Time series analyses of biological and environmental variables for Suisun Bay and the Sacramento and San Joaquin rivers

EXTRACT (SEE PDF FOR FULL ABSTRACT): Arima analysis was used to compute cross-correlations between principal component axes that described environmental variables, chlorophyll concentration and zooplankton density for the Sacramento and San Joaquin rivers and Suisun Bay. ... Cross-correlations among the time series may provide information about links between environmental and biological variables within the estuary and the possible influence of climate.

Impact assessment of Farakka barrage on environmental issues at Bheramara Upazila, Bangladesh

Different problems have been created on the downstream territory, especially on Bheramara on the bank of mighty river Padma. The study is preferred to assess the impacts on river flow of Ganges water, and on fisheries, agriculture, irrigation, groundwater, livelihood, and biodiversity because of Farakka Barrage. Information were collected from various respondents among which 42% is farmer, 12% is fisherman, 36% is businessman and 10% is service holder. It is evident from this study that 65% of crops production were directly affected by Farakka Barrage, in which 34% crops were damaged due to scarcity of water, lowering the ground water level, less access to rainwater, etc. and 66% crops were invent for increasing char land, increasing soil fertility for the use of agrochemicals. Irrigation has been adversely affected because of 35% insufficient flow of water and 65% lowering the ground water level.

Biodiversity and socio-economic information of selected areas of Sri Lankan side of the Gulf of Mannar

Rapid biodiversity and socio-economic studies of the Gulf of Mannar were required as part of the process to propose the Sri Lankan side as a Biosphere Reserve. These included livelihoods; land use; infrastructure; biodiversity; agriculture; fisheries; archaeological and cultural significance; and development and environmental issues.

The relevance of limnological information in the development and management of inland fisheries

The purpose of this paper is not to justify the existence of limnologists in fishery science, but to illustrate the now well accepted view that limnology holds the key to the understanding of fish production, and that an understanding of environmental relationships and the modification rates at all trophic levels must be the basis of enlightened management.

Environmental factors influencing composition, abundance and distribution of water hyacinth

Relationships between nutrient concentrations and water hyacinth biomass and composition have been studied in the shallow inshore bays of lakes Victoria, Kyoga and Albert. Additional information was obtained from Victoria Nile, Albert Nile and Kagera River. In this section, seasonal changes in nutrients and oxygen concentrations are used to explain changes in water hyacinth composition, biomass and distribution in Lake Victoria. Lake Victoria is of particular interest because it experienced strong hyacinth infestations in 1995, a sink in 1998 and resurgence in 2001. The lake has also been extensively sampled and provides time series data in nutrient, oxygen, mixing and thermal stratification which provide an opportunity to relate water hyacinth distribution and biomass to environmental factors. The possible origins and impacts of nutrient loads into Lake Victoria are also discussed in relation to water hyacinth proliferation and distribution especially in relation to known 'hot-spots'.

Preparation of environmental monitoring plan pattern for surface water quality in Iran (Case study: Gharehsou River)

Using water quality management programs is a necessary and inevitable way for preservation and sustainable use of water resources. One of the important issues in determining the quality of water in rivers is designing effective quality control networks, so that the measured quality variables in these stations are, as far as possible, indicative of overall changes in water quality. One of the methods to achieve this goal is increasing the number of quality monitoring stations and sampling instances. Since this will dramatically increase the annual cost of monitoring, deciding on which stations and parameters are the most important ones, along with increasing the instances of sampling, in a way that shows maximum change in the system under study can affect the future decision-making processes for optimizing the efficacy of extant monitoring network, removing or adding new stations or parameters and decreasing or increasing sampling instances. This end, the efficiency of multivariate statistical procedures was studied in this thesis. Multivariate statistical procedure, with regard to its features, can be used as a practical and useful method in recognizing and analyzing rivers’ pollution and consequently in understanding, reasoning, controlling, and correct decision-making in water quality management. This research was carried out using multivariate statistical techniques for analyzing the quality of water and monitoring the variables affecting its quality in Gharasou river, in Ardabil province in northwest of Iran. During a year, 28 physical and chemical parameters were sampled in 11 stations. The results of these measurements were analyzed by multivariate procedures such as: Cluster Analysis (CA), Principal Component Analysis (PCA), Factor Analysis (FA), and Discriminant Analysis (DA). Based on the findings from cluster analysis, principal component analysis, and factor analysis the stations were divided into three groups of highly polluted (HP), moderately polluted (MP), and less polluted (LP) stations Thus, this study illustrates the usefulness of multivariate statistical techniques for analysis and interpretation of complex data sets, and in water quality assessment, identification of pollution sources/factors and understanding spatial variations in water quality for effective river water quality management. This study also shows the effectiveness of these techniques for getting better information about the water quality and design of monitoring network for effective management of water resources. Therefore, based on the results, Gharasou river water quality monitoring program was developed and presented.