Israel's Coastal Research Articles

Intensively exploited Mediterranean aquifers: resilience to seawater intrusion and proximity to critical thresholds

Abstract. We investigate seawater intrusion in three prominent Mediterranean aquifers that are subject to intensive exploitation and modified hydrologic regimes by human activities: the Nile Delta, Israel Coastal and Cyprus Akrotiri aquifers. Using a generalized analytical sharp interface model, we review the salinization history and current status of these aquifers, and quantify their resilience/vulnerability to current and future seawater intrusion forcings. We identify two different critical limits of seawater intrusion under groundwater exploitation and/or climatic stress: a limit of well intrusion, at which intruded seawater reaches key locations of groundwater pumping, and a tipping point of complete seawater intrusion up to the prevailing groundwater divide of a coastal aquifer. Either limit can be reached, and ultimately crossed, under intensive aquifer exploitation and/or climate-driven change. We show that seawater intrusion vulnerability for different aquifer cases can be directly compared in terms of normalized intrusion performance curves. The site-specific assessments show that (a) the intruding seawater currently seriously threatens the Nile Delta aquifer, (b) in the Israel Coastal aquifer the sharp interface toe approaches the well location and (c) the Cyprus Akrotiri aquifer is currently somewhat less threatened by increased seawater intrusion.

PLEISTOCENE LANDSNAILS FROM THE COASTAL PLAIN OF ISRAEL

ABSTRACT The landsnail fauna of five fossil layers from two sites in Israel's Coastal Plain, Shefayyim and Netanya, was analyzed. The layers date from about 45,000 years ago to Subrecent. Four species were found: The Jaminia ovularis-sulcidens complex, Trochoidea (Xerocrassa) davidiana, Xeropicta vestalis and Monacha syriaca—all present in the Coastal Plain today. Remarkable is the absence from all fossil layers of Theba pisana, the landsnail most abundant today in the Coastal Plain. As T. pisana has also not been found in any other Pleistocene sites in Israel, it is suggested that this species was introduced into Israel during historic times. Thereafter, competition with Xeropicta vestalis was inevitable, as both occupy a similar habitat. Rich morph diversity occurs in recent Xeropicta as compared with the fossil samples; it is tempting to suggest that this outburst of diversity is related to some ecological displacement into which Xeropicta was perhaps forced, due to competition with Theba. Within Jamin...

Settlement Fluctuations and Environmental Changes in Israel's Coastal Plain During the Early Bronze Age

The possibility of a decline of settlement in the coastal plain during the urban phases of the Early Bronze Age has been noted in passing by many researchers, but as these were usually working on a local or regional scale, the evidence has not yet been addressed systematically. In the present paper, we seek to quantify the extent of this decline, and attempt to explain it, by linking the archaeological data to climatic evidence which seems to point to environmental change at that time. In particular this took the form of increased precipitation which would have intensified existing drainage problems leading to increased flooding and the transformation of arable land into unhealthy marshland, which would have encouraged a decline in human settlement activity. We propose that these processes are responsible for the fact that the 'urban revolution' of the Early Bronze Age (characterized by large, densely occupied, fortified and relatively complex settlements) appears to have by-passed much of the coastal plain, where such developments are not attested before the 2nd millennium BC.

Qualitative hydrological and land-use planning tool for the Israel Coastal aquifer

Due to a variety of past and present land-usages on the aquifer ground surface, appropriate groundwater management should consider anthropogenic activities on the ground surface and the potential of unsaturated zone media to convey water and pollutants to the aquifer. The objective of this paper is to present an approach which generates guidelines and recommendations which can lead to sustainable development. This method assesses the lithological characteristics of the aquifer's vadose zone, indicating potential rechargeability, while weighting factors leading to potential groundwater pollution resulting from some land-use. Recommendations regarding land-use planning and aquifer recharge can then provide a qualitative ecological tool towards sustainable groundwater management. Owing to its location, its critical significance to the country's fresh water supply, and its available field data, Israel's Coastal aquifer is employed here as the study area for implementation of this approach.

The ‘principal components’ statistical method as a complementary approach to geochemical methods in water quality factor identification; application to the Coastal Plain aquifer of Israel

In general, Schoeller and Piper diagrams, as well as other classical techniques, facilitate the description of the various geochemical groups of water, and help to explain quality changes in an aquifer. We propose the use mainly of ‘principal components’ analysis for identification of relevant groups of water and the factors that bring about a change in their quality. The major advantage of this method is its suitability for simultaneous analysis of a great number of variables and observations. It is here being applied for the investigation of the Dan metropolitan region of Israel's Coastal Plain. The variables involved include major ions as well as the physical factors of depth of the well intake filter below sea-level, distance from the sea, and aquifer recharge. The primary purpose of this work is to demonstrate the use and reliability of principal components analysis (PCA) as a method complementary to classical approaches for hydrogeochemical research. Subsidiary purposes involve determination of the major water groups characterizing the Coastal Plain aquifer, identification of some of the principal variables that influence changes in water quality in the aquifer, and description of some of the geochemical phenomena contributing to change in aquifer water quality. The following results were achieved for the test area: 1. (1) Two major groups of water were identified: a low-salinity, calcium bicarbonate water occurring in the phreatic portion of the Coastal Plain aquifer, and a more saline, sodium chloride water characterizing the neighboring Cenomanian aquifer and the confined portions of the Coastal Plain aquifer. 2. (2) The major water input sources, such as rain, injection water, waste water, irrigation, etc., may vary in their influence upon resulting water quality; this water quality is affected by such physical factors as distance from the sea, depth of well intake filters below sea-level, proximity to streams and the lithology of the saturated and unsaturated zones. 3. (3) The evolutionary alteration in content of specific ions with time can be clearly visualized on the same graph by means of PCA. The universal applicability of such a statistical approach to other hydrological settings is noted.

Water Quality Factor Identification by the “Principal Components” Statistical Method

This paper proposes the means of using the “Principal Components” statistical method for identifying relevant groups of water and the factors that bring about a change in their quality. The major advantage of this method lies in its suitability for simultaneous analysis of a great number of variables and observations.It is here being applied for the investigation of Dan metropolitan region of Israel's Coastal Plain. The various parameters involved include major ions as well as the physical factors of depth to the water table, distance from the sea, and aquifer recharge. Results include:–the identification of two major groups of water: low salinity, calcium bicarbonate water occurring in the phreatic portion of the Coastal aquifer; and more saline, sodium chloride water characterizing the neighboring Cenomanian aquifer and the confined portions of the Coastal aquifer;–influence by distance from the sea, depth to water table, and aquifer lithology on the major water input sources, such as rain, injection water, waste water, irrigation, etc.–affect by such lithological factors as clay lenses which contribute to water quality changes as indicated by disequilibrium in several ionic ratios upon water resource management; and–clear visualization on the same graph of evolutionary alteration in specific ion content with time.

Settlement and Demographic Processes in Israel's Coastal Plain from the Chalcolithic to the Middle Bronze Age

This study of Israel's coastal plain goes beyond previous settlement and demographic discussions of ancient Palestine in several respects. It considers not only population totals for each period, but also their spatial distribution. Then it relates the empirical discussion on demography and settlement to various theories of sociocultural change that until now have not been applied to the region in the Chalcolithic and Middle Bronze Ages. After elaborating the details of the settlement and demographic changes from the Chalcolithic to MB II, this article suggests that the first urban culture in the Early Bronze Age emerged, to a large extent, in line with a Boserupian conception that population growth initiates a sociocultural transformation. In contrast, the second urban transformation, at the beginning of the Middle Bronze Age, seems to have been a more Malthusian one, in the sense that the urban transition increase.

Chloride concentration in groundwater, recharge rate and rate of deposition of chloride in the Israel Coastal Plain

The paper describes a study of the possibility of using chloride concentrations in groundwater for estimating recharge rates, the application being demonstrated on available data from the Coastal Plain Aquifer in Israel. The method can be applied where deposition rates of airborne chloride is known provided the matrix of the aquifer does not contain chloride. This condition would generally hold for more permeable aquifers where relicts of marine waters were washed out long ago.

Physical Master Plan of the Israel Coastal Strip

Physical Master Plan of the Israel Coastal Strip