A Spatial And Statistical Assessment Of The Vulnerability Of Texas Groundwater To Nitrate Contamination

Nitrate concentrations in Texas water wells are analyzed using spatial and statistical representations.

The Chernobyl Nuclear Power Plant (NPP) disaster that occurred in Ukraine on April 26, 1986, was one of the most devastating in human history. Using this as a case study, the AGU monograph Groundwater Vulnerability: Chernobyl Nuclear Disaster is devoted to the problem of groundwater vulnerability, where the results of long-term field and modeling investigations of radionuclide transport in soil and groundwater, within the Ukrainian part of the Dnieper River basin (Kyiv region of Ukraine), are discussed. The authors provide a comprehensive review of existing literature on the assessment of groundwater vulnerability and then describe an improved methodology, which is developed based on integration of the methods of hydrogeological zonation and modeling of anomalously fast migration of radioactive contaminants from the land surface toward groundwater. This volume also includes the evaluation of the effect of preferential and episodic flow on transport of radionuclides toward the aquifers and risk assessment of groundwater vulnerability, which can further assist future researchers in developing remediation technologies for improving drinking water quality. Further, this volume sheds light on the consequences of groundwater contamination from nuclear disasters and assists with assessing the risks associated with contamination and developing effective remediation technologies. Volume highlights include discussions of the following: Assessment of groundwater vulnerability to contamination from the Chernobyl nuclear disaster Novel analytical results of the 25-year investigations of groundwater contamination caused by Chernobyl-born radionuclides The wealth of data on different modes of radioactive transport in the atmosphere, water, and soils, and along the food chains The hydrogeological and physico-chemical processes and factors in groundwater contaminated zones The applicability of commonly used methods of the evaluation of groundwater vulnerability A unique method of fluid dynamics that involves an anomalously fast migration of contaminants through zones of preferential flow from the land surface toward groundwater Building confidence in the assessment of migration pathways of radionuclides in the biosphere Assessment and prediction of the consequences of the nuclear accident, which can shed light on protection from global nuclear accidents Analogue information for different nuclear waste disposal and environmental projects around the world

This guide will help resource managers, planners, and other decision makers better understand and assess water supplies and to define and manage protection areas for water sources. Developed for those who are interested in water resources, it can easily be used as text material for educational short courses.

Groundwater is an integral piece of California's groundwater resources. One of the most common contaminants present in groundwater is nitrate. Nitrate contamination is often a result of agricultural land use activities on the ground surface. The study area for this analysis is the Salinas Valley Groundwater Basin, an agriculturally dominated basin in coastal California. The Salinas Valley Basin is both one of the most agriculturally productive areas of the state, as well as one of the most nitrate-contaminated basins in the state. The purpose of this research was to develop a groundwater vulnerability map for nitrate pollution in the Salinas Valley. A groundwater vulnerability assessment was carried out using a modified DRASTIC model. DRASTIC is a U.S. EPA rank-sum model for assessing groundwater vulnerability that incorporates depth to water, net recharge, aquifer media, soil media, topography, impact of the vadose zone, and hydraulic conductivity. In order to modify the DRASTIC model to assess nitrate contamination specifically, a land use parameter was incorporated into the model. The results of this assessment found 2.9% of the Basin has very low vulnerability, 50.6% has low vulnerability, 42.9% has moderate vulnerability, and 3.6% has high vulnerability. The results of the groundwater vulnerability assessment could not be validated using measured nitrate concentrations in the Basin. Four possible reasons for the poor fit of this assessment have been identified: (1) the temporal variability of select DRASTIC parameters, (2) the inability of the land use parameter to accurately represent nitrate vulnerability, (3) the high spatial variable of nitrate contamination in the Basin, and (4) the static weights assigned to parameters by the DRASTIC model.

Geomorphology, geology and minerals, and livestock management are assessed together with regional land use and land use planning; and the overall biodiversity of the region is described. Complementary to environmental studies are social studies of the health, nutrition, employment, livelihood and disability status of the population. The Badia Programme has been able to combine modern approaches to information gathering (including techniques such as remote sensing) with the traditional knowledge of the Bedouin as twin cornerstones to achieving an understanding of the geography of this important and characteristic region of the Middle East. In the words of the project leaders 'We are learning that fragile as desert systems may be, they remain robust in terms of their ability to respond to change'. The result is, if not a textbook, a rich source of reference in human geography that will be useful to teachers and students.