scholarly journals Comparison of Fish, Macroinvertebrates and Diatom Communities in Response to Environmental Variation in the Wei River Basin, China

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3422
Author(s):  
Linfei Liu ◽  
Zongxue Xu ◽  
Fan Yang ◽  
Xuwang Yin ◽  
Wei Wu ◽  
...  

Land use changes usually lead to the deterioration of freshwater ecosystems and reduced biodiversity. Aquatic organisms are considered valuable indicators for reflecting the conditions of freshwater ecosystems. Understanding the relationship between organisms and land use type, as well as physiochemical conditions, is beneficial for the management, monitoring and restoration of aquatic ecosystems. In this study, fish, macroinvertebrates, and diatoms were investigated at 60 sampling sites in the Wei River basin from October 2012 to April 2013 to determine the relationships between the environment and aquatic organisms. The richness, abundance, Shannon diversity, evenness, Margalef diversity, and Simpson diversity were selected as biological indices for analyzing the correlation between these communities and environmental variables according to Pearson’s coefficient. Canonical correspondence analysis (CCA) was used to analyze the relationship between the biotic communities and environmental variables. The results showed that three diatom indices were weakly correlated with chemical oxygen demand (COD), qualitative Habitat Evaluation Index (QH), and dissolved oxygen (DO). Four macroinvertebrate indices were associated with total phosphorus (TP) while total nitrogen (TN), and agricultural land (AL) had a significant influence on assemblages, suggesting that macroinvertebrates could respond to nutrient levels in the Wei River basin. All land use types had a strong effect on fish indices except AL, indicating that fish would be better used as indicators of spatial changes in the aquatic ecosystem. In conclusion, fish and macroinvertebrates have the potential for use in routine monitoring programs in the Wei River basin.

2016 ◽  
Author(s):  
Hong Wang ◽  
Fubao Sun

Abstract. Under the Grain for Green project in China, vegetation recovery constructions have been widely implemented on the Loess Plateau for the purpose of soil and water conservation. Now it becomes controversial whether the recovery constructions of vegetation, particularly forest, is reducing streamflow in rivers of the Yellow River Basin. In this study, we choose the Wei River, the largest branch of the Yellow River and implemented with revegetation constructions, as the study area. To do that, we apply the widely used Soil and Water Assessment Tool (SWAT) model for the upper and middle reaches of the – Wei River basin. The SWAT model was forced with daily observed meteorological forcings (1960–2009), calibrated against daily streamflow for 1960–1969, validated for the period of 1970–1979 and used for analysis for 1980–2009. To investigate the impact of the LUCC (Land Use and land Cover Change) on the streamflow, we firstly use two observed land use maps of 1980 and 2005 that are based on national land survey statistics emerged with satellite observations. We found that the mean streamflow generated by using the 2005 land use map decreased in comparison with that using the 1980 one, with the same meteorological forcings. Of particular interest here, we found the streamflow decreased in agricultural land but increased in forest area. More specifically, the surface runoff, soil flow and baseflow all decreased in agricultural land, while the soil flow and baseflow of forest were increased. To investigate that, we then designed five scenarios including (S1) the present land use (1980), (S2) 10 %, (S3) 20 %, (S4) 40 % and (S5) 100 % of agricultural land was converted into forest. We found that the streamflow consistently increased with agricultural land converted into forest by about 7.4 mm per 10 %. Our modeling results suggest that forest recovery constructions have positive impact on both soil flow and base flow compensating reduced surface runoff, which leads to a slight increase in streamflow in the Wei River with mixed landscapes of Loess Plateau and earth-rock mountain.


2017 ◽  
Vol 21 (4) ◽  
pp. 1929-1945 ◽  
Author(s):  
Hong Wang ◽  
Fubao Sun ◽  
Jun Xia ◽  
Wenbin Liu

Abstract. Under the Grain for Green Project in China, vegetation recovery construction has been widely implemented on the Loess Plateau for the purpose of soil and water conservation. Now it is becoming controversial whether the recovery construction involving vegetation, particularly forest, is reducing the streamflow in the rivers of the Yellow River basin. In this study, we chose the Wei River, the largest branch of the Yellow River, with revegetated construction area as the study area. To do that, we apply the widely used Soil and Water Assessment Tool (SWAT) model for the upper and middle reaches of the Wei River basin. The SWAT model was forced with daily observed meteorological forcings (1960–2009) calibrated against daily streamflow for 1960–1969, validated for the period of 1970–1979, and used for analysis for 1980–2009. To investigate the impact of LUCC (land use and land cover change) on the streamflow, we firstly use two observed land use maps from 1980 and 2005 that are based on national land survey statistics merged with satellite observations. We found that the mean streamflow generated by using the 2005 land use map decreased in comparison with that using the 1980 one, with the same meteorological forcings. Of particular interest here is that the streamflow decreased on agricultural land but increased in forest areas. More specifically, the surface runoff, soil flow, and baseflow all decreased on agricultural land, while the soil flow and baseflow of forest areas increased. To investigate that, we then designed five scenarios: (S1) the present land use (1980) and (S2) 10 %, (S3) 20 %, (S4) 40 %, and (S5) 100 % of agricultural land that was converted into mixed forest. We found that the streamflow consistently increased with agricultural land converted into forest by about 7.4 mm per 10 %. Our modeling results suggest that forest recovery construction has a positive impact on both soil flow and baseflow by compensating for reduced surface runoff, which leads to a slight increase in the streamflow in the Wei River with the mixed landscapes on the Loess Plateau that include earth–rock mountain area.


Author(s):  
S. Yu ◽  
Z. Xu ◽  
W. Wu ◽  
D. Zuo

Abstract. The temporal effect of land use on streamwater quality needs to be addressed for a better understanding of the complex relationship between land use and streamwater quality. In this study, GIS and Pearson correlation analysis were used to determine whether there were correlations of land-use types with streamwater quality at the sub-basin scale in the Wei River basin, China, during dry and rainy seasons in 2012. Temporal variation of these relations was observed, indicating that relationships between water quality variables and proportions of different land uses were weaker in the rainy season than that in the dry season. Comparing with other land uses, agriculture and urban lands had a stronger relationship with water quality variables in both the rainy and dry seasons. These results suggest that the aspect of temporal effects should be taken into account for better land-use management.


2019 ◽  
Vol 653 ◽  
pp. 1077-1094 ◽  
Author(s):  
Lingtong Gai ◽  
João P. Nunes ◽  
Jantiene E.M. Baartman ◽  
Hongming Zhang ◽  
Fei Wang ◽  
...  

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3532
Author(s):  
Qianyang Wang ◽  
Yuan Liu ◽  
Qimeng Yue ◽  
Yuexin Zheng ◽  
Xiaolei Yao ◽  
...  

A gated recurrent unit (GRU) network, which is a kind of artificial neural network (ANN), has been increasingly applied to runoff forecasting. However, knowledge about the impact of different input data filtering strategies and the implications of different architectures on the GRU runoff forecasting model’s performance is still insufficient. This study has selected the daily rainfall and runoff data from 2007 to 2014 in the Wei River basin in Shaanxi, China, and assessed six different scenarios to explore the patterns of that impact. In the scenarios, four manually-selected rainfall or runoff data combinations and principal component analysis (PCA) denoised input have been considered along with single directional and bi-directional GRU network architectures. The performance has been evaluated from the aspect of robustness to 48 various hypermeter combinations, also, optimized accuracy in one-day-ahead (T + 1) and two-day-ahead (T + 2) forecasting for the overall forecasting process and the flood peak forecasts. The results suggest that the rainfall data can enhance the robustness of the model, especially in T + 2 forecasting. Additionally, it slightly introduces noise and affects the optimized prediction accuracy in T + 1 forecasting, but significantly improves the accuracy in T + 2 forecasting. Though with relevance (R = 0.409~0.763, Grey correlation grade >0.99), the runoff data at the adjacent tributary has an adverse effect on the robustness, but can enhance the accuracy of the flood peak forecasts with a short lead time. The models with PCA denoised input has an equivalent, even better performance on the robustness and accuracy compared with the models with the well manually filtered data; though slightly reduces the time-step robustness, the bi-directional architecture can enhance the prediction accuracy. All the scenarios provide acceptable forecasting results (NSE of 0.927~0.951 for T + 1 forecasting and 0.745~0.836 for T + 2 forecasting) when the hyperparameters have already been optimized. Based on the results, recommendations have been provided for the construction of the GRU runoff forecasting model.


2020 ◽  
Vol 12 (9) ◽  
pp. 3510 ◽  
Author(s):  
Dechao Chen ◽  
Acef Elhadj ◽  
Hualian Xu ◽  
Xinliang Xu ◽  
Zhi Qiao

Many catchments in northern Algeria, including the coastal Mitidja Basin in the north central part of the country have been negatively affected by the deterioration of water quality in recent years. This study aims to discover the relationship between land use change and its impact on water quality in the coastal Mitidja river basin. Based on the data of land use and water quality in 2000, 2010 and 2017, the relationship between land use change and surface water quality index in the Mitidja Watershed was discussed through GIS and statistical analysis. The results show that the physical and chemical properties of the Mitidja river basin have obvious spatial heterogeneity. The water quality of upstream was better than that of downstream. There was a significant spatial relationship between the eight water quality indicators and three land use types, including urban residential land, agricultural land and vegetation. In most cases, settlements and agricultural land are the dominant factors leading to river pollution, and higher vegetation coverage helps to improve water quality. The regression model revealed that percentage of urban settlement area was a predictor for NH4-N, BOD5, COD, SS, PO4-P, DO and pH, while vegetation was a predictor for NO3-N. The analysis also showed that during this period, urban settlement areas increased sharply, which has a significant impact on water quality variables. Agricultural land only had a significant positive correlation with PO4-P. The results provide an effective way to evaluate river water quality, control water pollution and land use management by landscape pattern.


2014 ◽  
Vol 28 (13) ◽  
pp. 4599-4613 ◽  
Author(s):  
Shengzhi Huang ◽  
Jianxia Chang ◽  
Qiang Huang ◽  
Yimin Wang ◽  
Yutong Chen

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