scholarly journals TRANSFORMATION OF RIVER RUNOFF IN PERMAFROST ZONE OF THE CENTRAL SIBERIA UNDER VARIOUS SCENARIOS OF FOREST COVER AND CLIMATE CHANGE

2021 ◽  
Keyword(s):  
Climate Change ◽  
River Runoff ◽  
Forest Cover ◽  
Permafrost Zone ◽  
Central Siberia

scholarly journals Zonal aspects of the influence of forest cover change on runoff in northern river basins of Central Siberia

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
A. Onuchin ◽  
Т. Burenina ◽  
А. Shvidenko ◽  
D. Prysov ◽  
A. Musokhranova
Keyword(s):  
River Runoff ◽  
Catchment Area ◽  
Forest Cover ◽  
River Basins ◽  
Forest Vegetation ◽  
Middle Taiga ◽  
Northern Eurasia ◽  
Runoff Formation ◽  
Forest Tundra

Abstract Background Assessment of the reasons for the ambiguous influence of forests on the structure of the water balance is the subject of heated debate among forest hydrologists. Influencing the components of total evaporation, forest vegetation makes a significant contribution to the process of runoff formation, but this process has specific features in different geographical zones. The issues of the influence of forest vegetation on river runoff in the zonal aspect have not been sufficiently studied. Results Based on the analysis of the dependence of river runoff on forest cover, using the example of nine catchments located in the forest-tundra, northern and middle taiga of Northern Eurasia, it is shown that the share of forest cover in the total catchment area (percentage of forest cover, FCP) has different effects on runoff formation. Numerical experiments with the developed empirical models have shown that an increase in forest cover in the catchment area in northern latitudes contributes to an increase in runoff, while in the southern direction (in the middle taiga) extensive woody cover of catchments “works” to reduce runoff. The effectiveness of geographical zonality in regards to the influence of forests on runoff is more pronounced in the forest-tundra zone than in the zones of northern and middle taiga. Conclusion The study of this problem allowed us to analyze various aspects of the hydrological role of forests, and to show that forest ecosystems, depending on environmental conditions and the spatial distribution of forest cover, can transform water regimes in different ways. Despite the fact that the process of river runoff formation is controlled by many factors, such as temperature conditions, precipitation regime, geomorphology and the presence of permafrost, the models obtained allow us to reveal general trends in the dependence of the annual river runoff on the percentage of forest cover, at the level of catchments. The results obtained are consistent with the concept of geographic determinism, which explains the contradictions that exist in assessing the hydrological role of forests in various geographical and climatic conditions. The results of the study may serve as the basis for regulation of the forest cover of northern Eurasian river basins in order to obtain the desired hydrological effect depending on environmental and economic conditions.

Effect of modelling scale on the assessment of climate change impact on river runoff

2013 ◽  
Vol 58 (4) ◽  
pp. 737-754 ◽  
Author(s):  
Mikołaj Piniewski ◽  
Frank Voss ◽  
Ilona Bärlund ◽  
Tomasz Okruszko ◽  
Zbigniew W. Kundzewicz
Keyword(s):  
Climate Change ◽  
River Runoff ◽  
Climate Change Impact ◽  
Change Impact

Modelling the climate change impact on the largest White Sea estuarine areas

2021 ◽  
Author(s):  
Evgeniya Panchenko ◽  
Andrei Alabyan ◽  
Inna Krylenko ◽  
Serafima Lebedeva
Keyword(s):  
Climate Change ◽  
Sea Level Rise ◽  
Sea Level ◽  
River Runoff ◽  
White Sea ◽  
Water Levels ◽  
Hydrodynamic Modelling ◽  
The White Sea ◽  
Runoff Changes ◽  
Flow Velocities

<p>Possible sea level rise and changes in hydrological regime of rivers are the major threats to estuarine systems. The sensibility of hydrodynamic regime of the Northern Dvina delta and the Onega estuary under various scenarios of climate change has been investigated. Hydrodynamic models HEC-RAS (USA, US Army Corps of Engineers Hydrologic Engineering Center) and STREAM_2D (Russia, authors V.Belikov et.al.) were used for analysis of estuarine flow regime (variations of water levels, discharges and flow velocities throughout tidal cycles). Input runoff changes were simulated for different climate scenarios using ECOMAG model (Russia, author Yu.Motovilov) based on data of global climate models (GSM) of CMIP5 project for the White Sea region.</p><p>ECOMAG modelling has demonstrated that the maximum river discharges averaged for 30-year period 2036 – 2065 can reduce for about 20 – 27% for the Onega and 15 – 20% for the Northern Dvina river compared against the historical period 1971 – 2000.Averaged minimum river discharges can reduce for about 33 – 45% for the Onega and 30 – 40% for the Northern Dvina.</p><p>The White Sea level rise by 0.27 m in average (with inter-model variation from 0.20 to 0.38 m) can took place by the middle of the XXI century according to input data of GSM models. The 12 scenarios of estuarine hydrodynamic changes were simulated for the both rivers based on combining river runoff changes and sea level elevation.</p><p>In general, the expected flow changes are negative for the local industry and population. According to modelling results for ‘high runoff/spring tide’ scenarios the flooding area in the Northern Dvina delta will increase by 13-20% depending on the intensity of sea level rise. In the low water seasons the distance from the river mouth to the upper boundary of the reach, where reverse currents can be observed, will move upstream by 8 - 36 km depending of sea/river conditions due to decrease in minimum river runoff. It may adversely effect on shipping conditions at the city of Arkhangelsk and on brackish water intrusion up-to industrial and communal water intakes.</p><p>The reverse currents also will intensify in the Onega estuary (tidal flow velocities increase for 11 – 19%) that leads to the change of the sediment regime and can significantly deteriorate the navigation conditions at the seaport of the Onega town. The problem of the intensification of salt intrusion can arise there as well.</p><p>The research was supported by the Russian Foundation for Basic Research (Projects No. 18- 05-60021 in development of the scenarios; No. 19-35-90032 in providing hydrodynamic modelling of the Onega; Project No. 19-35-60032 in providing hydrodynamic modelling of the Northern Dvina).</p>

scholarly journals Spatial-temporal changes in river runoff and terrestrial ecosystem water retention under 1.5 °C and 2 °C warming scenarios across China

2017 ◽  
Author(s):  
Ran Zhai ◽  
Fulu Tao ◽  
Zhihui Xu
Keyword(s):  
Climate Change ◽  
Interannual Variability ◽  
River Runoff ◽  
Water Retention ◽  
Terrestrial Ecosystem ◽  
Maximum Temperature ◽  
Climate Scenarios ◽  
Warming Scenario ◽  
Basin Scale ◽  
The Impact

Abstract. The Paris Agreement set a long-term temperature goal of holding the global average temperature increase to below 2.0 ℃ above pre-industrial levels, and pursuing efforts to limit this to 1.5 ℃, it is therefore important to understand the impacts of climate change under 1.5 ℃ and 2.0 ℃ warming scenarios for climate adaptation and mitigation. Here, climate scenarios by four Global Circulation Models (GCMs) for the baseline (2006–2015), 1.5 ℃ and 2.0 ℃ warming scenarios (2106–2115) were used to drive the validated Variable Infiltration Capacity (VIC) hydrological model to investigate the impacts of global warming on river runoff and Terrestrial Ecosystem Water Retention (TEWR) in China. The trends in annual mean temperature, precipitation, river runoff and TEWR were analysed at the grid and basin scale. Results showed that there were large uncertainties in climate scenarios from the different GCMs, which led to large uncertainties in the impact assessment. The differences among the four GCMs were larger than differences between the two warming scenarios. The interannual variability of river runoff increased notably in areas where it was projected to increase, and the interannual variability increased notably from 1.5 ℃ warming scenario to 2.0 ℃ warming scenario. By contrast, TEWR would remain relatively stable. Both extreme low and high river runoff would increase under the two warming scenarios in most areas in China, with high river runoff increasing more. And the risk of extreme river runoff events would be higher under 2.0 ℃ warming scenario than under 1.5 ℃ warming scenario in term of both extent and intensity. River runoff was significantly positively correlated to precipitation, while increase in maximum temperature would generally cause river runoff to decrease through increasing evapotranspiration. Likewise, precipitation also played a dominant role in affecting TEWR. Our findings highlight climate change mitigation and adaptation should be taken to reduce the risks of hydrological extreme events.

scholarly journals Assessment of Climate Change Awareness in the Kakamega-Nandi Forest Complex in the Western Region

2021 ◽  
pp. 33-48
Author(s):  
Wabusya Moses Wetiba ◽  
Mugatsia Tsingalia ◽  
Njira Njira Pili ◽  
Vincent Kakembo
Keyword(s):  
Climate Change ◽  
Forest Ecosystem ◽  
Forest Cover ◽  
Forest Ecosystems ◽  
Survey Design ◽  
Group Discussion ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Kakamega Forest ◽  
Ecosystem Complex

Aims: This study assessed the level of climate change awareness among the forest-adjacent communities in the Kakamega-Nandi forest ecosystem complex. Four locations were chosen for the study, Buyangu and Isecheno in the Kakamega forest, Kaptumo in Nandi South and Kipsamoite in Nandi North forest ecosystems. Study Design: A cross-sectional survey design was used to collect data from primary sources. Structured questionnaires were administered to the residents aged 25years and older within the study area. Place and Duration of Study: The Kakamega, north and south Nandi forest ecosystems in western Kenya between June -December 2019. Methodology: A total of 280 questionnaires were randomly administered to the forest-adjacent respondents with, Kakamega forest 163 respondents, South Nandi forest 60, while North Nandi had 57respondents. A total of 217 questionnaires were filled and returned and the information wherein used in data analysis. Focused Group Discussion and key informants were used to supplement data collects by the questionnaires. Results: Majority of the residents (54%) were less concerned about climate change. In addition, 85% of the respondents had very little knowledge on coping and adapting to the adverse impacts of climate change. Some 40 % and 45% of the respondents got information about climate through televisions and radios, respectively. Further analysis of the results revealed that climate change was responsible for fourteen key impacts. These included an increase in rainfall, prolonged drought, decrease in the quality and quantity of fresh water, decrease in food security, an increase in temperature, a decrease in agricultural resources, an increase in sickness and disease, a decrease in quality of life, flooding, decrease in forest cover, loss of homes, reduction in biodiversity, and rise in storm surge. A Chi test revealed a significant relationship between forest cover decline and changes in rainfall patterns (X2 = 111.86, df =12, p<0.001), increasing temperature (X2 = 80.492, df =12, p<0.001);, drought( (X2 = 204.84, df =16, p<0.001) and storm surges (X2 = 74.34, df =8, p<0.001)]. The respondents' level of education was significantly different from their level of climate change awareness (X2=44.88, df=4, p<0.001). Conclusion: Forest-adjacent communities in the Kakamega-Nandi forest ecosystem complex are vulnerable to climate change as a result of insufficient knowledge about climate change and its impacts. The Kakamega-Nandi forest ecosystem is already experiencing climate change effects such as erratic rainfall and increasing food insecurity.

scholarly journals Climate change impact on streamflow in large-scale river basins: projections and their uncertainties sourced from GCMs and RCP scenarios

2018 ◽  
Vol 379 ◽  
pp. 139-144 ◽  
Author(s):  
Olga N. Nasonova ◽  
Yeugeniy M. Gusev ◽  
Evgeny E. Kovalev ◽  
Georgy V. Ayzel
Keyword(s):  
Climate Change ◽  
River Runoff ◽  
Climate Change Impact ◽  
Large Scale ◽  
River Basins ◽  
Surface Model ◽  
Second Phase ◽  
Rcp Scenarios ◽  
Data Set ◽  
Change Impact

Abstract. Climate change impact on river runoff was investigated within the framework of the second phase of the Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP2) using a physically-based land surface model Soil Water – Atmosphere – Plants (SWAP) (developed in the Institute of Water Problems of the Russian Academy of Sciences) and meteorological projections (for 2006–2099) simulated by five General Circulation Models (GCMs) (including GFDL-ESM2M, HadGEM2-ES, IPSL-CM5A-LR, MIROC-ESM-CHEM, and NorESM1-M) for each of four Representative Concentration Pathway (RCP) scenarios (RCP2.6, RCP4.5, RCP6.0, and RCP8.5). Eleven large-scale river basins were used in this study. First of all, SWAP was calibrated and validated against monthly values of measured river runoff with making use of forcing data from the WATCH data set and all GCMs' projections were bias-corrected to the WATCH. Then, for each basin, 20 projections of possible changes in river runoff during the 21st century were simulated by SWAP. Analysis of the obtained hydrological projections allowed us to estimate their uncertainties resulted from application of different GCMs and RCP scenarios. On the average, the contribution of different GCMs to the uncertainty of the projected river runoff is nearly twice larger than the contribution of RCP scenarios. At the same time the contribution of GCMs slightly decreases with time.

scholarly journals Structure, Diversity, and Carbon Stocks of the Tree Community of Kumasi, Ghana

Forests ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 519 ◽  
Author(s):  
Bertrand Nero ◽  
Daniel Callo-Concha ◽  
Manfred Denich
Keyword(s):  
Climate Change ◽  
Species Richness ◽  
Forest Cover ◽  
Biological Diversity ◽  
Urban Forest ◽  
Urban Forestry ◽  
Sampling Technique ◽  
Total Carbon ◽  
Mitigation And Adaptation ◽  
Structure Diversity

Urban forestry has the potential to address many urban environmental and sustainability challenges. Yet in Africa, urban forest characterization and its potential to contribute to human wellbeing are often neglected or restrained. This paper describes the structure, diversity, and composition of an urban forest and its potential to store carbon as a means of climate change mitigation and adaptation in Kumasi. The vegetation inventory included a survey of 470,100-m2 plots based on a stratified random sampling technique and six streets ranging from 50 m to 1 km. A total of 3757 trees, comprising 176 species and 46 families, were enumerated. Tree abundance and species richness were left skewed and unimodally distributed based on diameter at breast height (DBH). Trees in the diameter classes >60 cm together had the lowest species richness (17%) and abundance (9%), yet contributed more than 50% of the total carbon stored in trees within the city. Overall, about 1.2 million tonnes of carbon is captured in aboveground components of trees in Kumasi, with a mean of 228 t C ha−1. Tree density, DBH, height, basal area, aboveground carbon storage, and species richness were significantly different among green spaces (p < 0.05). The diversity was also significantly different among urban zones (p < 0.0005). The DBH distribution of trees followed a modified reverse J-shaped model. The urban forest structure and composition is quite unique. The practice of urban forestry has the potential to conserve biological diversity and combat climate change. The introduction of policies and actions to support the expansion of urban forest cover and diversity is widely encouraged.

Opportunities for Reaping the Benefits of REDD+ in Sikkim Himalaya for Conservation and Enhancement of Carbon Stock

2017 ◽  
Vol 40 (3) ◽  
pp. 209-215
Author(s):  
Mohommad Shahid ◽  
◽  
L.K. Rai ◽  
Keyword(s):  
Climate Change ◽  
Forest Cover ◽  
Carbon Sink ◽  
Forest Degradation ◽  
Forest Cover Change ◽  
Change Analysis ◽  
Carbon Sequestration Potential ◽  
Sequestration Potential ◽  
Article 5

Paris Agreement recognized the role of forests as carbon sink for mitigation of climate change, under Article 5 as REDD+, i.e., reducing emissions from deforestation and forest degradation and role of conservation, sustainable management of forests and enhancement of forest carbon stocks. Forest cover change analysis was done between two time periods 2005 and 2015 to assess the forest degradation. Carbon sequestration potential of the forests of Sikkim for mitigating climate change is also estimated. Benefits of implementing of REDD+ in Sikkim involving local communities as stakeholder to conserve and sustainably manage the forest is assessed. Gaps and challenges faced by the stakeholder in implementing REDD+ at project level are also highlighted.

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

&lt;p&gt;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.&lt;br&gt;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).&lt;br&gt;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.&lt;br&gt;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.&lt;br&gt;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.&lt;br&gt;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.&lt;/p&gt;

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