scholarly journals IMPACT OF LAND DRAINAGE ON THE RIVERS RUNOFF/PERIODIŠKAI ŠLAPIU ŽEMIU SAUSINIMO DRENAŽU ITAKA UPIU NUOTEKIUI/ВЛИЯНИE ОСУШЕНИЯ ДРЕНАЖЕМ ПЕРИОДИЧЕСКИ ИЗБЫТОЧНО УВЛАЖНЯЕМЫХ ЗЕМЕЛЬ НА РЕЧНОЙ СТОК

2009 ◽  
Vol 17 (4) ◽  
pp. 226-235 ◽  
Author(s):  
Antanas Lukianas ◽  
Rasa Ruminaitė
Keyword(s):  
River Basin ◽  
Spring Flood ◽  
Wetland Area ◽  
Drainage Systems ◽  
Wetland Drainage ◽  
Land Drainage ◽  
River Basin District ◽  
Summer Rain ◽  
Rain Floods

The dependence of runoff characteristics of the Lielupe River basin district rivers: the Mūša River, the Levuo River and the Tatula River on the wetland drainage is analysed in the article. The wetland covers 70–89% of the total area in the basins of these rivers. It was established, that drainage of 80–91% of wetland area had not changed the runoff characteristics. The excess of water is removed through the drainage systems most intensively during spring and summer rain floods. The analysis of the runoff of spring flood and summer rain floods revealed that the area of drained land had not changed the runoff characteristics. The tenuous positive or negative relations (coefficients of correlation from ‐0.52 to 0.19) between the area of drained wetland and the runoff characteristics were established. Santrauka Šlapių žemių sausinimo Lietuvoje įtaka upių nuotėkiui iki šiol vertinama nevienareikšmiškai, nes ji gana sudėtinga ir įvairiapusė. Straipsnyje analizuojama Lielupės baseino upių Mūšos, Lėvens ir Tatulos nuotėkio charakteristikų priklausomybė nuo periodiškai šlapių žemių sausinimo drenažo sistema. Šių upių baseinuose periodiškai šlapių mineralinių žemių plotai sudaro 70–89 % viso baseino ploto (pelkės užima tik 3,2–7,5 %). Analizuota sausinimo, nuotėkio bei jo pasiskirstymo per metus kaitos charakteristikos, nuotėkio netolygumo dėsningumai. Tiriant nustatyta, kad per pastaruosius 40 metų nagrinėjamų upių baseinuose nusausintų žemių plotai padidėjo nuo 4–7 % (šlapių žemių fondo) iki 80–91 %. Vandens perteklius iš sausinimo sistemos pasišalina per pavasario potvynius bei vasaros poplūdžius. Analizuojant pavasario potvynių ir vasaros poplūdžių duomenis akivaizdu, kad nusausintų žemių plotas neturi įtakos upių nuotėkio charakteristikų pokyčiui. Tarp nusausintų žemių ploto ir nuotėkio charakteristikų nustatytos labai silpnos teigiamos arba neigiamos sąsajos (koreliacijos koeficientai nuo –0,52 iki 0,19). Резюме Влияние осушения избыточно увлажненных земель на речной сток в Литве до сих пор оценивается неоднозначно, так как это влияние сложно и многообразно. В статье анализируются характеристики изменения речного стока и его внутригодового распределения, закономерности его неравномерности в бассейнах рек Муша, Левуо и Татула (эти реки составляют район речных бассейнов Лелупе), в которых периодически избыточно увлажняемые земли составляют 70−89% от площади бассейнов. Исследованиями установлено, что площади осушенных земель в исследуемых речных бассейнах за последние 40 лет увеличились с 4−7% (от фонда избыточно увлажненных земель) до 80−91%. Несмотря на то, что большая часть избыточно увлажненных земель уже осушена, это не оказывает существенного влияния на речной сток. Избыток влаги осушительными системами наиболее интенсивно удаляется в течение весенних половодий и летних паводков, поэтому изменения речного стока из-за осушения происходят в течение тех же сезонов. При анализе зависимости изменения слоя речного стока в течение весенних половодий и летних паводков (в долях от годового стока) от площади осушения установлено отсутствие корреляционной связи, либо эта связь является слабой (коэффициенты корреляции изменяются от −0,52 до 0,19).

scholarly journals Features of the Spring Flood Formation in the Arpa River Basin

2021 ◽  
pp. 126-152
Author(s):  
Keyword(s):  
River Basin ◽  
Weighted Average ◽  
Close Correlation ◽  
Annual Runoff ◽  
Average Height ◽  
Spring Flood ◽  
Correlation Relationship ◽  
Catchment Areas ◽  
The Mean ◽  
Maximum Runoff

The article considers main physical and geographical factors affecting the runoff, spring flood of rivers in the Arpa River basin, and analyzes the regularities of their spacetime distribution. The authors have obtained correlation relationship between the values of the flood runoff layer, the mean module maximum runoff and weighted average height of the catchment area of the Arpa River, between the mean annual maximum runoff module for the period floods and catchment areas of rivers. These dependencies can be used for preliminary estimates of the spring flood runoff of unexplored rivers of the territory under consideration. A close correlation between the values of the annual runoff and the runoff of the spring flood in the section of the Arpa River – Dzhermuk has been also revealed. It can be used for forecasting the annual flow.

The «rainfall-runoff» system and its long-term fluctuations in the Siverskyi Donets River Basin (Ukraine)

2021 ◽  
Author(s):  
Hanna Bolbot ◽  
Vasyl Grebin
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
River Basin ◽  
Air Temperature ◽  
River Runoff ◽  
Annual Runoff ◽  
Annual Precipitation ◽  
Spring Flood ◽  
Current Period

<p>The current patterns estimation of the water regime under climate change is one of the most urgent tasks in Ukraine and the world. Such changes are determined by fluctuations in the main climatic characteristics - precipitation and air temperature, which are defined the value of evaporation. These parameters influence on the annual runoff distribution and long-term runoff fluctuations. In particular, the annual precipitation redistribution is reflected in the corresponding changes in the river runoff.<br>The assessment of the current state and nature of changes in precipitation and river runoff of the Siverskyi Donets River Basin was made by comparing the current period (1991-2018) with the period of the climatological normal (1961-1990).<br>In general, for this area, it was defined the close relationship between the amount of precipitation and the annual runoff. Against the background of insignificant (about 1%) increase of annual precipitation in recent decades, it was revealed their redistribution by seasons and separate months. There is a decrease in precipitation in the cold period (November-February). This causes (along with other factors) a decrease in the amount of snow and, accordingly, the spring flood runoff. There are frequent cases of unexpressed spring floods of the Siverskyi Donets River Basin. The runoff during March-April (the period of spring flood within the Ukrainian part of the basin) decreased by almost a third.<br>The increase of precipitation during May-June causes a corresponding (insignificant) increase in runoff in these months. The shift of the maximum monthly amount of precipitation from May (for the period 1961-1990) to June (in the current period) is observed.<br>There is a certain threat to water supply in the region due to the shift in the minimum monthly amount of precipitation in the warm period from October to August. Compared with October, there is a higher air temperature and, accordingly, higher evaporation in August, which reduces the runoff. Such a situation is solved by rational water resources management of the basin. The possibility of replenishing water resources in the basin through the transfer runoff from the Dnieper (Dnieper-Siverskyi Donets channel) and the annual runoff redistribution in the reservoir system causes some increase in the river runoff of summer months in recent decades. This is also contributed by the activities of the river basin management structures, which control the maintenance water users' of minimum ecological flow downstream the water intakes and hydraulic structures in the rivers of the basin.<br>Therefore, in the period of current climate change, the annual runoff distribution of the Siverskyi Donets River Basin has undergone significant changes, which is related to the annual precipitation redistribution and anthropogenic load on the basin.</p>

scholarly journals Using citizen science to improve the conservation of the European Eel (Anguilla anguilla) in the Thames River Basin District

2019 ◽  
Vol 38 (2) ◽  
pp. 281-291 ◽  
Author(s):  
Joe P. Pecorelli ◽  
Kirsty H. Macphie ◽  
Charlotte Hebditch ◽  
Darry R. J. Clifton-Dey ◽  
Ian Thornhill ◽  
...  
Keyword(s):  
Citizen Science ◽  
River Basin ◽  
Anguilla Anguilla ◽  
European Eel ◽  
River Basin District ◽  
Thames River

Estimation of the annual runoff distribution of the Siverskyi Donets River Basin in the period of current climate change

2020 ◽  
Author(s):  
Hanna Bolbot ◽  
Vasyl Grebin
Keyword(s):  
Climate Change ◽  
River Basin ◽  
Annual Runoff ◽  
Low Flow ◽  
Left Bank ◽  
Spring Flood ◽  
Current Period ◽  
Current Climate ◽  
Annual Runoff Distribution ◽  
The Right

<p>The most urgent tasks facing hydrologists of Ukraine and the world include identifying patterns of rivers hydrological regime against the background of global warming, and assessing these changes. Changes in the annual runoff distribution under climate change impact require separate investigation of anthropogenically altered catchments, such as the Siverskyi Donets River Basin. Siverskyi Donets is the largest river in Eastern Ukraine and the main source of water supply for Kharkiv, Luhansk and Donetsk regions.</p><p>The annual runoff distribution of the Siverskyi Donets River Basin was evaluated by two periods: to the beginning of pronounced climatic changes and the current period. The research is proposed for three water year types: wet year, average year and dry year. The Siverskyi Donets Basin is a complicated water body with peculiar physico-geographical conditions, because of that annual runoff distribution is somewhat different for the left-bank tributaries, right-bank tributaries and, in fact, the Siverskyi Donets River itself.</p><p>It is found that the most runoff of the wet year for both periods is in the spring months. The current period is characterized by a much smaller runoff of spring flood (from the volume of annual runoff) than in the previous period. The annual runoff distribution is offset. Some differences can be observed between the left and right tributaries. For the left-bank tributaries, which has less anthropogenic load, climate change has led to a significant increase of winter and summer-autumn low flow periods. On the right tributaries of the Siverskyi Donets, which are flowing within the industrial part of the Donbass, the low flow period has not changed, or even decreased. Such situation is due to the decrease of mine water disposal because of the industrial production decrease in the region.</p><p>The largest part of the annual runoff in the average year falls on February and March. In the current period, the spring flood has decreased, but the summer and autumn low flow period has increased. The left-bank tributaries runoff during the winter low period is decrease. Instead, the runoff attributable to the autumn and winter low period has increased for the right-bank tributaries and the Siverskyi Donets itself.</p><p>Analyzing the runoff distribution of dry year, we can conclude that the most wet is February. At present, in dry years, spring flood practically are not allocated from the hydrograph; the baseflow months runoff significantly increased. The volume of winter runoff of the Siverskyi Donets River Basin is increased. Actually, for the Siverskyi Donets River the runoff of the summer period has increased and the runoff of the winter and autumn periods has decreased at the present stage.</p><p>The annual runoff distribution of the Siverskyi Donets River Basin in the current climate change has undergone significant changes: the spring flood has decreased and the summer-autumn low flow has increased.</p>

Cost-Benefit Analysis of Wetland Drainage

1983 ◽  
Vol 15 (2) ◽  
pp. 227-235 ◽  
Author(s):  
J K Bowers
Keyword(s):  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
Benefit Analysis ◽  
Agricultural Improvement ◽  
Wetland Drainage ◽  
Project Appraisal ◽  
Land Drainage ◽  
Imminent Threat ◽  
Agricultural Yields ◽  
Second Use

The wetland areas of England are under imminent threat of drainage for agricultural improvement. The immediate cause is the local drainage surveys produced under the Water Act 1973. Problems identified in these surveys are subjected to cost-benefit appraisal. Examination of a selection shows that these appraisals are technically defective and result in an overstatement of the benefits and in an overinvestment in land drainage. The main defects are: first, a failure to assess amenity and conservation losses; second, use of prices that contain a substantial element of income transfer which is not netted out; third, a failure to properly calculate the rate of land conversion—a crucial variable; fourth, the project appraisal period is arbitrarily chosen or treated as a variable; fifth, the use of theoretical rather than expected agricultural yields; sixth, the level of flood protection aimed at is too high for the stated objective; and, last, anticipated flood losses are not deducted.

Sign in / Sign up

Export Citation Format

Share Document