scholarly journals Relation of change in water levels in surficial and Upper Floridan aquifers and lake stage to climatic conditions and well-field pumpage in Northwest Hillsborough Northeast Pinellas, and South Pasco counties, Florida

1992 ◽  
2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Hendri Irwandi ◽  
Mohammad Syamsu Rosid ◽  
Terry Mart

AbstractThis research quantitatively and qualitatively analyzes the factors responsible for the water level variations in Lake Toba, North Sumatra Province, Indonesia. According to several studies carried out from 1993 to 2020, changes in the water level were associated with climate variability, climate change, and human activities. Furthermore, these studies stated that reduced rainfall during the rainy season due to the El Niño Southern Oscillation (ENSO) and the continuous increase in the maximum and average temperatures were some of the effects of climate change in the Lake Toba catchment area. Additionally, human interventions such as industrial activities, population growth, and damage to the surrounding environment of the Lake Toba watershed had significant impacts in terms of decreasing the water level. However, these studies were unable to determine the factor that had the most significant effect, although studies on other lakes worldwide have shown these factors are the main causes of fluctuations or decreases in water levels. A simulation study of Lake Toba's water balance showed the possibility of having a water surplus until the mid-twenty-first century. The input discharge was predicted to be greater than the output; therefore, Lake Toba could be optimized without affecting the future water level. However, the climate projections depicted a different situation, with scenarios predicting the possibility of extreme climate anomalies, demonstrating drier climatic conditions in the future. This review concludes that it is necessary to conduct an in-depth, comprehensive, and systematic study to identify the most dominant factor among the three that is causing the decrease in the Lake Toba water level and to describe the future projected water level.


2001 ◽  
Vol 56 (3) ◽  
pp. 401-410 ◽  
Author(s):  
Bryan Shuman ◽  
Jennifer Bravo ◽  
Jonathan Kaye ◽  
Jason A. Lynch ◽  
Paige Newby ◽  
...  

AbstractSediment cores collected along a transect in Crooked Pond, southeastern Massachusetts, provide evidence of water-level changes between 15,000 cal yr B.P. and present. The extent of fine-grained, detrital, organic accumulation in the basin, inferred from sediment and pollen stratigraphies, varied over time and indicates low water levels between 11,200 and 8000 cal yr B.P. and from ca. 5300 to 3200 cal yr B.P. This history is consistent with the paleohydrology records from nearby Makepeace Cedar Swamp and other sites from New England and eastern Canada and with temporal patterns of regional changes in effective soil moisture inferred from pollen data. The similarities among these records indicate that (1) regional conditions were drier than today when white pine (Pinus strobus) grew abundantly in southern New England (11,200 to 9500 cal yr B.P.); (2) higher moisture levels existed between 8000 and 5500 cal yr B.P., possibly caused by increased meridonal circulation as the influence of the Laurentide ice sheet waned; and (3) drier conditions possibly contributed to the regional decline in hemlock (Tsuga) abundances at 5300 cal yr B.P. Although sea-level rise may have been an influence, moist climatic conditions during the late Holocene were the primary reason for a dramatic rise in water-table elevations.


Author(s):  
M. I. Romashchenko ◽  
M. V. Yatsyuk ◽  
A. M. Shevchenko ◽  
S. A. Shevchuk ◽  
O. M. Kozytsky ◽  
...  

Relevance of research. As a result of row of reasons of socio-economic character, there has been a decrease in volumes and a decrease in the efficiency of the use of drained land over the last two decades, primarily within river floodplains. The purpose of the study is to determine the prospects and problems of the development of reclaimed areas of the Irpin river floodplain under transformed climatic conditions and the nature of land use. Research methods - field surveys, monitoring observations of water levels in canals and groundwater levels, systematic and cartographic data analysis and hydrological calculations. Research results and main conclusions. Based on the research findings in the typical pilot territories of Irpin’s drainage-irrigation system (DIS), the current state and main problems of the use of drained lands within the Irpen’s river floodplain are characterized, as well as the prospects for the further development of reclaimed floodplain areas during the transformation of climatic conditions and land use are determined.  It has been established that significant factors influencing the decrease in the level of use of drained agricultural land of the floodplain for its intended purpose are the fragmentation of land shares, the limited financial capabilities of their owners, the nationwide tolerance for long-term non-use of reclaimed lands, as well as the tendency to increase the number of peat fires and floodplain buildings development. It was determined that the unsatisfactory technical condition of a significant part of the on-farm drainage canals of the Irpin’s DIS, the majority of hydrotechnical water control structures on them, siltation of the estuarine parts of closed drainage collectors and a decrease in the depth of its occurrence in areas with peat deposits due to their runoff, precipitation, mechanical removal and burning out ensuring a favorable water regime of soils and protection of the agricultural lands from flooding on the floodplain of the Irpin’s River without redesign or modernization of the DIS. It is noted that the perspective direction of the use of drained floodplain lands is the cultivation of berry crops with an application of drip irrigation. I It is determined that, taking into account the potential negative water and environmental consequences of housing, especially multi-story, floodplain development, its use as a town-planning resource should be geographically limited and aimed primarily at creating of recreational areas and to be carried out in compliance with the requirements of water and land legislation.


2020 ◽  
Vol 92 (1) ◽  
pp. 41-54
Author(s):  
Adam Choiński ◽  
Jerzy Jańczak ◽  
Ptak Mariusz

Water-level fluctuations are among the primary factors determining the functioning of lakes. The volume to which lake basins are filled with water is of major importance to the courses of many processes and phenomena. A particular amount of water in a lake, and water-table stability, are also important from the point of view of human activity, as these elements help determine the quantity and accessibility of the water resources lakes have to offer, and therefore the possibilities for them to be used by different branches of the economy, e.g. industry, agriculture or tourism. The work detailed here is thus a presentation of trends as regards water-level fluctuations in 16 lakes in Poland, over the period 1956–2015. The study results, obtained for the first time in relation to such a long time scale and extending to around a dozen lakes, aim to point to the scale and direction of water-level fluctuations in times of the intensive transformation of the natural environment. They were obtained by reference to water-level observations made by the Institute of Meteorology and Water Management – National Research Institute (IMiGW-PIB). Specifically, data referring to the (November-October) hydrological year were analysed for trends as regards mean annual water levels using the Mann-Kendall test. Results point to major variability in the courses noted for these levels over the analysed multiannual period. Nevertheless, three overall situations could be designated from within the group of cases analysed, i.e. increase, decrease or lack of a trend. The first group includes Lakes Sławskie, Jamno, Łebsko, Nidzkie, and Studzieniczne (where increases were statistically significant at p=0.05); the second, Lakes Ostrzyckie and Ełckie (decreases significant at p=0.05); and the last group all remaining lakes, i.e. Charzykowskie, Jeziorak and Rajgrodzkie, Biskupińskie, Drwęckie and Białe, Gopło, Roś, and Wigry. It was, however, noted that in many cases analysed periods of alternating increase and decrease in water level were to be observed. The causes of such fluctuations were complex, but inter alia reflected droughts of several years’ duration, periods featuring higher-than-average precipitation, and local conditions. In general, water-level fluctuations in lakes result from natural and anthropogenic factors determining the hydrological conditions in catchments. And in the context of the lakes considered here, the courses of water-level fluctuations were mostly a reflection of local, rather than wider climatic conditions – a fact i.a. illustrated by the lack of cohesive regional designations. The situation is different from that of, for example, the thermal or ice regimes of Polish lakes, in relation to which observed similarities in properties are seen to be determined mainly by climatic factors. Information of this kind may be of key importance to the (quantitative and qualitative) management of water resources in the context of the climate change being observed currently.


The Holocene ◽  
2020 ◽  
Vol 30 (7) ◽  
pp. 1029-1042 ◽  
Author(s):  
Binita Phartiyal ◽  
Randheer Singh ◽  
Priyanka Joshi ◽  
Debarati Nag

A multi-proxy study using mineral magnetism, sediment texture, total organic content, palynofacies and diatoms was conducted in one of the highest proglacial lake situated at North Pulu (5098 m a.s.l.) of Ladakh sector of NW Himalaya – a high-altitude cold arid desert. This study presents climatic variations that occurred between 5412 and 419 cal. yr BP (14C AMS chronology). Directly recharged by meltwater from Khardung glacier, this proglacial lake provides a complete record of past climatic variability due to continuous sedimentation and this attribute makes it an exceptionally important geochronological archive for climatic studies. This first high-resolution palaeolimnology record from Karakoram Himalayas shows intermittent warm and cold periods in which the cold events are short but sudden events recorded at 5700, 4600, 4400, 4200, 3800, 3500, 3000, 1800–1700, 1200, 910, 840 and 770–710 cal. yr BP. Between 5412 and 4840 cal. yr BP, an oxic lake condition existed with freeze–thaw action, prominent weathering, more sediment generation and less organic productivity. The following period till 4410 cal. yr BP was cold and dry, a transition phase to the next warmer phase. Between 4410 and 2064 cal. yr BP, climate ameliorated to somewhat moderate warm climate and relatively high lake levels. Glacial melting due to a warm climate resulted in high TOC%, and well-preserved OM indicating reducing conditions in the lake system. From 2064 to 1711 cal. yr BP cold conditions and from 1272 to 1182 cal. yr BP warmer conditions are seen with large appearance in Amphora ovalis indicating increased nutrients input and moderate water levels. This was followed by warmer climatic conditions between 1182 and 958 cal. yr BP. LIA in the region is experienced between 958 and 644 cal. yr BP with anoxic condition. Between 644 and 419 cal. yr BP, climatic condition was again warmer comparatively. However, this warming was not so severe and only had a regional impact.


1993 ◽  
Vol 40 (3) ◽  
pp. 343-350 ◽  
Author(s):  
Annie Vincens ◽  
Françoise Chalié ◽  
Raymonde Bonnefille ◽  
Joel Guiot ◽  
Jean-Jacques Tiercelin

AbstractPalaeoclimatic estimates of mean annual temperature and rainfall in the southern Tanganyika basin between 25,000 and 9000 yr B.P. have been established from two pollen sequences based on the best-analogue method. The results give evidence of a mean temperature decrease of about 4.2°C during the last glaciation, a value consistent with that previously obtained in the catchment area on the Burundi Highlands. This cooling was synchronous with a decrease of mean annual precipitation of about 180 mm/yr. Postglacial climatic conditions were established by 12,700 yr B.P., with warming and wetness continuing to increase from this date onward. These new palaeoclimatic data will be useful for hydrological reconstructions of Lake Tanganyika, particularly during the last glacial age for which the magnitude of water-level fall has been a controversial issue; our rainfall estimates are more consistent with low values (-250 to -300 m fall) than with high ones (-600 m) previously proposed.


2020 ◽  
Vol 21 (5) ◽  
pp. 589-596
Author(s):  
O. V. Balun

The article deals with the problem of stable operation of various structures of drainage systems on heavy soils in the natural and climatic conditions of the Novgorod region during the first years after construction and after 30 years of operation. The experiment examines the effectiveness of drainage using shallow drainage structures with the depth of 70 cm and two variants of medium-deep drainage (110 cm) with filling the drainage trench with sand-gravel mixture (PGS) and wood chips to the arable horizon. Analysis of groundwater dynamics showed that the rate of groundwater decline in the early spring period in the first years of operation on all experimental variants was approximately the same: 2.0-2.4 cm/day. In recent years in the shallow drainage variant, the decrease in ground water levels occurred more slowly (2.3 cm/day) compared to the standard drainage variants (3.8-3.9 cm/day). The average humidity of the root layer of the soil during the growing season in experimental closed drainage systems has not increased for 30 years. The average moisture reserves for the growing season in the experimental systems were: 177 mm in the shallow drainage variant in 1991, 168 mm in 2018; 165 and 154 mm for the standard drainage with drainage chips backfill, respectively; 164 and 123 mm in the PGS backfill variant, respectively. The highest reliability and durability were shown by collectors with PGS backfill of the drainage trench, which have maintained a consistently high efficiency over a thirty-year period. During the drought period, shallow drainage systems provided more favorable conditions according to the degree of moisture in the root layer: in 2018, the shortest period of moisture lack in the root layer of the soil (10 days) was observed in shallow drainage systems, and the longest (1 month) - in systems with backfill of the drainage trench with PGS.


2006 ◽  
pp. 72-75
Author(s):  
György Szuhányi

Subcarpathia is one of the richest regions in surface waters in the Ukraine. Due to its geographical, relief and climatic conditions, it belongs to the active precipitation zone, where great floods frequently occur. As a result of many years of observation, it can be concluded that the interactions of many natural factors can lead to various floods in the catchment area of the river Tisza. These are mostly hydro-meteorological factors, which can lead to great floods with the characteristics of the formed flow. Human activity also significantly influences the occurance of floods: clearing, which can accelerate the process of the runoff, ploughing in the catchment area, which can lead to erosion and the utilisation of areas endangered by floods for various economic sectors.A series of questions arose in recent years regarding the formation of floods: what could be the causes of floods and what actions need to be made to prevent them. The evaluation of floods made us conclude that passive protection by using dams does not always ensure protection against floods as these were constructed in different times for different water levels. Many factors can affect the whole process which cannot be foreseen, therefore the development of new solutions and new technologies is necessary in flood protection.


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