Cascade Dam-Induced Hydrological Disturbance and Environmental Impact in the Upper Stream of the Yellow River

Abstract

The construction of a dam converts the natural streamflow to human control. It is necessary to learn the accumulated effect of cascade dams on hydrological characteristics, sediment and nutrient pollution discharge. The current research describes the analysis and simulation of streamflow, sand concentration and nutrient pollutant discharge alterations caused by the construction of a cascade of eight dams along the Longliu section of the upper stream of the Yellow River. The analysis shows that the maximum monthly streamflow difference between the inlet and outlet of the Longliu section decreased from 430 to 115 m 3 /s, after the appearance of the cascade dams between 1977 and 2006. In the same period, the correlation coefficient (R 2 ) of monthly streamflow between the inlet and outlet of Longliu dropped from 0.959 to 0.375. The peak of streamflow shifted from June to May and October. The difference in sand concentration between two sections decreased from 0.52 to 0.39 kg/m 3 , which was the direct consequence of the operation of the reservoirs. The R 2 value of sand concentrations of the inlet and outlet were also reduced from 0.504 to 0.356. A t-test analysis indicates that the original hydrological nature was significantly disturbed by the cascade dams. The influence of the dams on nutrient pollutant transport was simulated by the SWAT model. This simulation suggests that the cascade dams decreased the discharge of total nitrogen and total phosphorus from 15.4 × 10 3 t and 1,996 t to 0.4 × 10 3 t and 328 t, respectively. In conclusion, the accumulated impact of cascade dams on streamflow, sand concentration and nutrient pollutant discharge were analyzed, which were helpful for understanding the environmental features of the entire watershed. 914 W. Ouyang et al.

Quantitative analysis on the environmental impact of large-scale water transfer project on water resource area in a changing environment

“…The capability of each model can be fully utilized through modularization strategies during the establishment of the comprehensive coupled model. In this study, the related modules of the regional climate-weather research and forecasting (CWRF) model and regional climate model version 3 (RegCM3) are selected for the simulation of atmospheric water circulation and energy process (Liang et al, 2005a(Liang et al, ,b, 2012Yuan and Liang, 2011;Pal et al, 2007); related modules of the water and energy transfer processes (WEP) model are selected for the simulation of natural hydrological cycle (Jia et al, 2001); a water allocation model is used for the simulation of social water circulation (Zhao et al, 2007); related modules of geoprocess (GEOPRO) model, community land model (CLM) and dynamic global vegetation model (DGVM) are selected for the simulation of natural vegetation (Oleson et al, 2004;Steffen et al, 1996); and related modules of DSSAT are selected for crops (Jones et al, 2003). The essential simulation process and characteristics of the selected prototype models are listed in Table 1.…”

“…What is more, the environmental and ecological influence of project under the background of global climate change is extremely complex; thus, there is considerable uncertainty. Present relevant studies are short of global, comprehensive and systematic research as they are focused on a certain aspect of the environmental influence, such as the hydrological situation, pollutant transport patterns and biodiversity (Morais, 2008;Hu et al, 2008;Koutsos et al, 2010;Ouyang et al, 2011), or they are targeted at a certain area, such as the water-output area, water-intake area and the river delta (Xu et al, 2011;Ligon et al, 2011;Restrepo and Cantera, 2011). The climate change aspect has been inadequately treated in the environmental impact assessment of large water transfer projects.…”

Considering the Order and Symmetry to Improve the Traditional RVA for Evaluation of Hydrologic Alteration of River Systems

“…Hydrologic alterations and their impact on ecosystems have been extensively studied using numerous statistical tools and methods (Chen et al 2007;Ouyang et al 2011;Sun and Feng 2013;Laize et al 2014;Mittal et al 2016). The indicators of hydrologic alteration (IHA) developed by Richter et al (1996) and supported by The Nature Conservancy (TNC) in the United States (Richter et al 1996) is one of the most widely used tools (Lin et al 2014a) to evaluate hydrologic alteration of river systems.…”

Spatial Distribution of Fragmentation by Diversion-Typed Hydroelectric Plant Exploitation in East Baoxing Catchment from 1999 to 2013

“…Two different scales, watershed scale and on-site area, were used to compare the changes in grassland and water area [20] to show vegetation response to hydropower cascade exploitation in upper stream of Yellow River. The accumulated impact of cascade dams on stream flow, sand concentration and nutrient pollutant discharge were also analyzed [21], which were helpful for understanding the environmental features of the entire watershed. Most of the above researchers focused on the influencing degree evaluation of HCE on the landscape, however, few studies have attempted to identify the spatial-temporal distribution of landscape fragmentation [3,22].…”