Building capacity for integrated coastal management in developing countries

The need for building human and institutional capacity has been identified in Agenda 21 of the UNCED conference as well as by a number of international environmental institutions as essential for integrated coastal management (ICM) and sustainable development in developing coastal states. There is a growing need for coastal management practitioners and organizations with expertise in planning and implementation for ICM. The application of strategies for institutional development and building human capacity in coastal management and other fields shows that short-term intensive training efforts and long-term institutional strengthening programs are appropriate to address the issues and needs of ICM. An overview of the experience of the URI/USAID International Coastal Resources Management Program in Sri Lanka, Thailand and Ecuador presents lessons learned for strengthening ICM efforts in developing countries.     

Pyroclastic flow generated by crater-wall collapse and outpouring of the lava pool of Arenal Volcano, Costa Rica

The pyroclastic flow that issued from the Arenal summit crater on 28 August 1993 came from the collapse of the crater wall of the cone and the drainage of a lava pool. The 3-km-long pyroclastic flow, 2.2ǂ.8᎒⁶ m³ in volume, was confined to narrow valleys (30-100 m wide). The thickness of the pyroclastic deposit ranged from 1 to 10 m, and its temperature was about 400 °C, although single bombs were up to 1,000 °C. The deposit is clast-supported, has a bimodal grain size distribution, and consists of an intimate mixture of finely pulverized rock ash, lapilli, small blocks, and cauliflower bread-crusted bombs, in which are set meter-size lava fragments and juvenile and non-juvenile angular blocks, and bombs up to 7 m in diameter. Large faceted blocks make up 50% of the total volume of the deposit. The cauliflower bombs have deep and intricate bread-crust texture and post-depositional vesiculation. It is proposed that the juvenile material was produced entirely from a lava pool, whereas faceted non-juvenile blocks come from the crater-wall collapse. The concentration and maximum diameter of cauliflower bread-crusted bombs increases significantly from the base (rockslide + pyroclastic flow) to the top (the pyroclastic flow) of the deposit. An ash cloud deposited accretionary lapilli in the proximal region (outside of the pyroclastic flow deposit), and very fine ash fell in the distal region (between 5 and 30 km). The accretionary lapilli deposit is derived from the fine, elutriated products of the flow as it moved. A turbulent overriding surge blew down the surrounding shrubbery in the flow direction. The pyroclastic flow from August 1993, similar to the flows of June 1975, May 1998, August 2000, and March 2001, slid and rolled rather than being buoyed up by gas. They grooved, scratched, and polished the surfaces over which they swept, similar to a Merapi-type pyroclastic flow. However, the mechanism of the outpouring of a lava pool and the resulting flows composed of high- to moderate-vesiculated, cauliflower bread-crusted bombs and juvenile blocks have not been described before. High-frequency earthquake swarms, followed by an increase in low-frequency volcanic events, preceded the 1975, 1993, and 2000 eruptions 2-4 months before. These pyroclastic flow events, therefore, may be triggered by internal expansion of the unstable cone in the upper part because of a slight change in the pressure of the magma column (gas content and/or effusive rate). This phenomenon has important short-term, volcanic hazard implications for touristic development of some parts on the flanks of the volcano.     

Value of Climate Forecasts for Adjusting Farming Strategies in Sub-Saharan Africa

Sustaining and increasing crop production and productivity has to be a major policy thrust for developing countries. Using a simulation approach different production strategies were evaluated conditioned on climate information to derive optimal strategies to help farmers reduce risk and increase productivity. By examining the existence of options in this case planting dates the study provides an analyses of the expected value and risks associated with changing decisions based on the availability of climate forecasts. The 15-March planting date produced the highest mean yield for the two cultivars examined although 1-April, 15-April and 1-May plantings had one to zero probability of crop failures compared to 15-March with crop failures in 4 out of 20 years. Results indicate losses of between 25 and 35 kg/day due to delays in planting from 15-March planting to 1-June planting for the 120- and 150-day cultivar. El niño years were associated with positive yield deviations for both cultivars and most planting dates. Farmers are known to make tactical adjustments to their management in light of information perceived relevant to the prospects of forthcoming crop. Although in its present form most current forecast products do not provide information on onset of the rainfall, however the information they do provide could play a crucial role in helping farmers reduce the risks posed by climatic variability.     

Long‐term streamflow trends in Hawai'i and implications for native stream fauna

Climate change has fundamentally altered the water cycle in tropical islands, which is a critical driver of freshwater ecosystems. To examine how changes in streamflow regime have impacted habitat quality for native migratory aquatic species, we present a 50‐year (1967–2016) analysis of hydrologic records in 23 unregulated streams across the five largest Hawaiian Islands. For each stream, flow was separated into direct run‐off and baseflow and high‐ and low‐flow statistics (i.e., Q10 and Q90) with ecologically important hydrologic indices (e.g., frequency of flooding and low flow duration) derived. Using Mann–Kendall tests with a running trend analysis, we determined the persistence of streamflow trends through time. We analysed native stream fauna from ~400 sites, sampled from 1992 to 2007, to assess species richness among islands and streams. Declines in streamflow metrics indicated a general drying across the islands. In particular, significant declines in low flow conditions (baseflows), were experienced in 57% of streams, compared with a significant decline in storm flow conditions for 22% of streams. The running trend analysis indicated that many of the significant downward trends were not persistent through time but were only significant if recent decades (1987–2016) were included, with an average decline in baseflow and run‐off of 10.90% and 8.28% per decade, respectively. Streams that supported higher native species diversity were associated with moderate discharge and baseflow index, short duration of low flows, and negligible downward trends in flow. A significant decline in dry season flows (May–October) has led to an increase in the number of no‐flow days in drier areas, indicating that more streams may become intermittent, which has important implications for mauka to makai (mountain to ocean) hydrological connectivity and management of Hawai'i's native migratory freshwater fauna.     

Can 234U–230Th dating be used to date large semi‐arid tufas? Challenges from a study in the Naukluft Mountains,Namibia

The large, extensive tufa deposits of the semi‐arid Naukluft Mountains, Namibia are potentially important palaeoenvironmental indicators in an area with few proxy records. Tufas are reliable indicators of increased moisture availability, and have been shown to be amenable to ²³⁴U–²³⁰Th dating, although two challenges are detrital contamination and open‐system behaviour. Densely cemented tufa facies are good candidates for dating, minimising these problems. We report attempts to date five densely‐cemented units, which are only found rarely within the Naukluft deposits. We applied a detailed methodology using multiple subsample analysis, measurement of insoluble residues, application of ‘isochron’ mixing lines, and attempted open‐systems modelling, alongside observations of micromorphology and cathodoluminescence in order to assess the validity of any obtained dates. Surprisingly, densely cemented tufas were found not always to be suitable for dating. Two units contained detrital contamination, which could not be corrected for using a single leachate correction or ‘isochron’ methods. Two units contained ‘excess ²³⁰Th’. This could result under a closed‐system if initial (²³⁴U/²³⁸U) was sufficiently high. Alternatively this may be the result of open‐system behaviour, and loss of uranium, or incorporation of initial unsupported ²³⁰Th, which render samples unsuitable for ²³⁴U–²³⁰Th dating. Micromorphological appearance and cathodoluminescence behaviour are used to explore these possibilities. This study exemplifies the need for careful sample selection, and highlights the importance of analysing multiple subsamples from any tufa sample. The detailed methodology applied proves to be a powerful tool for identifying the range of problems that can be encountered when selecting suitable candidate samples for successful dating. It also shows that semi‐arid tufa sequences may contain very little material suitable for dating. A reliable age of c 80 ka was obtained for a banded unit within a large fluvial barrage, with less reliable dates suggesting tufa deposition during times since >350 ka through to the late Holocene. Copyright © 2010 John Wiley & Sons, Ltd.     

Value of Climate Forecasts for Adjusting Farming Strategies in Sub-Saharan Africa

Sustaining and increasing crop production and productivity has to be a major policy thrust for developing countries. Using a simulation approach different production strategies were evaluated conditioned on climate information to derive optimal strategies to help farmers reduce risk and increase productivity. By examining the existence of options in this case planting dates the study provides an analyses of the expected value and risks associated with changing decisions based on the availability of climate forecasts. The 15-March planting date produced the highest mean yield for the two cultivars examined although 1-April, 15-April and 1-May plantings had one to zero probability of crop failures compared to 15-March with crop failures in 4 out of 20 years. Results indicate losses of between 25 and 35 kg/day due to delays in planting from 15-March planting to 1-June planting for the 120- and 150-day cultivar. El niño years were associated with positive yield deviations for both cultivars and most planting dates. Farmers are known to make tactical adjustments to their management in light of information perceived relevant to the prospects of forthcoming crop. Although in its present form most current forecast products do not provide information on onset of the rainfall, however the information they do provide could play a crucial role in helping farmers reduce the risks posed by climatic variability.     

Within‐colony variation in skeletal mineralogy of Adeonellopsis sp. (Cheilostomata: Bryozoa) from New Zealand

Three colonies of the erect, robust branching, cheilostome bryozoan Adeonellopsis sp. were collected from Doubtful Sound, New Zealand, to investigate within‐colony variation in carbonate mineralogy. One‐hundred‐and‐twenty‐one sections from 9 branches were found to contain mostly aragonite, with calcite ranging from 1.1 to 7.3 wt% (mean ± SD = 2.4 ± 1.2 wt%, n = 120). The magnesium (Mg) content in calcite ranged from 5.3 to 13.1 wt% magnesium carbonate (8.8 ± 1.0 wt% MgCO₃; n = 120). Calcite content decreased with increasing age proximally along the branch, indicating that secondary thickening is achieved with aragonite. In contrast, an oscillating trend in Mg content along branches suggests that seasonal or interannual environmental parameters may influence this geochemical parameter. Mineralogical variability highlights the need for multiple samples from the same colony to be measured when determining quantitative carbonate mineralogy in bryozoans. Bimineralic bryozoans such as Adeonellopsis sp. may have lower preservation potential than monomineralic bryozoans, and consequently may not survive diagenesis to become fossils. Bimineralic species may also be more vulnerable to dissolution pressure and possible ocean acidification than monomineralic calcitic taxa.     

Beyond “Lawn People”: The Role of Emotions in Suburban Yard Management Practices

Many recent studies have applied satellite remote sensing data to large-scale hydrologic and biospheric modeling. It is widely accepted that the thermal infrared observations from the Advanced Very High Resolution Radiometer (AVHRR) have the potential to estimate land surface conditions, such as surface temperature, near surface air temperature, and near surface water vapor. In this study, algorithms to estimate all three variables are presented and applied to an area covering the state of Oklahoma for a six day period in August, 1994. The results were validated using ground observations from the 111 station Oklahoma Mesonet. Validation of the remote sensing algorithms with Mesonet observations produced comparable results to previous validation studies. In addition, the validation process revealed inadequacies in thermal modeling that had not been detected in previous validation studies leading to the development of a new approach to estimate atmospheric water vapor.     

Covariance among North Sea ecosystem state indicators during the past50 years — Contrasts between coastal and open waters

Regime shift and principal component analysis of a spatially disaggregated database capturing time-series of climatic, nutrient and plankton variables in the North Sea revealed considerable covariance between groups of ecosystem indicators. Plankton and climate time-series span the period 1958–2003, those of nutrients start in 1980. In both regions, the period from 1989 to 2001 identified in principal component 1 had warmer surface waters, higher Atlantic inflow and stronger winds, than the periods before or after. However, it was preceded by a regime shift in both open (PC2) and coastal (PC3) waters during 1977 towards more hours of sunlight and higher water temperature, which lasted until 1997. The relative influence of nutrient availability and climatic forcing differed between open and coastal North Sea regions. Inter-annual variability in phytoplankton dynamics of the open North Sea was primarily regulated by climatic forcing, specifically by sea surface temperature, Atlantic inflow and co-varying wind stress and NAO. Coastal phytoplankton variability, however, was regulated by insolation and sea surface temperature, as well as Si availability, but not by N or P. Regime shifts in principal components of hydrographic and climatic variables (explaining 55 and 61% of the variance in coastal and open water variables) were detected using Rodionov's sequential t-test. These shifts in hydroclimatic variables which occurred around 1977, 1989, 1997 and 2001, were synchronized in open and coastal waters, and were tracked by open water chlorophyll and copepods, but not by coastal plankton. North–central–south or open-coastal spatial breakdowns of the North Sea explained similar amounts of variability in most ecosystem indicators with the exception of diatom abundance and chlorophyll concentration, which were clearly better explained using the open-coastal configuration.