scholarly journals SPATIAL-TEMPORAL ASPECTS OF THE HYDROLOGICAL REGIME IN CATCHMENTS AFTER CLEARCUTTING

ASJ. ◽  
2021 ◽  
Vol 1 (48) ◽  
pp. 24-35
Author(s):  
T. Burenina ◽  
A. Onuchin
Keyword(s):  
River Basin ◽  
Forest Regeneration ◽  
River Flow ◽  
Hydrological Regime ◽  
Annual Runoff ◽  
Yenisei Ridge ◽  
Structure Changes ◽  
Temporal Aspects ◽  
The Impact

This article discusses the spatial and temporal aspects of hydrological processes in catchments after logging for different landscape conditions of Central Siberia. For this discussion, the results of our own research in the Sayan Mountains, the Yenisei Ridge, the Angara River basin, the Khamar-Daban ridge and literature data were involved. It analyzed the impact of felling area to change the river flow and development of the erosion at the catchment area. The annual runoff, its seasonal structure and sediment discharge change significantly in dependence on as area of clearcutting so area of river basin. The authors analyzed the results of observations of the restoration of the water balance in the experimental logging sites of small catchments and the dynamics of runoff in large rivers. Research has shown the vegetation cover structure changes continuously on logged sites during post-logging forest regeneration and future post-cutting hydrologic regime scenarios are determined both by further climatic changes and by vegetation succession trajectories. The role of the time as a factor to decrease erosion at watershed after logging depends of many regional and local features of landscapes and of initial soil mineralized by logging. For the forests of Khamar-Daban mountainous in Baikal basin the model of soil erosion at watersheds after logging was developed.  

scholarly journals Impact of urbanized landscapes on the river flow in Europe

2019 ◽  
pp. 78-87
Author(s):  
N. I. Koronkevich ◽  
K. S. Melnik
Keyword(s):  
River Basin ◽  
Russian Federation ◽  
River Runoff ◽  
River Flow ◽  
River Basins ◽  
Annual Runoff ◽  
The Russian Federation ◽  
Urbanized Areas ◽  
The Impact ◽  
Moscow River

Global urban landscapes were growing rapidly during last decades. The impact of this growth on annual river runoff of foreign European and Russian river basins was shown in this article. Calculations for Moscow river basin were taken as a basis for computations. The performed calculations show, that 1% of urbanization area increase also enhances total river runoff at 1%. At the same time 1% growth of watertight territories (included in urbanized landscapes) leads to an increase in runoff by 2–3%. The growth of urbanized areas led to a smaller increase in runoff (2–3 times) in the past (in comparison with current period) due to a less established system of diversion from urbanized landscapes. Calculations were made for Spree, Thames, Seine river basins in comparison Moscow River basin. Impact of capitals landscapes (Berlin, London, Paris, and Moscow) on river runoff was estimated initially, and then the influence of other urbanized areas located in river basins. As a result, the general influence of all urbanized territories was defined. According to results of conducted calculations, modern urbanized areas led to an increase of annual river runoff by more than 9% in Spree river basin, more than 20% of the Thames, over 11% of the Seine and 10% in the basin of Moscow River in comparison with changes during the period of norm calculation (from the end of 19th century till the beginning of the 1960s of the 20th century). According to the results of conducted calculations, modern total annual runoff increase is 2.2–4.5% for Europe and 0.2–0.3% for the Russian Federation in comparison with changes during the period of norm calculation, and in relation to the runoff from the most populated their parts is 3.5-6.9% and 1-2%, respectively. In addition, it can be expressed in km3 with following values: 44.9–89.8 (for foreign Europe) and 7.2–14.3 (for the Russian Federation). For the whole Europe (including European territory of Russia), the runoff increases by 50–100 km3 (or by 2–4%) per year. Actually, this is not so much in percentage terms, though in terms of volume – these values are close to annual runoff of such river as Neva.

scholarly journals Effects of Dam Construction in the Wang River on Sediment Regimes in the Chao Phraya River Basin

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2146
Author(s):  
Warit Charoenlerkthawin ◽  
Matharit Namsai ◽  
Komkrit Bidorn ◽  
Chaipant Rukvichai ◽  
Balamurugan Panneerselvam ◽  
...  
Keyword(s):  
River Basin ◽  
River Flow ◽  
Sediment Load ◽  
Annual Runoff ◽  
Sediment Supply ◽  
Dam Construction ◽  
Average Annual Runoff ◽  
Chao Phraya River ◽  
The Impact ◽  
Total Sediment

The Wang River is one of the major tributaries of the Chao Phraya River (CPR) system in Thailand as the key riverine sediment source supplying the Chao Phraya Delta that has experienced severe shoreline retreat in the past six decades. Historical and observed river flow and sediment data measured during 1929–2019 were used to assess the variation in total sediment load along the Wang River and evaluate the effects of three major dam constructions on sediment supplied from the Wang River to the CPR. Results indicated that sediment loads increased toward downstream. Variation in long-term total sediment load (TSL) along the river suggested that construction of the Kiew Lom Dam in 1972 did not cause a reduction in sediment yield in the Wang River Basin because it impounded less than 20% of the average annual runoff, while the Mae Chang and Kiew Koh Ma Dams caused downstream sediment reduction. These three dams are located in the upper and middle river basins, and their effects on sediment load in the Wang River are ameliorated by additional sediment supplied from the lower basin. Results confirmed that construction of these three major dams in the Wang River did not greatly impact sediment supply from the Wang River to the CPR system. The dam site and sediment load variation along the river are the primary factors controlling the impact of the dam construction.

The impact of a crisis on entrepreneurial orientation of family firms: The role of organisational decline and generational change

2021 ◽  
pp. 026624262110366
Author(s):  
Ana M Moreno-Menéndez ◽  
Unai Arzubiaga ◽  
Vanessa Díaz-Moriana ◽  
José C Casillas
Keyword(s):  
Entrepreneurial Orientation ◽  
Family Firms ◽  
Theory And Practice ◽  
Stability And Convergence ◽  
Generational Change ◽  
Entrepreneurial Behaviour ◽  
Temporal Aspects ◽  
Alternative Hypotheses ◽  
The Impact

This article critically analyses entrepreneurial orientation (EO) in family firms after a major crisis, to investigate how firms with equal initial levels of EO reach different levels over time. Based on two alternative hypotheses (stability and convergence), we analysed whether the EO of family firms remains intact, strengthens, or weakens after a crisis. Based on an examination of a database of 151 family firms collected in 2004 and 2017, our findings reveal that compared to firms with higher pre-crisis EO levels, those with lower levels saw a larger increase post crisis. Furthermore, unlike the latter group, the former was able to maintain high pre-crisis levels even after the crisis. In addition, we also we found this relationship between pre-crisis and post-crisis EO levels to be influenced by two key periodic discontinuities, namely, organisational decline and generational change contingencies. These findings advance our understanding of temporal aspects of EO and heterogeneous entrepreneurial behaviour among family firms with significant implications for both theory and practice.

scholarly journals An evaluation of the effect of future climate on runoff in the Dongjiang River basin, South China

2015 ◽  
Vol 368 ◽  
pp. 257-262
Author(s):  
K. Lin ◽  
W. Zhai ◽  
S. Huang ◽  
Z. Liu
Keyword(s):  
Climate Change ◽  
River Basin ◽  
South China ◽  
Annual Runoff ◽  
Future Climate ◽  
Weather Data ◽  
Future Climate Change ◽  
Dongjiang River ◽  
The Future ◽  
The Impact

Abstract. The impact of future climate change on the runoff for the Dongjiang River basin, South China, has been investigated with the Soil and Water Assessment Tool (SWAT). First, the SWAT model was applied in the three sub-basins of the Dongjiang River basin, and calibrated for the period of 1970–1975, and validated for the period of 1976–1985. Then the hydrological response under climate change and land use scenario in the next 40 years (2011–2050) was studied. The future weather data was generated by using the weather generators of SWAT, based on the trend of the observed data series (1966–2005). The results showed that under the future climate change and LUCC scenario, the annual runoff of the three sub-basins all decreased. Its impacts on annual runoff were –6.87%, –6.54%, and –18.16% for the Shuntian, Lantang, and Yuecheng sub-basins respectively, compared with the baseline period 1966–2005. The results of this study could be a reference for regional water resources management since Dongjiang River provides crucial water supplies to Guangdong Province and the District of Hong Kong in China.

scholarly journals Effect of Land Use Land Cover and Climate Change on River Flow and Soil Loss in Didessa River Basin, South West Blue Nile, Ethiopia

Hydrology ◽  
2018 ◽  
Vol 6 (1) ◽  
pp. 2 ◽  
Author(s):  
Kinati Chimdessa ◽  
Shoeb Quraishi ◽  
Asfaw Kebede ◽  
Tena Alamirew
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Land Cover ◽  
River Basin ◽  
Sediment Yield ◽  
Soil Loss ◽  
River Flow ◽  
Land Use Land Cover ◽  
The Impact ◽  
Soil Losses

In the Didessa river basin, which is found in Ethiopia, the human population number is increasing at an alarming rate. The conversion of forests, shrub and grasslands into cropland has increased in parallel with the population increase. The land use/land cover change (LULCC) that has been undertaken in the river basin combined with climate change may have affected the Didessa river flow and soil loss. Therefore, this study was designed to assess the impact of LULCC on the Didessa river flow and soil loss under historical and future climates. Land use/land cover (LULC) of the years 1986, 2001 and 2015 were independently combined with the historical climate to assess their individual impacts on river flow and soil loss. Further, the impact of future climates under Representative Concentration Pathways (RCP2.6, RCP4.5 and RCP8.5) scenarios on river flow and soil loss was assessed by combining the pathways with the 2015 LULC. A physically based Soil and Water Assessment Tool (SWAT2012) model in the ArcGIS 10.4.1 interface was used to realize the purpose. Results of the study revealed that LULCC that occurred between 1986 and 2015 resulted in increased average sediment yield by 20.9 t ha−1 yr−1. Climate change under RCP2.6, RCP4.5 and RCP8.5 combined with 2015 LULC increased annual average soil losses by 31.3, 50.9 and 83.5 t ha−1 yr−1 compared with the 2015 LULC under historical climate data. It was also found that 13.4%, 47.1% and 87.0% of the total area may experience high soil loss under RCP2.6, RCP4.5 and RCP8.5, respectively. Annual soil losses of five top-priority sub catchments range from 62.8 to 57.7 per hectare. Nash Stuncliffe Simulation efficiency (NSE) and R2 values during model calibration and validation indicated good agreement between observed and simulated values both for flow and sediment yield.

IMPACT OF FUTURE CLIMATE CHANGE (2020–2059) ON THE HYDROLOGICAL REGIME IN THE HEIHE RIVER BASIN IN SHAANXI PROVINCE, CHINA

2019 ◽  
Vol 01 (01) ◽  
pp. 1950003 ◽  
Author(s):  
AIDI HUO ◽  
XIAOFAN WANG ◽  
YUXIANG CHENG ◽  
CHUNLI ZHENG ◽  
CHENG JIANG
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
River Basin ◽  
Hydrological Regime ◽  
Annual Runoff ◽  
Heihe River Basin ◽  
Shaanxi Province ◽  
Future Climate Change ◽  
Heihe River ◽  
The Heihe River Basin

Assessing the impacts of climate change on hydrological regime and associated social and economic activities (such as farming) is important for water resources management in any river basin. In this study, we used the popular Soil and Water Assessment Tool (SWAT) to evaluate the impacts of future climate change on the availability of water resources in the Heihe River basin located within Shaanxi Province, China, in terms of runoff and streamflow. The results show that over the next 40 years (starting in 2020 till 2059), changes in the averaged annual runoff ratio are approximately [Formula: see text]11.0%, [Formula: see text]6.4%, 7.2%, and 20.4% for each of the next four consecutive decades as compared to the baseline period (2010–2019). The predicted annual runoff demonstrates an increase trend after a reduction and may result in increased drought and flood risk in the Heihe River basin. To minimize or mitigate these impacts, various adaptation methods have been proposed for the study area, such as stopping irrigation, flood control operation; reasonable development and utilization of regional underground water sources should be implemented in Zhouzhi county and Huyi region in the lower reaches of Heihe River basin.

scholarly journals The Spatiotemporal Variations of Runoff in the Yangtze River Basin under Climate Change

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Ziwei Xiao ◽  
Peng Shi ◽  
Peng Jiang ◽  
Jianwei Hu ◽  
Simin Qu ◽  
...  
Keyword(s):  
River Basin ◽  
Yangtze River ◽  
Yangtze River Basin ◽  
Annual Runoff ◽  
Sensitivity Analyses ◽  
The Yangtze River ◽  
The Yangtze River Basin ◽  
The Impact ◽  
Lower Stream ◽  
Precipitation And Temperature

A better understanding of the runoff variations contributes to a better utilization of water resources and water conservancy planning. In this paper, we analyzed the runoff changes in the Yangtze River Basin (YRB) including the spatiotemporal characteristics of intra-annual variation, the trend, the mutation point, and the period of annual runoff using various statistical methods. We also investigated how changes in the precipitation and temperature could impact on runoff. We found that the intra-annual runoff shows a decreasing trend from 1954 to 2008 and from upper stream to lower stream. On the annual runoff sequence, the upstream runoff has a high consistency and shows an increasing diversity from upper stream to lower stream. The mutation points of the annual runoff in the YRB are years 1961 and 2004. Annual runoff presents multitime scales for dry and abundance changes. Hurst values show that the runoffs at the main control stations all have Hurst phenomenon (the persistence of annual runoff). The sensitivity analyses of runoff variation to precipitation and temperature were also conducted. Our results show that the response of runoff to precipitation is more sensitive than that to temperature. The response of runoff to temperature is only one-third of the response to precipitation. A decrease in temperature may offset the impact of decreasing rainfall on runoff, while an increase in both rainfall and temperature leads to strongest runoff variations in the YRB.

scholarly journals Climate Change Effects on Hydropower Potential in the Alcantara River Basin in Sicily (Italy)

2013 ◽  
Vol 17 (19) ◽  
pp. 1-22 ◽  
Author(s):  
G. T. Aronica ◽  
B. Bonaccorso
Keyword(s):  
Climate Change ◽  
River Basin ◽  
Coupled Model ◽  
Daily Rainfall ◽  
Hydrological Regime ◽  
Future Climate Change ◽  
Hydropower Generation ◽  
Energy Potential ◽  
Hydropower Potential ◽  
The Impact

Abstract In recent years, increasing attention has been paid to hydropower generation, since it is a renewable, efficient, and reliable source of energy, as well as an effective tool to reduce the atmospheric concentrations of greenhouse gases resulting from human activities. At the same time, however, hydropower is among the most vulnerable industries to global warming, because water resources are closely linked to climate changes. Indeed, the effects of climate change on water availability are expected to affect hydropower generation with special reference to southern countries, which are supposed to face dryer conditions in the next decades. The aim of this paper is to qualitatively assess the impact of future climate change on the hydrological regime of the Alcantara River basin, eastern Sicily (Italy), based on Monte Carlo simulations. Synthetic series of daily rainfall and temperature are generated, based on observed data, through a first-order Markov chain and an autoregressive moving average (ARMA) model, respectively, for the current scenario and two future scenarios at 2025. In particular, relative changes in the monthly mean and standard deviation values of daily rainfall and temperature at 2025, predicted by the Hadley Centre Coupled Model, version 3 (HadCM3) for A2 and B2 greenhouse gas emissions scenarios, are adopted to generate future values of precipitation and temperature. Synthetic series for the two climatic scenarios are then introduced as input into the Identification of Unit Hydrographs and Component Flows from Rainfall, Evapotranspiration and Streamflow Data (IHACRES) model to simulate the hydrological response of the basin. The effects of climate change are investigated by analyzing potential modification of the resulting flow duration curves and utilization curves, which allow a site's energy potential for the design of run-of-river hydropower plants to be estimated.

scholarly journals LARGE AND SMALL RESERVOIRS OF UKRAINE: REGIONAL AND BASIN DISTRIBUTION FEATURES

2021 ◽  
pp. 6-17
Author(s):  
V.K. KHILCHEVSKYI ◽  
V.V. GREBIN
Keyword(s):  
River Basin ◽  
River Flow ◽  
River Basins ◽  
Small Reservoirs ◽  
National Importance ◽  
Distribution Features ◽  
The Status ◽  
Rental Rate

The aim of the study was to establish the territorial patterns of the distribution of reservoirs in administrative regions and river basin districts, to identify the role of large, medium and small reservoirs in the balance of river flow regulation in Ukraine. In Ukraine, there are only 1054 reservoirs, among which there are six large reservoirs of the Dnieper cascade and the Dniester reservoir, and all the remaining 99.3% (1047 reservoirs) belong to the middle (M), small (S) and very small (VS) categories. For convenience, we call this group with the abbreviation MSVS-reservoirs. All reservoirs have a total volume of 55.13 km3. Thus, reservoirs regulate 32% of the total river flow of the country, amounting to 170.3 km3 per year. There are two main patterns of territorial distribution of reservoirs: large reservoirs are located on large rivers (Dnieper and Dniester) and are of national importance; MSVS-reservoirs – were created to provide water to industrial regions (for example, Donetsk, Kharkiv) and have regional or local significance. In terms of the volume of accumulated water, Ukraine is a country of large reservoirs. The six reservoirs of the Dnieper cascade contain 79% of the water, in the Dniester – 6%, in the MSVS-reservoirs – 15%. The volume of reservoirs in the Dnieper cascade is 43.71 km3, which is 82% of the average long-term runoff of the Dnieper (53.5 km3 per year). The operation of the Dniester reservoir (3.0 km3), which was created in the transboundary city of Dniester (Ukraine – Moldova), is carried out taking into account the water management interests of the two countries. MSVS-reservoirs are unevenly distributed over the territory of Ukraine. The largest number of them is concentrated in the arid central and southeastern regions of Ukraine, 45% of the total number of MSVS-reservoirs is located in the region of the river basin Dnieper. The largest total values of the total volume and area of MSVS-reservoirs is in the Odesa region due to the Danube lakes, which have been granted the status of reservoirs. In the use of territorial communities in Ukraine, there are 72% of the MSVS-reservoirs, 28% – leased. Among the regions of Ukraine, most of all are rented MSVS-reservoirs in the Transcarpathian region – 78%. In the Zaporizhye region, 56% of the MSVS-reservoirs are leased, in the Ternopil region – 54%. There are leases of MSVS-reservoirs in Ivano-Frankivsk and Lviv regions. Low values of the lease indicator were in the Autonomous Republic of Crimea (4%), in Kherson (7%), Vinnitsa (8%) and Volyn regions (10% each). Among the regions of river basins, there are more leased MSVS-reservoirs in the regions of the river basins. Southern Bug – 35%, Dnieper – 32%. The minimum rental rate was in the region of the Crimean river basin (4%). There is a lease of MSVS-reservoirs in the area of the river basin. Vistula.

scholarly journals The Impact of Climate Change on the High Water Levels of a Small River in Central Europe Based on 50-Year Measurements

Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1269
Author(s):  
Andrzej Boczoń ◽  
Anna Kowalska ◽  
Andrzej Stolarek
Keyword(s):  
Climate Change ◽  
Potential Evapotranspiration ◽  
Hydrological Regime ◽  
Natura 2000 ◽  
High Water ◽  
Annual Runoff ◽  
Water Levels ◽  
Strong Impact ◽  
Northeastern Poland ◽  
The Impact

Climate change affects many elements of the natural environment and strongly influences the hydrology of rivers. In this study, we investigated trends in temperature, precipitation, and the water level characteristics in the small lowland river Lebiedzianka in northeastern Poland for the 50 year long period of observations (1970–2019). We recorded significant increase in air temperature and potential evapotranspiration, but the annual sum of precipitation did not change. We found significant downward trends for annual runoff. The results show a steady decrease in the number of days with high water levels. These changes caused by global warming will have a strong impact on forest habitats associated with high water levels and periodic inundations. In Europe, many of these precious habitats are protected under the Natura 2000 network as sites of high heritage value; nevertheless, their sustainability will be at risk due to the ongoing changes in their hydrological regime.

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