Groundwater Potential Mapping of the Major Aquifer in Northeastern Missan Governorate, South of Iraq by Using Analytical Hierarchy Process and GIS

As a result of the increasing demand for water in recent years, particularly after the emergence of drought conditions in Iraq, water policies in neighboring countries and the need to expand the uses of water for the purpose of food security, there is a truly urgent need for reassessment of groundwater resources in the light of modern efficient techniques for better managing and protecting of the aquifer system. In this study an attempt was made to delineate groundwater availability zones for the major aquifer in northeast Missan governorate, south of Iraq using GIS and analytical hierarchy process (AHP) decision making technique. Because of the data lacking, a total set of four criteria/features believed to be influencing groundwater productivity in the area were selected and mapped to demarcate groundwater potential classes after assign appropriate weights using AHP. All thematic layers were integrated and analyzed in ArcGIS 9.3 software. The final groundwater potential map was produced by linear weighted combination technique. The delineated groundwater potential map was finally verified using the available abstraction rates of existing wells. The prediction accuracy of the developed model was 72%. The groundwater potential map of the study area reveals three distinct zones: high, moderate, and low groundwater availability. The areas covered by these zones were 1138, 554, and 157 km2 for low, moderate, and high zones, respectively. The results demonstrate that the groundwater resources in the study area require careful management and pumping extraction plans. The generated model will help as a guideline for designing a suitable groundwater exploration plan in the future and thereby help efficient planning of scare groundwater in the study area. Keywords: Groundwater, GIS, AHP, Missan governorate, Ira

Rising groundwater levels in the Neapolitan area and its impacts on civil engineering structures, agricultural soils and archaeological sites

The rise of groundwater levels (GWLr) is a worldwide phenomenon with several consequences for urban and rural environment, cultural heritage and human health. In this thesis the phenomenon and its effects are analysed in two sectors of the Metropolitan City of Naples (southern Italy). These areas are the central sector of the eastern plain of Naples and the Cumae archaeological site in the western coastal sector of Phlegraean Fields. The triggering mechanism of GWLr is attributed to anthropogenic and natural causes, as the groundwater rebound (GR) process and the relative sea level rise due to volcano-tectonic subsidence of coastal areas. In the eastern plain of Naples, the interruption of pumping for public and private purposes occurred in 1990, leading to a progressive increase of piezometric levels with values up to 16.54 m. Since the end of 2000s, episodes of groundwater flooding (GF) have been registered on underground structures and agricultural soils. The historical piezometric levels and a comprehensive conceptual model of the aquifer have been reconstructed, as well as a first inventory of GF episodes and the hydrogeological controlling factors of GF occurrence have been detected. The economic consequences of GF have been analysed for an experimental building of study area, in which a sharp increment of expenditures has been registered. These costs include technical and legal support, construction and maintenance of GF mitigation measures and electricity consumption. Others GWLr-induced phenomena have been recognised, as ground vertical deformation and variations of the groundwater contamination. A relationship between GWLr and ground uplift emerges from the coupled analysis of piezometric and interferometric data, referred to the 1989-2013 period. The ground deformation occurs in response to the recovery of pore-pressure in the aquifer system, reaching an uplift magnitude up to 40-50 mm. In the 1989-2017 period, the piezometric levels and the concentrations of some natural contaminants in groundwater (Fe, Mn, fluorides) show opposite trends, conversely the same rising trend has been observed with nitrates. These different responses to piezometric rise are related to the lack of mobilization of deep fluids due to the interruption of pumping and to the reduction of the surficial contaminants' time travel caused by a shorter thickness of the vadose zone. In the western sector of Phlegraean Fields, the naturally triggered GWLr has caused GF in the Cumae archaeological site for the last decade, threatening safeguard and conservation of the archaeological heritage. From an integrated hydrogeological, hydrochemical and isotopic survey, a considerable contamination of groundwater resulted, due to the presence of rising highly mineralized fluids, mobilized during pumping periods, and others anthropogenic sources of contamination. Lastly, a novel methodology for groundwater flooding susceptibility (GFS) assessment has been developed by using machine learning techniques and tested in the eastern plain of Naples. Points of GF occurrence have been connected to environmental predisposing factors through Spatial Distribution Models' algorithms to estimate the most prone areas' distribution. Ensemble Models have been carried out to reduce the uncertainty associated with each algorithm and increase its reliability. Mapping of GFS has been realized by dividing occurrence probability values into five classes of susceptibility. Results show an optimal correspondence between GF points' location and the highest classes (93% of GF points falls into high and very high classes). The results of this research provide new knowledge on the GWLr phenomenon that has impacted a large territory of the Metropolitan City of Naples. The methodological approach used can be exported in others hydrogeological contexts to characterize GWLr and its impacts. In addition, the implemented GFS methodology represents a new tool to assist local government authorities, planners and water decision-makers in addressing the problems deriving from GF, and a first step for the evaluation of GF risk as required by Italian and European legislation

Analyses of groundwater contribution to a riverine wetland

Rainfall, runoff, overbank flow and groundwater, all contribute water to wetlands. Each transport element is associated with unique modeling approaches and uncertainties. Transpiration is perhaps the hardest to quantify as it is subject to all the variability of plant growth. Transpiration causes land area to lose moisture and the loss amount depends on precipitation incidence, the temperature and type and extent of vegetation. Plants can intercept virtually all recharge during the growing season and almost none from late fall to early spring in northeastern United States. Thus, an improvement in the transpiration element can contribute considerably to an improved groundwater contribution estimate of the wetland water budget. The study site is a riverine wetland at Monmouth Battlefield State Park in Manalapan, New Jersey. Using USGS MODFLOW, a simulation is adapted to the site specific conditions of geology (from in-situ permeability tests), topography (from surveyed elevations and also USGS Topo Map) and vegetation (by assigning different evapotranspiration coefficients to different vegetation covers). Hydrologic factors (i.e. rain data) are reflected in the model. Simulation product is validated using the collected data from monitoring wells. The final product is a wetland hydrologic model for a highly localized prediction of groundwater contribution to a wetland’s water budget capable of estimating evapotranspiration. It was concluded that from 1709 millimeters (mm) of precipitation over modeling period (May 2012 to August 2013), 1000 and 835 mm or a daily average of 2.0 and 1.7 mm/day were lost to the atmosphere through evapotranspiration for forest and farm side of the study area, respectively

Proceedings of the joint Russian-American hydrogeology seminar

Hydrogeology research has been very active in both Russia and the US because of the concerns for migration of radioactive and chemical contaminants in soils and geologic formations, as well as for water problems related to mining and other industrial operations. Russian hydrogeologists have developed various analysis and field testing techniques, sometimes in parallel with US counterparts. These Proceedings come out of a Seminar held to bring together a small group (about 15) of active Russian researchers in geologic flow and transport associated with the disposal of radioactive and chemical wastes either on the soils or through deep injection wells, with a corresponding group (about 25) of American hydrogeologists. The meeting was intentionally kept small to enable informal, detailed and in-depth discussions on hydrogeological issues of common interest. Out of this interaction, the authors hope that, firstly, they will have learned from each other and secondly, that research collaborations will be established where there is the opportunity. This proceedings presents the summaries and viewgraphs from the presentations. What cannot be conveyed here is the warm and cooperative atmosphere of these interactions, both inside and outside the formal sessions, which may well lead to future collaborations