Analysis of the role of climatic and human factors in runoff variations (case study: Lighvan River in Urmia Lake Basin, Iran)

2019 ◽  
Vol 11 (1) ◽  
pp. 291-302 ◽  
Author(s):  
R. Kanani ◽  
A. Fakheri Fard ◽  
M. A. Ghorbani ◽  
Y. Dinpashoh
Keyword(s):  
Climate Change ◽  
Human Factors ◽  
Human Activities ◽  
Climatic Factors ◽  
Hydrologic Model ◽  
Climatic Variables ◽  
Data Series ◽  
Lake Basin ◽  
Discharge Data ◽  
The Impact

Abstract In recent years, river flows have significantly decreased due to regional or global climate change and human activities, especially in the arid and semi-arid regions. In this study, the effects of climate change and human activities on the runoff responses were examined using hydrologic sensitivity analysis and hydrologic model simulation in the Lighvan basin located in the northwest of Iran. The Mann–Kendall test was applied to identify the trends in hydroclimatic data series. Also, the Pettitt test was used to detect change points in the annual discharge values and climatic variables. The results showed that there was negative trend in discharge data series, and examination of the climatic factors indicated that there was an increase in the temperature values and a decrease in the relative humidity values at the basin. The rapid changes in runoff values and most of the climatic variables occurred in the mid-1990s. The effect percentages of the human factors and climatic factors on runoff reduction in all the models used were 65–84% and 16–35%, respectively. Therefore, the impact of human activities on the river flow changes was significant.

Response of karst springs to climate change and anthropogenic activities: the Niangziguan Springs, China

2009 ◽  
Vol 33 (5) ◽  
pp. 634-649 ◽  
Author(s):  
Yonghong Hao ◽  
Yajie Wang ◽  
Yuen Zhu ◽  
Yi Lin ◽  
Jet-Chau Wen ◽  
...  
Keyword(s):  
Climate Change ◽  
Human Activities ◽  
Anthropogenic Activities ◽  
Grey System Theory ◽  
Spring Discharge ◽  
Second Phase ◽  
Groundwater Abstraction ◽  
Discharge Data ◽  
The Impact ◽  
Niangziguan Springs

Discharge from the largest karst spring in north China, the Niangziguan Springs, has been declining since the 1950s. This paper examines the response of these springs to climatic change and anthropogenic influence by attempting a model-based discrimination between phases in the stream discharge record. In Niangziguan Springs Basin, the exploitation of karst groundwater began in 1979. Accordingly, the spring discharge data were divided into two phases: pre-1979 and post-1979. In the first phase (1957—78) the spring discharge was believed to be affected solely by climate change, and in the second phase (1979—2007) the spring discharge was influenced by both climate change and human activities. Using grey system theory, a discharge model was estimated for the first phase. Extrapolating the model, we obtained a projection of the spring discharge during the second phase. Using a water balance calculation, we discerned the respective effects of climate change and human activities on depletion of spring discharge for the second phase. The results show that the contribution of climate change to depletion of Niangziguan Springs is 2.30m3/s and the contribution of anthropogenic activities ranges from 1.89 to 2.90 m3/s, although this assumes a constant for the climate change effect. Accordingly, the anthropogenic effects have been approaching and surpassing the effects of climate change during the second phase. With respect to the impact of human activities on spring discharge, groundwater abstraction accounts for only about 34—52% of the declines; 48—66% of the declines are related to other human activities, such as dewatering from coal mining, dam building and deforestation.

scholarly journals Assessing the Sensitivity of Main Crop Yields to Climate Change Impacts in China

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 172
Author(s):  
Yuan Xu ◽  
Jieming Chou ◽  
Fan Yang ◽  
Mingyang Sun ◽  
Weixing Zhao ◽  
...  
Keyword(s):  
Climate Change ◽  
Crop Yield ◽  
Food Production ◽  
Crop Yields ◽  
Climatic Factors ◽  
Climatic Data ◽  
The South ◽  
The North ◽  
Output Elasticity ◽  
The Impact

Quantitatively assessing the spatial divergence of the sensitivity of crop yield to climate change is of great significance for reducing the climate change risk to food production. We use socio-economic and climatic data from 1981 to 2015 to examine how climate variability led to variation in yield, as simulated by an economy–climate model (C-D-C). The sensitivity of crop yield to the impact of climate change refers to the change in yield caused by changing climatic factors under the condition of constant non-climatic factors. An ‘output elasticity of comprehensive climate factor (CCF)’ approach determines the sensitivity, using the yields per hectare for grain, rice, wheat and maize in China’s main grain-producing areas as a case study. The results show that the CCF has a negative trend at a rate of −0.84/(10a) in the North region, while a positive trend of 0.79/(10a) is observed for the South region. Climate change promotes the ensemble increase in yields, and the contribution of agricultural labor force and total mechanical power to yields are greater, indicating that the yield in major grain-producing areas mainly depends on labor resources and the level of mechanization. However, the sensitivities to climate change of different crop yields to climate change present obvious regional differences: the sensitivity to climate change of the yield per hectare for maize in the North region was stronger than that in the South region. Therefore, the increase in the yield per hectare for maize in the North region due to the positive impacts of climate change was greater than that in the South region. In contrast, the sensitivity to climate change of the yield per hectare for rice in the South region was stronger than that in the North region. Furthermore, the sensitivity to climate change of maize per hectare yield was stronger than that of rice and wheat in the North region, and that of rice was the highest of the three crop yields in the South region. Finally, the economy–climate sensitivity zones of different crops were determined by the output elasticity of the CCF to help adapt to climate change and prevent food production risks.

The impact of drought on tree growth in Mediterranean sites

2021 ◽  
Author(s):  
Giovanna Battipaglia ◽  
Francesco Niccoli ◽  
Arturo Pacheco-Solana
Keyword(s):  
Climate Change ◽  
Tree Growth ◽  
Sustainable Forest Management ◽  
Climatic Factors ◽  
Management Strategies ◽  
Ring Width ◽  
Limiting Factor ◽  
Individual Tree ◽  
Annual Growth Rings ◽  
The Impact

<p>Climate-induced forest mortality is a critical issue in the Mediterranean basin, with major consequences for the functioning of these key ecosystems. Indeed, in Mediterranean ecosystems, where water stress is already the most limiting factor for tree performance, climatic changes are expected to entail an increase in water deficit. In this context, annual growth rings can provide short- (e.g., years) and long-term (e.g., decades) information on how trees respond to drought events. With climate change, <em>Pinus pinaster</em> and <em>Pinus pinea</em> L. are expected to reduce their distribution range in the region, being displaced at low altitudes by more drought tolerant taxa such as sub Mediterranean <em>Quercus</em> spp.</p><p>This study aims was to assess the physiological response of <em>Pinus</em> and <em>Quercus</em> species growing in the Vesuvio National park, located in Southern Italy and where an increase of temperature and drought events has been recorded in the recent years. Our preliminary results underlined the importance of temperature on the tree ring width of all the analyses species. The high temperatures can cause a change in the constant kinetics of the RuBisCo, leading to a consequent decrease in carboxylation rate and thus to a reduction in tree growth. On the other hand, also precipitation seemed to affect the growth of the sampled trees: indeed, in all the chronologies a reduction in growth was found after particular dry years: for example, the low rainfall in 1999 (455 mm/year) determined a drastic decline in growth in 2000 in all the species. In addition to the climatic factors, competition can also play an important role in the growth rate: dendrochronological analyzes have highlighted how stand specific properties (i.e. density, structure and composition) can influence individual tree responses to drought events. The knowledge of those researches should be integrated into sustainable forest management strategies to minimize the potential impacts of climate change on forest ecosystems.</p>

Hydrological modelling and anthropogenic water use

2021 ◽  
Author(s):  
Ponnambalam Rameshwaran ◽  
Ali Rudd ◽  
Vicky Bell ◽  
Matt Brown ◽  
Helen Davies ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Use ◽  
Hydrological Model ◽  
Model Performance ◽  
River Flows ◽  
Discharge Data ◽  
New Approach ◽  
Water Demands ◽  
The Impact ◽  
Grid Based

<p>Despite Britain’s often-rainy maritime climate, anthropogenic water demands have a significant impact on river flows, particularly during dry summers. In future years, projected population growth and climate change are likely to increase the demand for water and lead to greater pressures on available freshwater resources.</p><p>Across England, abstraction (from groundwater, surface water or tidal sources) and discharge data along with ‘Hands off Flow’ conditions are available for thousands of individual locations; each with a licence for use, an amount, an indication of when abstraction can take place, and the actual amount of water abstracted (generally less than the licence amount). Here we demonstrate how these data can be used in combination to incorporate anthropogenic artificial influences into a grid-based hydrological model. Model simulations of both high and low river flows are generally improved when abstractions and discharges are included, though for some catchments model performance decreases. The new approach provides a methodological baseline for further work investigating the impact of anthropogenic water use and projected climate change on future river flows.</p>

The impact of climate change and human activities on the Aral Sea Basin over the past 50 years

2020 ◽  
Vol 245 ◽  
pp. 105125 ◽  
Author(s):  
Xuanxuan Wang ◽  
Yaning Chen ◽  
Zhi Li ◽  
Gonghuan Fang ◽  
Fei Wang ◽  
...  
Keyword(s):  
Climate Change ◽  
Human Activities ◽  
Aral Sea ◽  
Aral Sea Basin ◽  
Impact Of Climate Change ◽  
The Past ◽  
The Impact

scholarly journals Separating the Impacts of Climate Change and Human Activities on Runoff: A Review of Method and Application

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2201 ◽  
Author(s):  
Feng Zeng ◽  
Ming-Guo Ma ◽  
Dong-Rui Di ◽  
Wei-Yu Shi
Keyword(s):  
Climate Change ◽  
Research Methods ◽  
Human Activities ◽  
Future Research ◽  
Research Needs ◽  
Relevant Research ◽  
Impact Of Climate Change ◽  
The Impact ◽  
Impacts Of Climate Change

Separating the impact of climate change and human activities on runoff is an important topic in hydrology, and a large number of methods and theories have been widely used. In this paper, we review the current papers on separating the impacts of climate and human activities on runoff, summarize the progress of relevant research methods and applications in recent years, and discuss future research needs and directions.

scholarly journals Attribution Analysis of Hydrological Drought Risk Under Climate Change and Human Activities: A Case Study on Kuye River Basin in China

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1958 ◽  
Author(s):  
Zhang ◽  
Wang ◽  
Zhou
Keyword(s):  
Climate Change ◽  
River Basin ◽  
Human Activities ◽  
Large Scale ◽  
Research Area ◽  
Drought Severity ◽  
Drought Risk ◽  
Drought Duration ◽  
Recurrence Period ◽  
The Impact

This study conducted quantitative diagnosis on the impact of climate change and human activities on drought risk. Taking the Kuye river basin (KRB) in China as the research area, we used variation point diagnosis, simulation of precipitation and runoff, drought risk assessment, and attribution quantification. The results show that: (1) the annual runoff sequence of KRB changed significantly after 1979, which was consistent with the introduction of large-scale coal mining; (2) under the same drought recurrence period, the drought duration and severity in the human activity stage were significantly worse than in the natural and simulation stages, indicating that human activities changed the drought risk in this area; and (3) human activities had little impact on drought severity in the short duration and low recurrence period, but had a greater impact in the long duration and high recurrence period. These results provide scientific guidance for the management, prevention, and resistance of drought; and guarantee sustainable economic and social development in the KRB.

scholarly journals Impact of Three Gorges Reservoir Water Impoundment on Vegetation–Climate Response Relationship

2020 ◽  
Vol 12 (17) ◽  
pp. 2860
Author(s):  
Mengqi Tian ◽  
Jianzhong Zhou ◽  
Benjun Jia ◽  
Sijing Lou ◽  
Huiling Wu
Keyword(s):  
Human Activities ◽  
Three Gorges Reservoir ◽  
Climatic Factors ◽  
Residual Analysis ◽  
Sensitivity Index ◽  
Climate Response ◽  
Three Gorges ◽  
Response Relationship ◽  
The Impact ◽  
Water Impoundment

In recent years, the impact of global climate change and human activities on vegetation has become increasingly prominent. Understanding vegetation change and its response to climate variables and human activities are key tasks in predicting future environmental changes, climate changes and ecosystem evolution. This paper aims to explore the impact of Three Gorges Reservoir (TGR) water impoundment on the vegetation–climate response relationship in the Three Gorges Reservoir Region (TGRR) and its surrounding region. Firstly, based on the SPOT/VEGETATION NDVI and ERA5 reanalysis datasets, the correlation between climatic factors (temperature and precipitation) and NDVI was analyzed by using partial correlation coefficient method. Secondly, nonlinear fitting method was used to fit the mapping relationship between NDVI and climatic factors. Then, the residual analysis was conducted to evaluate the impact of TGR impoundment on vegetation–climate response relationship. Finally, sensitivity index (SI), sensitivity variation index (SVI) and difference index (DI) were defined to quantify the variation of vegetation–climate response relationship before and after water impoundment. The results show that water impoundment might have some impacts on the response of vegetation–climate, which gradually reduced with increasing distance from the channel; comparing with the residual analysis method, the SI and DI index methods are more intuitive, and combining these two methods may provide new ideas for the study of the impact of human activities on vegetation.

Hydrological Frequency Calculation Method Study of Urban Rivers Runoff under Changing Environment

2012 ◽  
Vol 170-173 ◽  
pp. 2023-2026 ◽  
Author(s):  
Cui Song Yu ◽  
Xiao Na Guo
Keyword(s):  
Climate Change ◽  
Random Element ◽  
Hydrologic Model ◽  
Statistic Analysis ◽  
Urban Rivers ◽  
Frequency Curve ◽  
Runoff Series ◽  
Frequency Calculation ◽  
Hydrometric Station ◽  
The Impact

The consistency of hydrological series has been destroyed by the impact of human activities and climate change. Hydrological series is consist of certain component and random element. The random and certain components of hydrological series are identified and separated through statistic analysis. The certain element is determined by using hydrologic model while the consistancy of random element is confirmed directly by hydrological frequency curve. And then add them together. The runoff series of the Huangtai Hydrometric Station in the Xiaoqing River is for example. It proves effective and feasible and the result accord with the reality of the basin.

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