Micha Klein

Anti clockwise hysteresis in suspended sediment concentration during individual storms: Holbeck catchment; Yorkshire, England

Abstract Analysis of the flow sediment hysteresis shape may assist in determining the sediment source area in a small basin. A clockwise hysteresis occurs when sediment is derived from the bed and banks of the channel or areas adjacent to the channel, whereas an anti-clockwise hysteresis occurs when the upper part of the slopes is the sediment source area.

Fluvial adjustment of the Lower Jordan River to a drop in the Dead Sea level

Water utilization in the upper part of the Jordan Basin has led to a significant reduction in inflow to the Dead Sea. Over the last 70 years, a drop of about 22 m in mean sea level has occurred and has resulted in a continual adjustment of the Lower Jordan River. The impacts of this lowering on the channel morphology of the Lower Jordan River were examined using aerial photographs. Until the late 1970s, the drop in the sea level was small but still led to channel extension. Since the early 1980s, a rapid drop in sea level took place leading to major changes in channel morphology and deep incisions. The greatest change in channel width was recorded near the river mouth. Between 1850 and 1980, there were only insignificant changes in channel sinuosity, but subsequently, a 25% increase of channel sinuosity has been recorded. Most of changes in the channel sinuosity were recorded in the newly exposed area. Over the last 30 years, the active channel width has narrowed by almost four times. Until the late 1980s, the channel was relatively stable with minor bank collapses and only one bar detected near the Jisr Abdallah. During the 1990s, a number of bars developed along the channel. The downcutting is in parallel with the sea level drop resulting in the development of terraces along the lower part of the study reach. In 1983, the channel incision reached 8 km upstream and by 1993 it was about 11 km.

Rate of sedimentation in Lake Kinneret, Israel: spatial and temporal variations

The rate of sedimentation in Lake Kinneret was measured over several years by means of sediment traps, in up to seven different locations in the lake. Gross sedimentation rates measured in the sediment traps vary from about 1·5 kg m−2 a−1 in the deepest part of the lake up to 10 kg m−2 a−1 near the mouth of the upper Jordan river. The rate of sedimentation near the Jordans inflow is highly correlated to flow discharge in the river, while in the centre of the lake the seasonal sedimentation pattern is mainly correlated to the bloom period of Peridinium gatunense. During the bloom period of Peridinium gatunense sedimentation rates all over the lake are very similar, indicating that the Peridinium is evenly distributed in the lake. The average suspended sediment discharge of the upper Jordan river flowing into the lake is 41 000 ton a−1.Copyright

Water Balance of the Upper Jordan River Basin

Abstract Sharing water in the Jordan basin has been a key topic in the recent peace talks between Israel and its neighbors. Knowing the quantity of water available is a prerequisite to water sharing. Many different values have been published in recent years. Different sources report Jordans discharge flow into Lake Kinneret anywhere from 460 to 800 Mm3/year. The aim of this article is to present a water balance for the Jordan basin for a 15-year period. The years 1977–1978 to 1991–1992 were studied for the basins water budget, as they represent the present day (1998) land use. The results show that Lake Kinneret has a yearly average input (= output) of 770 Mm3. Israel uses some 800 Mcm3/year from the entire Jordan basin, of which 440 Mm3 is used within the basin and the rest outside. There is about 100 Mm3 for future utilization in the watershed. The yearly Jordans discharge to the Dead Sea is 220–250 Mm3. Reporting by various secondary data sources is compared to primary data findings to illustrate th...

Holocene evolution of the Haifa Bay area, Israel, and its influence on ancient tell settlements

The geographical evolution of Haifa Bay and Zevulun Plain, Israel, from the late Pleistocene to the Holocene, is based on detailed analysis of drilled cores. At the beginning of the Holocene the Bay area was still under terrestrial conditions. Only about 9500 to 9000 cal. yr BP, when sea level rose to about 35-30 m below present sea level (b.s.l.), did Nile-derived sand start to bypass the Carmel headland and Haifa Bay come into existence as a morphological feature. Between 8000 and 7150 cal. yr BP, when sea level was 14-10 m b.s.l., the invading sea crossed the present-day coastline. At about 6800 to 6600 cal. yr BP sea level rose to about 5 m b.s.l. and flooded the Zevulun Plain up to 2 km inland, and the River Qishon estuary up to 4 km inland. It is still unknown exactly when the sea reached its maximum penetration inland but later, about 4000 years ago, the coastline in the research area was still east of the present-day coast, up to 3 km in the Zevulun Plain and 4.8 km in the River Qishon estuary. When the coastline started to retreat westward, the reclamation was followed by intensive deposition of shallow marine sand and aeolian dunes, while to the east, different wetland conditions developed. The archaeological data indicate that during the Early Bronze Age I and Early Bronze Age II, dated to between 5600 and 4700 cal. yr BP, and even later, during the Middle Bronze Age II period, about 4600 to 3500 cal. yr BP, the coastline was still east of the present-day coast, but it never actually reached the bases of most of the tells, as has been suggested, except for Tel Akko and Tel Abu Hawam.

The environmental impact of marina development on adjacent beaches: a case study of the Herzliya marina, Israel

Abstract The objectives of this study were to identify coastal changes to the north and south of the Herzliya (Israel) marina using remote sensing techniques, and to compare them to the changes forecast by a physical model built by the Coastal and Marine Engineering Research Institute, at the Technion, Israel Institute of Technology, Haifa, Israel (CAMERI). The initial physical model output predicted coastal erosion north of the marina. The proposed solution to this problem was the building of detached breakwaters, complying with the planning demands and confined to the area studied. By adding such breakwaters, the model predicted soil accumulation and under-predicted the degree of erosion. It is clear from ground evidence that this solution only ‘pushed’ the area of erosion northward. The model also did not predict coastal erosion already occurring 750 m north of the marina and ignored any changes in the area south of the marina.

Sea-Level Changes in the Mediterranean: Past, Present, and Future – A Review

The study of geological and historical sea-level changes constitutes an important aspect of climate change and global warming research. In addition to the imminent hazards resulting from the inundation of low-lying areas along coastal regions, the rise in sea level can also cause erosion of beaches, salt intrusion into freshwater aquifers, and other damage to the coastal environment. The utmost importance of current changes in sea level is attributed to its impact on diverse ecological systems in coastal regions (Klein et al., 2004).

Sediment Transport along the Coast of Israel: Examination of Fluorescent Sand Tracers

Abstract The method of labeled natural sand particles was used to study sediment transport along the central Mediterranean coast of Israel. Six portions of 300 kg each were tagged with various fluorescent colors, and distributed at six different locations in the vicinity of the Herzliya Marina. The tagged sand was scattered at the end of autumn, and sampled three times during the winter. Sampling was interrupted in mid-January because of unexpected dredging at the marina canal entrance. The samples were analyzed at the Yigal Allon Kinneret Limnological Laboratory. The wave climate during that time was analyzed using wave data from Ashdod (40 km south). Wave directions measured in Ashdod were corrected to make them applicable to the Herzliya coast, in accordance with suggested directional shift values. Seven wave storms with significant wave heights of over 2.5 m were observed. Two of them clearly indicate a dominant direction from the southwest and two others from the northwest. However, the time durations and the relative angles between the wave directions and the orthogonal to the coast of the storms propagating from the southwest are essentially larger than those arriving from the northwest. The following results were noted: (i) The drift of tagged sand particles correlated to longshore sediment transport at all depths was in a northern direction throughout the field experiment. The longest distance of transport was 5 km over a period of 36 days. (ii) “Onshore” sediment transport was present; sand from 15 m depth was found at 8 m depth. (iii) The cross-shore sediment transport carried sand to a depth of 8 m, but no colored sand from shallow water (2–4 m) was found deeper than 8 m. (iv) Although sedimentation at the marina entrance during the experiment was high, only small amounts of tagged sand were found at the entrance. (v) Findings of tagged sand showed the main area of sedimentation to be along the marinas main breakwater.

Morphological changes of the artificial inlets of the Bardawil lagoon

Abstract The topographic changes in the shoreline around the artificial inlets of the Bardawil lagoon have been studied using aerial photographs. The amount of sediment dredged during the years 1970–1977 is about 50% of the amount predicted in 1970. It is suggested that the difference between the two is the result of the ‘new’ sediment budget of the South-East Mediterranean due to the effect of Asswan High Dam.

Morphological changes in the last 200 years in the mouth of the Na'aman River, northern coastal plain, Israel

Lichter, M., Zviely, D., and Klein, M. 2009. Morphological changes in the last 200 years in the mouth of the Na’aman River, northern coastal plain, Israel. Isr. J. Earth sci. 58: 63–80. The Na’aman River mouth is located in Haifa Bay, at the northern end of the Nile littoral cell of Israel’s Mediterranean coast. This study documents the morphological changes to this river’s mouth over the last 200 years based on three historical maps from 1799 to 1930 as well as a series of 54 aerial photographs taken between 1945 and 2005. Mapping of morphological features and vegetation cover in the vicinity of the changing mouth was performed with a Geographic Information System (GIS); quantitative and qualitative parameters were derived from this mapping. The temporal and spatial patterns of the mouth migration were characterized and factors influencing its morphology such as vegetation cover, stream discharge, wave regime, and anthropogenic changes were analyzed. The Na’aman River mouth intermittently flows in a permanent channel along the back of the north–south beach berm. The channel remains stable for several years until a major flood diverts it. The mouth migrated 1.5 km, both north and south, along the coast during the last 200 years, about equally in either direction. An increase in vegetation cover over the years restricted the migration of the channel. River floods may cause the “resetting” of the mouth morphology and its location, but if the channel is robust, even large floods are unable to divert it. Wave direction does not seem to af fect the deflection of the channel. Anthropogenic intervention in the natural course of the mouth took place in two ways: artificial opening of the mouth to prevent flooding hazard and control the mosquito habitat, and channel diversion intended to prevent the pollution of nearby bathing beaches.