Geochemistry of sulphate-bearing water of Akra Kaur Dam,Gwadar, Balochistan,Pakistan and its assessment for drinking and irrigation purposes

This paper is an attempt to study the geochemistry of Akra Kaur Dam (AKD) water, north of Gwadar city, southern Balochistan. Representative water samples were collected from AKD reservoir to assess the suitability of water for drinking and agriculture purposes. The major ionic composition is suggestive for freshwater. The average ionic composition demonstrate SO₄ > Ca > Na > Cl > HCO₃ > Mg > K. The plots on Piper diagram reflected Ca–Mg–SO₄ type of water facies. High Ca/SO₄ and Ca/Mg ratios revealed that the water has influence of gypsum dissolution. The negative ratio of chloro-alkaline indices indicated reverse exchange between Ca and Mg in water occurred with Na and K in rocks. The pH, electrical conductivity, total dissolved salts, Ca, Mg, Na, K, HCO₃, Cl and SO₄ concentrations in the dam water were below the permissible limit, however, Na and SO₄ were above the desirable limit, set by the World Health Organization. Important parameters such as residue sodium carbonate, sodium percent, sodium adsorption ratio, permeability index, magnesium content and Kelley’s ratio were calculated to evaluate the suitability of water for irrigation purpose. The result were compared with standard permissible limits and found satisfactory. The health and agriculture hazards of sulphate-bearing water were also discussed.     

Modelling the formation of individual galaxies: A morphology problem for CDM?

We use a semi-analytic model of halo formation to study the dynamical history of giant field galaxies like the Milky Way. We find that in a concordance LCDM cosmology, most isolated disk galaxies have remained undisturbed for 8–10 Gyr, such that the age of the Milky Way's thin disk is unremarkable. Many systems also have older disk components which have been thickened by minor mergers, consistent with recent observations of nearby field galaxies. We do have a considerable problem, however, reproducing the morphological mix of nearby galaxies. In our fiducial model, most systems have disk-to-bulge mass ratios of order 1, and look like S0s rather than spirals. This result depends mainly on merger statistics, and is unchanged for most reasonable choices of our model parameters. We discuss two possible solutions to this morphology problem in LCDM. This revised version was published online in August 2006 with corrections to the Cover Date.     

Mapping and assessment-based modeling of soil fertility differences in the central and eastern parts of the Black Sea region using GIS and geostatistical approaches

This study was carried out on arable lands of the central and eastern Black Sea regions including eight provinces (Artvin, Giresun, Gümü?hane, Ordu, Rize, Samsun, Sinop, and Trabzon). The present study aims to generate a soil fertility map for agricultural lands in the central and eastern parts of the Black Sea region. The main objective of this research is to quantify soil fertility by developing a soil fertility index (SFI) model at the regional level. The related objectives were to map the spatial distribution of soil fertility by using auxiliary variables and to model soil fertility within the study region. To accomplish this, a data set for soil fertility differences was collected and a model was developed to predict the spatial distribution of differences across the region. The study area was divided into 2.5 × 2.5-km grid squares. A total of 3400 soil samples were collected from the surface (0–20 cm) of each grid intersection point. The geostatistical method was used to generate the SFI distribution map of the study area for surface soils. Of the total study area, 93.76% had good (S1) or moderately fertile (S2) soil while 6.15% of the area had marginally fertile (S3) soil. Only a very small area (N) had low-fertility soil.     

Artificial neural networks for predicting DGPS carrier phase and pseudorange correction

Artificial neural networks (ANNs) were used to predict the differential global positioning system (DGPS) pseudorange and carrier phase correction information. Autoregressive moving average (ARMA) and autoregressive (AR) models were bounded with neural networks to provide predictions of the correction. The neural network was employed to realize time-varying implementation. Online training for real-time prediction of the carrier phase enhances the continuity of service of the differential correction signals and, therefore, improves the positioning accuracy. When the correction signal from the DGPS was lost, the artificial neural networks predicted the correction data with good accuracy for the navigation system during a limited period. Comparisons of the prediction results using the two models are given.

Preliminary investigation of underground settlements of Nevşehir Castle region using 2.5-D electrical resistivity tomography: Cappadocia,Turkey

The Nev?ehir Castle region located in the middle of Cappadocia with approximately cone shape is investigated for the existence of an underground city using the geophysical method of electrical resistivity tomography. Underground cities are commonly known to exist in Cappadocia. The current study has obtained important clues that there may be another one under the Nev?ehir Castle region. Several 2.5-D resistivity profiles totaling approximately 4 km in length surrounding the Nev?ehir Castle are measured to determine the distribution of electrical resistivities under the study area. Several high resistivity anomalies with a depth range 8–20 m are discovered to associate with a systematic void structure beneath the Nev?ehir Castle. Because of the high-resolution resistivity measurement system currently employed, we were able to isolate the void anomalies from the embedding structure. Using 3-D visualization techniques, we show the extension of the void structure under the measured profiles.     

Modelling,encoding and transforming of open geographic data to examine interoperability between GIS applications

The interoperability of geographic data sets is required between geo-information system applications to use geographic data sets effectively. Thus, international standardisation organisation/technical committee 211 standards supporting model-driven architecture were examined to test the ability of producing interoperable geographic data sets. With Turkey case, unified modelling language application schemas were designed for base geographic data themes and encoded to data interchange model based on geography markup language. To test the applicability of the open data models, extract-transform-load (ETL) tools were developed and applied for case applications such as topographic map and web urban atlas. This study gives a methodology and indicates that ETL tools should be created to enable multiple uses of geo-data sets without spending time and labour. However, data model design should be refined and kept as simple as possible because data transformation is laborious to use the models in the applications.     

GHG mitigation of agricultural peatlands requires coherent policies

As soon as peat soil is drained for agricultural production, the peat starts to degrade, which causes emissions to the atmosphere. In countries with large peatland areas, the GHG mitigation potential related to management of these soils is often estimated as the highest amongst the measures available in agriculture. Although the facts are well known, the policies leading to diminished emissions are often difficult to implement. We have analysed the reasons why the mitigation potential is not fully utilized and what could be done better in national implementation of climate policies. Four cases are used to illustrate the necessary steps to reach mitigation targets: determining the amount and properties of peat soils, estimating the potential, costs and feasibility of the mitigation measures, and selecting and implementing the best measures. A common feature for all of the cases was that national and international climate policies have increased the public interest in GHG emissions from peat soils and increased the pressure for mitigation. Basically the same factors restrict the implementation of mitigation measures in all countries with significant peat soil areas. The most important of these is lack of policy coherence, e.g. ignoring climate policies when planning land use or agricultural policies. We conclude that GHG mitigation is achieved only if other policies, especially national regulations and strategies, are in line with climate policies.

Policy relevance

Agricultural peat soils could be used to help reach GHG mitigation goals in many countries, but the full potential of mitigation of peat soils is not used. Although peatland cultivation inevitably leads to loss of the whole peat layer and high emissions, there are few incentives or regulation to effectively minimize these losses. This article discusses the possibilities to reduce GHG emissions from agricultural peat soils, with specific emphasis on the barriers of implementing mitigation measures nationally. The lessons learned from the selected cases emphasize the role of all policy makers and their cooperation in planning coherent policies for achieving the goals determined by climate policies.