Status of land use in Mil-Aran Karabakh cadastral region

Mil-Aran Karabakh cadastral region includes Barda, Agjabadi, Beylagan, Tartar regions as a whole, Aghdam, Aghdara region and Khojavend plain lands. Gray-meadow, meadow-forest, subasar alluvial meadow, gray, meadow-swamp, chestnut, meadow-chestnut soils are spread in the territory of this cadastral region. Grass-gray soils are transitional and are distributed in the strip between the gray-brown (chestnut) and meadow gray-brown (chestnut) soils of the dry steppes and the gray soils growing in drier conditions. Very large areas of the described lands are used for irrigated agriculture. The subasar regime of rivers and the resulting fresh alluvial sediments play a key role in the formation of subasar meadow-forest soils. During the autumn season, especially during floods, the rhythm of soil formation is repeatedly disrupted. This, of course, is reflected in the properties and morphological structure of these soils. Areas with gray soils have an arid semi-desert and dry steppe climate with an average annual temperature of 13.5-14.60. The temperature of the hot months is much higher. Unlike subasar meadow-forest lands of our republic, subasar-meadow soils are formed under meadows and shrubs. Rich grasses play an important role in enriching these soils with organic matter and ash elements. Meadow-swamp lands are spread in a relatively limited area of the republic. These soils are usually formed in the low and lowlands of the relief. The ecological and geographical features of the meadow-brown soils are in many respects similar to those of the brown soils. However, hydrothermal conditions are distinguished by the large seasonal differences, additional moisture due to surface and ground moisture. Our area is subject to varying degrees of salinization and erosion. We know that saline soils are lands with salts that are easily soluble in water in a 2-meter layer of soil. The effect of groundwater on soil salinization also depends on the degree of mineralization of that water. In this case, the crisis rate of groundwater mineralization is taken. Key words: Groundwater, mineralization rate,salt accumulation, irrigated soils, drainage rate

Assessment of Groundwater Mineralization Processes in Mbakaou Area (Adamawa Plateau – Cameroon), by Using Conventional Diagrams and Multivariate Statistical Analysis

Management of groundwater require knowing their qualities and hydrogeochemical processes whereby these waters acquire their mineralization. The population of Mbakaou in Adamawa Plateau consumes groundwater from a doubtful quality water supply structures (wells, boreholes and catchments). This study was carried out to highlight groundwater quality and processes that govern water mineralization. So, to achieve this, 11 water samples were analyzed (1 rain water, 1 well, 3 springs and 6 boreholes). After analyzing the samples and comparing the obtained values to World Health Organization (WHO) standards, multivariate statistical analysis including Principal Component Analysis (PCA) were applied. Results show that these waters samples are fresh, generally of good quality compared to WHO standards and weakly mineralized (35 to 247.9 mg/l), due to the short residence time. Calcium and magnesium bicarbonate facies is the main water type. Nitrates are the most common pollutants and reveal high vulnerability of saprolite aquifer than fractured aquifer. The groundwater mineralization is influenced by precipitation, base ion exchange process, anthropogenic activities and water-rock interaction through silicate weathering. The PCA analysis yielded three factors that explained 89.33 % of the total variance. Factor 1 (62.60 %), factor 2 (15.54 %) and factor 3 (11.19 %) made respectively the difference between water samples influenced by precipitation or water rock interaction from those influenced by both water-rock interaction with precipitation or anthropogenic activities and those for water rock interaction with ion exchange process.

Coastal Aquifer Salinization in Semi-Arid Regions: The Case of Grombalia (Tunisia)

Groundwater resources are facing increasing pressure especially in semi-arid regions where they often represent the main freshwater resource to sustain human needs. Several aquifers in the Mediterranean basin suffer from salinization and quality degradation. This study provides an assessment of Grombalia coastal aquifer (Tunisia) based on multidisciplinary approach that combines chemical and isotopic (δ2H, δ18O, 3H, 14C and δ13C) methods to characterize the relation between groundwater quality variation and aquifer recharge. The results indicate that total dissolved solids exceed 1000 mg/L in the most of samples excepting the recharge area. In addition to water–rock interaction, evaporation and nitrate pollution contributing to groundwater mineralization, the reverse cation exchange process constitute an important mechanism controlling groundwater mineralization with enhancing risk of saltwater intrusion. Environmental isotope tracers reveal that groundwater is evolving within an open system to close system. A significant component of recent water that is recharging Grombalia aquifer system is confirmed by applying correction models based on the δ13C values and 14C activities and tritium contents. However, this recharge, which is mainly associated to the return flow of irrigation water, contributes to the groundwater salinization, especially for the shallow aquifer.

RECLAMATION OF IRRIGATED LANDS OF SYRDARYA REGION EFFECT OF CONDITION ON AUTUMN WHEAT GRAIN YIELD

This article focuses on improving the reclamation of irrigated lands in Syrdarya region, increasing soil fertility, efficient use of available water resources in the context of water scarcity, irrigated land in the region from 2013 to 2019, groundwater level, groundwater mineralization, drainage results of data on reconstruction, soil salinity and winter wheat grain yield over the years

Hydrodynamic and hydrochemical evolution of the Bajo Guadalhorce Valley alluvial aquifer (Málaga, S Spain) in the last 40 years

<p>Groundwater flowing through coastal aquifers is increasingly impacted by human pressures as consequence of a growing demand on drinking water, tourism and agriculture, among others. Thus, groundwater availability very often depend on its quality since water salinization and pollution are the main challenges for water management because of seawater and freshwater interaction. Therefore, it is crucial to monitor the availability of groundwater and its quality under changing scenarios where this water resource can be specially threatened.</p><p>This study aims to assess the spatial distribution and time evolution of groundwater levels and hydrochemistry of the alluvial aquifer of the Bajo Guadalhorce Valley (Málaga, S Spain) for the evaluation of its quantitative and qualitative status. To that, groundwater level, electrical conductivity and Cl<sup>-</sup> and SO<sub>4</sub><sup>2-</sup> concentrations of water have been measured in a field sampling campaign carried out in the alluvial aquifer of the Bajo Guadalhorce Valley (Málaga, S Spain) in April 2017. Additionally, historical data from the last 40 years have been compiled.</p><p>Results show that groundwater generally flow towards the Guadalhorce River, where gaining relationship remains more patent in its lower river stretch, and the Mediterranean Sea. Some negative groundwater elevations close to the coastal fringe are observed in several piezometers because of pumping during the study period. Electrical conductivity values were, generally, lower than 4 mS/cm in all samples and the major changes in groundwater mineralization were determined in the Guadalhorce River Mouth. In this aquifer sector, substantial increases in groundwater mineralization were identified, up to 50% in some observation points. Cl<sup>-</sup> and SO<sub>4</sub><sup>2-</sup>concentrations in groundwater (the more concentrated solutes of all) evolve similarly in time to that of electrical conductivity, with maximum recorded values up to 10000 mg/l and 2000 mg/l, respectively, the coastal area in 2017.</p><p>Changes in EC and Cl<sup>-</sup> and SO<sub>4</sub><sup>2-</sup> concentrations in the river mouth area could be related to the land use changes that took place here between 1997 and 2003, where channelization works resulted in the splitting of the river in two branches. This could have affected to the aquifer hydrodynamics, due to the reduced groundwater discharge to the river mouth area between both branches. This could have favored the mixing among surface water, sea water and groundwater. Also, the urbanized area has increased over the years, reducing the recharge area of this part of the aquifer, but also flowing groundwater has increased because of pumping reduction (up to 7 hm<sup>3</sup>/year). The presence of Cl<sup>- </sup>in the aquifer, as well as SO<sub>4</sub><sup>2-</sup>, is due to evaporite dissolution and the interaction with the Mediterranean Sea in the coastal area. An extra input of SO<sub>4</sub><sup>2-</sup> comes from of the fertilizers used in agriculture.</p><p>The availability of long-term hydrogeological data in a coastal aquifer (1976-2017) has allowed to check a remarkable salinization in the coastal area, caused by land use modifications. So, the monitoring of hydrogeological data is a very important tool to be used by land managers in coastal aquifers, where groundwater can be seriously endangered by human activities.</p>

Mineralization mechanisms of groundwater in a semi-arid area in Algeria: statistical and hydrogeochemical approaches

The study area of Ain Oussera (3,790 km2) is located in the semi-arid high plains of the Saharian Atlas (200 km south of Algiers). Groundwater investigated in the present study is from the Albian formations which are considered as a major source for drinking and irrigation water. The objective of this study is to identify the different hydrochemical processes controlling the groundwater mineralization. For this purpose, chemical analyses were performed on 31 wells sampled during May 2014. The chemical study (total dissolved solids (TDS), Piper, chemical correlation) allowed the origins of groundwater mineralization to be identified. The dissolution of evaporate minerals, precipitation of carbonate minerals, and ion exchange reactions have been identified as major sources of mineralization processes. Anthropogenic processes due to human activities (sewage effluents and agricultural fertilizers) also contribute to the mineralization of the water. The results of principal component analysis also confirm that both natural and anthropogenic processes contribute to the chemical composition of groundwater in the study area.

Understanding Groundwater Mineralization Changes of a Belgian Chalky Aquifer in the Presence of 1,1,1-Trichloroethane Degradation Reactions

An abandoned industrial site in Belgium, located in the catchment of a chalk aquifer mainly used for drinking water, has been investigated for groundwater pollution due to a mixture of chlorinated solvents with mainly 1,1,1-trichloroethane (1,1,1-TCA) at high concentrations. The observed elevated groundwater mineralization was partly explained by chemical reactions associated with hydrolysis and dehydrohalogenation (HY/DH) of 1,1,1-TCA in the chalky aquifer. Leaching of soluble compounds from a backfilled layer located in the site could also have influenced the groundwater composition. In this context, the objective of this study was to investigate the hydrochemical processes controlling groundwater mineralization through a characterization of the backfill and groundwater chemical composition. This is essential in the context of required site remediation to define appropriate remediation measures to soil and groundwater. Groundwater samples were collected for chemical analyses of chlorinated aliphatic hydrocarbons, major ions, and several minor ones. X-Ray Diffraction Analysis (XRD), Scanning Electron Microscopy (SEM) and a leaching test according to CEN/TS 14405 norm were carried out on the backfill soil. δ34S and δ18O of sulphate in groundwater and in the backfill eluates were also compared. Both effects influencing the groundwater hydrochemistry around the site were clarified. First, calcite dissolution under the 1,1,1-TCA degradation reactions results in a water mineralization increase. It was assessed by geochemical batch simulations based on observed data. Second, sulphate and calcium released from the backfill have reached the groundwater. The leaching test provided an estimation of the minimal released quantities.