scholarly journals Responses of Streamflow to Climate Change and Human Activities in a River Basin, Northeast China

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Hanwen Zhang ◽  
Wei Xu ◽  
Xintong Xu ◽  
Baohong Lu
Keyword(s):  
Water Resources ◽  
Linear Regression ◽  
River Basin ◽  
Human Activities ◽  
Annual Runoff ◽  
Regression Method ◽  
Linear Regression Method ◽  
Climate Elasticity ◽  
The Impact

It is now common knowledge that many water resources stresses relate to access to water within a basin. Yi River Basin, a typical river basin characterized by intensive agricultural processes, significant population growth, and water management, has been undergoing grave water problems. In this paper, the long-term trend of precipitation and streamflow in Yi River Basin, from 1964 to 2010, was investigated via Mann-Kendall test. The change point occurred in the year 1965 dividing the long-term series into two periods. Climate elasticity method and linear regression method were implemented to quantify the impact of precipitation and human activities on runoff and presented basically consistent results of the percentage change in an annual runoff for the postchange period. The results reveal that the decline of annual runoff in postchange period is mainly attributed to precipitation variability of 53.66–58.25% and human activities of 46.34–41.74%, as estimated by climate elasticity method and linear regression method, respectively. This study detected the changes in the precipitation-streamflow relationship and investigated the possible causes in the Yi River, which will be helpful for providing a reference for the management of regional water resources.

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 Quantifying the Impact of Linear Regression Model in Deriving Bio-Optical Relationships: The Implications on Ocean Carbon Estimations

Sensors ◽  
2019 ◽  
Vol 19 (13) ◽  
pp. 3032 ◽  
Author(s):  
Bellacicco ◽  
Vellucci ◽  
Scardi ◽  
Barbieux ◽  
Marullo ◽  
...  
Keyword(s):  
Linear Regression ◽  
Regression Method ◽  
Linear Regression Method ◽  
Type I ◽  
Ocean Colour ◽  
Data Set ◽  
Argo Floats ◽  
In Situ Data ◽  
Carbon Biomass ◽  
The Impact

Linear regression is widely used in applied sciences and, in particular, in satellite optical oceanography, to relate dependent to independent variables. It is often adopted to establish empirical algorithms based on a finite set of measurements, which are later applied to observations on a larger scale from platforms such as autonomous profiling floats equipped with optical instruments (e.g., Biogeochemical Argo floats; BGC-Argo floats) and satellite ocean colour sensors (e.g., SeaWiFS, VIIRS, OLCI). However, different methods can be applied to a given pair of variables to determine the coefficients of the linear equation fitting the data, which are therefore not unique. In this work, we quantify the impact of the choice of “regression method” (i.e., either type-I or type-II) to derive bio-optical relationships, both from theoretical perspectives and by using specific examples. We have applied usual regression methods to an in situ data set of particulate organic carbon (POC), total chlorophyll-a (TChla), optical particulate backscattering coefficient (bbp), and 19 years of monthly TChla and bbp ocean colour data. Results of the regression analysis have been used to calculate phytoplankton carbon biomass (Cphyto) and POC from: i) BGC-Argo float observations; ii) oceanographic cruises, and iii) satellite data. These applications enable highlighting the differences in Cphyto and POC estimates relative to the choice of the method. An analysis of the statistical properties of the dataset and a detailed description of the hypothesis of the work drive the selection of the linear regression method

scholarly journals Religiosity and Halal Certification: Its Effect on Interest in Buying Traditional Food

2022 ◽  
Vol 6 (2) ◽  
pp. 79
Author(s):  
Najmudin Najmudin ◽  
Syihabudin Syihabudin
Keyword(s):  
Data Analysis ◽  
Linear Regression ◽  
Research Method ◽  
Quantitative Methods ◽  
Regression Method ◽  
Linear Regression Method ◽  
Traditional Food ◽  
Questionnaire Data ◽  
Multiple Linear Regression Method ◽  
The Impact

This study aims to determine (1)—the influence of religiosity on the interest in buying traditional food of sate bandeng. (2). The effect of halal certification on the interest in buying traditional food of sate bandeng. And (3). The impact of religiosity and halal certification on interest in buying traditional food of sate bandeng. This research is the millennial consumers of traditional food of Sate Bandeng Kang Cepi Kaujon, Serang City, Banten Province. The research method used is quantitative. Methods of data collection using a questionnaire. Data were processed using SPSS version 23 software. Data analysis used the multiple linear regression method. The results of this study indicate that (1). Religiosity affects an interest in buying traditional food of Sate Bandeng. (2). Halal certification affects an interest in buying traditional food of sate bandeng (3). Religiosity and halal certification have a positive and significant impact on interest in buying traditional food of Sate Bandeng. Consumers’ interest in buying traditional food of Sate Bandeng is influenced by religiosity and halal certification as much as 48.8 percent. In comparison, the remaining 51.2 percent is influenced by other variables not examined in this study.

Nonstationary frequency analysis for annual runoff and sediment load of the Wujiang River

2020 ◽  
Author(s):  
Rongrong Li
Keyword(s):  
River Basin ◽  
Human Activities ◽  
Sediment Load ◽  
Heavy Rain ◽  
Annual Runoff ◽  
Statistical Characteristics ◽  
Explanatory Variables ◽  
Wujiang River ◽  
Before And After ◽  
The Impact

<p>The hydrological series can no longer meet the stationarity hypothesis due to the influence of climate variability and human activities. The process of runoff and sediment load changed significantly under a changing environment. Analyzing the variations of runoff and sediment load and exploring the main influencing causes leading to their changes will be of great help to understand the dynamic process of water and sediment in river basin. Many studies have considered the effects of rainfall and reservoir on the downstream runoff or sediment: the impact of rainfall on runoff or sediment load is normally performed by comparing the statistical characteristics before and after an extreme weather event (e.g. heavy rain of the Yangtze river in 1998); the effect of reservoirs is usually determined by comparing the pre-dam and post-dam frequencies of runoff or sediment load. In this study, the major influencing factors of annual runoff and sediment load in Wujiang River basin were identified firstly based on the results of trend analysis and change-point diagnosis for runoff and sediment load. Then, Generalized Addictive Models in Location, Scale, and Shape (GAMLSS) is used to describe the rainfall and reservoir impacts on nonstationarity of runoff and sediment load, in which, distribution parameters (including the location, scale and shape parameter) are expressed as a function of the explanatory variables. The results show that: (1) runoff and sediment load of Wujiang River decrease with the intensification of climate change and human activities; (2) runoff is mainly affected by rainfall, the operation of cascade reservoirs has critical effect on the sediment load; (3) the correlation between runoff and sediment closely related to the nonstationarity of sediment load, namely, the sediment load change can directly lead to the alteration of dependence between runoff and sediment.</p>

scholarly journals Quantitative Estimation of the Impact of Precipitation and Land Surface Change on Hydrological Processes through Statistical Modeling

2016 ◽  
Vol 2016 ◽  
pp. 1-15 ◽  
Author(s):  
Muhammad Saifullah ◽  
Zhijia Li ◽  
Qiaoling Li ◽  
Muhammad Zaman ◽  
Sarfraz Hashim
Keyword(s):  
Linear Regression ◽  
Land Surface ◽  
Quantitative Estimation ◽  
Precipitation Variability ◽  
Annual Runoff ◽  
Catchment Scale ◽  
Surface Change ◽  
Regression Methods ◽  
The Impact

Precipitation variability and land surface changes are the two primary factors that affect basin hydrology, and thus estimation of their impact is of great importance for sustainable development at a catchment scale. In this study, we investigated the long-term changes in precipitation and runoff, from 1961 to 2011, in the Yihe River basin by Mann-Kendall test. A new method of trend pattern was put forward and used to identify the trends of precipitation and runoff, which indicated that the basin had a decreasing trend in annual runoff. The change point occurred in the year 1985 dividing the long-term series into two periods. Precipitation elasticity and linear regression methods were used to quantify the impact of precipitation and land surface change on runoff and provided consistent results of the percentage change in an annual runoff for the postchange period. Use of these methods reveals that the reduction in annual runoff is mainly due to precipitation variability of 56.38–67.68% and land surface change of 43.62–32.32%, as estimated by precipitation elasticity and linear regression methods, respectively. Due to the rapid growth of urbanization, the land surface change increased from 1990 to 2010. The result of this study can provide a reference for the management of regional water resources.

scholarly journals Impact of Delay on Cost Overrun in Construction Projects in Algeria

2019 ◽  
Vol 5 (2) ◽  
pp. 25
Author(s):  
Salhi Roumeissa
Keyword(s):  
Linear Regression ◽  
Construction Projects ◽  
Project Success ◽  
Regression Method ◽  
Linear Regression Method ◽  
Cost Overrun ◽  
Simple Linear Regression ◽  
Schedule Delay ◽  
Proposed Model ◽  
The Impact

Project success is the ultimate goal of the various project stackeholders (Salhi.R 2018). Asuccessful project means that the project is completed on time, within the agreed budget and according to the contract specifications. Delay is one of the most reccuring problems in construction project in Algeria, and it is considered as the main cause of cost overrun, time overrun, disput and claims.The objective of this paper is to mesure the impact of schedule delay on cost overrun, using the simple linear regression method and the coefficient of correlation. The proposed model can be used by practitioners as predictive mesure to address possible cost overrun.

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