and gibbsite. XRD and SEM studies have revealed that kaolinite is well-crystallized variety and the platy crystals are scarcely broken in the sedimentary clays.

These sedimentary kaolins are considered to have been formed by intense tropical weathering of the khondalites, and subsequently transported and deposited with high organic input into lakes near the weathering crust over the basement rock. Besides, the surficial parts of the sedimentary deposits are extensively lateritized with the formation of goethite and hematite by Quaternary tropical weathering processes.

Abstract

Placer gold grains in the Nilambur Valley of Wynad Gold Field in southern India are characterized by very high purity levels (985–1000). Their Ag-depleted core compositions, enhanced grain size and microscale growth patterns correlate with gold grains associated with laterite profiles in the weathering fronts.

From the morphological and chemical evolution of gold grains associated with primary, supergene and secondary deposits in this region, we identified a two-stage process for the evolution of the highly pure placers, which shows that gold in the primary veins was mobilized, chemically purified, and reconcentrated in the laterite profiles, effecting enhanced purity and grain growth before transfer to the fluvial system. Further refinement was achieved during fluvial transport, generating natural concentrations of pure gold in the placers.

Abstract

Gold grains from laterite horizons of Nilambur region in northern Kerala exhibit typical morphological characteristics and secondary growth patterns indicative of chemical dissolution, migration and reprecipitation by low temperature fluids attending tropical weathering. Proton-induced X-ray emission (PIXE) analyses of secondary gold grains yielded characteristic spectra for Au, along with Ti and Fe, in the near-absence of Ag and Cu.

This study provides the first direct evidence for the formation of extremely pure gold by natural chemical reconcentration process, principally dictated by the oxidation reactions of iron sulphide minerals associated with the primary mineralization. The results have important bearing on the recently realized economic potential of gold in laterites.

Abstract

Forest fire is a common problem in the Western Ghats regions of Kerala. Therefore forest fire risk analysis is necessary for forest management. The present study area is also prone to forest fires. The present study deals with the identification of fire risk zones in Peppara Wildlife Sanctuary, Western Ghats mountain region, Kerala using GIS and Remote Sensing techniques. The forest fires are caused due to environmental and human related factors. This study considered 5 factors namely, land use/land cover, slope, elevation, distance from road, and distance from human settlements. Relevant thematic layer maps representing these factors that are related to forest fire occurrence have been prepared by using Geographic Information System (GIS) and Remote Sensing (RS) software tools.A multi parametric weighted index model was used to prepare the fire risk zone map using ArcGIS and ERDAS Imagine software tools. The forest fire risk zones were segmented into four, viz., low, moderate, high and very high risk zones. Forest fire risk maps are useful tools for the efficient planning and management of forest in the Western Ghats mountain region.