Interactive effects of pH and temperature on native and alien mussels from the west coast of South Africa

Global warming and ocean acidification influence marine calcifying organisms, particularly those with external shells. Among these, mussels may compensate for environmental changes by phenotypic plasticity, but this may entail trade-offs between shell deposition, growth and reproduction. We assessed main and interactive effects of pH and temperature on four mussel species on the west coast of South Africa (33°48′ S, 18°27′ E) in October 2012 by comparing shell dissolution, shell growth, shell breaking force and condition index of two native species, the ribbed mussel Aulacomya atra and the black mussel Choromytilus meridionalis, and two aliens, the Mediterranean mussel Mytilus galloprovincialis and the bisexual mussel Semimytilus algosus. Live mussels and dead shells were exposed for 42 days to seawater of pH 7.5 or 8.0, at 14 °C or 20 °C. Low pH, high temperature and their combination increased shell dissolution of the two aliens but their growth rates and condition indices remained unchanged. Aulacomya atra also experienced greater shell dissolution at a low pH and high temperature, but grew faster in low-pH treatments. For C. meridionalis, shell dissolution was unaffected by pH or temperature; it also grew faster in low-pH treatments, but had a lower condition index in the higher temperature treatment. Shell strength was not determined by thickness alone. In most respects, all four species proved to be robust to short-term reduction of pH and elevation of temperature, but the native species compensated for greater shell dissolution at low pH by increasing growth rate, whereas the aliens did not, so their invasive success cannot be ascribed to benefits accruing from climate change.     

Identification and analysis of airborne laser swath mapping data in a novel feature space

Several novel features are examined to determine their effectiveness in separating buildings from trees in airborne laser swath mapping (ALSM) data. New one- and two-dimensional distance measures are created to quantify the separability of the classes using the different features. Several features involving the intensity of the laser returns were found to be highly effective at separating the classes. The new distance measure provides insight into what makes a good/bad feature when discriminating between classes. It also lays the groundwork for future classification of ALSM data by providing a systematic method of ranking features to be used for classification.     

Variations of Surface Air Temperature Over the Land Areas in and Around the Bay of Bengal

The inter-annual variation and linear trends of the surface air temperature in the regions in and around the Bay of Bengal have been studied using the time series data of monthly and annual mean temperature for 20–40 years period within 1951–1990. The study area extends from Pusma Camp of Nepal in the north and Kuala Lumpur of Malaysia in the south and between 80--100 ° E. The annual variation of temperature has also been studied using the mean monthly temperature for the variable time frames 1961–1975, 1976–1990 and 1961–1990. The trend of temperature has been analyzed using linear regression technique with the data from 1961–1990, which showed that the warming trend is dominant over the study areas except for a few stations. It has been found that Nepal shows predominant warming trends. Bangladesh and the adjacent areas of India and the northern part of Bay of Bengal adjacent to the Bangladesh coast have shown strong warming trends of the annual temperature with maximum at Dhaka (0.037 °C/year). The near equatorial zone, i.e., southern India, Sri Lanka and part of Thailand and Malaysia (Kuala Lumpur) shows warming trends in the annual mean temperature with strong warming at Pamban and Anuradhapura (around 0.04 °C/year). The cooling trends have been observed at a few stations including Port Blair, Yangoon and Cuttack. Further analysis shows the presence of prominent ENSO scale of variations with time period 4–7 years and 2–3 years for almost all the stations. The decadal mode with T >7 years is present in some data series. The results of the variations of temperature with respect to the Southern Oscillation Index (SOI) show that SOI has some negative correlation with temperature for most of the stations except those in the extreme northeast. It has been found that positive anomaly of temperature has been observed for El Niño events and negative anomaly for the La Nina events.     

Application of artificial neural networks in regional flood frequency analysis: a case study for Australia

Regional flood frequency analysis (RFFA) is widely used in practice to estimate flood quantiles in ungauged catchments. Most commonly adopted RFFA methods such as quantile regression technique (QRT) assume a log-linear relationship between the dependent and a set of predictor variables. As non-linear models and universal approximators, artificial neural networks (ANN) have been widely adopted in rainfall runoff modeling and hydrologic forecasting, but there have been relatively few studies involving the application of ANN to RFFA for estimating flood quantiles in ungauged catchments. This paper thus focuses on the development and testing of an ANN-based RFFA model using an extensive Australian database consisting of 452 gauged catchments. Based on an independent testing, it has been found that ANN-based RFFA model with only two predictor variables can provide flood quantile estimates that are more accurate than the traditional QRT. Seven different regions have been compared with the ANN-based RFFA model and it has been shown that when the data from all the eastern Australian states are combined together to form a single region, the ANN presents the best performing RFFA model. This indicates that a relatively larger dataset is better suited for successful training and testing of the ANN-based RFFA models.     

Underutilized plant species in Far West Nepal

Underutilized plant species help to alleviate common food insufficiencies by providing alternative food supply. They also complement primary health care, furnishing raw materials where the cultivation of staple cereal crops is least feasible and health care is pursued indigenously. Research and promotion of extraction, utilization, and conservation of underutilized species lead to exploration of new staple crops and motivate people to consume in a sustainable manner. The present study describes the current status, uses, and management of underutilized plant species in Far West Nepal. The relative importance of 49 underutilized plant species was computed employing a Relative Importance (RI) technique. The use-values assigned to the species fall into six use-categories: beverage, fodder, food & edible, medicinal, vegetable and veterinary. A total of 22 species appeared in multiple use-categories, while the rest were characterized by a single use-category. Based on relative importance and frequency, Ficus semicordata, Debregesia longifolia, Girardinea diversifolia, Hydrocotyle nepalensis, Garuga pinnata, Aloe vera and Pyrus pashia offer the most potential for future. Underutilized plants proved important to folk medicine and food. These species persist because they remain useful to local people as means of subsistence, production, and primary health care. The findings are important so far as they point up the role of underutilized plants in national food security policy and health care, spelling out their potentialities and cross cutting relationships.     

A modified normalized input-output minimization （Mod-NIOM） method for seismic wave propagation modeling

A new method for wave propagation modeling is introduced in this paper. By using the constraint optimization (Lagrange multiplier) method, the sum of weighted squared Fourier amplitudes is minimized when subjected to a constraint. The sum of the maximum amplitudes obtained from all output models is normalized to unity and is taken as a constraint. In this method, all the actual time histories are considered as outputs and dealt with equally. Independently of the combinations of time histories (or the first ...     

澜沧江和怒江流域的气候变化及其对径流的影响

采用VIP（Vegetation Interface Processes）模型和HIMS（Hydro-Informatic Modeling System）模型,模拟分析了1957-2012年澜沧江和怒江流域（简称两江流域）水资源量的演变。根据CMIP5 RCP2.6,RCP4.5和RCP8.5情景预测,模拟了2030年代和2050年代流域水资源的变化。研究发现,过去50年间,两江流域的气温都呈升高趋势,但海拔较高的上游地区升幅大于下游。年总降水量的变化趋势不明显,但春季降水增加趋势明显。两江流域年总水资源量为650亿～ 850亿m3,水资源总量长期变化趋势不明显,其中澜沧江的波动性（1.884,最大与最小之比）大于怒江。空间上水资源量呈现北低－南高的格局。在未来,两江流域气温仍呈增加趋势,降水呈增加趋势,径流呈增加趋势,空间变异性趋小,但较强的季节性变化对水资源安全仍具有较大的挑战性。     

Paving the way for conservation?

Limestone pavement is a unique part of Britain's physical landscape. Along with other forms of naturally weathered rock, it is under threat from exploitation for the horticultural market. Valued for its delicate and sculptured form, limestone pavement has been frequently used as decorative stone in rockeries and other landscaped ground. If this unique landscape is to be protected, its exploitation must stop. Yet it must be remembered that the use of rock in gardens and landscaped ground has an important role in raising the public profile of geology within urban areas. We have a simple message: the use of limestone pavement is wrong and must stop, but the use of other forms of stone in urban gardens is beneficial for the Earth sciences.     

Glacial hazards in the Rolwaling valley of Nepal and numerical approach to predict potential outburst flood from glacial lake

In recent years, climate change and retreating glaciers constitute a major hazard in the Himalaya of South Asia. Glacial lakes are rapidly developing or increasing due to climate change. The rapid development of the lake may cause outburst of the lake. The outburst discharge from the glacial lake can cause catastrophic flooding and disaster in downstream area. Therefore, it is necessary to investigate the impact of climate change on glacial lakes and to understand the characteristics of the glacial lake outburst. In this study, the field assessment of Tsho Rolpa Glacial Lake in the Himalaya of Nepal has been presented and the impact of climate change on this glacial lake has been discussed. The Tsho Rolpa Glacial Lake is the largest and most potentially dangerous glacial lake in Nepal. In addition, a numerical model has been also developed for computing the characteristics of glacial lake outburst due to moraine dam failure by seepage and water overtopping. The numerical model is tested for the flume experimental cases. The simulated results of the outburst discharge, the dam surface erosion, and the temporal variation of the moisture movement in the dam are compared with those obtained from the hydraulic model experiments. The moisture profile calculated by numerical model was agreeable with the experimental moisture profile. The simulated failure surface of the dam due to seepage by considering the suction in slope stability analysis gave more agreeable results than the Janbu's simplified method. The results of the outburst discharge and dam surface erosion also agreed with the experimental results.     

An assessment of Yarsagumba (Ophiocordyceps sinensis) collection in Dhorpatan Hunting Reserve,Nepal

Yarsagumba （Ophiocordyceps sinensis）, an endemic species to the Himalayas and Tibetan Plateau, is one of the most valuable medicinal mushrooms in the world. In Nepal, it is distributed largely in isolated patches of alpine grasslands of 3,000-5,000 m elevation. Although it is reported from 27 northernmost districts of Nepal, the local distribution pattern of this species is largely unknown. Furthermore, the collection system and local management regime of this species are not well documented. We conducted a field survey at Dhorpatan Hunting Reserve （DHR） among the different stakeholders in January-June 2012 to assess collection sites, patterns and trends and to understand the management regime. We estimated that about 75 kg of Yarsagumba is collected every year from DHR and the amount has been declining since 2008. To manage the resource, locals have initiated regulating the collection by issuing permits, taxing to the collectors, and monitoring the activities of harvesters with the help of park authorities. The revenue generated at local level from the permits has been used for community developmental activities.