Assessing the probability of land submergence for lowland rice cultivation in Africa using satellite imagery and geospatial data

Sub-Saharan African countries are being strongly urged to enhance their rice production, because their rice consumption and importation rates have been rapidly increasing in recent years. Areas planted to rice in Africa are classified agro-ecologically into rainfed upland, rainfed lowland, and irrigated. Rainfed lowland includes extensive areas of unexploited land that has great potential for the promotion of rice growing. For the unexploited rainfed lowlands of Ghana, we have been studying the development of low-cost rice-farming systems that require no large-scale irrigation or land reclamation. For such systems, it is important to select suitable areas where water for rice farming can be obtained naturally; floodwaters offer promise for this purpose. Delineation and mapping of floodwater prone areas suitable for rice production is important for successful utilization of this land resource. Here, we propose a method of assessing flood probability from submergence frequency, as estimated from satellite imagery and geospatial data. ALOS/PALSAR images acquired in May, June, August, and September 2010 were used to classify land and water, and then a submerged-area map was produced. From the results, we were able to accurately detect non-submerged areas and submerged areas with water depths of at least 3?cm. The number of times classified into submerged area was defined as submergence frequency, and it was approximated by distance from reservoirs representing White Volta River, ponds, and swamps. In addition, flood extent derived from reservoirs was simulated using digital elevation model (DEM). Finally, a flood probability assessment map was produced by integration of the estimated submergence frequency and flood extent simulation. The results of a comparison of soil moisture data measured at 69 points in the field and the NDVIs computed by ALOS/AVNIR showed that areas with high potential for flooding retained high levels of soil moisture and were more likely to show less deterioration of vegetation in the dry season. The validation of these results confirmed the adequacy of the flood probability assessment method.     

Water quality assessment of the Tubarão River through chemical analysis and biomarkers in the Neotropical fish Geophagus brasiliensis

The Tubarão River rises in Santa Catarina, Brazil, and has been historically affected by coal mining activities around its springhead. To evaluate its water conditions, an investigation regarding a possible decontamination gradient associated with the increased river flow toward the estuary, as well as the influence of seasonality over this gradient was performed through a series of biomarkers (vitellogenin, comet assay, lipid peroxidation, protein carbonylation, gluthatione, gluthatione S-transferase, acetylcholinesterase, light microscopy in liver, and scanning electron microscopy in gills) and chemical analysis (polycyclic aromatic hydrocarbons (PAHs) in bile and metal analysis in sediment) in the cichlid Geophagus brasiliensis. Two collections (summer and winter) were made in four distinct sites along the river, while sediments were sampled between those seasons. As expected, the contamination linked exclusively to mining activities was not observed, possibly due to punctual inputs of contaminants. The decontamination gradient was not observed, although seasonality seemed to have a critical role in the responses of biomarkers and availability of contaminants. In the summer, the fish presented higher histopathological damages and lower concentrations of PAHs, while in the winter they showed both higher genetic damage and accumulation of PAHs. The Tubarão suffers impacts from diverse activities, representing health risks for wild and human populations.     

Monitoring water quality in reservoirs for human supply through multi-biomarker evaluation in tropical fish

Paraíba do Sul River is located at a very densely inhabited region of Brazil crossing the three most industrialized states of the country (S?o Paulo, Minas Gerais and Rio de Janeiro states). As a result, industrial and farming residues as well as urban sewage are frequently disposed without appropriate treatment. The current study aimed at investigating the water quality in three reservoirs along the Paraíba do Sul River (Ilha dos Pombos, Santa Cecília and Santa Branca), through physiological, morphological, biochemical, and genetic biomarkers. The bioindicator chosen was the catfish Pimelodus maculatus, sampled during the dry (June 2008) and rainy (February 2009) seasons. Also, some water physicochemical parameters were analyzed from the sampling sites, but displayed no alterations according to the Brazilian Agency for Water Quality Legislation. Branchial carbonic anhydrase activity was inhibited in the dry season, while renal carbonic anhydrase activity was inhibited in the rainy season in the Santa Branca reservoir, indicating disturbance of osmoregulatory and acid-base regulation processes. Histopathological alterations were observed in the gills (neoplasic and tissue hyperplasia processes) and liver (necrosis), indicating serious damage to the functional integrity of these organs. A high incidence of melanomacrophage centers was observed in the liver, suggesting an intense immune response in all reservoirs. Acetylcholinesterase and catalase activity showed also differences corroborating some morphological results. Likewise, the induction of the micronucleus and DNA damage indicate genotoxicity, but mainly in the Santa Branca reservoir. Thus, the health status of P. maculatus warrants caution in the use of the water from the 3 reservoirs for direct human consumption, particularly after the accidental spill of endosulfan in November 2008, three months before the rainy season sampling.     

Risk of Hunger Under Climate Change, Social Disparity, and Agroproductivity Scenarios

Considering the projected population growth in the twenty-first century, some studies have indicated that global warming may have negative impacts on the risk of hunger. These conclusions were derived based on assumptions related to social and technological scenarios that involve substantial and influential uncertainties. In this paper, focusing on agrotechnology and food access disparity, we analyzed food availability and risk of hunger under the combined scenarios of food demands and agroproductivity with and without climate change by 2100 for the B2 scenario in the Special Report on Emissions Scenarios. The results of this study suggest that (1) future food demand can be satisfied globally under all assumed combined scenarios, and (2) a reduction of food access disparity and increased progress in productivity are just as important as climate change mitigation for reducing the risk of hunger.     

Destruction of polychlorinated naphthalenes by a high-temperature melting treatment (GeoMelt process)

A series of treatment experiments were carried out to evaluate the applicability of a high-temperature melting treatment (GeoMelt process) to the destruction of polychlorinated naphthalene (PCN) formulation. We started with 10-kg-scale experiments in which a small melting furnace was used and then scaled up to a 1-t-scale experiment in which a melting furnace that resembled an actual treatment system was used. These runs were evaluated whether destruction efficiency (DE) of total PCNs was more than 99.999 % and whether concentrations of PCNs and polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDDs/DFs) in vitrified materials, emission gas, and scrubber water were below the target levels. Because DE values and the target levels of PCNs and PCDDs/DFs in these runs were satisfactory, then we carried out a demonstrative experiment using the actual treatment system and confirmed destruction of PCNs. Based on good results of the demonstrative experiment, stock of PCN formulation was successfully treated continuously.     

Utilization of Triacetylcellulose Waste for the Production of Carbonaceous Adsorbents

Triacetylcellulose(TAC)-based globular activated carbons having the adsorption capacity comparable with commercial ones have been derived using a carbonization system developed for this purpose. The carbonization of TAC proceeds through a liquid phase causing bubbling due to the emission of the decomposition gases. The phosphorus compounds resulting from the starting material of TAC waste promote the activation reactions to produce micro-pores.     

Finite element analysis of knee injury risks in car-to-pedestrian impacts

In vehicle-pedestrian collisions, lower extremities of pedestrians are frequently injured by vehicle front structures. In this study, a finite element (FE) model of THUMS (total human model for safety) was modified in order to assess injuries to a pedestrian lower extremity. Dynamic impact responses of the knee joint of the FE model were validated on the basis of data from the literature. Since in real-world accidents, the vehicle bumper can impact the lower extremities in various situations, the relations between lower extremity injury risk and impact conditions, such as between impact location, angle, and impactor stiffness, were analyzed. The FE simulation demonstrated that the motion of the lower extremity may be classified into a contact effect of the impactor and an inertia effect from a thigh or leg. In the contact phase, the stress of the bone is high in the area contacted by the impactor, which can cause fracture. Thus, in this phase the impactor stiffness affects the fracture risk of bone. In the inertia phase, the behavior of the lower extremity depends on the impact locations and angles, and the knee ligament forces become high according to the lower extremity behavior. The force of the collateral ligament is high compared with other knee ligaments, due to knee valgus motions in vehicle-pedestrian collisions.     

Photodegradation of tetraphenyltin contained in polychlorinated biphenyl-based transformer oil simulants in alkaline 2-propanol solution

The photodegradation of tetraphenyltin (TePT) contained in polychlorinated biphenyl (PCB)-based transformer oil simulants by ultraviolet (UV) irradiation in alkaline 2-propanol solutions was examined. In the absence of PCBs, the TePT level fell to below 1% of the initial concentration within 30 min. In the absence of both PCBs and an alkali, the concentrations of tri-, di-, and monophenyltins initially increased to a few milligrams per liter, and then reduced to below the detection limits within 90 min. The addition of an alkali to the reaction solution slightly accelerated the photodecomposition of TePT. The decomposition of other phenyltins (PTs) was also accelerated. When PCBs with concentrations of approximately 80 times the initial TePT concentration were added, only a small fraction of the TePT decomposed within 100 min. Moreover, the levels of PTs did not change during irradiation. TePT and other PTs did decompose when the level of PCBs was reduced to the same concentration as that of TePT; however, the decomposition rates were slower than those in the absence of PCBs. In the actual treatment process, TePT and other PTs in PCB-based transformer oil are decomposed by catalytic reduction, which is used after UV irradiation. Therefore, in the actual treatment of PCB-based transformer oil wastes, pollution due to PTs can be prevented.     

SEISMIC REFRACTION ANALYSIS OF WATERSHED MANTLE RELATED TO SOIL,GEOLOGY AND HYDROLOGY1

ABSTRACT: An extensive hammer seismic refraction survey was carried out in three contiguous watersheds (217, 89, and 190 acres) on a laccolith near Sturgis, South Dakota to test its utility in rugged mountain terrain. Isopachs (lines connecting points of equal mantle thickness), area-elevation curves (hypsometry), and structure contours were used together with drill cores, petrography, hydrographs, and soil information to interpret the nature and role of porous mantle in the waterflow behavior of the watersheds. Refraction profiles produced only one geologically meaningful seismic contrast within the loccolith. Drill cores indicated a shallow stony profile on a sheeted horizon terminating on isotropic crystalline rock impervious except for tight joints. Means of refraction and core interpretations were not statistically different. Apparent seismic discontinuities deeper within the bedrock lacked geological identity. Storm hydrographs and water yields are better related to soil type differences and porous mantle distribution than to average porous mantle depth. On the other hand, slope of flow-duration curves correlate with average porous mantle depth. Porous mantle isopachs also indicate that measured flow from each basin is total area flow. Thus, porous mantle isopachs and hypsometry, and soil type delineation are complimentary in our interpretation of watershed behavior.