scholarly journals Assessment of streamflows in the Hornád river basin and analysis of trends

2021 ◽  
Vol 1209 (1) ◽  
pp. 012022
Author(s):  
P Nagy
Keyword(s):  
Climate Change ◽  
Water Management ◽  
Time Series ◽  
River Basin ◽  
Extreme Rainfall ◽  
Dry Season ◽  
Trend Test ◽  
Surface And Groundwater ◽  
Daily Flows

Abstract Climate change is a global phenomenon. The more frequent occurrence of dry periods, which last longer but also extreme rainfall, needs to be reduced for better water management. During the dry season, the quantity and quality of surface and groundwater decreases. Water is important for agriculture, agriculture and ecosystems. This study was focused on the occurrence of trends in daily flows in the Hornád basin at selected hydrological stations for the period 1960-2011. The Mann-Kendall trend test is used to evaluate trends in hydrometeorological time series.

scholarly journals Are Soybean Yields Getting a Free Ride From Climate Change? Evidence From Argentine Time Series

2018 ◽  
Author(s):  
Hildegart Ahumada ◽  
Magdalena Cornejo
Keyword(s):  
Climate Change ◽  
Time Series ◽  
Extreme Rainfall ◽  
Co2 Concentration ◽  
Interesting Case ◽  
Extreme Rainfall Events ◽  
Beneficial Effects ◽  
Positive Effects ◽  
Long Run ◽  
Equilibrium Correction

Soybean yields are often indicated as an interesting case of climate change mitigation due to the beneficial effects of CO2 fertilization. In this paper we econometrically study this effect using a time series model of yields in a multivariate framework for a main producer and exporter of this commodity, Argentina. We have to deal with the upward behavior of soybean yields trying to identify which variables are the long-run determinants responsible of its observed trend. With this aim we adopt a partial system approach to estimate subsets of long-run relationships due to climate, technological and economic factors. Using an automatic selection algorithm we evaluate encompassing of the different obtained equilibrium correction models. We found that only technological innovations due to new crop practices and the use of modified seeds explain soybean yield in the long run. Regarding short run determinants we found positive effects associated with the use of standard fertilizers and also from changes in atmospheric CO2 concentration which would suggest a mitigation effect from global warming. However, we also found negative climate effects from periods of droughts associated with La Niña episodes, high temperatures and extreme rainfall events during the growing season of the plant.

scholarly journals Assessment of the impact of climate change on the freshwater availability of Kaduna River basin, Nigeria

2018 ◽  
Vol 38 (1) ◽  
pp. 105-114 ◽  
Author(s):  
Gloria C. Okafor ◽  
Kingsley N. Ogbu
Keyword(s):  
Climate Change ◽  
River Basin ◽  
Water Availability ◽  
Hydrological Cycle ◽  
Temporal Trends ◽  
Kendall Test ◽  
Well Being ◽  
Trend Test ◽  
Climate Indices ◽  
The Impact

AbstractChanges in runoff trends have caused severe water shortages and ecological problems in agriculture and human well-being in Nigeria. Understanding the long-term (inter-annual to decadal) variations of water availability in river basins is paramount for water resources management and climate change adaptation. Climate change in Northern Nigeria could lead to change of the hydrological cycle and water availability. Moreover, the linkage between climatic changes and streamflow fluctuations is poorly documented in this area. Therefore, this study examined temporal trends in rainfall, temperature and runoff records of Kaduna River basin. Using appropriate statistical tools and participatory survey, trends in streamflow and their linkages with the climate indices were explored to determine their amplifying impacts on water availability and impacts on livelihoods downstream the basin. Analysis indicate variable rainfall trend with significant wet and dry periods. Unlike rainfall, temperature showed annual and seasonal scale statistically increasing trend. Runoff exhibit increasing tendency but only statistically significant on annual scale as investigated with Mann–Kendall trend test. Sen’s estimator values stood in agreement with Mann–Kendall test for all variables. Kendall tau and partial correlation results revealed the influence of climatic variables on runoff. Based on the survey, some of the hydrological implications and current water stress conditions of these fluctuations for the downstream inhabitants were itemized. With increasing risk of climate change and demand for water, we therefore recommend developing adaptive measures in seasonal regime of water availability and future work on modelling of the diverse hydrological characteristics of the entire basin.

MITIGATION OF TIME SERIES APPROACH ON CLIMATE CHANGE ADAPTATION ON RAINFALL OF WADI AL-AQIQ, MADINAH, SAUDI ARABIA

2017 ◽  
Vol 79 (5) ◽  
Author(s):  
Norhan Abd Rahman ◽  
Zulkifli Yusop ◽  
Zekai Şen ◽  
Saud Taher ◽  
Ibrahim Lawal Kane
Keyword(s):  
Climate Change ◽  
Time Series ◽  
Saudi Arabia ◽  
State Space ◽  
General Circulation ◽  
Temporal Dynamics ◽  
Resource Planning ◽  
General Circulation Models ◽  
Trend Test ◽  
Fluctuation Analysis

Rainfall record plays a significant role in assessment of climate change, water resource planning and management. In arid region, studies on rainfall are rather scarce due to intricacy and constraint of the available data. Most available studies use more advanced approaches such as A2 scenario, General Circulation Models (GCM) and the like, to study the temporal dynamics and make projection on future rainfall. However, those models take no account of the data patterns and its predictability. Therefore, this study uses time series analysis methodologies such as Mann- Kendall trend test, de-trended fluctuation analysis and state space time series approaches to study the dynamics of rainfall records of four stations in and around Wadi Al-Aqiq, Kingdom of Saudi Arabia (KSA). According to Mann-Kendall trend test there are decreasing trend in three out of the four stations. The de-trended fluctuation analysis revealed two distinct scaling properties that spells the predictability of the records and confirmed by state space methods. 

scholarly journals Modelling of Extreme Hydrological Events on a Tisza River Basin Pilot Area, Hungary

2018 ◽  
Vol 11 (3-4) ◽  
pp. 57-66
Author(s):  
Dávid Béla Vizi ◽  
János Fehér ◽  
Attila Lovas ◽  
Sándor Kovács
Keyword(s):  
Climate Change ◽  
Water Management ◽  
River Basin ◽  
Climate Models ◽  
Water Demands ◽  
Hydrological Extremes ◽  
Additional Task ◽  
Extreme Hydrological Events ◽  
Tisza River ◽  
Proper Operation

Abstract Climate change takes more and more challenges to the water management. Future predictions show that the possibility of extreme floods and drought events are increasing, thus an additional task of the water management can be the fulfilment of the increasing water demands. These new extreme hydrological situations need to be properly handled in water management. The paper presents the first modelling results of the JOINTISZA project carried out on a selected sub-basin of the Tisza River, which is endangered by hydrological extremes. Our aim was to demonstrate the applicability of a one-dimensional hydrodynamic model to study the effects of the climate change. Future hydrological trends were introduced in the river basin and it was assessed how the results of climate models can be used for further hydrodynamic modelling. To address challenges of climate change and supply the stakeholders with an adequate amount of water, proper operation of the reservoir and the irrigation canals are needed. The use of hydrological modelling can be helpful to adequately distribute water resources.

scholarly journals GLACIER VOLUME CHANGE ESTIMATION USING TIME SERIES OF IMPROVED ASTER DEMS

2016 ◽  
Vol XLI-B8 ◽  
pp. 489-494 ◽  
Author(s):  
Luc Girod ◽  
Christopher Nuth ◽  
Andreas Kääb
Keyword(s):  
Climate Change ◽  
Time Series ◽  
Volume Change ◽  
Thermal Emission ◽  
Aster Data ◽  
Rational Polynomial ◽  
The Cross ◽  
Cross Track ◽  
Along Track

Volume change data is critical to the understanding of glacier response to climate change. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) system embarked on the Terra (EOS AM-1) satellite has been a unique source of systematic stereoscopic images covering the whole globe at 15m resolution and at a consistent quality for over 15 years. While satellite stereo sensors with significantly improved radiometric and spatial resolution are available to date, the potential of ASTER data lies in its long consistent time series that is unrivaled, though not fully exploited for change analysis due to lack of data accuracy and precision. Here, we developed an improved method for ASTER DEM generation and implemented it in the open source photogrammetric library and software suite MicMac. The method relies on the computation of a rational polynomial coefficients (RPC) model and the detection and correction of cross-track sensor jitter in order to compute DEMs. ASTER data are strongly affected by attitude jitter, mainly of approximately 4 km and 30 km wavelength, and improving the generation of ASTER DEMs requires removal of this effect. Our sensor modeling does not require ground control points and allows thus potentially for the automatic processing of large data volumes. <br><br> As a proof of concept, we chose a set of glaciers with reference DEMs available to assess the quality of our measurements. We use time series of ASTER scenes from which we extracted DEMs with a ground sampling distance of 15m. Our method directly measures and accounts for the cross-track component of jitter so that the resulting DEMs are not contaminated by this process. Since the along-track component of jitter has the same direction as the stereo parallaxes, the two cannot be separated and the elevations extracted are thus contaminated by along-track jitter. Initial tests reveal no clear relation between the cross-track and along-track components so that the latter seems not to be easily modeled analytically from the first one. We thus remove the remaining along-track jitter effects in the DEMs statistically through temporal DEM stacks to finally compute the glacier volume changes over time. Our method yields cleaner and spatially more complete elevation data, which also proved to be more in accordance to reference DEMs, compared to NASA’s AST14DMO DEM standard products. <br><br> The quality of the demonstrated measurements promises to further unlock the underused potential of ASTER DEMs for glacier volume change time series on a global scale. The data produced by our method will help to better understand the response of glaciers to climate change and their influence on runoff and sea level.

scholarly journals GLACIER VOLUME CHANGE ESTIMATION USING TIME SERIES OF IMPROVED ASTER DEMS

2016 ◽  
Vol XLI-B8 ◽  
pp. 489-494
Author(s):  
Luc Girod ◽  
Christopher Nuth ◽  
Andreas Kääb
Keyword(s):  
Climate Change ◽  
Time Series ◽  
Volume Change ◽  
Thermal Emission ◽  
Aster Data ◽  
Rational Polynomial ◽  
The Cross ◽  
Cross Track ◽  
Along Track

Volume change data is critical to the understanding of glacier response to climate change. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) system embarked on the Terra (EOS AM-1) satellite has been a unique source of systematic stereoscopic images covering the whole globe at 15m resolution and at a consistent quality for over 15 years. While satellite stereo sensors with significantly improved radiometric and spatial resolution are available to date, the potential of ASTER data lies in its long consistent time series that is unrivaled, though not fully exploited for change analysis due to lack of data accuracy and precision. Here, we developed an improved method for ASTER DEM generation and implemented it in the open source photogrammetric library and software suite MicMac. The method relies on the computation of a rational polynomial coefficients (RPC) model and the detection and correction of cross-track sensor jitter in order to compute DEMs. ASTER data are strongly affected by attitude jitter, mainly of approximately 4 km and 30 km wavelength, and improving the generation of ASTER DEMs requires removal of this effect. Our sensor modeling does not require ground control points and allows thus potentially for the automatic processing of large data volumes. <br><br> As a proof of concept, we chose a set of glaciers with reference DEMs available to assess the quality of our measurements. We use time series of ASTER scenes from which we extracted DEMs with a ground sampling distance of 15m. Our method directly measures and accounts for the cross-track component of jitter so that the resulting DEMs are not contaminated by this process. Since the along-track component of jitter has the same direction as the stereo parallaxes, the two cannot be separated and the elevations extracted are thus contaminated by along-track jitter. Initial tests reveal no clear relation between the cross-track and along-track components so that the latter seems not to be easily modeled analytically from the first one. We thus remove the remaining along-track jitter effects in the DEMs statistically through temporal DEM stacks to finally compute the glacier volume changes over time. Our method yields cleaner and spatially more complete elevation data, which also proved to be more in accordance to reference DEMs, compared to NASA’s AST14DMO DEM standard products. <br><br> The quality of the demonstrated measurements promises to further unlock the underused potential of ASTER DEMs for glacier volume change time series on a global scale. The data produced by our method will help to better understand the response of glaciers to climate change and their influence on runoff and sea level.

Synergistic impacts of climate and land cover change, and water management on terrestrial hydrology over headwaters with an integrated attribution framework

2020 ◽  
Author(s):  
Peng Ji ◽  
Xing Yuan
Keyword(s):  
Climate Change ◽  
Water Management ◽  
Land Cover ◽  
Land Cover Change ◽  
River Basin ◽  
Yellow River ◽  
Yellow River Basin ◽  
Anthropogenic Climate Change ◽  
Surface Model ◽  
Streamflow Extremes

&lt;p&gt;Located over eastern Tibetan Plateau, the upper Yellow River basin (UYRB) provides about half of the total annual discharge of the entire Yellow River basin in northern China, and influences more than one hundred million people over downstream regions. In the Anthropocene, human activities such as greenhouse gases emission, human-induced land cover change and water management are changing the terrestrial hydrological process and streamflow extremes over UYRB. However, quantifying their separate influence&amp;#160;is a great challenge due to limited observations and difficulty in modeling hydro-thermal processes over alpine regions.&lt;/p&gt;&lt;p&gt;Here we find significant fingerprints of anthropogenic climate change and land cover change in decreasing total water storage and increasing extremely low streamflow over UYRB headwater. While anthropogenic climate change, reservoir operation and land cover change significantly decreasing the probability of extreme flooding event over the UYRB by 31%, 45% and 10% respectively. The newly-developed Conjunctive Surface-Subsurface Process version 2 (CSSPv2) land surface model was first implemented at a high resolution (3km) over the UYRB. Comprehensive evaluations show the model well captures the variation and variability of hydrological variables. Simulations with and without land cover change were then compared to assess the impact of land cover change, while reservoir influence was calculated by comparing the modeled naturalized streamflow with observed streamflow. CSSPv2 was also driven by CMIP5 outputs with natural or anthropogenic forcings to assess influence of anthropogenic climate change. An integrated hydro-climate attribution framework was finally used to unify the contributions of different factors. Our results highlight the local-scale human influences (including land cover change and water management) on the streamflow extremes, which are still not well incorporated in current global climate models for detection and attribution studies.&lt;/p&gt;

scholarly journals Land use and climate change impacts on the hydrology of the upper Mara River Basin, Kenya: results of a modeling study to support better resource management

2011 ◽  
Vol 15 (7) ◽  
pp. 2245-2258 ◽  
Author(s):  
L. M. Mango ◽  
A. M. Melesse ◽  
M. E. McClain ◽  
D. Gann ◽  
S. G. Setegn
Keyword(s):  
Climate Change ◽  
Land Use ◽  
East Africa ◽  
River Basin ◽  
Management Practices ◽  
Cultural Landscapes ◽  
Dry Season ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Resource Managers

Abstract. Some of the most valued natural and cultural landscapes on Earth lie in river basins that are poorly gauged and have incomplete historical climate and runoff records. The Mara River Basin of East Africa is such a basin. It hosts the internationally renowned Mara-Serengeti landscape as well as a rich mixture of indigenous cultures. The Mara River is the sole source of surface water to the landscape during the dry season and periods of drought. During recent years, the flow of the Mara River has become increasingly erratic, especially in the upper reaches, and resource managers are hampered by a lack of understanding of the relative influence of different sources of flow alteration. Uncertainties about the impacts of future climate change compound the challenges. We applied the Soil Water Assessment Tool (SWAT) to investigate the response of the headwater hydrology of the Mara River to scenarios of continued land use change and projected climate change. Under the data-scarce conditions of the basin, model performance was improved using satellite-based estimated rainfall data, which may also improve the usefulness of runoff models in other parts of East Africa. The results of the analysis indicate that any further conversion of forests to agriculture and grassland in the basin headwaters is likely to reduce dry season flows and increase peak flows, leading to greater water scarcity at critical times of the year and exacerbating erosion on hillslopes. Most climate change projections for the region call for modest and seasonally variable increases in precipitation (5–10 %) accompanied by increases in temperature (2.5–3.5 °C). Simulated runoff responses to climate change scenarios were non-linear and suggest the basin is highly vulnerable under low (−3 %) and high (+25 %) extremes of projected precipitation changes, but under median projections (+7 %) there is little impact on annual water yields or mean discharge. Modest increases in precipitation are partitioned largely to increased evapotranspiration. Overall, model results support the existing efforts of Mara water resource managers to protect headwater forests and indicate that additional emphasis should be placed on improving land management practices that enhance infiltration and aquifer recharge as part of a wider program of climate change adaptation.

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