The impact of varying spatial resolution of climate models on future rainfall simulations in the Pra River Basin (Ghana)

Abstract This work compares future projections of rainfall over the Pra River Basin (Ghana) using data from five climate models for the period 2020–2049, as referenced to the control period 1981–2010. Bias-correction methods were applied where necessary and models' performances were evaluated with Nash–Sutcliffe Efficiency, root-mean-square error and coefficient of determination. Standardised Anomaly Index (SAI) was used to determine variability. The onset and cessation dates and length of the rainy season were determined by modifying the Walter–Olaniran method. The ensemble means of the models projected a 1.77% decrease in rainfall. The SAI showed that there would be drier than normal years with the likelihood of drought occurrence in 2021, 2023, 2031 and 2036. The findings showed that high-resolution models (≤25 km) were more capable of simulating rainfall at the basin scale than mid-resolution models (26–150 km) and projected a 20.13% increase. Therefore, the rainfall amount is expected to increase in the future. However, the projected increase in the length of the dry season by the ensemble of the models suggested that alternative sources of water would be necessary to supplement rainfed crop production for food security.

Download Full-text

Application of SWAT in Hydrological Simulation of Complex Mountainous River Basin (Part II: Climate Change Impact Assessment)

Water ◽

10.3390/w13111548 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1548

Author(s):

Suresh Marahatta ◽

Deepak Aryal ◽

Laxmi Prasad Devkota ◽

Utsav Bhattarai ◽

Dibesh Shrestha

Keyword(s):

Climate Change ◽

River Basin ◽

Climate Models ◽

Assessment Tool ◽

Swat Model ◽

Global Climate Models ◽

Climate Data ◽

The Future ◽

The Impact ◽

Mountainous River

This study aims at analysing the impact of climate change (CC) on the river hydrology of a complex mountainous river basin—the Budhigandaki River Basin (BRB)—using the Soil and Water Assessment Tool (SWAT) hydrological model that was calibrated and validated in Part I of this research. A relatively new approach of selecting global climate models (GCMs) for each of the two selected RCPs, 4.5 (stabilization scenario) and 8.5 (high emission scenario), representing four extreme cases (warm-wet, cold-wet, warm-dry, and cold-dry conditions), was applied. Future climate data was bias corrected using a quantile mapping method. The bias-corrected GCM data were forced into the SWAT model one at a time to simulate the future flows of BRB for three 30-year time windows: Immediate Future (2021–2050), Mid Future (2046–2075), and Far Future (2070–2099). The projected flows were compared with the corresponding monthly, seasonal, annual, and fractional differences of extreme flows of the simulated baseline period (1983–2012). The results showed that future long-term average annual flows are expected to increase in all climatic conditions for both RCPs compared to the baseline. The range of predicted changes in future monthly, seasonal, and annual flows shows high uncertainty. The comparative frequency analysis of the annual one-day-maximum and -minimum flows shows increased high flows and decreased low flows in the future. These results imply the necessity for design modifications in hydraulic structures as well as the preference of storage over run-of-river water resources development projects in the study basin from the perspective of climate resilience.

Download Full-text

The Public Sector Mediation Process

Journal of Conflict Resolution ◽

10.1177/002200277802200202 ◽

1978 ◽

Vol 22 (2) ◽

pp. 209-240 ◽

Cited By ~ 129

Author(s):

Thomas A. Kochan ◽

Todd Jick

Keyword(s):

New York ◽

Public Sector ◽

Personal Characteristics ◽

Mediation Process ◽

Municipal Governments ◽

The Public ◽

Situational Characteristics ◽

Alternative Sources ◽

Using Data ◽

The Impact

This paper develops and tests a model of the labor mediation process using data from a sample of negotiations involving municipal governments and police and firefighter unions in the State of New York. The test of the model also incorporates an estimate of the impact of a change in the statutory impasse procedures governing these groups. The model examines the impact of (1) alternative sources of impasse, (2) situational characteristics, (3) strategies of the mediators, and (4) personal characteristics of the mediators on the probability of settlement, percentage of issues resolved in mediation, movement or compromising behavior, and the tendency to hold back concessions in mediation. The results indicate that the change in the impasse procedure had a marginal affect on the probability of settlement in the small to medium cities in the sample but little or no effect on the larger cities. Furthermore, a number of other measures of the sources of impasse and mediator strategies and characteristics had a stronger impact on the effectiveness of the mediation process than the nature of the impasse procedure.

Download Full-text

Methods and techniques of research motivation and satisfaction of employees

Trendovi u poslovanju ◽

10.5937/trendpos2102059p ◽

2021 ◽

Vol 9 (2) ◽

pp. 53-63

Author(s):

Dragana Pešić-Jenačković

Keyword(s):

Analysis Of Variance ◽

Employee Motivation ◽

Test Point ◽

Coefficient Of Determination ◽

Business Success ◽

Chi Square ◽

Methods And Techniques ◽

Chi Square Test ◽

Using Data ◽

The Impact

Motivation and employee satisfaction are very important precondition for the effectiveness of work and the achievement of set goals for individuals and organizations. Consequently, continuous measurement of employee motivation and satisfaction is essential to improve company's efficiency and improve human resource use. The results of a well-planned, detailed and adequate methods and techniques of research on employee motivation and satisfaction can be applied to the design of various schemes in order to reduce absenteeism and employee turnover and overall business success. In this paper, the emphasis is on the methodology of researching employee motivation and satisfaction. In addition to the elaboration of questionnaires with scales for measuring the motivation and satisfaction of employees, it is explained in which situations, in which types of questions and answers, respectively, types of data, and how certain statistical techniques are applied, such as: T-test, One-factor analysis of variance (ANOVA), Chi-square test, Point-two-series correlations. Also, the importance of using the subsequent post hoc test (LSD comparison) in the analysis of variance, as well as the indicators of correlation, the strength of the impact, such as: phi correlation coefficient, Kramer's coefficient and contingency coefficient, is pointed out in the Chi-square test. In addition to the mentioned techniques and indicators from SPSS, the role of certain indicators (eta squared and coefficient of determination) is calculated, which are calculated using data from research results and with the help of certain formulas

Download Full-text

Evaluation of Future Climate and Potential Impact on Streamflow in the Upper Nan River Basin of Northern Thailand

Advances in Meteorology ◽

10.1155/2020/8881118 ◽

2020 ◽

Vol 2020 ◽

pp. 1-15

Author(s):

Miyuru B. Gunathilake ◽

Yasasna V. Amaratunga ◽

Anushka Perera ◽

Imiya M. Chathuranika ◽

Anura S. Gunathilake ◽

...

Keyword(s):

River Basin ◽

Minimum Temperature ◽

Climate Models ◽

Hydrological Modeling ◽

Winter Season ◽

Future Climate ◽

Maximum Temperature ◽

Monthly Precipitation ◽

Northern Thailand ◽

The Impact

Water resources in Northern Thailand have been less explored with regard to the impact on hydrology that the future climate would have. For this study, three regional climate models (RCMs) from the Coordinated Regional Downscaling Experiment (CORDEX) of Coupled Model Intercomparison Project 5 (CMIP5) were used to project future climate of the upper Nan River basin. Future climate data of ACCESS_CCAM, MPI_ESM_CCAM, and CNRM_CCAM under Representation Concentration Pathways RCP4.5 and RCP8.5 were bias-corrected by the linear scaling method and subsequently drove the Hydrological Engineering Center-Hydrological Modeling System (HEC-HMS) to simulate future streamflow. This study compared baseline (1988–2005) climate and streamflow values with future time scales during 2020–2039 (2030s), 2040–2069 (2050s), and 2070–2099 (2080s). The upper Nan River basin will become warmer in future with highest increases in the maximum temperature of 3.8°C/year for MPI_ESM and minimum temperature of 3.6°C/year for ACCESS_CCAM under RCP8.5 during 2080s. The magnitude of changes and directions in mean monthly precipitation varies, with the highest increase of 109 mm for ACESSS_CCAM under RCP 4.5 in September and highest decrease of 77 mm in July for CNRM, during 2080s. Average of RCM combinations shows that decreases will be in ranges of −5.5 to −48.9% for annual flows, −31 to −47% for rainy season flows, and −47 to −67% for winter season flows. Increases in summer seasonal flows will be between 14 and 58%. Projection of future temperature levels indicates that higher increases will be during the latter part of the 20th century, and in general, the increases in the minimum temperature will be higher than those in the maximum temperature. The results of this study will be useful for river basin planners and government agencies to develop sustainable water management strategies and adaptation options to offset negative impacts of future changes in climate. In addition, the results will also be valuable for agriculturists and hydropower planners.

Download Full-text

Uncertainty Impacts of Climate Change and Downscaling Methods on Future Runoff Projections in the Biliu River Basin

Water ◽

10.3390/w11102130 ◽

2019 ◽

Vol 11 (10) ◽

pp. 2130 ◽

Cited By ~ 3

Author(s):

Zhu ◽

Zhang ◽

Wu ◽

Qi ◽

Fu ◽

...

Keyword(s):

Climate Change ◽

River Basin ◽

Water Resource Management ◽

Climate Models ◽

Dynamical Downscaling ◽

Global Climate ◽

Global Climate Models ◽

Liaoning Province ◽

Lower Envelope ◽

The Impact

This paper assesses the uncertainties in the projected future runoff resulting from climate change and downscaling methods in the Biliu River basin (Liaoning province, Northeast China). One widely used hydrological model SWAT, 11 Global Climate Models (GCMs), two statistical downscaling methods, four dynamical downscaling datasets, and two Representative Concentration Pathways (RCP4.5 and RCP8.5) are applied to construct 22 scenarios to project runoff. Hydrology variables in historical and future periods are compared to investigate their variations, and the uncertainties associated with climate change and downscaling methods are also analyzed. The results show that future temperatures will increase under all scenarios and will increase more under RCP8.5 than RCP4.5, while future precipitation will increase under 16 scenarios. Future runoff tends to decrease under 13 out of the 22 scenarios. We also found that the mean runoff changes ranging from −38.38% to 33.98%. Future monthly runoff increases in May, June, September, and October and decreases in all the other months. Different downscaling methods have little impact on the lower envelope of runoff, and they mainly impact the upper envelope of the runoff. The impact of climate change can be regarded as the main source of the runoff uncertainty during the flood period (from May to September), while the impact of downscaling methods can be regarded as the main source during the non-flood season (from October to April). This study separated the uncertainty impact of different factors, and the results could provide very important information for water resource management.

Download Full-text

Selection of Bias Correction Methods to Assess the Impact of Climate Change on Flood Frequency Curves

Water ◽

10.3390/w11112266 ◽

2019 ◽

Vol 11 (11) ◽

pp. 2266 ◽

Cited By ~ 4

Author(s):

Enrique Soriano ◽

Luis Mediero ◽

Carlos Garijo

Keyword(s):

Climate Change ◽

Bias Correction ◽

Climate Models ◽

Climate Model ◽

Control Period ◽

Flood Frequency ◽

Climate Projections ◽

The Future ◽

Flood Quantiles ◽

The Impact

Climate projections provided by EURO-CORDEX predict changes in annual maximum series of daily rainfall in the future in some areas of Spain because of climate change. Precipitation and temperature projections supplied by climate models do not usually fit exactly the statistical properties of the observed time series in the control period. Bias correction methods are used to reduce such errors. This paper seeks to find the most adequate bias correction techniques for temperature and precipitation projections that minimizes the errors between observations and climate model simulations in the control period. Errors in flood quantiles are considered to identify the best bias correction techniques, as flood quantiles are used for hydraulic infrastructure design and safety assessment. In addition, this study aims to understand how the expected changes in precipitation extremes and temperature will affect the catchment response in flood events in the future. Hydrological modelling is required to characterize rainfall-runoff processes adequately in a changing climate, in order to estimate flood changes expected in the future. Four catchments located in the central-western part of Spain have been selected as case studies. The HBV hydrological model has been calibrated in the four catchments by using the observed precipitation, temperature and streamflow data available on a daily scale. Rainfall has been identified as the most significant input to the model, in terms of its influence on flood response. The quantile mapping polynomial correction has been found to be the best bias correction method for precipitation. A general reduction in flood quantiles is expected in the future, smoothing the increases identified in precipitation quantiles by the reduction of soil moisture content in catchments, due to the expected increase in temperature and decrease in mean annual precipitations.

Download Full-text

Evaluating the influence of hydrological condition on the phosphorus loads in an agricultural river basin using the SWAT model

Hydrology Research ◽

10.2166/nh.2021.165 ◽

2021 ◽

Author(s):

Cui Jian ◽

Yue Zhao ◽

Wenchao Sun ◽

Yan Chen ◽

Bo Wu ◽

...

Keyword(s):

River Basin ◽

Pollution Control ◽

Assessment Tool ◽

Swat Model ◽

River Basin Management ◽

Hydrological Conditions ◽

Basin Scale ◽

Phosphorus Loads ◽

Using Data ◽

And Control

Abstract Excessive phosphorus is an important cause of eutrophication. For river basin management, source identification and control of nonpoint source (NPS) pollution are difficult. In this study, to explore influences of hydrological conditions on phosphorus, the Soil and Water Assessment Tool (SWAT) model is applied to the Luanhe River basin in North China. Moreover, influences of the spatial scale of the livestock and poultry amount data on estimations of phosphorus loads are also discussed. The results show that applying town-level livestock and poultry amount data allows the model to perform better when estimating phosphorus loads, indicating that using data at a finer administrative level is necessary. For the typical wet year, the estimated annual phosphorus load was 2.6 times that in the typical dry year. Meanwhile, the contribution of pollution in summer to the annual load is greater in the wet year than that in the dry year. The spatial distributions of subbasins with high unit loads of phosphorus differ under different hydrological conditions, meaning that critical areas for pollution control vary with the wetness of each year. All these findings indicate that for pollution control at basin scale, considering the seasonal and interannual variabilities in hydrological conditions is highly demanded.

Download Full-text

Improving runoff estimates from regional climate models: a performance analysis in Spain

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-9-175-2012 ◽

2012 ◽

Vol 9 (1) ◽

pp. 175-214

Author(s):

D. González-Zeas ◽

L. Garrote ◽

A. Iglesias ◽

A. Sordo-Ward

Keyword(s):

Time Series ◽

Large Scale ◽

Climate Models ◽

Regional Climate ◽

Regional Climate Models ◽

Hydrologic Model ◽

Direct Runoff ◽

Interpolation Methods ◽

Basin Scale ◽

The Impact

Abstract. An important aspect to assess the impact of climate change on water availability is to have monthly time series representative of the current situation. In this context, a simple methodology is presented for application in large-scale studies in regions where a properly calibrated hydrologic model is not available, using the output variables simulated by regional climate models (RCMs) of the European project PRUDENCE under current climate conditions (period 1961–1990). The methodology compares different interpolation methods and alternatives to generate annual times series that minimize the bias with respect to observed values. The objective is to identify the best alternative to obtain bias-corrected, monthly runoff time series from the output of RCM simulations. This study uses information from 338 basins in Spain that cover the entire mainland territory and whose observed values of naturalised runoff have been estimated by the distributed hydrological model SIMPA. Four interpolation methods for downscaling runoff to the basin scale from 10 RCMs are compared with emphasis on the ability of each method to reproduce the observed behavior of this variable. The alternatives consider the use of the direct runoff of the RCMs and the mean annual runoff calculated using five functional forms of the aridity index, defined as the ratio between potential evaporation and precipitation. In addition, the comparison with respect to the global runoff reference of the UNH/GRDC dataset is evaluated, as a contrast of the "best estimator" of current runoff on a large scale. Results show that the bias is minimised using the direct original interpolation method and the best alternative for bias correction of the monthly direct runoff time series of RCMs is the UNH/GRDC dataset, although the formula proposed by Schreiber also gives good results.

Download Full-text

The impact of agroecological factors on morphological traits of maize

Genetika ◽

10.2298/gensr2003203t ◽

2020 ◽

Vol 52 (3) ◽

pp. 1203-1213

Author(s):

Marijenka Tabakovic ◽

Mile Secanski ◽

Rade Stanisavljevic ◽

Snezana Mladenovic-Drinic ◽

Milena Simic ◽

...

Keyword(s):

Yield Components ◽

Morphological Traits ◽

Crop Production ◽

Dry Matter ◽

Genetic Material ◽

Maize Yield ◽

Coefficient Of Determination ◽

Lower Variability ◽

Chemical Traits ◽

The Impact

Climate changes are one of the crucial issues of modern agriculture. These changes imply the increase in average temperatures and the frequent occurrence of temperature extremes. Such conditions are stressful to maize concerning the expression of its traits. This paper presents the analysis of the maize yield concerning the yield components, morphological and chemical traits under various agroecological conditions. The objective of the study was to evaluate variability of grain yield (GY) and yield components (ear length, EL and number of kernel rows, NKR), morphological traits (plant height, PH and ear height, EH), as well as chemical traits (the whole plant dry matter, PDM and the ear dry matter, EDM), and the effect of the environment on the intensity of expression of these traits. Fifteen genotypes developed by crossing of six inbred lines were used as a material in the study carried out during the two-year period in one location. Obtained results indicate that traits were more pronounced in maize hybrids than in the parental components including the lower variability of the traits expression. NKR did not affect the yield unlike the EL, whose coefficient of determination was R2 = 0.600 in both production years. The environmental effect was high for all traits except NKR. PDM and EDM were closely related to PH and EH, but they also depended on the EL and the NKR. Variations in meteorological conditions have a significant impact on the final goal of the production, the yield. Prevailing agro-ecological conditions should be a major guideline in planning the crop production and selecting the genetic material.

Download Full-text

Assessment and Mitigation of Streamflow and Sediment Yield under Climate Change Conditions in Diyala River Basin, Iraq

Hydrology ◽

10.3390/hydrology6030063 ◽

2019 ◽

Vol 6 (3) ◽

pp. 63 ◽

Cited By ~ 3

Author(s):

Mahmoud S. Al-Khafaji ◽

Rana D. Al-Chalabi

Keyword(s):

Climate Change ◽

Sediment Yield ◽

Climate Models ◽

Assessment Tool ◽

Coefficient Of Determination ◽

Base Period ◽

Important Challenge ◽

Diyala River ◽

The Impact ◽

Water Assessment

The impact of climate change on the streamflow and sediment yield in the Derbendkhan and Hemrin Watersheds is an important challenge facing the water resources of the Diyala River in Iraq. The Soil and Water Assessment Tool (SWAT) was used to project this impact on streamflow and sediment yield until year 2050 by applying five climate models for scenario A1B involving medium emissions. The models were calibrated and validated based on daily observed streamflow and sediment recorded for the periods from 1984 to 2013 and 1984 to 1985, respectively. The Nash–Sutcliffe efficiency and coefficient of determination values for the calibration (validation) were 0.61 (0.53) and 0.6 (0.62) for Derbendkhan and Hemrin, respectively. In addition, the average of the future predictions for the five climate models indicated that the streamflow (sediment yield) for the Derbendkhan and Hemrin Watersheds would decrease to 49% (43.7%) and 20% (30%), respectively, until 2050, compared with the observed flow of the base period from 1984 to 2013. The spatial analysis showed that 10.4% and 68% of the streamflow comes from Iraqi parts of the Derbendkhan and Hemrin Watersheds, respectively, while 10% and 60% of the sediment comes from the Iraqi parts of the Derbendkhan and Hemrin Watersheds, respectively. Deforestation of the northern part of the Hemrin Watershed is the best method to decrease the amount of sediment entering the Hemrin Reservoir.

Download Full-text