Sustainability of Water Quality and Ecology最新文献

Control and management of stormwater volume and water quality is an important concern in Iran and there is little or insufficient scientific information in assessing domestic roof harvested rainwater quality by suitable indicators. The objectives of this study were (1) to determine water quality factors which vary significantly with roof materials and first flush, (2) to select an indicator from these factors that can be used for water quality monitoring in roof runoff and (3) to find out whether a relationship exists between the resulting roof runoff water quality (WQI) and air quality parameters. Factor analysis (FA) was used to identify water quality factors and discriminant analysis (DA) was used to determine the factors and an indicator most sensitive to first flush and posterior roof runoff within mosaic tile and bitumen roofing material. Therefore, seven water quality parameters were measured in 28 runoff samples collected from two mosaic tile and bitumen roofs in seven rainfall events. FA identified three factors that explained 82.8% of the variation in water quality parameters. Discriminant analysis selected phosphate and nitrate as the most sensitive parameters in domestic roof harvested rainwater. Correlation analysis of the resulting roof runoff WQI with the air quality parameters showed that the indicator has significant correlation with most air quality parameters. Forward stepwise general regression model revealed that the roof water quality indicator values were explained by air SO₂. This suggests that domestic roof harvested rainwater quality could be controlled by air quality characteristics.

Estuaries are increasingly affected by deteriorating water quality associated with a burgeoning human population. As such, there is a need to establish water quality baselines and elucidate whether shifts in water quality are attributed to anthropogenic activities or the dynamic nature of estuaries. Here we investigate an extensive water quality dataset collected from 2006 to 2015 within the Loxahatchee River, Florida watershed. Results indicate substantial spatial variation in water quality within the watershed, though most locations were in line with established state water quality standards. Chlorophyll a state nutrient criteria had the greatest number of exceedances over the period of record in brackish and marine river regions, while freshwater regions exhibited the most variable water quality conditions overall. Water quality appears to be largely influenced by suburban stormwater runoff, septic tank effluent, and relic row crop agricultural practices, though more work is required to identify point and non-point sources of nutrient loading. Most sites were phosphorus-limited, likely as an indirect result of anthropogenic activities, phosphorus adsorption to carbonate sediments, and freshwater phosphorus limitation. Systematic water quality monitoring efforts are critical to help resource managers improve the ecological integrity of estuaries.

The water availability in Kazakhstan is 37000 m³ per one km² and 3650 m³ per capita a year, an amount that is lower than the world average (around 6000 m³) (Knoema, 2016). It is expected that water availability falls to 2300 m³ per capita in a year by 2030 (FAO, 2016a). Water pollution is a further problem for exploiting available water resources. In fact, 50–70% of surface water resources in Kazakhstan have been rated “polluted” and “highly polluted” in terms of ecological status (ICSD, 2016). Apart from that, water use efficiency remains very low. The average efficiency of canal water delivery systems is only 15–20% compared to 70–90% in most developed countries (FAO, 2016b). A number of institutional and policy measures have been implemented to enhance the sustainability of water resource use and water security; however, the country is still facing a number of problems of water use in a sustainable manner. This study provides stakeholders’ assessment of the critical factors that affect the sustainable management of water resources in Kazakhstan. The study rests on the results from the interviews that are further examined using the SWOC approach (Strengths, Weaknesses, Opportunities, and Challenges) and the Analytic Hierarchy Process (AHP) technique. The study demonstrates and prioritizes 32 critical SWOC factors relevant to the sustainable management of water resources in Kazakhstan. The study also determines four key stakeholder groups with differing opinions regarding the SWOC factors, which could potentially impact final policy implementation. Creating a comprehensive regulatory framework alongside decentralising water management from state water authorities to community-based water-user associations as well as investment to innovative irrigation technologies are likely to contribute towards a more equitable and efficient water distribution.

Wetland ecosystem services provide social benefits. These services are vulnerable due to human activities. The present research concerns perceptions of declining wetland ecosystem services and their effects on water quality parameters. The percentages of provisioning, regulating, cultural and supporting services were found to overshadow ecosystem services, such that generation of goods and values in the studied wetlands are in jeopardy. Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), turbidity, conductivity, Total Dissolved Solids (TDS), Dissolved Oxygen (DO), heavy metals and salts were measured as indicators of water quality. Many significant correlations were observed and many of these parameters exceeded regulatory limits. Lead (Pb) in wetland 0.09 mg/L far exceeded the safe limit (0.01–0.05 mg/L), while turbidity in wetland 21.12 was too high to sustain fish. Wetland water pH was significantly correlated (p ≤ 0.01) with Cd. TDS was found to have a significant (p ≤ 0.01; p ≤ 0.05; p ≤ 0.1) correlation with conductivity, Ca²⁺, BOD, and DO. The conductivity increased (p ≤ 0.01) with increasing Ca²⁺ concentrations. COD was significantly different (p ≤ 0.1) with Pb, Cd and Cl⁻. BOD increased with increasing Ca²⁺ concentrations (p ≤ 0.05). Continuous monitoring of water quality indicators (turbidity, EC, pH, DO, TDS, COD, BOD, cations, and anions) is crucial for improving of wetland ecosystem services and sustainability of communities.

Access to safe drinking water is an important public health and development issue at national, regional and local levels. Community drinking water supplies such as piped water, dug wells and springs are the predominant sources in rural villages and towns in Ethiopia. A retrospective analysis was conducted on microbial quality of community drinking water sources that had been processed from 2004–2014. Water samples were collected from 36 districts in west Amhara region. As per standard operational procedures, bacteriological analyses had been performed using multiple tube fermentation technique. A total of 1030 drinking water samples from (tap water n = 680), wells (n = 198), spring (n = 128) and reservoir (n = 24) were analyzed for microbial qualities. Overall, 29.0% (95% CI: 26.3–31.8%) and 44.7% (95% CI: 41.7–47.7%) of water samples had Escherichia coli and total coliforms (TC), respectively. Furthermore, 52.0%, 43.0%, and 20.2% of water samples from wells, spring and tap water were positive for E. coli. For faecal coliforms, 72.1% of drinking water supplies complied with World Health Organization and Ethiopian Standards. Tap water samples were 3.8 times less likely to be faecal contaminated than water samples from dug wells and spring water sources (OR = 3.8, 95% CI: 2.8–5.1, P = 0.001). This ten year trend analyses showed that microbial qualities of community drinking water supplies were not to the standards. This study reinforces the need to monitor microbial quality and chlorine treatment of community water supplies.

The Texas Water Availability Modeling (WAM) System consists of the generalized Water Rights Analysis Package (WRAP), which is applicable for river systems located anywhere, and WRAP input datasets for the river basins of Texas. The WRAP/WAM system has been applied for over a decade in planning studies and administration of a water rights allocation system. Environmental flow standards for selected river systems in Texas have recently been established through a legislatively mandated process based on flow regimes with subsistence, base, pulse, and overbank flow components that describe the magnitude, frequency, duration, and timing of flows required to maintain sound ecosystems. WRAP and WAM capabilities for integrating environmental flow requirements in water allocation and associated water availability modeling have been greatly expanded as necessary to implement the new environmental flow standards. The modeling system and lessons learned in its implementation in Texas are relevant elsewhere.

Adequate river quality monitoring is of major importance for riverine environmental sustainability. This study develops a methodology for real-time water quality measurement in a river at 30 m spatial and 1 day temporal scales using the satellite remote sensing technique to support daily water quality monitoring usually done at gauges. Considering the limited spatio-temporal resolutions of all the current satellite products, this study integrates the corrected band-specific Landsat and Moderate-resolution Imaging Spectroradiometer (MODIS) surface reflectance values, identified by a physically-based approach, with the observed pollutant concentrations. A combination of regression analysis and genetic algorithm (GA) based multivariate nonlinear formulations among the Landsat versus MODIS surface reflectances and Landsat surface reflectance versus in-situ pollutant concentration is used to estimate eight water quality parameters. All the possible combinations of the Landsat and MODIS satellite bands containing the spectral signature of pollutants are selected as independent variables. Linear and nonlinear regression analysis is carried out for these combinations using the SPSS software to get the best (significant) correlated relations which are, further, enhanced using the GA. This formulation is applied and tested in the Brahmani River located in eastern India’s Odisha state for its real-time application; and water quality mapping is carried out for a typical river reach of the Brahmani River. A Monte-Carlo simulation based uncertainty and sensitivity analysis of the used algorithms reveal that the methods have the potential to be used in ungauged river reaches.