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1.
Syed Ashraful Alam Mike Starr 《Mitigation and Adaptation Strategies for Global Change》2013,18(7):979-999
This paper analyzes potential impacts of climate change on biomass carbon (C) density and water-use (actual evapotranspiration, AET) of savannah woodlands in Sudan. Climate change scenarios were developed from five General Circulation Models (GCMs; CGCM2, CSIRO2, ECHam4, HadCM3 and PCM) under two IPCC (Intergovernmental Panel on Climate Change) emission scenarios (A1FI and B1). Baseline (1961-90) climate and climate change scenarios for 2080s for eight map sheet grids (1° latitude x 1.5° longitude) were constructed. Compared to baseline values, mean annual precipitation (MAP) showed both increases (+112 to +221 mm) and decreases (?13 to ?188 mm) but mean annual temperature (MAT) only showed increases (+1.2 to +8.3 °C). Baseline biomass C densities showed an exponential relationship with MAP (y?=?6.798 e 0.0054x, R2?=?0.70). Depending on climate change MAP, biomass C densities increased (+14 to +241 g C m?2) or decreased (?1 to ?148 g?C m?2). However, because of uncertainty in biomass C density estimates, the changes were only significant (P <0.05) for some of the climate change scenarios and for grids with MAP >260 mm. Under A1FI emission scenarios, only HadCM3 did not have a significant effect while under B1 emission scenarios, only CGCM2 and ECHam4 had a significant effect on biomass C density. AET also showed both increases (+100 to +145 mm for vertisols and +82 to +197 mm for arenosols) and decreases (?12 to ?178 mm for vertisols and ?12 to ?132 mm for arenosols). The largest relative changes in AET (up to 31 %) were associated with grids receiving the lowest rainfall. Thus, even if MAP increases across the study region, the increase will have little impact on biomass levels in the driest areas of the region, emphasizing the need for improved management and use of savannah woodlands. 相似文献
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Rusidan Lubis Michael V. Martin B. Starr McMullen 《Journal of the American Water Resources Association》1987,23(4):673-680
ABSTRACT: Grain transportation is a major economic activity on the multiple use Snake-Columbia River System. Congress is currently considering increased transportation user fees aimed at recapturing federal expenditures for waterway operations and maintenance. Three types of fee structure and four levels of cost recovery are evaluated using a network program model. In each case traffic is diverted away from the river to other Puget Sound ports via truck and rail transport modes. Grain shippers in the region will be adversely affected by a higher transport bill. The Lower Columbia River port economic activities will be negatively affected; however, competitive uses of the river, recreation, and hydroelectric generation will likely benefit modestly. 相似文献
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L Ukonmaanaho M Starr J Mannio T Ruoho-Airola 《Environmental pollution (Barking, Essex : 1987)》2001,114(1):63-75
Mean annual (1994-1996) budgets for Cd, Cu, Ni, Pb and Zn at two background, forested catchments, VK and HJ, in Finland are presented. Budgets for plots (VK3, HJ1 and HJ4) included throughfall (TF), litterfall (LF) and soil leaching fluxes, and for catchments terrestrial retention and leaching and lake sedimentation fluxes. Total deposition (TD) loads were relatively low (Cd < 0.1, Cu < 2, Ni < 1, Pb < 3 and Zn < 5 mg m-2 year-1) and that even in these areas almost half of the TD was in the form of dry deposition. Retention of TD within catchments was > or = 77% for all metals, except for Ni at VK (54%). For Cu and Pb, the retention was 94-97%. Most of the retention (74-97%) took place in the terrestrial part of the catchment, lake sedimentation accounting for the remainder. Plot-scale soil leaching fluxes at 40 cm of Cd, Cu (VK3) and Ni (VK3) were greater (> or = 100%) than TD inputs. Most of the catchment retention must therefore have taken place either deeper in the soil or in the lowland peatland areas. The humus layer was particularly effective in retaining Cu and Cd (65-81% and 51-78% of total inputs to the forest floor (TF + LF)). The retention of Pb by the humus layer was less than expected (26-54% of TF + LF). Litterfall was a particularly important internal flux for Zn. 相似文献
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Life cycle assessment of biogas upgrading technologies 总被引:1,自引:0,他引:1
Starr K Gabarrell X Villalba G Talens L Lombardi L 《Waste management (New York, N.Y.)》2012,32(5):991-999
This article evaluates the life cycle assessment (LCA) of three biogas upgrading technologies. An in-depth study and evaluation was conducted on high pressure water scrubbing (HPWS), as well as alkaline with regeneration (AwR) and bottom ash upgrading (BABIU), which additionally offer carbon storage. AwR and BABIU are two novel technologies that utilize waste from municipal solid waste incinerators - namely bottom ash (BA) and air pollution control residues (APC) - and are able to store CO(2) from biogas through accelerated carbonation processes. These are compared to high pressure water scrubbing (HPWS) which is a widely used technology in Europe. The AwR uses an alkaline solution to remove the CO(2) and then the solution - rich in carbonate and bicarbonate ions - is regenerated through carbonation of APC. The BABIU process directly exposes the gas to the BA to remove and immediately store the CO(2), again by carbonation. It was determined that the AwR process had an 84% higher impact in all LCA categories largely due to the energy intensive production of the alkaline reactants. The BABIU process had the lowest impact in most categories even when compared to five other CO(2) capture technologies on the market. AwR and BABIU have a particularly low impact in the global warming potential category as a result of the immediate storage of the CO(2). For AwR, it was determined that using NaOH instead of KOH improves its environmental performance by 34%. For the BABIU process the use of renewable energies would improve its impact since accounts for 55% of the impact. 相似文献
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Marjo Palviainen Leena Finér Ari Laurén Samuli Launiainen Sirpa Piirainen Tuija Mattsson Mike Starr 《Ambio》2014,43(2):218-233
The long-term impacts of current forest management methods on surface water quality in Fennoscandia are largely unexplored. We studied the long-term effects of clear-cutting and site preparation on runoff and the export of total nitrogen (total N), total organic nitrogen (TON), ammonium (NH4-N), nitrate (NO3-N), total phosphorus (total P), phosphate (PO4-P), total organic carbon, and suspended solids (SS) in three paired-catchments in Eastern Finland. Clear-cutting and soil preparation were carried out on 34 % (C34), 11 % (C11), and 8 % (C8) of the area of the treated catchments and wide buffer zones were left along the streams. Clear-cutting and soil preparation increased annual runoff and total N, TON, NO3-N, PO4-P, and SS loads, except for SS, only in C34. Runoff increased by 16 % and the annual exports of total N, TON, NO3-N, and PO4-P by 18, 12, 270, and 12 %, respectively, during the 14-year period after clear-cutting. SS export increased by 291 % in C34, 134 % in C11, and 16 % in C8 during the 14, 6, and 11-year periods after clear-cutting. In the C11 catchment, NO3-N export decreased by 12 %. The results indicate that while current forest management practices can increase the export of N, P and SS from boreal catchments for many years (>10 years), the increases are only significant when the area of clear cutting exceeds 30 % of catchment area. 相似文献
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Starr M Ukonmaanaho L Sibley PK Hazlett PW Gordon AM 《Environmental monitoring and assessment》2007,125(1-3):123-136
Open precipitation and throughfall was collected at a Norway spruce stand in Finland using funnel-type collectors and at a
black spruce stand in Canada using trough-type collectors. The presence or absence of a rim on the funnel, funnel diameter
(9, 14 and 20 cm) and length of sampling period (1, 2 and 4 weeks) on monthly values were evaluated at the Norway spruce stand,
and the number of collectors required for defined levels of accuracy and precision of throughfall loads to be reached and
the influence of the spatial arrangement of collectors on solute concentrations was studied at both stands. The presence of
a rim had no significant effect on open precipitation and throughfall amounts, but did on throughfall DOC, Ca2+, Mg2+, K+, Na+ and Cl− ion loads. Deposition loads increased with decreasing funnel diameter; for open precipitation, this was due to increased
catch efficiency while for throughfall the increase was attributed to canopy interaction and leaching of litter trapped in
the collectors. Calculated monthly H+ loads decreased and those for all other constituents increased with collection period length. Using 15 collectors at the
Norway spruce stand would allow throughfall loads to be determined to within 20% of the true mean weekly value with a confidence
level of 95% for most solute, but not for NH4
+–N, NO3
−–N, Mg2+ and SO4
2−-S. Using 15 trough collectors, the same confidence level at the more heterogeneous black spruce stand would only be achieved
for H+, Cl−, DOC and SO4
2−-S loads. In both stands, using either random or systematic placements of throughfall collectors gave similar results. 相似文献