Papers by Timothy Randhir
Hydrology Research, Dec 30, 2022
Hydropower projects involve enormous investments that require an efficient cost-benefit framework... more Hydropower projects involve enormous investments that require an efficient cost-benefit framework and optimization model for proper development. Dams and hydropower plants have many impacts on the environment. These environmental impacts are often not included in the economic calculations and planning of the projects, which leads to the loss of natural resources. The primary purpose of this research is to incorporate environmental impacts into optimization and decision-making. A comprehensive simulation-optimization model is developed to optimize hydropower decisions. The positive and negative values of environmental impacts are incorporated into an economic objective function under different scenarios, and optimal design was done for each scenario. The results show that considering environmental economics affects the multipurpose hydropower project's NPV and decision outcomes. Considering environmental impacts compared to not considering them has reduced NPV of the project by 13.9%. The results emphasize the importance of including these impacts to achieve sustainable development and management.
SWAT-SF: A flexible SWAT-based model for watershed-scale water and soil salinity modeling
Journal of Contaminant Hydrology, 2022
Natural and anthropogenic complex processes release salts into the environment. These change the ... more Natural and anthropogenic complex processes release salts into the environment. These change the balances of natural systems in the watersheds. Models can assist study of salinity processes throughout watersheds. This study proposes a flexible water and soil salinity module for the Soil and Water Assessment Tool (SWAT) that can profitably incorporate expert scientific judgments into a deterministic salinity framework to adapt predicted salinity processes to actual salinity processes watershed-scale. The proposed flexible salinity model (SWAT-SF) was developed using new equations for salinity assessment and then successfully applied to the Dehram River Basin located south of Iran that endangers natural and anthropogenic salinity problems. The SWAT-SF model uses a general framework that can be utilized with/without the direct guidance of experts for the determination of salinity processes, the extent of the salinity, identification and investigation of the saline site, assessment and management of the salinity, and evaluation of salinity economics throughout the world.
اکوهیدرولوژی, Jun 22, 2021
Water Air and Soil Pollution, Aug 21, 2014
Natural resource habitats, which are isolated from the surface water bodies, are often unregulate... more Natural resource habitats, which are isolated from the surface water bodies, are often unregulated and face a higher risk of degradation. Vernal pools, habitats for amphibians, are vulnerable to external stressors that often lead to decline in biodiversity. There is a need to protect these through conservation measures at a spatially targeted level. This study is conducted in the Middle Connecticut River Watershed of Massachusetts State. We evaluate the risk faced by isolated vernal pools at the subwatershed scale. The assessment involves the impact of agricultural intensity and vernal pool distribution in proximity to agriculture parcels. This is performed using geoprocessing techniques within a geographic information system (GIS). The spatial data are used in a nonlinear regression model to evaluate potential stressors to vernal pool existence. The model included land use, geographic features, and hydrographic factors. Agriculture and open land positively influence vernal pool existence, because of vernal pool association with low-lying areas. In addition, elevation showed a negative influence on the number of vernal pool habitats. The results of the spatial risk evaluation of habitat are helpful to target efforts on specific subwatersheds in conserving vernal pool habitats.
Agronomy
Salt stress is a major issue in agriculture and crop production that influences global food secur... more Salt stress is a major issue in agriculture and crop production that influences global food security. Mitigation options to address salt stress through agronomic practices can help manage this issue. Experiments were performed in two summer seasons in an experimental farm to test the impact of three salinity levels (S): 300 (control), 1000, 2000, and 3000 ppm, and two salicylic acid (SA) levels, including 1.0 and 1.50 mM, and their interaction on growth and yield of eggplant (Solanum melongena L.) hybrid Suma. The results showed that increasing S levels up to 3000 ppm reduced plant and fruit physical characteristics, as well as leaf and fruit chemical characteristics, especially leaf total chlorophyll, carotenoids, relative water, fruit nitrogen, phosphorus, and potassium contents, which led to a reduction in total yield per plant. However, an insignificant effect was observed in the control level and 1000 ppm saline water in leaf area, fruit length, leaf total chlorophyll content, ...
Life
Plant diseases are biotic stresses that restrict crop plants’ ability to develop and produce. Num... more Plant diseases are biotic stresses that restrict crop plants’ ability to develop and produce. Numerous foliar diseases, such as chocolate spots, can cause significant production losses in Vicia faba plants. Certain chemical inducers, including salicylic acid (SA), oxalic acid (OA), nicotinic acid (NA), and benzoic acid (BA), were used in this study to assess efficacy in controlling these diseases. A foliar spray of these phenolic acids was used to manage the impacts of the biotic stress resulting from disease incidence. All tested chemical inducers resulted in a significant decrease in disease severity. They also enhanced the defense system of treated plants through increasing antioxidant enzyme activity (Peroxidase, polyphenol oxidase, β-1, 3-glucanase, and chitinase) compared to the corresponding control. Healthy leaves of faba plants recorded the lowest (p < 0.05) values of all antioxidant activities compared to those plants infected by Botrytis fabae. Moreover, the separation...
Diversity
The types and intensification of land use in the watershed affect the living organisms in aquatic... more The types and intensification of land use in the watershed affect the living organisms in aquatic ecosystems differently; this impact will also vary according to temporal and spatial scales. Understanding these interactions is crucial in the design of biomonitoring programs to detect the effect of different pollutants in freshwater ecosystems and improve watershed management and conservation strategies. Therefore, this paper qualitatively reviews biomonitoring studies in freshwater ecosystems to evaluate the impact of different land use types on multiple scales in watersheds. The paper is organized into four sections. The first section presents biomonitoring in different freshwater systems (streams, rivers, lakes, and reservoirs). In the second section, we describe the biomonitoring characteristics of the main land use types. In the third section, we explain how spatial and temporal scales affect biomonitoring. Finally, in the fourth section, we focus on biomonitoring planning and f...
Agronomy
Fennel fruits (Foeniculum vulgare Mill.) represent one of the plant-based natural spices. This st... more Fennel fruits (Foeniculum vulgare Mill.) represent one of the plant-based natural spices. This study aims to improve the fruit yield and essential oil (EO) quality by reducing the undesirable component, estragole, under different fertilizer treatments. The fertilizers included chemical nitrogen, phosphorus, and potassium (NPK), and also the organic additive, rabbit manure (RM). For bio-fertilization, plants were inoculated with a mixture of N-fixing bacteria, and P- and K-solubilizing bacteria with/without vesicular-arbuscular mycorrhizal fungi. The results showed that fruit and EO yield parameters, total phenolic content (TPC), total flavonoid content (TFC), and DPPH scavenging activity of fruit extracts were enhanced by fertilizer treatments in both growing seasons. NPK at 150% of the recommended dose (NPK150) and RM at 60 m3/fed (RM60) recorded the highest values of plant height, umbel number/plant, 100-fruit weight, fruit yield, chlorophyll, carbohydrates, N and P content, EO co...
PLOS Water
The changes in energy balance resulting from land-use change may significantly affect the amount ... more The changes in energy balance resulting from land-use change may significantly affect the amount and timing of water loss to the atmosphere as evapotranspiration (ET). Also, these will impact water fluxes in the watershed system, influencing runoff rate, flow volume, intensity, and frequency of floods. During the past century, land-use change in the SuAsCo (Sudbury-Assabet and Concord) watershed has altered basin hydrology, sediment, and nutrient load that is detrimental to water resources in SuAsCo. This study uses an integrated physically-based model Hydrological Simulation Program-FORTRAN (HSPF), along with Land Transformation Model (LTM), to assess predicted temporal and spatial changes in water, nutrient, and sediment yields for future land-use scenarios of 2035, 2065, and 2100. Results showed that a 75% increase in effective impervious area and a 50% decrease in forest area in 2100 (from 2005 baseline levels) are projected to cause a 3% increase in annual streamflow and a 69% ...
Monitoring Groundwater Storage Based on Satellite Gravimetry and Deep Learning
Natural Resources Research
A Multi-Indicator, Non-Cooperative Game Model to Resolve Conflicts for Aquifer Restoration
Water Resources Management
An integrated framework for simultaneously modeling primary and secondary salinity at a watershed scale
Journal of Hydrology
Development of the support vector regression–particle swarm optimization simulation‐optimization model for the assessment of a novel groundwater quality index
Water and Environment Journal
The assessment and prediction of the groundwater resource quality are required for the sustainabl... more The assessment and prediction of the groundwater resource quality are required for the sustainable management of this crucial resource. This study develops a new index for assessing and a model for predicting the quality of groundwater resources. The groundwater quality index (GWQI), the Shannon entropy method, was used to determine the weight of parameters, and the complex proportional assessment multi‐decision criteria method was used to score the GWQI. Water quality parameters, including TDS, EC, TH, , , , pH, , , and , were used as decision criteria. The support vector regression–particle swarm optimization )SVR‐PSO( simulation–optimization model is developed to predict new GWQI (C‐GWQI) of the aquifer. The development of this new index called C‐GWQI is one of the innovations of this article. Based on these approaches, the index is used to determine three water quality classes (optimum, permissible, and impermissible) for drinking water following World Health Organization (WHO) ...
Species richness patterns of waterbirds overwintering on the Jiangsu coast for coastal reclamation
Ocean & Coastal Management
Abstract It is vital to identify factors that affect the overwintering of waterbirds for conserva... more Abstract It is vital to identify factors that affect the overwintering of waterbirds for conservation purposes. In this study, during the winter of 2018–2019, we documented 177,414 individuals of 74 species of waterbirds in the Jiangsu coastal area, an important but poorly known overwintering location. Of the species observed, 12 were listed as threatened. We found that natural wetlands loss is a significant contributor to population declines among overwintering waterbird species in the Jiangsu coastal area, greater than anthropogenic disturbance. This loss has forced waterbirds to choose artificial wetlands, where a total of 47 species were detected. Sorted by key zones for overwintering waterbirds, 16 surveying zones were identified in the area, and most are not fully protected. Thus, conservation efforts aimed at waterbirds should focus on at least 12 conservation gaps in diversity hotspots, emphasizing the management of artificial wetlands in the Jiangsu coastal area.
Tropical and Subtropical Agroecosystems, Aug 31, 2021
Background: Technology adoptions are the main challenge to achieve transition toward sustainable ... more Background: Technology adoptions are the main challenge to achieve transition toward sustainable livestock production. Objective: This research evaluated factors that influence the silvopastoral technology adoption in Chiapas, Mexico. Methodology: Used an integrative methodology relates variables institutional performance, knowledge, and perception of producers on livestock system and interaction between actors. The above was linked to a physical context with satellite imagines analysis to identify components adopted in the field. Results: It was found that the type of producer, the location of the property, and the form of institutional support limit the adoption of herd management and feed production intensification technologies such as protein banks and forage banks. Implications: This methodology helped identify the limiting factors for adoption, understand the project process, and identify strategies towards sustainable practices. Conclusion: The low adoption of technologies is determined by the decision-making of producers on factors such as pest and disease control, climatic, economic and access to machinery and equipment that are influenced by the social synergies that can be built with technicians and with other producers.
Stimulatory effects of growth-promoting bacteria on growth, nutritional composition, and yield of kale plants
Journal of Plant Nutrition, 2022
Fig. 3 in Assessing large mammal and bird richness from camera-trap records in the Hukaung Valley of Northern Myanmar
Fig. 3. Trend lines, correlations and p-values for the relationship between number of camera trap... more Fig. 3. Trend lines, correlations and p-values for the relationship between number of camera trap nights per season per area (effort) versus number of species photographed (diversity) in the Core study area (solid line & solid circle) and at and near camera trap locations Outside the Core area (dash line & hollow circle) in the Hukaung Valley, Myanmar (season [= year] data from Naing 2015).
Fig. 1 in Assessing large mammal and bird richness from camera-trap records in the Hukaung Valley of Northern Myanmar
Fig. 1. Location of Hukaung Valley Wildlife Sanctuary and Core study area (hatched) in Northern M... more Fig. 1. Location of Hukaung Valley Wildlife Sanctuary and Core study area (hatched) in Northern Myanmar.
Mammalian And Avian Biodiversity In The Hukaung Valley Of Northern Myanmar
Forecasting urban water consumption using bayesian networks and gene expression programming
Earth Science Informatics, 2022
Forecasting Urban Water Consumption (UWC) has a significant impress in efficient urban water mana... more Forecasting Urban Water Consumption (UWC) has a significant impress in efficient urban water management in rapidly growing cities in arid regions. Enhancing forecasting accuracy of UWC using novel models is a crucial requirement in order to the management of smart cities. In this study, Bayesian Networks (BN) is developed as a probabilistic model and compared to Gene Expression Programming (GEP) model as an evolutionary algorithm for forecasting UWC. The amount of current water consumption predicts future water consumption. The scenario with sunshine hours was added to the parameter set as the best scenario in both BN and GEP models based on comparison of Root Mean Square Error (0.11, 0.16), Mean Absolute Relative Error (0.02, 0.05), Max Root Error (0.26, 0.26), and Coefficient of determination (0.8, 0.7), respectively. The outcomes indicate that the BN model provided a more desirable efficiency compared to the GEP model. Furthermore, it can be concluded that the sunshine hour has a considerable influence on UWC, and the ability of the BN model is greatly enhanced by adding this predictor to forecast UWC in a city in an arid region with rapid population growth. BN and GEP models were developed for forecasting Urban Water Consumption. The BN model provided a more accurate and desirable performance than the GEP model. The forecasting of UWC was enhanced using new predictors comparing to former models.
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Papers by Timothy Randhir