77 research outputs found

    ASSESSMENT OF SPOT SATELLITE DATA FOR TROPICAL VEGETATION INVENTORY AND MONITORING IN SUMATRA

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    Following  a  previous  vegetation  mapping  in  Sumatra  island  (Indonesia),  an  assessment  of  SPOT satellite capability to handle specific problems related to vegetation identification and monitoring from  remote sensing data has been undertaken. Results of visual interpretation and multispectral analysis have shown the usefulness of SPOT data  for the appraisal  of  tropical  vegetation  at medium  scale. This was  particularly  striking  for  the  swampy  vegetation types  including mangroves  and  for  the  secondary vegetation,  for which  significant  improvements have been brought by multispectral classifications. A 20 m ground resolution is neither sufficient  to provide information on  primary  forest  patterns,  nor  to  identify  properly  logged  over  areas.  Never theless,  several  degrees  of depletion  of  the  forest  and  all  the  serial  stages  have  been  identified,  which  is  a  considerable  progress compared with previous remote sensing means. SPOT is a very good alternative to medium scale aerial photographs for the production of medium  scale (1 : 100 000 to 1 : 250 000) vegetation and land-use maps

    Assessment of Spot Satellite Data for Tropical Vegetation Inventory and Monitoring in Sumatra

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    Following a previous vegetation mapping in Sumatra island (Indonesia), an assessment of SPOT satellite capability to handle specific problems related to vegetation identification and monitoring from remote sensing data has been undertaken. Results of visual interpretation and multispectral analysis have shown the usefulness of SPOT data for the appraisal of tropical vegetation at medium scale. This was particularly striking for the swampy vegetation types including mangroves and for the secondary vegetation, for which significant improvements have been brought by multispectral classifications. A 20 m ground resolution is neither sufficient to provide information on primary forest patterns, nor to identify properly logged over areas. Never theless, several degrees of depletion of the forest and all the serial stages have been identified, which is a considerable progress compared with previous remote sensing means. SPOT is a very good alternative to medium scale aerial photographs for the production of medium scale (1 : 100 000 to 1 : 250 000) vegetation and land-use maps

    Suitability of Local Resource Management Practices Based on Supernatural Enforcement Mechanisms in the Local Social-cultural Context

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    Environmental anthropological studies on natural resource management have widely demonstrated and thematized local resource management practices based on the interactions between local people and supernatural agencies and their role in maintaining natural resources. In Indonesia, even though the legal status of local people's right to the forest and forest resources is still weak, the recent transition toward decentralization presents a growing opportunity for local people to collaborate with outsiders such as governmental agencies and environmental nongovernmental organizations in natural resource management. In such situations, in-depth understanding of the value of local resource management practices is needed to promote self-directed and effective resource management. Here, we focus on local forest resource management and its suitability in the local social-cultural context in central Seram, east Indonesia. Local resource management appears to be embedded in the wider social-cultural context of the local communities. However, few intensive case studies in Indonesia have addressed the relationship between the Indigenous resource management practices closely related to a people's belief in supernatural agents and the social-cultural context. We illustrate how the well-structured use of forest resources is established and maintained through these interactions. We then investigate how local resource management practices relate to the social-cultural and natural resources context of an upland community in central Seram and discuss the possible future applications for achieving conservation

    CO 2 Solubility in Kimberlite melts CO 2 Solubility in Kimberlite melts

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    International audienceCarbon dioxide is the most abundant volatile in kimberlite melts and its solubility exerts a prime influence on the melt structure, buoyancy, transport rate and hence eruption dynamics. The actual primary composition of kimberlite magma is the matter of some debate but the solubility of CO2 in kimberlitic melts is also poorly constrained due to difficulties in quenching these compositions to a glass that retains the equilibrium CO2 content. In this study we used a range of synthetic, melt compositions with broadly kimberlitic to carbonatitic characteristics which can, under certain conditions, be quenched fast enough to produce a glass. These materials are used to determine the CO2 solubility as a function of chemical composition and pressure (0.05-1.5 GPa). Our results suggest that the solubility of CO2 decreases steadily with increasing amount of network forming cations from ~ 30 wt% CO2 at 12 wt% SiO2 down to ~ 3 wt% CO2 at 40 wt% SiO2. For low silica melts, CO2 solubility correlates non-linearly with pressure showing a sudden increase from 0.1 to 100 MPa and a smooth increase for pressure > 100 MPa. This peculiar pressure-solubility relationship in low silica melts implies that CO2 degassing must mostly occur within the last 3 km of ascent to the surface having potential links with the highly explosive nature of kimberlite magmas and some of the geo-morphological features of their root zone. We present an empirical CO2 solubility model covering a large range of melt composition from 11 to 55 wt% SiO2 spanning the transition from carbonatitic to kimberlitic at pressures from 1500 to 50 MPa
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