Publication Date: 2024
Water Resources Management (09204741)38(3)pp. 881-892
In this study, variations of macroinvertebrates are considered as a criterion for assessing biological diversity and ecosystem health in the downstream reach of a river-reservoir system. Unlike most of the previous studies, this biological diversity index is then used in a multi-objective reservoir operation optimization model as an objective function instead of a constraint. Two objectives of supplying water demand and ecological diversity were maximized for the case of the Aboulabbas Dam in Khuzestan Province in southwest of Iran. Based on the historical records of water quality and macroinvertebrate samples, a relationship between these two parameters was used in the optimization model formulation. Evaluation of the results in a 10-year period and comparison with single-objective optimization shows that using the proposed methodology, the biodiversity and ecosystem health has been improved while achieving an acceptable level of water supply reliability. © The Author(s), under exclusive licence to Springer Nature B.V. 2024.
Publication Date: 2023
Journal of Hydrology (00221694)626
Satellite-based terrestrial water storage changes have been recorded using the Gravity Recovery and Climate Experiment (GRACE) satellite which causing it an important dataset in hydrology and other related fields. GRACE dataset is widely utilized in many studies, but its coarse spatial resolution is a limiting drawback. Machine-learning approaches (e.g., ANN and SVM) are commonly applied in spatially downscaling. However, their input formation, which is in vector form, is a limitation of considering neighbor relations between the gridded-based inputs, specifically in spatial downscaling. Thus, developing an appropriate, simple, fast, and novel model to spatially downscale GRACE resolution is initially necessary for its utilizations. In this study, a Spatially Promoted Support Vector Machine (SP-SVM) model is innovatively proposed for GRACE downscaling from 0.5° to 0.25°. This promotion is investigated utilizing the distances between the unknown target points (with 0.25°) and their surrounding GRACE-valued points (0.5°), called their Distance Effect Coefficient (DEC), as the SP-SVM model input. In addition, the efficiencies of different in-situ and satellite-based datasets (fifteen variables from May 2005 to August 2020) are evaluated as the inputs of the GRACE downscaling models. After finding the most influential datasets, showing the best correlation with the GRACE, their best combinations in GRACE downscaling are identified. Based on the results, the set of PERSIANN-CDR without delay, the in-situ evaporation with a 1-month delay, and the soil moisture in 0–10 cm depth with a 1-month delay show the best performance in GRACE downscaling. The results of GRACE downscaling by the SP-SVM approach are also compared with the ones based on a usual statistical SVM (S-SVM) model, consisting of an intermediate bias interpolation to improve the estimations through a bias correction step. The results show that the SP-SVM model outperforms the common statistical SVM-based. Thus, compared with the usual S-SVM approach, the proposed SP-SVM (linear) model could be used as a simpler and more accurate model for downscaling any variable in a hierarchical process. © 2023
Publication Date: 2021
Journal Of Environmental Health Science And Engineering (2052336X)19(2)pp. 1613-1621
Coronavirus disease 2019 (COVID-19) and its spread prevention actions (SPAs) have affected a large number of human activities globally in 2020-2021. Temporary lockdowns, stay-at-home policies, movement restrictions, and personal health care actions have relatively changed the daily life routine in urban areas which can eventually affect the characteristics of municipal wastewater (MW). This study evaluates the performance of wastewater treatment plants (WWTPs) during COVID-19 pandemic and related SPAs. This evaluation also considers MW variations in quality and quantity and compares the performance of WWTPs (2020) with earlier data (2015–2019). For this purpose, 23 WWTPs located in Isfahan province, Iran, were chosen as the study area and classified based on their locations, biological treatment unit, and capacities. Results indicate that the inflow of WWTPs increased 20 % on average during SPAs, while the concentrations of COD and BOD in MW decreased 23 and 16 %, respectively. Nevertheless, the performance of WWTPs remained rather constant. It is concluded that increasing the dilute domestic proportion of MW, particularly in smaller communities, as a matter of COVID-19 SPAs could not impose adverse impacts on wastewater treatment operations and pollution removal. Different types of secondary treatment units, such as activated sludge, stabilization pond, and aerated lagoon showed stable performances. However, disinfection was enhanced in WWTPs in order to reduce the probability of viral transmission via wastewater for reuse. This study also recommends that the characteristics of MW, and not treated wastewater, can be used as an indicator for coordinating SPAs in similar epidemics. This notification can be helpful for the management of WWTPs and risk control in urban areas. © 2021, Springer Nature Switzerland AG.
Publication Date: 2014
Journal Of Environmental Health Science And Engineering (2052336X)12(1)
The ecosystem health of rivers downstream of dams is among the issues that has become focus of attention of many researchers particularly in the recent years. This paper aims to deal with the question, how the environmental health of a river ecosystem can be addressed in water resources planning and management studies. In this study, different parameters affecting the ecosystem of river-reservoir systems, as well as various biological components of river ecosystems have been studied and among them, benthic macro-invertebrates have been selected. Among various bio-indices, biodiversity indices have been selected as the evaluation tool. The case study of this research is Aboulabbas River in Khuzestan province in Iran. The relationship between the biodiversity indices and physicochemical parameters have been studied using correlation analysis, Principal Component Analysis (PCA), and Genetic Programming (GP). Margalef index was selected as the appropriate bio-index for the studied catchment area. The relationship found in this study for the first time between the Margalef bio-index and physicochemical parameters of water in the Aboulabbas River has proved to be a useful tool for water resources managers to assess the ecosystem status when only physicochemical properties of water are known. © 2014 Yazdian et al.; licensee BioMed Central Ltd.
