Causes of Land Subsidence in the Kingdom of Saudi Arabia

The occurrence of land subsidence in the Kingdom Saudi Arabia is either natural or man-made. Natural land subsidence occurs due to the development of subterranean voids by a solution of host rocks in carbonate and evaporite terrains, over many areas of Saudi Arabia. Man-induced land subsidence is either due to the removal of groundwater in the agricultural areas or to wetting of unstable soils. Therefore, earth fissures and a lowering of the ground surface in unconsolidated sediments took place in alluvial plains and volcanic vent terrains. Unstable soils include Sabkha soils and loess sediments. These types of soils occur in coastal plains, desert areas and volcanic terrains. When this soil is wetted either during agricultural activities, waste disposal or even during a rain storm, subsidence takes place due to either the removal of salts from the Sabkha soil or the rearrangement of soil particles in loess sediments.     

湖北中洲子牛轭湖最近70年孢粉-炭屑记录及其对气候和人类活动的响应

根据长江中游湖北省荆江段中洲子牛轭湖孔深为89cm的ZZ-2钻孔（29°48'02N,112°45'14E）孢粉-炭屑记录,结合器测气候数据、前人建立的年代序列、粒度分析和县志记载等,探讨了近70年来ZZ-2孔孢粉-炭屑记录对植被和气候变化以及人类活动的响应。1940年到2012年研究区气候总体表现为冷暖、干湿交替,对应中洲子牛轭湖ZZ-2钻孔的5个孢粉-炭屑组合带：1940~1961年间,乔木花粉含量的减少、农作物花粉含量和炭屑浓度增加与人类砍伐森林、耕地增加和焚烧活动增强有关;1962~1967年间,水生草本及蕨类孢子含量增加是汛期长江水倒灌、或洪水事件的反映;1968~1982年,乔木花粉增加、湿地和林地面积增加,是实施湿地保护政策的响应;1983~1997年间,伴随着松属花粉明显减少,枫杨花粉显著增加,说明经过人工育林,枫杨成为当地的优势种;1998~2012年间,水生草本花粉及大炭屑（粒径大于125μm）含量增加,是实施退耕还湖政策、大量耕地被鱼塘替代、湿地面积扩大以及人类活动加剧的结果。中洲子牛轭湖孢粉-炭屑组合可以清晰的揭示研究区不同时期的环境变化和人类活动事件,如长江流域的大洪水（1949年、1954年、1980年和1983年大洪水）以及“大炼钢铁”（1958年）、人工造林（1982年）和退田还湖（1998年）等事件。     

Formulation of the Caspian Sea’s legal regime using a joint zone approach

The legal regime of the Caspian Sea has been determined under Treaties 1921 and 1940 by and between Iran and former Soviet Union. In fact, we are neither to explain it nor to determine. As understood from the provisions therein, the exploitation and use of the Caspian Sea by both countries are based on the Condominium. However, there is a 10-nautical mile strip as exclusive fishing areas which have been allocated to the states under the 1940 treaty. It means that Soviet Union and Iran may benefit the marine livings resources out of that strip on an equal manner. This right also includes the seabed and underlying bed. So, the legal regime of this sea may be based on a 10-nautical mile exclusive region for all five states and the remaining part as common and joint area under an agreement until an explaining and supervising organization is established to exploit and supervise over living and non-livings resources.     

Rock slope stability and design in Arafat–Muzdalifa area,Saudi Arabia

The present contribution is a complete study extending before, during, and after the excavation of the mountain side that lying north of road 7. It includes slope stability analysis, rock cut design, and rockfall modeling for natural slope and rock cut face. Neoproterozoic granodiorite and biotite granite forming the slope body have medium to very high strengths. Mineral compositions and textures of these intact rocks control the strength values. These rocks are intensively dissected by fractures that are filled with montmorillonite and chlorite. The high plasticity and slippery nature of these filling materials represent the main problem that may face a rock cut designer because they damage the mechanical properties of these fractures. The problem begins with the selection of the rock mass classification that deals with the fracture fillings and extends during the stability analysis and the suggestion of mitigation and supporting measures. The rock masses building the natural slope are suffered by plane, wedge, and toppling failures. Therefore, two rock cut designs are suggested to avoid the hazards related to these failures and considering the construction cost as well. Rockfall modeling for the natural slope and rock cut designs was done to assess the hazards related to these falling of the blocks. The kinetic energy of falling blocks is represented on the roadway by the coverage distance and block rebound amplitude. Slope height has a positive effect on the values of these distance and amplitude, whereas the steepness of berm height has a negative effect on them. Coverage distance is a function to the location of rockfall barrier and to the width of road ditch, while the amplitude controls the barrier height.     

Impact of Reservoir Permeability,Permeability Anisotropy and Designed Injection Rate on CO2 Gas Behavior in the Shallow Saline Aquifer at the CaMI Field Research Station,Brooks, Alberta

Natural Resources Research - Carbon capture and storage is part of Canada’s climate change action plan to reduce greenhouse gas emissions. The Containment and Monitoring Institute Field...     

Seasonal variations in temperature,salinity and density in the southern coastal waters of the Caspian Sea

Variability in water temperature, salinity and density was investigated based on field measurements near Anzali Port, in the Southern Caspian Sea in 2008. Seasonal changes of seawater properties were mainly observed through the upper 100 m layer, while below this layer seasonal variations of the parameters were minor. Vertical structure of the temperature in the southern coastal waters of the Caspian Sea is characterized by a significant seasonal thermocline between 20–50 m depths with vertical variation in temperature about 16°C in midsummer (August). Decrease of the thermocline occurs with the general cooling of the air and sea surface water, and deepening of the mixed layer during late of autumn and winter. Seasonal averages of the salinity were estimated in a range of 12.27–12.37 PSU. The structure of thermocline and pycnocline indicated agreement between changes of temperature and density of seawater. Seasonal pycnocline was observed in position of the thermocline layer.     

Dynamics of shock waves in a contracting cloud

The contraction of an interstellar cloud is followed. The results indicates that there are shock waves appear during contraction. In order to study the effect of shock waves, two models have been studied. The post-shock temperature for the two models are, respectively, 3006 K and 2984 K. The density increases by more than three orders of magnitude. The gas is generally cooled by atoms, molecules, and grains. The dominant cooling process changes according to the chemical composition and the temperature of the gas. The thermal equilibrium depends on the existing physical conditions.     

Downscaling and projection of precipitation from general circulation model predictors in an equatorial climate region by the automated regression-based statistical method

The authors have applied an automated regression-based statistical method, namely, the automated statistical downscaling (ASD) model, to downscale and project the precipitation climatology in an equatorial climate region (Peninsular Malaysia). Five precipitation indices are, principally, downscaled and projected: mean monthly values of precipitation (Mean), standard deviation (STD), 90th percentile of rain day amount, percentage of wet days (Wet-day), and maximum number of consecutive dry days (CDD). The predictors, National Centers for Environmental Prediction (NCEP) products, are taken from the daily series reanalysis data, while the global climate model (GCM) outputs are from the Hadley Centre Coupled Model, version 3 (HadCM3) in A2/B2 emission scenarios and Third-Generation Coupled Global Climate Model (CGCM3) in A2 emission scenario. Meanwhile, the predictand data are taken from the arithmetically averaged rain gauge information and used as a baseline data for the evaluation. The results reveal, from the calibration and validation periods spanning a period of 40 years (1961–2000), the ASD model is capable to downscale the precipitation with reasonable accuracy. Overall, during the validation period, the model simulations with the NCEP predictors produce mean monthly precipitation of 6.18–6.20 mm/day (root mean squared error 0.78 and 0.82 mm/day), interpolated, respectively, on HadCM3 and CGCM3 grids, in contrast to 6.00 mm/day as observation. Nevertheless, the model suffers to perform reasonably well at the time of extreme precipitation and summer time, more specifically to generate the CDD and STD indices. The future projections of precipitation (2011–2099) exhibit that there would be an increase in the precipitation amount and frequency in most of the months. Taking the 1961–2000 timeline as the base period, overall, the annual mean precipitation would indicate a surplus projection by nearly 14~18 % under both GCM output cases (HadCM3 A2/B2 scenarios and CGCM3 A2 scenario). According to the model simulation, the September–November periods might be the more significant months projecting the increment of the precipitation amount around over 50 %, while the precipitation deficit would be seen in March–May periods.     

Regional bivariate modeling of droughts using L-comoments and copulas

The regional bivariate modeling of drought characteristics using the copulas provides valuable information for water resources management and drought risk assessment. The regional frequency analysis (RFA) can specify the similar sites within a region using L-comoments approach. One of the important steps in the RFA is estimating regional parameters of the copula function. In the present study, an optimization-based method along with the adjusted charged system search are introduced and applied to estimate the regional parameters of the copula models. The capability of the proposed methodology is illustrated by copula functions on drought events. Three commonly used copulas containing Clayton, Frank and Gumbel are employed to derive the joint distribution of drought severity and duration. The result of the new method are compared to the method of moments and after applying several goodness-of-fit tests, the results indicate that the new method provides higher accuracy than the classic one. Furthermore, the results of the upper tail dependence coefficient indicate that the Gumbel copula is the best-fitted copula among the other ones for modeling drought characteristics.