scholarly journals Estimation of the Nutrient and Chlorophyll a Reference Conditions in Taihu Lake Based on A New Method with Extreme–Markov Theory

2018 ◽  
Vol 15 (11) ◽  
pp. 2372 ◽  
Author(s):  
Liang Wang ◽  
Yulin Wang ◽  
Haomiao Cheng ◽  
Jilin Cheng
Keyword(s):  
Time Series ◽  
Resource Management ◽  
Chlorophyll A ◽  
Water Resource ◽  
Lake Water ◽  
Water Resource Management ◽  
Taihu Lake ◽  
Reference Conditions ◽  
New Method ◽  
Series Data

The nutrient reference conditions of lakes play a key role for lake water quality control and water resource management. The inferential models are important methods for calculating reference values; however, the dependence and “cluster” in time series make time series data difficult to be applied in these methods. A new method based on Markov chain theory, which is used for modeling the dependence of data, and extreme statistics was proposed. The new method was used to estimate the nutrient and chlorophyll a reference conditions in Taihu Lake, which is the third largest freshwater lake in China. The results showed that there was remarkable dependence between the effective observations of total nitrogen (TN), total phosphorus (TP), and chlorophyll a. The recommended reference conditions of TN, TP, and chlorophyll a in Taihu Lake were 0.69 mg/L, 0.029 mg/L, and 1.89 μg/L. Their 95% confidence intervals were 0.62–0.76 mg/L, 0.028–0.030 mg/L, and 1.55–2.23 μg/L. These results were consistent with previous researches, which showed that the proposed method is reliable and effective. The length of the intervals was remarkably reduced when compared with several methods. This implied that the proposed method could make full use of the observation data in time series and significantly improve the precision of the estimation results of reference conditions. In general, the proposed method could provide high precision and reliable lake nutrient reference conditions, which would be beneficial to lake water resource management and can be used for estimating the TN, TP, and chlorophyll a reference conditions of other lakes.

Proposal of a typology of karst systems functioning based on relevant indicators of karst springs hydrodynamics

2021 ◽  
Author(s):  
Guillaume Cinkus ◽  
Naomi Mazzilli ◽  
Hervé Jourde
Keyword(s):  
Time Series ◽  
Resource Management ◽  
Water Resource ◽  
Water Resource Management ◽  
Spring Discharge ◽  
Karst Water ◽  
Discharge Time ◽  
Wide Range ◽  
Karst Systems ◽  
Hydrological Functioning

<p>10% of the world’s population is dependent on karst water resources for drinking water. Understanding the functioning of these complex and heterogeneous systems is therefore a major challenge for long term water resource management. Over the past century, different methods have been developed to analyse hydrological series, and subsequently characterize the functioning of karst systems. These methods can be considered as a preliminary step in the development and design of hydrological models of karst functioning for sustainable water resource management. Recent progress in analytical tools, as well as the emergence of data bases of discharge time series (e.g. the French SNO KARST database and the WoKaS database at global scale) allow reconsidering former typology of karst system hydrodynamic responses. Ten karst systems and associated spring discharge time series were considered for developing the typology. The systems are well-known with a high-quality monitoring and they cover a wide range of hydrological functioning, which ensure the relevance of the analyses. The methodology for the assessment and the development of the typology consisted in (i) the analysis of springs discharge time series according to four different methods, (ii) the selection or proposal of the most relevant indicators of karst systems hydrodynamics, and (iii) the interpretation of the information from these indicators based on principal component analysis and clustering techniques. A typology of karst systems accounting for 6 different classes is finally proposed, based on 3 aspects of functioning: the capacity of dynamic storage, the draining dynamic of the capacitive function and the variability of the hydrological functioning. The typology was applied to a wider dataset composed of spring discharge of 78 karst systems. The results show a relevant distribution of the systems among the different classes.</p>

scholarly journals Estimation of annual reference condition of Chlorophyll-a based on the segmental linear regression and power-law relationship in Taihu Lake

2018 ◽  
Vol 19 (1) ◽  
pp. 107-114
Author(s):  
Liang Wang ◽  
Zulin Hua ◽  
Yulin Wang
Keyword(s):  
Water Quality ◽  
Linear Regression ◽  
Chlorophyll A ◽  
Power Law ◽  
Taihu Lake ◽  
Reference Conditions ◽  
Reference Value ◽  
Reference Condition ◽  
New Method ◽  
Change Points

Abstract The reference conditions of Chlorophyll-a in lakes should be established in order to improve the water quality in these water bodies. A new method using segmental linear regression was developed to estimate the reference condition of Chlorophyll-a. The method can overcome the shortcomings of other methods, such as the quantile-selection-based method, which contains a certain level of subjectivity. The new method was used to estimate the annual reference condition of Chlorophyll-a in Taihu Lake. The log–log segmental regression results indicate that the distribution of specific volume (reciprocal of concentration) of Chlorophyll-a in Taihu Lake had a power-law tail. Both segmental regression and bootstrap approaches show two credible change points in the power-law relationship. This study's analysis shows that the value of 4.4 mg·m−3 was an appropriate annual reference value of Chlorophyll-a in Taihu Lake. Thus, the method would be useful in determining the numerical reference conditions of Chlorophyll-a for other shallow lakes.

Catchment surveillance for water resource management

Waterlines ◽  
1997 ◽  
Vol 16 (1) ◽  
pp. 23-25
Author(s):  
Barry Lloyd ◽  
Teresa Thorpe
Keyword(s):  
Resource Management ◽  
Water Resource ◽  
Water Resource Management

Water Resources Management in the Semi-Arid Central Valley of California

1987 ◽  
Vol 19 (9) ◽  
pp. 97-106
Author(s):  
J. J. Vasconcelos
Keyword(s):  
Resource Management ◽  
Ground Water ◽  
Water Resource ◽  
Water Resource Management ◽  
Arid Regions ◽  
Central Valley ◽  
The United States ◽  
Policy Makers ◽  
Ground Water Resource ◽  
Semi Arid

Hater resource managers in semi-arid regions are faced with some unique problems. The wide variations in precipitation and stream flows in semi-arid regions increase man's dependence on the ground water resource for an ample and reliable supply of water. Proper management of the ground water resource is absolutely essential to the economic well being of semi-arid regions. Historians have discovered the remains of vanished advanced civilizations based on irrigated agriculture which were ignorant of the importance of proper ground water resource management. In the United States a great deal of effort is presently being expended in the study and control of toxic discharges to the ground water resource. What many public policy makers fail to understand is that the potential loss to society resulting from the mineralization of the ground water resource is potentially much greater than the loss caused by toxic wastes discharges, particularly in developing countries. Appropriations for ground water resource management studies in developed countries such as the United States are presently much less than those for toxic wastes management and should be increased. It is the reponsibility of the water resource professional to emphasize to public policy makers the importance of ground water resource management. Applications of ground water resource management models in the semi-arid Central Valley of California are presented. The results demonstrate the need for proper ground water resource management practices in semi-arid regions and the use of ground water management models as a valuable tool for the water resource manager.

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