Uncertainty analysis for evaluating flow regime alteration of Jinsha River based on Indicators of Hydrologic Alteration

2021 ◽  
Author(s):  
Xingyu Zhou ◽  
Xiaorong Huang ◽  
Hongbin Zhao
Keyword(s):  
Uncertainty Analysis ◽  
Flow Regime ◽  
Hydrologic Alteration ◽  
Jinsha River

scholarly journals Development of a revised method for indicators of hydrologic alteration for analyzing the cumulative impacts of cascading reservoirs on flow regime

2020 ◽  
Vol 24 (8) ◽  
pp. 4091-4107
Author(s):  
Xingyu Zhou ◽  
Xiaorong Huang ◽  
Hongbin Zhao ◽  
Kai Ma
Keyword(s):  
Flow Regime ◽  
Negative Impact ◽  
Rate Of Change ◽  
Low Flow ◽  
Outlet Section ◽  
Cumulative Impacts ◽  
Hydrologic Alteration ◽  
Jinsha River ◽  
Flow Part ◽  
Cascading Reservoirs

Abstract. The impacts of reservoirs, especially multiple reservoirs, on the flow regimes and ecosystems of rivers have received increasing attention. The most widely used metrics to quantify the characteristics of flow regime alterations are the indicators of hydrologic alteration (IHAs) which include 33 parameters. Due to the difference in the degree of alteration and the intercorrelation among IHA parameters, the conventional method of evaluating IHA parameters that assigns the same weight to each indicator is obviously inadequate. A revised IHA method is proposed by utilizing the projection pursuit (PP) and real-coded accelerated genetic algorithm (RAGA). Data reliability is analyzed by using the length of record (LOR) method. The projection values reflecting the comprehensive characteristics of the evaluation parameters are calculated. Based on these methods, a scientific and reliable evaluation of the cumulative impacts of cascading reservoirs on the flow regime was made by examining the Jinsha River. The results showed that with the increase in the number of reservoirs, the alteration degrees of IHA parameters gradually increased in groups 1, 2, 3 and 4 but decreased in group 5 (each group addresses the magnitude, timing, frequency, duration and rate of change in turn), and the flow duration curves showed a declining trend at the high-flow part and an increasing trend at the low-flow part. The flow regime alteration of the outlet section was more stable than before. This change had a negative impact on downstream fish reproduction and ecological protection. An attempt at ecological regulation was made to simulate the natural rising process of water, and four major Chinese carps have a positive response to the flood peak process caused by manual regulation.

scholarly journals Anthropogenic and Climate Effects on a Free Dam Tropical River: Measuring the Contributions on Flow Regime

2020 ◽  
Vol 12 (23) ◽  
pp. 10030
Author(s):  
Verônica Léo ◽  
Hersília Santos ◽  
Letícia Pereira ◽  
Lilia Oliveira
Keyword(s):  
Climate Change ◽  
Flow Regime ◽  
River Flow ◽  
Human Impacts ◽  
Global Climate ◽  
Rate Of Change ◽  
Hydrologic Alteration ◽  
Tropical River ◽  
Range Of Variability Approach ◽  
Flow Components

The demand for freshwater resources and climate change pose a simultaneous threat to rivers. Those impacts are often analyzed separately, and some human impacts are widely evaluated in river dynamics—especially in downstream areas rather than the consequences of land cover changes in headwater reaches. The distinction between anthropogenic and climate on the components of the flow regime is proposed here for an upstream free dam reach whose watershed is responsible for the water supply in Rio de Janeiro. Indicators of hydrologic alteration (IHA) and the range of variability approach (RVA) combined with statistical analyses of anthropogenic and climate parameters indicated that (1) four river flow components (magnitude, frequency, duration, and rate of change) were greatly altered from the previous period (1947 to 1967) and the actual (1994 to 2014); (2) shifts in the sea surface temperature of the Atlantic correlated with flow magnitude; (3) the cattle activity effects on the flow regime of the studied area decreased 42.6% of superficial discharge; global climate change led to a 10.8% reduction in the same river component. This research indicated that climate change will impact the intensification of human actions on rivers in the southeast Brazilian headwaters.

Trend Analysis on the Flow Alteration in the Nature Reserve, Upstream of Yangtze River

2014 ◽  
Vol 641-642 ◽  
pp. 132-136 ◽  
Author(s):  
Chen Shen ◽  
Lei Hua Dong ◽  
Yi Cheng Wang ◽  
Shun Xin Feng ◽  
Ying Wang
Keyword(s):  
Flow Regime ◽  
Aquatic Ecosystems ◽  
Yangtze River ◽  
Nature Reserve ◽  
Annual Runoff ◽  
Optimal Operation ◽  
Hydrologic Alteration ◽  
Flood Peak ◽  
Flow Alteration ◽  
Hydropower Stations

National Nature Reserve for the Rare and Endemic Fishes in the Upper Reaches of the Yangtze River (RURYR) in China has been established to protect the extraordinarily perfect aquatic ecosystem since 2005. However, four cascade hydropower stations located in the upstream of RURYR will impound and generate electricity gradually, which may change the natural flow regime there. Since flow regime is of great importance to maintaining the healthy and integrity of aquatic ecosystems, it is essential to study the rules of its variation. The flow alteration in RURYR was characterized by Indicators of Hydrologic Alteration (IHA) during 1960-2010, and its trends and the change rules were analyzed for further study on environmental flow and multi-objective optimal operation. The results indicate that in terms of almost no change in total annual runoff, the flow shows a decreasing trend in the flood season, especially in August and October, but an increasing trend in the dry season (from January to June). The variation trend seems reduce the flood risk as a good purpose, however, along with the multi-operation of the cascade reservoirs, the loss of flood peak will increase more significantly, which is harmful to the aquatic ecosystems.

Impact assessment of anthropogenic interpositions on hydrological regimes of Godavari and Krishna River Basins, India

2020 ◽  
Author(s):  
Rahul Kumar Singh ◽  
Dr. Manoj Kumar Jain
Keyword(s):  
Flow Regime ◽  
Anthropogenic Activities ◽  
River Basins ◽  
Low Flow ◽  
Hydrologic Alteration ◽  
Riverine Ecosystems ◽  
Godavari River ◽  
Hydrological Alteration ◽  
Biotic Diversity ◽  
The Impact

<p>The rivers around the world have been transformed due to various anthropogenic activities and have led to the altered natural flow regime, which is crucial for controlling the essential environmental conditions within the river which in turn forms the biotic diversity. This study quantifies the adverse impacts due to the construction of dams on the hydrology of the Godavari and Krishna River Basins over the last half a century. The quantification of hydrologic alteration at five representative gauging stations of both the rivers has undertaken using Indicator of Hydrological Alteration (IHA) and the Flow Health (FH) methods based on the Range of Variability approach. To evaluate the alterations of flow regime due to the impact of dams (anthropogenic) only, the data for wet and dry years were excluded from the analysis as these represent the impact of climate variability. The IHA results reveal that the average monthly flow (especially from June to September), annual extreme streamflow indices (1-, 3-, and 7-day maxima flow), and rise and fall rates were among the most affected ones when compared to the pre-impacted period. The improved overall hydrologic alteration values for the Dhalegaon, Nowrangpur, K. Agraharam, and Vijayawada stations were found approximately 75.5%, 73.2%, 76.9 %, and 67.9 % respectively, suggesting a significant impact on the overall riverine ecosystem. The flow health (FH) analysis scores for high flow (HF) (K.Agraharam and Yadgir) highest monthly (HM) (Dhalegaon, K.Agraharam, and Yadgir), Low Flow (LF) (Dhalegaon) and flood flow intervals (FFI) (Dhalegaon and Vijayawada) during the test period were in the very high alteration range and these all hydrological indicator represents important ecological functions in both the rivers. The results showed in this study may guide in strategizing the multi-step process needed to improve the riverine ecosystems of Godavari and Krishna Basins and their ecological functioning.</p><p>Keywords: Hydrological alteration; Krishna River; Godavari River; Ecosystem</p>

scholarly journals Development of a revised IHA method for the cumulative impacts of cascade reservoirs on flow regime

2020 ◽  
Author(s):  
Xingyu Zhou ◽  
Xiaorong Huang ◽  
Hongbin Zhao ◽  
Kai Ma
Keyword(s):  
Flow Regime ◽  
Evaluation Method ◽  
Comprehensive Evaluation ◽  
Negative Impact ◽  
Projection Pursuit ◽  
Outlet Section ◽  
Cumulative Impacts ◽  
Jinsha River ◽  
The Difference ◽  
Group 5

Abstract. The impacts of reservoirs, especially multiple reservoirs, on the flow regimes and ecosystems of rivers have received increasing attention. The most widely used metrics to quantify the characteristics of flow regime alterations are the indicators of hydrologic alteration (IHA) which include 33 parameters. Due to the difference in the degree of alteration and the intercorrelation among IHA parameters, the comprehensive evaluation method that assigns the same weight to each indicator is obviously inadequate. A revised IHA method is proposed by utilizing the projection pursuit (PP) and real-coded accelerated genetic algorithm (RAGA). Data reliability is analysed by using the length of record (LOR) method. The projection values reflecting the comprehensive characteristics of the evaluation parameters are calculated. Based on these methods, a scientific and reliable evaluation of the cumulative impacts of cascading reservoirs on the flow regime was made by examining the Jinsha River. The results showed that with the continuous construction of reservoirs, the alteration degrees of IHA parameters gradually increased in Groups 1, 2, 3, and 4, but decreased in Group 5, and the flow duration curves showed characteristics of a head drop and tail lift. The flow regime alteration of the outlet section was more stable than before. This change had a negative impact on downstream fish reproduction and ecological protection. An attempt at ecological regulation was made to simulate the natural rising process of water.

ASSESSMENT OF HYDROLOGICAL CHANGES IN THE ŠUŠVĖ RIVER

2015 ◽  
Author(s):  
Gražina ŽIBIENĖ ◽  
Alvydas ŽIBAS ◽  
Goda BLAŽAITYTĖ
Keyword(s):  
Hydrological Regime ◽  
Maximum Flow ◽  
Environmental Flow ◽  
Physical Structure ◽  
River Channels ◽  
Hydrologic Alteration ◽  
Water Conditions ◽  
Flow Components ◽  
The Impact ◽  
Large Floods

The construction of dams in rivers negatively affects ecosystems because dams violate the continuity of rivers, transform the biological and physical structure of the river channels, and the most importantly – alter the hydrological regime. The impact on the hydrology of the river can occur through reducing or increasing flows, altering seasonality of flows, changing the frequency, duration and timing of flow events, etc. In order to determine the extent of the mentioned changes, The Indicators of Hydrologic Alteration (IHA) software was used in this paper. The results showed that after the construction of Angiriai dam, such changes occurred in IHA Parameters group as: the water conditions of April month decreased by 31 %; 1-day, 3-days, 7-days and 30-days maximum flow decreased; the date of minimum flow occurred 21 days later; duration of high and low pulses and the frequency of low pulses decreased, but the frequency of high pulses increased, etc. The analysis of the Environmental Flow Components showed, that the essential differences were recorded in groups of the small and large floods, when, after the establishment of the Šušvė Reservoir, the large floods no longer took place and the probability of frequency of the small floods didn’t exceed 1 time per year.

Sign in / Sign up

Export Citation Format

Share Document