Fire Danger Monitoring Using ERS-1 SAR Images in the Case of Northern Boreal Forests

Research was carried out to assess the potential of imaging radar systems formonitoring forest fire danger. In Canada, daily forest fire danger ratings are generated by the Canadian ForestFire Danger Rating System (CFFDRS), based on estimates of fire weather indices (FWI) and measured foliar moisturecontent (FMC). To evaluate the potential of imaging radar, an experiment was conducted using test sitesconsisting of jack pine, black spruce and white spruce stands located in the MacKenzie river basin, NorthwestTerritories, Canada. Radar image intensity values from ERS-1 SAR imagery collected over these stands in 1994 werecompared to FWI indices and FMC data. FWI indices were calculated using data from local weather stations.Seasonal trends in radar backscatter (⁰) were shown to correlate with temperature and precipitation. Significant relationships were found between ⁰ and FWI codes and indices, particularly in thecase of the black spruce stands, with slow-drying fuels, like duff moisture code (DMC), drought code (DC), and build-upindex (BUI). Rates of changes in ⁰were related to rates of changes in FMC, particularly in the case ofthe jack pine stands for old FMC and in the case of white spruce stands for composite FMC.     

IGU commission on changing rural systems

The International Geographical Union Reports

IGU commission on changing rural systems     

The use of multivariate statistics to elucidate patterns of floodplain sedimentation at different spatial scales

Floodplains are depositional features of riverine landscapes that display complex sedimentation patterns that are amenable to multi‐scale approaches. We examined sedimentation in the Lower Balonne floodplain, Queensland, Australia, at three different spatial scales: the channel (10³ km), floodplain process zone (10 km) and geomorphic unit (10² m) scales, and compared scale‐related patterns evident from stratigraphy with those evident from quantitative multivariate analysis. Three stratigraphic sequences were found in the Lower Balonne floodplain: generally fining upward, episodic fining upward, and mud‐dominated. Stratigraphical analysis revealed the detailed character of sedimentary sequences embedded within the scale patterns derived from multivariate analysis. Multivariate statistical analyses of a range of textural and geochemical data revealed different patterns of floodplain sedimentation at each scale. At the channel scale, sediment texture and geochemistry were more heterogeneous in the Culgoa River than in Briarie Creek. At the floodplain process zone scale clear patterns of sediment texture and geochemistry were observed along the upper, mid and lower floodplain process zones of Briarie Creek, but not along the Culgoa River. At the geomorphic unit scale, clear patterns of sediment texture and geochemistry were observed among the bank, buried channel and flat floodplain units of the Culgoa River, but were not as clear in Briarie Creek. Recognition of rivers as hierarchically organized systems is an emerging paradigm in river science. Our study supports this paradigm by demonstrating that different sedimentation patterns occur at different scales to reveal a hierarchically organized floodplain environment. Copyright © 2006 John Wiley & Sons, Ltd.     

More than a century of bathymetric observations and present-day shallow sediment characterization in Belfast Bay, Maine, USA: implications for pockmark field longevity

Mechanisms and timescales responsible for pockmark formation and maintenance remain uncertain, especially in areas lacking extensive thermogenic fluid deposits (e.g., previously glaciated estuaries). This study characterizes seafloor activity in the Belfast Bay, Maine nearshore pockmark field using (1) three swath bathymetry datasets collected between 1999 and 2008, complemented by analyses of shallow box-core samples for radionuclide activity and undrained shear strength, and (2) historical bathymetric data (report and smooth sheets from 1872, 1947, 1948). In addition, because repeat swath bathymetry surveys are an emerging data source, we present a selected literature review of recent studies using such datasets for seafloor change analysis. This study is the first to apply the method to a pockmark field, and characterizes macro-scale (>5 m) evolution of tens of square kilometers of highly irregular seafloor. Presence/absence analysis yielded no change in pockmark frequency or distribution over a 9-year period (1999–2008). In that time pockmarks did not detectably enlarge, truncate, elongate, or combine. Historical data indicate that pockmark chains already existed in the 19th century. Despite the lack of macroscopic changes in the field, near-bed undrained shear-strength values of less than 7 kPa and scattered downcore ¹³⁷Cs signatures indicate a highly disturbed setting. Integrating these findings with independent geophysical and geochemical observations made in the pockmark field, it can be concluded that (1) large-scale sediment resuspension and dispersion related to pockmark formation and failure do not occur frequently within this field, and (2) pockmarks can persevere in a dynamic estuarine setting that exhibits minimal modern fluid venting. Although pockmarks are conventionally thought to be long-lived features maintained by a combination of fluid venting and minimal sediment accumulation, this suggests that other mechanisms may be equally active in maintaining such irregular seafloor morphology. One such mechanism could be upwelling within pockmarks induced by near-bed currents.     

Early-stage transformation of coastal marine governance in Vietnam?

This paper examines an apparent ‘early stage’ governance transformation in the Tam Giang Lagoon, Vietnam. In this context, the role of key policy windows for innovative governance practice is assessed (e.g., changes to Land and Fisheries Laws). Also examined is the emergence of recent initiatives to catalyze a wider shift in governance practice in the region, including the formation of co-management institutional networks that contribute to trust building and learning, and the allocation of collective territorial use rights for fisheries. While these changes are consistent with experiences in other coastal marine contexts, the paper shows that place-based and longitudinal research is necessary to explain and predict the conditions and incentives that catalyze governance shifts. Differences between a governance change and more fundamental transformation are difficult to discern using point-in-time analysis. Moreover, the results show that current declines in ecological conditions in the lagoon may not be reversed by changes to access rights or the emergence of co-management. Rather, these governance changes may simply help to stabilize the situation and buy time until other livelihood opportunities arise. Assessments of governance transformation thus need to be linked to ecological outcomes (i.e., reversing degradation of coastal marine systems, avoiding biophysical tipping points) which may not be easily identified in the short-term. Despite uncertainty, the emergence of policy windows, evidence of institutional innovation, and small-scale rights allocation experiments, all suggest important shifts in the trajectory of governance are underway in the Tam Giang Lagoon.     

Jurassic planktonic foraminifera from the United Kingdom

Unequivocal planktonic foraminifera have been discovered in Oxfordian strata from Dorset and Scotland. These assemblages are, in part, coeval with previously reported occurrences of planktonic taxa in the Oxfordian of Normandy and Seine Maritime (France). Three species are now reported from the United Kingdom for the first time: Globuligerina oxfordiana ( Grigelis, 1958 ), Haeuslerina helvetojurassica ( Haeusler, 1881 ) and Compactogerina sp. cf. C. stellapolaris ( Grigelis, 1977 ). There appears to be a close relationship between the distribution of these planktonic taxa in the UK and a marked sea-level highstand.     

Historical Trends of Benthic Invertebrate Biodiversity Spanning 182 Years in a Southern New England Estuary

Benthic invertebrates support numerous ecosystem functions and services including shellfish production, energy flow to fishes, and biogeochemical cycles. The decline of marine biodiversity worldwide has raised concerns about effects on ecosystems. To examine biodiversity trends of Narragansett Bay over time, a list was compiled of all benthic invertebrate species collected from the bay since 1834. The list covers 104 studies spanning 182 years and currently holds 1214 unique taxa from 21 phyla, the majority of all animal phyla on Earth. A permuted estimator of number of species suggested there are about 300 more yet to be discovered. Widely varying sampling gear and sieve mesh sizes precluded the use of abundance data. Instead, multidimensional scaling and taxonomic distinctness were used with presence-absence data to examine biodiversity trends. The changes in community composition and decline of benthic biodiversity (p?<?0.01) since 1855 are what would be expected of a community that gradually deteriorated in the face of increasing anthropogenic stressors. Taxonomic distinctness had negative correlations (p?<?0.05) with human population in the watershed, total nitrogen inputs, and inputs of metals. This loss of benthic biodiversity has implications for ecosystem functions and services. As some of the stressors waned in the last two or three decades, following passage of environmental legislation in the 1970s, biodiversity appeared to show a partial recovery. An inventory of species, how it has changed over time, and understanding what caused those changes are important for assessing whether remediation programs are achieving improved water quality and ecosystem health.     

Managing Groundwater to Ensure Ecosystem Function

Groundwater is a critical resource not only for human communities but also for many terrestrial, riparian, and aquatic ecosystems and species. Yet groundwater planning and management decisions frequently ignore or inadequately address the needs of these natural systems. As a consequence, ecosystems dependent on groundwater have been threatened, degraded, or eliminated, especially in arid regions. There is growing acknowledgment that governmental protections for these ecological resources are necessary, but current legal, regulatory and voluntary provisions are often inadequate. Groundwater management premised on “safe yield,” which aims to balance human withdrawals with natural recharge rates, typically provides little to no consideration for water needed by ecosystems. Alternatively, the “sustainable yield” concept aims to integrate social, economic and environmental needs for groundwater, but the complexity of groundwater systems creates substantial uncertainty about the impact that current or future groundwater withdrawals will have on ecosystems. Regardless of the legal or regulatory framework, guidance is needed to help ensure environmental water needs will be met, especially in the face of pressure to increase human uses of groundwater resources. In this paper, we describe minimum provisions for planning, managing, and monitoring groundwater that collectively can lower the risk of harm to groundwater-dependent ecosystems and species, with a special emphasis on arid systems, where ecosystems and species may be especially reliant upon and sensitive to groundwater dynamics.