Assimilative capacity of the atmosphere at Gorakhpur with respect to air pollution

The present study aims at seasonal and diurnal pollution potential at Gorakhpur in east Uttar Pradesh. To assess the pollution potential, meteorological data for five year period (1982-86) of Gorakhpur have been analyzed for four seasons viz; winter (December-February), summer (March-May), monsoon (June-September) and post monsoon (October-November). Season wise wind roses, stability, stability wind roses have been prepared and season wise diurnal variation of mixing height and ventilation coefficient have also been worked out. It is found that Gorakhpur has a better diffusion capacity in summer and poor in post monsoon followed by winter. Afternoon hours are better for vertical mixing. The winds are predominantly from southwest to west in all seasons except in monsoon when it blows from northeast to east. Based on this study, an appropriate location for industrialization has been suggested.

Assimilative capacity of the atmosphere at Lucknow with respect to air pollution

The present study aim at seasonal and diurnal pollution potential at Lucknow, the capital of Uttar Pradesh. To assess the pollution potential, meteorological data for five year period (1982-86) of Lucknow have been analyzed for four season, viz.; Winter (December-February), Summer (March-May), Southwest Monsoon (June-September) and Post Monsoon (October-November). Seasonwise wind roses, stability, stability wind roses have been prepared and season wise diurnal variation of mixing height and ventilation coefficient have also been worked out. It is found that Lucknow has a better diffusion capacity in summer and poor in winter. Afternoon hours are better for vertical mixing. The winds are predominant from west to north direction in all season except in monsoon where it blows from east direction.

Comparison of Deterministic and Statistical Models for Water Quality Compliance Forecasting in the San Joaquin River Basin, California

Model selection for water quality forecasting depends on many factors including analyst expertise and cost, stakeholder involvement and expected performance. Water quality forecasting in arid river basins is especially challenging given the importance of protecting beneficial uses in these environments and the livelihood of agricultural communities. In the agriculture-dominated San Joaquin River Basin of California, real-time salinity management (RTSM) is a state-sanctioned program that helps to maximize allowable salt export while protecting existing basin beneficial uses of water supply. The RTSM strategy supplants the federal total maximum daily load (TMDL) approach that could impose fines associated with exceedances of monthly and annual salt load allocations of up to $1 million per year based on average year hydrology and salt load export limits. The essential components of the current program include the establishment of telemetered sensor networks, a web-based information system for sharing data, a basin-scale salt load assimilative capacity forecasting model and institutional entities tasked with performing weekly forecasts of river salt assimilative capacity and scheduling west-side drainage export of salt loads. Web-based information portals have been developed to share model input data and salt assimilative capacity forecasts together with increasing stakeholder awareness and involvement in water quality resource management activities in the river basin. Two modeling approaches have been developed simultaneously. The first relies on a statistical analysis of the relationship between flow and salt concentration at three compliance monitoring sites and the use of these regression relationships for forecasting. The second salt load forecasting approach is a customized application of the Watershed Analysis Risk Management Framework (WARMF), a watershed water quality simulation model that has been configured to estimate daily river salt assimilative capacity and to provide decision support for real-time salinity management at the watershed level. Analysis of the results from both model-based forecasting approaches over a period of five years shows that the regression-based forecasting model, run daily Monday to Friday each week, provided marginally better performance. However, the regression-based forecasting model assumes the same general relationship between flow and salinity which breaks down during extreme weather events such as droughts when water allocation cutbacks among stakeholders are not evenly distributed across the basin. A recent test case shows the utility of both models in dealing with an exceedance event at one compliance monitoring site recently introduced in 2020.

Impact of Global Warming on Dissolved Oxygen and BOD Assimilative Capacity of the World’s Rivers: Modeling Analysis

For rivers and streams, the impact of rising water temperature on biochemical oxygen demand (BOD) assimilative capacity depends on the interplay of two independent factors: the waterbody’s dissolved oxygen (DO) saturation and its self-purification rate (i.e., the balance between BOD oxidation and reaeration). Although both processes increase with rising water temperatures, oxygen depletion due to BOD oxidation increases faster than reaeration. The net result is that rising temperatures will decrease the ability of the world’s natural waters to assimilate oxygen-demanding wastes beyond the damage due to reduced saturation alone. This effect should be worse for nitrogenous BOD than for carbonaceous BOD because of the former’s higher sensitivity to rising water temperatures. Focusing on streams and rivers, the classic Streeter–Phelps model was used to determine the magnitude of the maximum or “critical” DO deficit that can be calculated analytically as a function of the mixing-point BOD concentration, DO saturation, and the self-purification rate. The results indicate that high-velocity streams will be the most sensitive to rising temperatures. This is significant because such systems typically occur in mountainous regions where they are also subject to lower oxygen saturation due to decreased oxygen partial pressure. Further, they are dominated by salmonids and other cold-water fish that require higher oxygen levels than warm-water species. Due to their high reaeration rates, such systems typically exhibit high self-purification constants and consequently have higher assimilation capacities than slower moving lowland rivers. For slow-moving rivers, the total sustainable mixing-point concentration for CBOD is primarily dictated by saturation reductions. For faster flowing streams, the sensitivity of the total sustainable load is more equally dependent on temperature-induced reductions in both saturation and self-purification.

Comparison of Assimilative Capacity and Trophic Index for Various Parts of the Sevastopol Bay Water Area

The ecological state of the marine shallow water ecosystem (the case of the Sevastopol Bay) is analyzed by the ratio of assimilative capacity and E-TRIX index depending on the anthropogenic load level for the whole bay ecosystem. As part of analysis, the eastern, central, western parts of the bay were distinguished as well as the Yuzhnaya Bay (southern part). Calculations of the assimilative capacity and E-TRIX index for ecosystems of different parts of the Sevastopol Bay were performed using the in situ data of inorganic nitrogen for the period 1998–2012 obtained from the MHI RAS oceanographic data bank. The paper compares values of ecosystem assimilative capacity calculated for inorganic nitrogen as a prevailing pollutant in municipal and storm wastewaters and E-TRIX trophic index of the sea ecosystem, with the technogenic load and biological process seasonality (warm and cold periods) of nutrient income taken into account. This allowed to properly distinguish water areas, which are most vulnerable in terms of formation of negative ecological events, up to disasters. According to the obtained data, such an area is that of the Yuzhnaya Bay. The second vulnerable water area is the eastern apex part of the Sevastopol bay exposed to the Chernaya River discharge. As the results showed, the situation worsens during winter and spring freshets due to increase in content of inorganic nitrogen forms in the Chernaya River runoff. The ecosystem of the western bay part adjoining the open sea is the safest in terms of nitrate nitrogen assimilative capacity, whereas the central part ecosystem appears to be the cleanest in terms of E-TRIX. The ecosystem most exposed to ecological risks in terms of both indices (assimilative capacity and E-TRIX) is that of the Yuzhnaya Bay (the southern part of the Sevastopol Bay). The observed imbalance of distribution of the calculated trophic index E-TRIX and assimilative capacity in different parts of the Sevastopol Bay is due to various nature of these quantities. The assimilative capacity of an ecosystem is defined by physical, chemical and biological processes given a dynamic removal of pollutants from the ecosystem, whereas E-TRIX is determined, in general, by seasonal variability of nutrient income into the ecosystem.

assimilative capacity analysis and total maximum daily load strategy for smart water management

<p>Due to steep terrain, uneven rainfall, and high-speed streams, Taiwan's water environmental vulnerability is relatively high. Under the impact of climate change and environmental variation, Taiwan faces more and more challenges in water environmental management. Although environmental development can bring economic benefit, it can also impact the environment. Therefore, it is important to consider environmental assimilative capacity for maintaining a balance condition between environmental development and environmental protection. This study assesses the environmental assimilative capacity of several water systems in Taiwan. The total maximum daily load (TMDL) strategy considers water quality management from effluent-based control to ambient-based management to protect waterbodies based on their assimilative capacity. It is determined by a target water quality concentration and the assimilative capacity of the receiving waterbody. The concept of TMDL is similar in flood management and control. The purpose of this study is to discuss the total maximum environmental assimilative capacity of these water systems and to propose smart water management strategies for decreasing the water environmental risk and impact. Highly flexible and intelligent water management is essential for sustainable environmental development.</p>