Status of river basin projects, Connecticut : October 1987 /

"March 1988."

Co-occurrence of Helicobacter pylori with faecal bacteria in Nairobi river basin: public health implications.

Introduction: Overwhelming evidence implicates Helicobacter pylori (H. pylori) as an etiologic agent of gastrointestinal diseases including gastric cancer. The mode of transmission of this pathogen remains poorly understood. Objective: This investigation is to establish the presence of H. pylori in the waters of the Nairobi river basin and the predictive value the presence of fecal indicator bacteria would have for H. pylori. Methodology: Physical, chemical and biological assessment of water quality of rivers in Nairobi were carried out using standard methods. H. pylori DNA in water was detected using highly specific primers of glmM gene (294pb). Results: There was high presence of faecal bacteria in the waters sampled. H. pylori DNA was detected in two domestic wells and one river. The wells were located in two different regions of the water basin but influenced by similar human activities. Conclusion: The high presence of faecal bacteria in the waters sampled did not parallel the H. pylori detection in the same waters. H. pylori was detected in the Nairobi river basin, but there was no relationship between the numerical levels of fecal bacteria and H. pylori.

Distribution of Ra-226, Th-232 and K-40 in soils and sugar cane crops at Corumbatai river basin, São Paulo State, Brazil

The common use of phosphate fertilizers NPK and amendments in sugar cane crops in Brazilian agriculture may increase the Ra-226, Th-232 and K-40 activity concentrations in soils and their availability for plants and human food chain. Thus, the main aim of this study was to evaluate the distribution of Ra-226, Th-232 and K-40 in soils and sugar cane crops in the Corumbatai river basin, São Paulo State, Brazil. The gamma spectrometry was utilized to measure the Ra-226, Th-232 and K-40 activity concentration in all samples. The soil-to-sugar cane transfer factors (TF) were quantified using the ratio between the radionuclide activity concentration in sugar cane and its activity concentration in soil. The results show that, although radionuclides incorporated in phosphate fertilizers and amendments are annually added in the sugar cane crops, if utilized in accordance with the recommended rates, their use does not lead to hazards levels in soils. The soil-to-sugar cane transfer of radionuclides occurred in the following order K-40 > Ra-226 > Th-232. Therefore, under these conditions, radionuclides intake through consumption of sugar is not hazardous to human health. (C) 2009 Elsevier Ltd. All rights reserved.

Limnoperna fortunei (Dunker, 1857) (Mollusca, Bivalvia, Mytilidae): first record in the São Francisco River basin, Brazil.

Limnoperna fortunei (Dunker, 1857) is a small mytilid native to Southeast Asia. It was introduced in South America in early 1990 and has dispersed from Argentina to central Brazil, and until 2014 has been restricted mainly to the Paraná and Uruguay river basins. The present note reports the occurrence of Limnoperna fortunei for the first time in the São Francisco River basin in northeastern Brazil. The establishment of L. fortunei in these regions will require close attention from the government and also by society.

Changes in biomass, chemical composition and nutritive value of Spartina alterniflora due to organic pollution in the Itanhaém River Basin (SP, Brazil)

Foram comparados a biomassa, a composição química e o valor nutritivo da macrófita aquática emersa S. alterniflora em um rio impactado por descargas de efluentes domésticos (Rio Guaú) e em um rio bem conservado (Rio Itanhaém). Amostras de S. alterniflora, água e sedimento foram coletadas nos dois rios, em novembro de 2001. O rio Guaú apresentou as maiores concentrações de N-Total e P-Total na água (415 e 674 µg.L-1, respectivamente) e sedimento (0,25 e 0,20% de Massa Seca, respectivamente), em relação a água (NT = 105 µg.L-1; PT= 20 µg.L-1) e sedimento (NT = 0,12% MS; PT = 0,05% MS) do rio Itanhaém. A biomassa aérea (316 g MS.m-2) e subterrânea (425 g MS.m-2) de S. alterniflora no rio Guaú foram significativamente maiores do que no rio Itanhaém (146 e 115 g MS.m-2). Além disto, os valores de NT, proteínas, PT, lipídios e carboidratos solúveis foram significativamente maiores na biomassa de S. alterniflora no rio Guaú. Por outro lado, a fração de parede celular e os teores de polifenóis foram maiores na biomassa de S. alterniflora no rio Itanhaém. Concluiu-se que o lançamento de efluentes domésticos em corpos d'água pode aumentar a biomassa e alterar a composição química de S. alterniflora. A maior disponibilidade de N e P no rio Guaú, provavelmente, é a causa dos maiores valores de biomassa, NT, PT, lipídeos e carboidratos solúveis em S. alterniflora neste rio.

Climate change and irrigation water requirement at Jaguaribe river basin, semi-arid northeast of Brazil.

Summary: Climate change has a potential to impact rainfall, temperature and air humidity, which have relation to plant evapotranspiration and crop water requirement. The purpose of this research is to assess climate change impacts on irrigation water demand, based on future scenarios derived from the PRECIS (Providing Regional Climates for Impacts Studies), using boundary conditions of the HadCM3 submitted to a dynamic downscaling nested to the Hadley Centre regional circulation model HadRM3P. Monthly time series for average temperature and rainfall were generated for 1961-90 (baseline) and the future (2040). The reference evapotranspiration was estimated using monthly average temperature. Projected climate change impact on irrigation water demand demonstrated to be a result of evapotranspiration and rainfall trend. Impacts were mapped over the target region by using geostatistical methods. An increase of the average crop water needs was estimated to be 18.7% and 22.2% higher for 2040 A2 and B2 scenarios, respectively. Objective ? To analyze the climate change impacts on irrigation water requirements, using downscaling techniques of a climate change model, at the river basin scale. Method: The study area was delimited between 4º39?30? and 5º40?00? South and 37º35?30? and 38º27?00? West. The crop pattern in the target area was characterized, regarding type of irrigated crops, respective areas and cropping schedules, as well as the area and type of irrigation systems adopted. The PRECIS (Providing Regional Climates for Impacts Studies) system (Jones et al., 2004) was used for generating climate predictions for the target area, using the boundary conditions of the Hadley Centre model HadCM3 (Johns et al., 2003). The considered time scale of interest for climate change impacts evaluation was the year of 2040, representing the period of 2025 to 2055. The output data from the climate model was interpolated, considering latitude/longitude, by applying ordinary kriging tools available at a Geographic Information System, in order to produce thematic maps.

Shallow Groundwater Quality and Geochemistry in the Shields River Basin, South-Central Montana

Water samples were collected from 33 domestic wells, 2 springs, and 3 streams in the Shields River Basin (Basin) in southwest Montana. Samples were collected in 2013 to describe the chemical quality of groundwater in the Basin. Sampling was done to assess potential impacts to water quality from recent exploratory oil and gas drilling and to establish baseline water quality conditions. Wells were selected in areas near and away from oil and gas drilling and in areas susceptible to contamination. Water samples from surface water sites were collected in October to characterize base flow conditions. Physical characteristics of the land surface, soils, and shallow aquifers were used to assess groundwater susceptibility to contamination from the land surface. This analysis was completed using GIS. Samples were analyzed for major ions, trace metals, water isotopes of oxygen and hydrogen. A subset (24) of samples were analyzed for tritium and organic constituents (GRO, DRO, BTEX, methane, ethylene, and ethane). One sample exceeded the human health drinking water standard for selenium. Dissolved methane and ethylene gas were detected in six samples at concentrations less than 0.184 milligrams per liter. Three locations were resampled in 2014, and no methane or ethylene was detected. Shallow groundwater and streams are generally calcium- or sodium-bicarbonate type water with total dissolved solids concentration less than 300 milligrams per liter. Some wells produce either sodium-chloride or sodium-sulfate type water suggesting slower flow paths and more rock-water interaction. Tritium concentrations suggest that older water (TU< 0.8), recharged prior to the mid-1950’s, is generally sodium type, whereas younger water (TU > 4) is generally a calcium type. Water-quality data from this study were compared to available historic data in the Basin. Additionally, the USGS Produced Waters Geochemical database was queried for chemical data of produced waters from reservoir rocks throughout Montana and the surrounding states. Comparisons to historic and produced water chemical data suggest no impact to shallow groundwater quality from exploratory oil and gas drilling.

Water Demand and Allocation in the Mara River Basin, Kenya/Tanzania in the Face of Land Use Dynamics and Climate Variability

The Mara River Basin (MRB) is endowed with pristine biodiversity, socio-cultural heritage and natural resources. The purpose of my study is to develop and apply an integrated water resource allocation framework for the MRB based on the hydrological processes, water demand and economic factors. The basin was partitioned into twelve sub-basins and the rainfall runoff processes was modeled using the Soil and Water Assessment Tool (SWAT) after satisfactory Nash-Sutcliff efficiency of 0.68 for calibration and 0.43 for validation at Mara Mines station. The impact and uncertainty of climate change on the hydrology of the MRB was assessed using SWAT and three scenarios of statistically downscaled outputs from twenty Global Circulation Models. Results predicted the wet season getting more wet and the dry season getting drier, with a general increasing trend of annual rainfall through 2050. Three blocks of water demand (environmental, normal and flood) were estimated from consumptive water use by human, wildlife, livestock, tourism, irrigation and industry. Water demand projections suggest human consumption is expected to surpass irrigation as the highest water demand sector by 2030. Monthly volume of water was estimated in three blocks of current minimum reliability, reserve (>95%), normal (80–95%) and flood (40%) for more than 5 months in a year. The assessment of water price and marginal productivity showed that current water use hardly responds to a change in price or productivity of water. Finally, a water allocation model was developed and applied to investigate the optimum monthly allocation among sectors and sub-basins by maximizing the use value and hydrological reliability of water. Model results demonstrated that the status on reserve and normal volumes can be improved to ‘low’ or ‘moderate’ by updating the existing reliability to meet prevailing demand. Flow volumes and rates for four scenarios of reliability were presented. Results showed that the water allocation framework can be used as comprehensive tool in the management of MRB, and possibly be extended similar watersheds.

The vulnerability of aquatic systems of the Upper Napo River Basin (Ecuadorian Amazon) to human activities

Aquatic ecosystems exhibit different vulnerabilities to anthropogenic disturbances. I examined this problem in the Upper Napo River Basin (UNRB), Ecuador. I ranked from 1 to 5 aquatic ecosystem uniqueness, health and threats. I stratified the basin into five Ecological Drainage Units (EDU), 48 Aquatic Ecological Systems (AES), and 203 macrohabitats. I found main threats (habitat conversion/degradation, land development, mining, oil industries, and water diversion) cover 54% of the UNRB, but have different scores and extents in each EDU. I assessed the health of 111 AESs, under three land use treatments, by analyzing the streamside zone, physical forms, water quality, aquatic life, and hydrology. Overall, health of AESs varied from 5 to 2.58, with 5 being the highest level of health. Threats and health of AESs were inversely related (F=34.119, P

Supporting land use change modelling with automated monitoring of land use dynamics in the La Plata River Basin.

2008

Sensor TTC - the La Plata River basin application: policy cases, main land use change drivers and case studies.

2008

Biophysical indicators based on satellite images in an irrigated area at the São Francisco River Basin, Brazil.

The Jaíba Irrigated Perimeter is a large irrigated agriculturearea, located in the region Forest Jaíba between the SãoFrancisco and Verde Grande rivers, in the Brazilian semi-arid region. In 2014, irrigators thisthe region face losses in theinterruption of new plantings in irrigated areas due to water scarcity. The objective ofthis study is combine the modelto estimate the Monteith BIO with the SAFER algorithm in the case of obtaining ET, to analyze the dynamics of naturalvegetation and irrigated crops in water scarcity period. For application of the model are necessary data frommeteorological stations and satellite images. Were used 23satellite images of MODIS withspatial resolution of 250mand temporal 16 days, of 2014 year. For analyze the results,we used central pivots irrigation mask of Minas Geraisstate, Brazil. In areas with irrigated agriculture with central pivot, the mean values of BIO over the year 2014 were88.96 kg.ha-1.d-1. The highest values occurred between April 23 and May 8, with BIO 139 kg.ha-1.d-1. For areas withnatural vegetation, the average BIO was 88.34 kg.ha-1.d-1with lower values in September. Estimates of ET varied withthe lowest values of ET observedin natural vegetation 1,91±1,22 mm.d-1and the highest values in irrigated area isobserved 3,51±0,97 mm.d-1. Results of this study can assist in monitoring of river basins, contributing to themanagement irrigated agriculture, with the trend of scarcity of water resources and increasing conflicts for the wateruse.

The recent occurrence, establishment and potential impact of Geophagus proximus (Cichlidae : Perciformes) in the Tiete River reservoirs: an Amazonian fish species introduced in the Parana Basin (Brazil)

The introduction of allochthonous fish species happens constantly in large bodies of freshwater, like as the reservoirs of Parana Basin, located in Brazilian southeast, representing a threat for local biodiversity. The fish species Plagioscion squamosissimus and Cichla ocellaris were introduced from the 1970s in several water bodies of this basin and had successfully established themselves in all six reservoirs located in the middle and lower Tiete River (SP, Brazil), particularly. After six decades from the first recorded species introduction, this hydrographic system remains open to the invasion of further fish species, owing to widespread fish-farming activity and by the channels opened between this system and other reservoirs and river basin. This study was an effort to confirm the Geophagus proximus occurrence in the six Tiete River reservoirs, verifying the actual introduction status and analyzing its potential environmental impacts on local species by the analysis of the population structure (abundance, body dimensions and feeding habits). By the results, this species was confirmed in the Ibitinga, Nova Avanhandava and Tres Irmaos reservoirs. The abundance and feeding analysis shows, respectively, it is successfully established in the Tres Irmaos reservoir with the same feeding habitats of local species, such as Geophagus brasiliensis. It was further shown to be very likely that G. proximus would spread throughout the reservoir system of the middle and lower Tiete River, in the manner of P. squamosissimus and C. ocellaris, and the competition pressure for food resources between G. proximus and the local species which represents a potential environmental impact system. These scientific evidences fortifies the knowledge basin for the implantation of a fish management system, to control and reduce the abundance of the invader and to prevent its becoming established in all the Tiete River Basin, avoiding the disastrous consequences for the native species of Parana River Basin.