Conceptualising State‐Controlled Resort Islands for an Environment‐Friendly Development of Tourism: The Maldivian Experience

The Maldives host a sophisticated and competitive international tourist industry which has replaced fishing as the dominant economic activity. With their rich tropical reef ecosystems and the abundant biodiversity of their marine environment, a total of 86 uninhabited islands had been converted into Resort Islands by the end of 2000. Resort Islands are equipped with comprehensive facilities for accommodation, food, recreation and leisure. They are also strictly reserved for foreign tourists and guarantee complete privacy. This gives the benefit of averting conflicts of acculturation with local islanders. In the arena of impacts on the physical environment, however, the consumptive leisure lifestyle of the tourists has been harmful to the Resort Islands as seen in sewage, garbage and waste pollution, as well as reef destruction and beach erosion. While the government of the Maldives takes great effort to harmonise tourism and the environment, the growth of mass tourism in the last 20 years has engendered grave environmental impacts. For future sustainable development of the Resort Islands, the tourists' environmental awareness must be increased to promote greater responsibility for the protection of the fragile coral and reef ecosystems of the Maldives.     

干旱、半干旱区域降水趋势可预报期限的初步研究

应用中国西北和美洲大陆中部干旱、半干旱区域７个长记录站的月降水量记录，分析了降水趋势的可预报期限问题。结果表明：月降水量标准化系数序列的可预报尺度为３个月左右。将该序列进行差分运算后，误差倍增时间会显著加长。     

Some features of the arid area variations over India: 1871–1984

Spatial variability of the annual rainfall over drier regions of India is studied by examining the variations in the arid areas. A long period (1871–1984) arid area series has been prepared for the entire country, including the two broad subregions of North India and Peninsular India, using annual rainfall data from 306 well distributed stations. Following an objectively determined criterion based on rainfall amount alone, the yearly area under arid conditions is obtained by totalling areas which received annual rainfall totals less than 560 mm. The interannual variability of the arid area series is large and its distribution is highly right-skewed, demonstrating large spatial variations in the annual rainfall over India. Statistical tests do not suggest any significant long-term trend in the arid area series, but persistently low values of the arid area after 1941 are noteworthy. Implications for the study of risk analysis and assessment of drought and desertification processes are discussed.     

不同生态系统CO2通量和浓度特征分析研究

本文利用1993～1994年日本国家农业环境研究所与中国科学院沙漠研究所合作在内蒙古奈曼地区实测的7种不同生态系统（沙丘、轻度放牧草原、中度放牧草原、重度放牧草原、无放牧草原、玉米田和大豆田）的净辐射、土壤热通量、两个高度的CO2浓度、温度、湿度和风速等资料，采用空气动力学方法，计算了CO2通量及其与环境和人为干扰因子的关系，并分析了不同下垫面的光合作用特征. 结果表明：各种下垫面CO2通量的共同特点是：在白天，CO2通量和梯度的输送方向是从大气向植被，在中午（11～13时）输送达到负的最大值； 在夜间，CO2通量和梯度输送方向与白天相反，是从植被向大气，在早晨（3～5时）达到正的最大值. 植被覆盖率及生物量不同的下垫面光合作用强度有明显差异，天气状况对光合作用也有一定影响.     

Irrigated area determination: a case study in the Province of San Juan,Argentina

Much of the central-western region of Argentina, where San Juan Province is located, experiences arid to semi-arid climatic conditions with low average annual rainfall accompanied by substantial evapotranspiration. Consequently, a viable crop industry depends to a large extent upon irrigation from major river systems. Increasing demand for water in the lower basin of the San Juan River is emphasizing the need for more accurate estimates of water used for irrigation. Since the water demand for a particular crop is very closely related to crop area, monitoring the area of crop under irrigation is considered a proxy for the amount of water used. Landsat 5 imagery for the growing season, field data and aerial photographs were used to evaluate crop area.     

Study of Aerodynamic Parameters on Different Underling Surfaces

Aerodynamic parameters including the zero-plane displacement (d), roughness length (20), and friction velocity (u*) on the different underlying surfaces of heavy-grazing site, medium-grazing site, light-grazing site, no-grazing site, dune, inter-dune, grassland, rice paddy site, wheat site, soybean site, and maize site have been computed based on the Monin-Obukhov similarity theory by utilizing the micrometeorologically observed data of dune and vegetation in the semi-arid area at Naiman, Inner Mongolia of China, conducted jointly by the Institute of Desert Research, Chinese Academy of Sciences and the National Institute of Agro-Environmental Sciences of Japan in 1990-1994. And their relationships between wind speed and Richardson number are analyzed. The aerodynamic characteristics of different man-made disturbed grassland ecosystems are also compared. Result shows that the vegetation coverage and the above-ground biomass decrease with the increase in man-made stress of the grassland. The roughness length for different underlying surfaces is closely related to vegetation height, above-ground biomass, and ground surface undulation, and Richardson number Ri is also its influencing factor. The friction velocity varies largely on different underlying surfaces, and it is positively proportional to wind speed and roughness length. The aerodynamic parameters of various times on the same underlying surface are different, too. Above results indicate that grassland and vegetation are of significance in preventing desertification, especially in the arid and semi-arid land ecosystems. And the results of this paper are also important for constructing the land surface physical process as well as regional climate model.     

Metals content in sediments of ephemeral streams with small reservoirs(the Negev Desert)

The content of 19 metals(chromium,cobalt,nickel,strontium,arsenic,magnesium,barium,cesium,gallium,rubidium,uranium,vanadium,zinc,lead,copper,cadmium,iron,manganese,and aluminum) in sediment in three ephemeral streams(Nahal Sansana,Nahal Revivim and Nahal Pura) with reservoirs in the Negev Desert is studied herein.The study was done in September 2016.The samples were collected from the surface layer of sediment(up to 10 cm) in the reservoirs and in the channels upstream and downstream of the reservoirs.Silt,which on average,accounted for 72% dominated in the sediment.In the spatial distribution of the particle size,sand and gravel fractions were deposited in the reservoirs.Aluminum,iron,and magnesium accounted for 99% of all analyzed metals.The Principal Component Analysis(PCA) and Hierarchical Cluster Analysis(HCA) showed that sediment in the Negev Desert channel upstream of the reservoirs had similar concentrations of metals.Similarities were also found between the analyzed reservoirs.The bottom sediment in reservoirs had higher concentrations of metals than sediment upstream and downstream of the reservoirs.The comparison of concentrations in upstream and downstream locations did not show any unambiguous trends because metal concentrations downstream from the reservoirs were not always lower than upstream of the reservoirs.The analysis of the sediment enrichment factor(EF) showed the highest value in the reservoirs and the lowest downstream of the reservoirs.The concentrations of most analyzed metals did not indicate the possibility of potential ecological risk(SQG).     

Monitoring vegetation dynamics in semi-arid African rangelands: Use and limitations of Earth observation data to characterize vegetation structure

Vegetation community structure is a key indicator of long-term vegetation change in semi-arid ecosystems. This study uses ground-based spectral measurements and a canopy reflectance model to investigate the potential of Earth observation data to characterize variations in vegetation structure along a grazing gradient in the eastern Kalahari, Botswana. Despite differences in the bidirectional reflectances of soil, plant litter, bush and grass canopies towards the end of a dry season, it is unlikely that Earth observation data can be used to estimate vegetation structure at this time. This is due to an ambiguity in the relationship between spectral reflectance and vegetation structure caused primarily by the limited dimensionality of reflectance data. Variations in canopy architecture cause differences in the level of inter-canopy shadowing but the net effect—lower reflectance with an increase in bush cover—parallels the darkening effects of any vegetation cover on relatively bright sandy soils in semi-arid environments. These results highlight the continued need for long-term ground-based ecological monitoring in conjunction with satellite-based monitoring of changes in vegetation cover.     

Sediment transport for desert watersheds in erodible materials

Sediment transport for five small watersheds in arid southern Israel, eroded into shales, chalks, anhydrites and alluvium is studied. Analysis includes data from three large watersheds in the southern United States. Results indicate that floodwater heavily laden with suspended load (10-60 per cent, by weight) is characteristic of watersheds cut in erodible materials. No correlation was found between environmental characteristics such as lithology, catchment area, angle of slope or rainfall intensity and suspended-sediment concentration or texture. The carrying capacity for sands, derived both from hillslopes and channel alluvium is greatly increased by high suspended silt concentration, the trend being (where R = ratio, % fines/% sand; C_s = suspended load concentration, per cent by weight). The high concentration of fine sediment effectively causes more sand transport than would normally occur. This is also true for transport of coarser clastics; higher velocities, typical of highly concentrated silt suspensions, increased competence for transporting pebbles and boulders. The action of a large variety of processes (splash, wash, rilling, gullying, sliding, mudflow) combine with low infiltration and high credibility to render every rainstorm erosionally effective, and high concentrations of washload increase both the capacity and competence of coarse clastic transport. Whole basins are thus subjected to high rates of denudation (2-10 mm/yr).     

First international payment for marine ecosystem services: The case of the Banc d’Arguin National Park,Mauritania

This article investigates whether the European Union-Mauritania fisheries agreement, which allocates part of the Europe's financial contribution to the conservation of marine ecosystems located within the Banc d’Arguin National Park, can be regarded as a payment for ecosystem service. A framework for qualification as such payment scheme was established based on an extensive literature review. The criteria identified for the qualification as a payment to ecosystem service pertain to: (1) the definition of the ecosystem service(s) involved; (2) the mechanism involved by the payment; and (3) the nature of the transaction. Interviews with local beneficiaries and subsequent data analysis led to the conclusion that this mechanism could be regarded as a payment to ecosystem service and so, through the European Union-Mauritania Fisheries agreement, the European Union were investing to protect local fish resources that could be exploited by its fishing fleet. This agreement, involving the first International Payment to Ecosystem Service of this kind, marks an important step towards better consideration of marine conservation in international public policy and foreign fishing policy in particular. However, this payment is small when compared to revenues generated through the exploitation of developing countries’ fishing grounds by fishing countries. Nevertheless it opens the door for more detailed applications of payment to ecosystem service schemes to other ecosystems contexts, and can provide a useful alternative source of financing of marine biodiversity conservation.