Non-flooded Areas Research Articles

Impact of Topography and Tidal Height on ALOS PALSAR Polarimetric Measurements to Estimate Aboveground Biomass of Mangrove Forest in Indonesia

This study is focused on investigating the impact of topography and tidal height on ALOS PALSAR polarimetric measurements on HH and HV for estimating aboveground biomass (AGB) of mangrove forest in Indonesia. We used multitemporal ALOS PALSAR polarimetric measurement that covered mangrove zone in Banyuasin, Cilacap, and Teluk Bintuni and also collected tidal height data within the same acquisition date with multitemporal ALOS PALSAR polarimetric measurement. We analyzed the distribution of flooding and nonflooding areas based on tidal height and SRTM topography data, created three profiles as region of interest (ROI), and got characteristics of backscatter value on HH and HV with different tidal height. The result of this study showed backscatter of the open mangrove zones during high tide with HH value less than −20 dB and HV value less than −25 dB whereas during low tide it showed an HH value around −20 to −10 dB and HV value around −25 to −10 dB. Backscatter of the middle mangrove zones at Cilacap, with low and flat topography, showed a deviation of backscatter on HV value of 1.6 dB. Finally, the average AGB of mangrove forest in Indonesia was estimated based on ALOS PALSAR polarimetric measurements.

Prevalence of antibodies against influenza virus in non-vaccinated equines from the Brazilian Pantanal.

The prevalence of antibodies against Equine Influenza Virus (EIV) was determined in 529 equines living on ranches in the municipality of Poconé, Pantanal area of Brazil, by means of the hemagglutination inhibition test, using subtype H3N8 as antigen. The distribution and possible association among positive animal and ranches were evaluated by the chi-square test, spatial autoregressive and multiple linear regression models. The prevalence of antibodies against EIV was estimated at 45.2% (95% CI 30.2 - 61.1%) with titers ranging from 20 to 1,280 HAU. Seropositive equines were found on 92.0% of the surveyed ranches. Equine from non-flooded ranches (66.5%) and negativity in equine infectious anemia virus (EIAV) (61.7%) were associated with antibodies against EIV. No spatial correlation was found among the ranches, but the ones located in non-flooded areas were associated with antibodies against EIV. A negative correlation was found between the prevalence of antibodies against EIV and the presence of EIAV positive animals on the ranches. The high prevalence of antibodies against EIV detected in this study suggests that the virus is circulating among the animals, and this statistical analysis indicates that the movement and aggregation of animals are factors associated to the transmission of the virus in the region.

Root behavior of savanna species in Brazil’s Pantanal wetland

The objective of this study was to determine the maximum depth, structure, diameter and biomass of the roots of common woody species in two savanna physiognomies (savanna woodland and open woody savanna) in Brazil’s Pantanal wetland. The root systems of 37 trees and 34 shrubs of 15 savanna species were excavated to measure their length and depth and estimate the total root biomass through allometric relationships with stem diameter at ground level. In general, statistical regression models between root weight and stem diameter at ground level showed a significance of P<0.05 and R2 values close to or above 0.8. The average depths of the root system in wetland savanna woodland and open woody savanna are 0.8±0.3m and 0.7±0.2m, respectively, and differ from the root systems of savanna woody species in non-flooding areas, whose depth usually ranges from 3 to 19 m. We attribute this difference to the adaptation of woody plant to the shallow water table, particularly during the wet season. This singularity of woody species in wetland savannas is important when considering biomass and carbon stocks for national and global carbon inventories.

Spatial and Seasonal CH4 Flux in the Littoral Zone of Miyun Reservoir near Beijing: The Effects of Water Level and Its Fluctuation

Wetlands, and especially their littoral zones, are considered to be CH4 emissions hotspots. The recent creation of reservoirs has caused a rapid increase in the area of the world’s littoral zones. To investigate the effects of water depth and water level fluctuation on CH4 fluxes, and how these are coupled with vegetation and nutrients, we used static closed chamber and gas chromatography techniques to measure CH4 fluxes in the littoral zone of a large reservoir near Beijing, China, from November 2011 to October 2012. We found that CH4 flux decreased significantly along a transect from open water to dry land, from 3.1 mg m−2 h−1 at the deep water site to approximately 1.3 mg m−2 h−1 at the shallow water site, and less than 0.01 mg m−2 h−1 in the non-flooded area. Water level influenced CH4 flux by affecting soil properties including soil redox potential, soil carbon and nitrogen, and bulk density. The largest emission of all was from the seasonally flooded site after a flooding event (up to 21.1 mg m−2 h−1), which may have been caused by vegetation decomposition. Submerged sites had greater emissions, while the driest site had lower emissions. Immediately after the monthly measurements had been made, we removed the aboveground vegetation to enable an assessment of the gas transportation per unit of biomass. Removal of biomass decreased emissions by up to 53%. These results indicated the dominant effect of water depth on CH4 flux through effects of soil conditions, plant species composition and distribution. This study suggests that temporally flooded wetlands, including littoral zones, contribute significantly to the global CH4 burden. However, the current challenge is to capture their spatial extent and temporal variation in the fluxes.

Flood Mapping With TerraSAR-X in Forested Regions in Estonia

In this study, an extensive flood in Estonia during spring 2010 was mapped with TerraSAR-X data acquired over both open and forested areas. This was the first time when a large scale flooding area was mapped in Estonia by means of spaceborne remote sensing. This was also the first time when X-band SAR images were successfully used for flood mapping under the forest canopy in the temperate forest zone. The tree height in the study region was 15-25 meters on average, and main tree species were birch (leaf-off condition), pine and spruce. The results were compared with ALOS PALSAR and Envisat ASAR images of the same flooding event. In the study area, TerraSAR-X provided on average 3.2 dB higher backscatter over mixed forest flooded areas compared to non-flooded areas. In deciduous and coniferous forests the difference in average backscatter between flooded and non-flooded forests was even greater, 6.2 dB and 4.0 dB, respectively. A supervised classification algorithm was developed to produce high resolution maps of the flooded area from the TerraSAR-X images to demonstrate the flood mapping capability at X-band. Our results show, that spaceborne X-band SAR data, which currently has the highest resolution among the SAR instruments in space, can be used to map floods under forest canopy in temperate zone despite its short wavelength and high attenuation.

SPATIAL AND CHEMOMETRIC ANALYSIS OF THE DISTRIBUTION OF METAL SPECIES IN FLOODED AND NONFLOODED SOILS FROM THE MIDDLE NEGRO RIVER BASIN, AMAZON

This study used chemometric tools and a Geographic Information System (GIS) to determine the influence of organic matter and anthropogenic activity on the distribution of metal species between two major communities of the Middle Negro River Basin-AM. Higher concentrations of metal species were determined in flooded regions. The chemometric analysis showed the affinity of organic matter for potentially toxic metals, indicating its selectivity. GIS spatial analysis has shown that proximity to urban areas is a variable that is likely to influence the pattern of concentration of organic matter, and consequently the distribution of metal species between flooded and non-flooded areas.

Does inundation risk affect leaf-cutting ant distribution? A study along a topographic gradient of a Costa Rican tropical wet forest

Abstract:Successional state of forest and availability of pioneer plants are recognized factors affecting densities of leaf-cutting ants. However little is known about how abiotic factors can shape nest distributions. We investigated the effect of topography, soil, forest successional state and inundation risk on nest density and size of Atta cephalotes colonies along streams in a tropical wet forest in Costa Rica. In each forest type, we surveyed 12 sites, each site comprising five transects (10 × 100 m) varying in topography and proximity to streambeds. We found no difference regarding nest size or density between forest types or soil consociation. Nest density varied with topographic environment, with significantly higher nest density on slope tops (farther from streambeds) and without colonies in valley bottoms (closer to streambeds). Nests found in areas affected by the last great inundation before our study were scarcer and smaller than nests in non-flooded areas. We showed that inundation events favour an accumulation of Atta colonies towards higher sites, where they are also allowed to become larger and may survive longer. Inundation risk may be a strong force shaping the distribution of leaf-cutting ant nests in tropical floodplain forests, even concealing the relevance of successional state of forest.

Vivipary in Ferocactus herrerae (Cactaceae) in northern Sinaloa, México

Vivipary implies an active embryonic development with seed germination in the mother plant. The viviparous species are concentrated mainly in tropical and coastal areas with temporary flooding; thus, salinity and moisture are the main factors related to vivipary. This reproductive strategy is a rare event in the Cactaceae; however, vivipary in this family has been reported for 53 species (3.7% of the family). Ferocactus herrerae is a viviparous cactus native of northwestern Mexico, for which it has been suggested that the overall proportion of viviparous plants is higher in coastal flooding areas relative to halophytic, nonflooding areas. Thus, in this research we determine the correlation of the salinity/moisture with the vivipary incidence in Ferocactus herrerae. We performed Independence Tests between the reproductive types (viviparous/non-viviparous) and three salinity/ moisture conditions in experimental sites in northern Sinaloa, Mexico. We had irrigation (Pueblito site), irrigation-salinity (UAS site), and control (San Jose site) sites. The Pueblito and UAS sites had 82% and 100% of viviparous plants compared with 56% recorded in the control. The UAS site produced 7 fruits per plant on average, with 43% viviparous, whereas the San Jose and Pueblito sites produced 18 fruits per plant with viviparous averages of 7.6% and 16.7% respectively. These results confirm that humid tropical and coastal environments are important in the development of vivipary in F. herrerae.

Heavy metals concentrations in selected areas used for urban agriculture in Dar es Salaam, Tanzania

This study was carried out to assess the concentration of heavy metals in selected areas used for urban agriculture in Dar es Salaam and compare them with permissible limit from the Tanzania Bureau of Standards (TBS) in order to establish risk levels. Samples were collected from six sites of Tazara mchichani, Ubungo darajani, Kigogo darajani, Temeke wailers, Tegeta and Bunju, which reflect frequently flooded and non-flooded areas and areas within the city and at the outskirts. The samples were analyzed for Zinc (Zn), Chromium (Cr), Cadmium (Cd), Lead (Pb) and Copper (Cu) as these are the common heavy metals in the city. The highest value of Cu (8.98 mg/kg), Zn (57.10 mg/kg) and Pb (33.70 mg/kg) were observed in Tazara Mchichani, which may reflect pollution from various manufacturing industries surrounding the areas including steel, iron, food processing and detergents. Bunju had the lowest Cu and Zn levels in the soil, averaging 1.92 mg/kg and 13.53 mg/kg, respectively, while Kigogo Darajani had the lowest Pb concentrations of 6.88 mg/kg. High and low values of Cr were observed in Tegeta and Temeke Wailes with the mean concentrations of 15.29 and 3.66 mg/kg respectively. The Cd level was high in Temeke Wailes, Kigogo Darajani and Tegeta with mean concentration of 0.26 mg/kg. The lowest Cadmium concentration (0.15 mg/kg) was observed at Tazara Mchichani. Heavy metal concentrations in the six sites were within the Tanzania Bureau of Standards (TBS) permissible limit, suggesting that no serious health hazards are expected. Flood seem not to influence toxic elements distribution as flooded area like Ubungo darajani, Tazara mchichani and Kigogo darajani had similar levels of concentrations of studied metals compared to non flooded areas of Temeke wailers, Tegeta darajani and Bunju. Key words: Floods, risk levels, health hazards, permissible limit.

주암호 복내 저수구역내 침수 자생식물의 질소 및 인 모니터링

BACKGROUND: Eutrophication occurs occasionally in reservoirs around lake in summer and early autumn. Lakeside macrophyte which is one of internal pollutants effects on water quality when it is submerged during rainy season. To improve water quality of water supply source in Boknae reservoir around Juam lake, characteristics of nutrient(N, P) uptake and release by submerged plants were investigated. METHODS AND RESULTS: In order to establish the management plan of submerged plants in Boknae reservoir around Juam lake, water level, rainfall, flooding and non-flooding areas, biomass of dominant plants, contents of nitrogen and phosphorus were investigated during 7 months(August, 2010 through February, 2011). Dominant plants were Miscanthus sacchariflorus(MISSA) and Carex dimorpholepis(CRXDM) in Boknae reservoir. Total plant area of Boknae reservoir in August, 2010 was 987,872 . In Boknae reservoir, flooding occurred from August until February caused by rainfall during rainy season. The total amounts of nitrogen and phosphorus uptakes by MISSA were 247 and 22 kg/total reservoir area, respectively. By CRXDM, the total amounts of nitrogen and phosphorus uptakes were 11,340 and 1,231 kg/total reservoir area, respectively. The total amounts of nitrogen and phosphorus residues by MISSA were 34 and 11 kg/total reservoir area, respectively. By CRXDM, the total amounts of nitrogen and phosphorus residues were 491 and 68 kg/total reservoir area, respectively. CONCLUSION(S): Total amounts of nitrogen and phosphorus releases in Boknae reservoir were 12,212 and 1,324 kg/total reservoir area, respectively. The results demonstrate that total nitrogen and total phosphorus in water were strongly influenced by submerged plants. Therefore, management plan for submerged plants during rainy season will be needed to improve water quality of water supply source in Boknae reservoir around Juam lake.

Prevalence and risk factors for Equine Infectious Anemia in Poconé municipality, northern Brazilian Pantanal

Serum samples collected from 547 equids in the Pantanal region of Brazil were evaluated for antibodies to Equine Infectious Anemia Virus (EIAV) by the agar gel immunodiffusion test. Risk factors associated with EIAV seropositivity were evaluated and spatial dependence investigated using a Spatial Lag Model. EIAV prevalence on farms in the Pantanal was 52.0% (13/25) with adjusted prevalence between equids of 31.5% (17.4–48.8% 95% CI). Intra-herd prevalence ranged from 5.0 to 77.0%. Statistical analysis demonstrated that farms and animals in regularly flooded areas had respectively 60 and 146 fold higher chance to be sero-positive than farms and animals located in non-flooded areas. Spatial Lag Model results were generally consistent with this conclusion although there was a negative spatial correlation between farms located within in regularly inundated regions, suggesting that other factors, such as management practices, probably play a significant role in transmission of EIAV. Equids with clinical signs were 3.74-fold more likely to be sero-positive than those without clinical signs. The results of this work reveal a high prevalence of EIAV in the Pantanal area of Brazil demonstrating that equids reared in this region are at great risk of infection.

The influence of spring floods on small mammal communities in the Nemunas River Delta, Lithuania

The influence of the annual spring floods on small mammal communities was studied in the Nemunas River Delta, SW Lithuania. The aim of the investigation was to compare the diversity of small mammals inhabiting spring-flooded meadows, meadows not subjected to flooding and spring-flooded forest in years characterized by differing heights and durations of spring flood. In the years of the high flood, the number of species and diversity index were higher, while index of dominance was less than in the years of low flood. Significantly, the highest proportions of Apodemus agrarius were recorded in spring-flooded meadows in years of high flood (41.7%), while Microtus oeconomus occurred in the highest proportions in spring-flooded meadows in years of low flood (66.8%) and in meadows not subjected to flooding (47.1%). In non-flooded areas, M. Oeconomus is not expelled by the floods and outcompetes other species. After high levels of flooding, during the process of re-population, the voles may be outcompeted by A. agrarius. In the absence of dominant species, greater opportunities existed for the establishment of more species (13 species in flooded meadows). Micromys minutus accounted for up to 19.5–30.1% in the years of high flood. We concluded that the annual spring floods in the Nemunas Delta had no long-term negative effects, the number of small mammal species and their abundance had been restored in just a few months. The worst consequences of the high flood were recorded in forest habitat. Spring floods, and especially the higher floods, are natural environmental agents, maintaining the high diversity of small mammals in meadows and reed-beds.

Vegetation Database of the Colombian Caribbean Region

Dry and humid forests around wetlands at the department of Cordoba, Caribbean region of Colombia Fragment forests around swamp complexes in several localities at the department of Cordoba were sampled with 77 plots. In each plot all individuals with height up to 1.5 m were censused, measuring their diameter at breast height, coverage and individual height. Inside each area, the herbaceous layer was inventoried with 5 plots of 2x2 m. Observations about disturbance (intervention class, grade, matrix and contrast type) were taken and physical-chemical soil conditions were characterized to complement the characterization with basis on floristic composition and structure. Using the Twinspan program (PC Ord ver. 4) global tables of group segregation were obtained with which a group differentiation was found. These groups showed a floristic composition closely related with the patterns observed on the field. Around the swamps, vegetation is grouped in the class Craveto tapieae-Astronietea guianensis, order Bursero simauroubaeCavanillesietalia platanifoliae characterized by the dominance of Cavanillesia platanifolia. In this humid forest formation (26 Lev), characterized by large-size individuals of Cavanillesia platanifolia, are included the association of Cratevo tapiae-Cavanillesion platanifoliae alliance like forests of Cordietum protacto-panamensis, Cappari odoratissimatis-Cavanilletum platanifoliae and the mixed palm Sabali mauritiformis-Cavanillesietum platanifoliae. There are also other plant communities that can be assigned to the dry forest formation (51 Lev) characterized by the dominance of tree or shrub size individuals principally Cochlospermum vitifolium, Apeiba aspera, Trichilia acuminata, Attalea butyraceae and Guazuma ulmifolia. Among the characterized associations are Cinnamomo triplinervis-Apeibetum asperae, Cochlospermo vitifoli-Attaleetum butyraceae, Cordia alliodorae-Attaleetum butyraceae and Adenocalymno inundati-Astronietum graveolentis. In this group, forests around the swamps in flooded and non-flooded areas (related to the tropical dry forest formation) have two formation types, one with vigorous elements, height up to 18 meters as the associations of the Dialio guinensis-Mataybion elegantis alliance that include the mixed palm Viticis capitatae-Acrocomietum aculeatae and the Xilopio aromaticae-Tapiretum guianensis. The Phillanto elsiae-Tabebuion roseae alliance includes low rise vegetation, woods and residual forests, as the Annono punicifoliae-Pithecellobietum lanceolati and the shoreline Symmerio paniculatae-Bactrietum guieenensis mangrove thickets in flooded areas. Another forest and thicket in flooded areas (5 Lev) are the “campanales” of Caseario tremulae-Samaneetum samanensis and the forests of the Coccolobo costatae-Acacietum huilanae association and the thickets dominated by Montrichardia arborescens. The structural arrangement, particularly classes distribution is related with type and degree of perturbation of the characterized communities; logging and grazing distort the disetaneo behaviour of natural forests where the higher’ percentage of individuals should be distributed in the first classes. The Caseario tremulae – Samaneetum samanensis association is a representative case where the intensive grazing has driven this flooded forest to degradation; this is observable in the height classes’ distribution, with the higher individuals’ percentage (31%) in class III. The intervention grade of the humid and dry tropical forests characterized in this study can be classified from low (26%) to high (13%) predominating the mid degree (61%) making evident the current pressure to which this ecosystems are subjected mainly due to land use change for animal breeding, agriculture or mining .However there are still fragmented forests with acceptable characteristics for conservation which will be a starting point for the formulation of ecological restoration models. This report describes the available content in the Vegetation Database of the Colombian Caribbean Region (GIVD ID SA-CO-002).

Late Quaternary sedimentary dynamics in Western Amazonia: Implications for the origin of open vegetation/forest contrasts

This work investigated the evolution of sedimentary environments during the latest Quaternary and their influence on the paradoxical occurrence of open vegetation patches in sharp contact with the Amazonian forest. The approach integrated pre-existing geological and floristic data from lowlands in the Brazilian Amazonia, with remote sensing imagery including multispectral optical images (TM, ETM+, and ASTER), Phased Array L-band Synthetic Aperture Radar (PALSAR), InSAR C-band SRTM-DEMs, and high resolution images obtained from Google Earth™. The detection of an abundance of paleomorphologies provided evidence of a scenario in which constant environmental shifts were linked to the evolution of fluvial and megafan depositional systems. In all studied areas, the open vegetation patches are not random, but associated with sedimentary deposits representative of environments either deactivated during the Holocene or presently in the process of deactivation. Sedimentary evolution would have determined the distribution of wetlands and terra firme in many areas of the Amazonian lowlands, and would have a major impact on the development of open vegetated patches within the modern rainforest. Subsiding areas were filled up with megafan deposits, and many fluvial tributaries were rearranged on the landscape. The close relationship between vegetation and the physical environment suggests that sedimentary history related to the evolution of depositional settings during the latest Quaternary played a major role in the distribution of flooded and non-flooded areas of the Amazonian lowlands, with a direct impact on the distribution of modern floristic patterns. As the depositional sites were abandoned and their sedimentary deposits were exposed to the surface, they became sites suitable for vegetation growth, first of herbaceous species and then of forest. Although climate fluctuations might have been involved, fault reactivation appears to have been the main cause of changes in depositional dynamics through time, a process that had an immediate effect on the development of large open vegetation patches intermingled with the Amazonian rainforest.

Quantifying soil salinity in areas invaded by Tamarix spp.

Elevated soil salinity is often associated with Tamarix invasion; however, it's unclear whether soils are more saline because of Tamarix or other environmental factors. Surface soil salinity was investigated along a flow-regulated, arid river with dense Tamarix of varying age to determine which factors best explain soil salinity. Flooding was the most important predictor, reducing salinity by nearly 70%. Soils under Tamarix had lower salinity than adjacent areas without woody cover in non-flooded areas suggesting that evaporation in arid environments may contribute more surface salts than Tamarix or may exacerbate plant inputs. Under most conditions, higher salinities were found under Tamarix than natives. An exception to this pattern was that soils under the smallest trees were more saline for natives. Relationships between soil salinity and stem size suggest that salts increase over time under Tamarix unless they are removed by flooding. However, the most mature stands had lower salinity than expected, reflecting some additional mechanism. Soil texture and distance from the river were important, but interacted strongly with other factors. The observed relationships between surface soil salinity and Tamarix stem size, a predictor of aboveground age, suggest Tamarix plays an active role in floodplain salinization within the sampled area.

Health Effects of Flooding in Rural Bangladesh

There is little information available on nontraumatic health risks as the result of floods, and on the factors that determine vulnerability to them (especially in low-income settings). We estimated the pattern of mortality, diarrhea, and acute respiratory infection following the 2004 floods in rural Bangladesh. We conducted controlled interrupted time-series analysis of adverse health outcomes, from 2001 to 2007, in a cohort of 211,000 residents of the Matlab region classified as flooded or nonflooded in 2004. Ratios of mortality, diarrhea, and acute respiratory infection rates in flooded compared with nonflooded areas were calculated by week for mortality and diarrhea, and by month for acute respiratory infection. We controlled for baseline differences as well as normal seasonal patterns in the flooded and nonflooded areas. Variations in flood-related health risks were examined by age, income level, drinking-water source, latrine type, and service area. After fully controlling for pre-flood rate differences and for seasonality, there was no clear evidence of excesses in mortality or diarrhea risk during or after flooding. For acute respiratory infection, we found no evidence of excess risk during the flood itself but a moderate increase in risk during the 6 months after the flood (relative risk = 1.25 [95% confidence interval = 1.06-1.47]) and the subsequent 18 months. We found little evidence of increased risk of diarrhea or mortality following the floods, but evidence of a moderate elevation in risk of acute respiratory infection during the 2 years after flooding. The discrepancies between our results and the apparent excesses for mortality and diarrhea reported in other situations, using less- controlled estimates, emphasize the importance of stringent confounder control.

Characterization and taxonomical note about Thai Erianthus germplasm collection: the morphology, flowering phenology and biogeography among E. procerus and three types of E. arundinaceus

Erianthus, one of the genus in Saccharum complex, is important genetic resources for sugarcane improvement. The morphology and flowering phenology of 108 accessions belonging to Erianthus procerus and three types of E. arundinaceus collected from throughout Thailand were compared. PCA analysis based on 22 characteristics clearly supported the separation of Type II and Type III of E. arundinaceus from E. procerus and Type I of E. arundinaceus according to their morphological characteristics, particularly their bud size, and the development of root primordia, which greatly affected axis I of the PCA analysis. E. procerus and Type I showed overlapping in many of their characteristics including their flowering periods. Flower characteristics such as rachis joint length, which were used for previous taxonomic classifications, were not available for the classification of the Thai samples because of the wide variation and overlapping among them. Most of these phenotype similarities and differences are considered to have developed convergently as a result of niche adaptation. Type II and III inhabit riverbanks and streambeds where floods occur frequently, while E. procerus and Type I mainly grow in non-flooding areas such as mountainous grassland, the edge of forests, and beside fields. All Thai Erianthus show unique geographic distributions in Thailand. In particular, the biogeographic boundary between Type II and Type III appeared to be located at the Isthmus of Kra. Although some types showed morphological similarities, reproductive isolation among the four groups seemed to be maintained by differentiation in geographic distribution, habitat preference, and flowering timing.

Clonal trial of five genotypes of camu-camu, Myrciaria dubia (h.b.k) mc. Vaugh, in non-flooded area

The objective of this research was to evaluate fruit yield, other agronomic characteristics and content of ascorbic acid (aa) of five promissory genotypes of “camu-camu” in non-flooded area of the experimental field “El Dorado”. The plantation has been established for 4 years and is located in 03° 56’ 50’’S, 73° 25’ 13’’W and 118 a.s.l. altitude, which is part of INIA-EEA“San Roque”4. The clones evaluated were MD-013, MD-014, MD-015, MD-017 and MD-020 and they stood out in the previous analysis in the national camu-camu germplasm collection of INIA. The experiment was established with a completely randomized block statistical design (CRBD) with five treatments and four replications, and each experimental unit consisted of nine plants, with a distance of 3 x 3 m. During the reproductive phenology which was 9 months long, nine variables were evaluated: Leaf length (cm), leaf width (cm), petiole length (cm), number of basal branches, basal branch diameter (cm), number of fruits, fruits weight (g), fruits yield (kg) and ascorbic acid (mg/100 g). As a result, “petiole length” was different statistically (F = 3.96, p = 0.028). The heritability was low for all the variables: “leaf length” (h2 = 0.13), “leaf width” (h2 = 0.06), “basal branches diameter” (h2 = 0.004), “number of fruits per plant” (h2 = 0.17), “ascorbic acid content” (h2 = 0.002), “petiole length” (h2 = 0.43), “number of basal branches” (h2 = 0.33), “weight of fruits per plant” (h2 = 0.29) and “fruits yield” (h2 = 0.26). However, fruit yield showed a range of 2.0 to 2.6 kg / plant (2200 to 2800 kg / ha). Key words: Ascorbic acid, “camu-camu”, heritability, Myrciaria dubia, yield.

Flood monitoring using multi-temporal COSMO-SkyMed data: Image segmentation and signature interpretation

The COSMO-SkyMed mission offers a unique opportunity to obtain radar data characterized by short revisit time, thus being useful for flood evolution mapping. A procedure to monitor an inundation event using multi-temporal COSMO-SkyMed data is presented in this paper. The methodology is based on an automatic image segmentation technique and on the use of a well-established electromagnetic model to correctly explain the radar return from the image segments. It is applied to a series of five COSMO-SkyMed images regarding an event chosen as a test bed, i.e., a flood occurred in Northern Italy in 2009. In order to associate the segments to the classes of flooded or non-flooded areas, some reference multi-temporal backscattering trends have been assumed with the aid of the theoretical model. Using these reference trends as a training set, a classification algorithm has been developed to generate a map of the flood evolution. Although the methodology needs to be further tested on different case studies, our investigation demonstrates the feasibility and the utility of a combined use of an electromagnetic scattering model and an advanced image processing technique for inundation monitoring.

The Long-term Effects of Flooding on Mortality in Rural Bangladesh

O-31C9-2 Background/Aims: Little evidence on the long-term health impact of flooding. To determine the extent to which flooding is accompanied by change in mortality over the 3 years following flooding in rural Bangladesh. Methods: Flooded and non-flooded areas at the time of severe flood in the summer of 2004 were identified by interviewing the head of 9524 baris (on average 5 households in a bari) which is 90% of all baris in the Matlab Health and Demographic Surveillance area with more than 220,000 residents. Mortality in the flooded areas in the 3 years after the 2004 flood was compared with mortality in the 3 years before the flood in the same areas, controlling for temporal patterns observed in “control” areas that were never flooded in 2004. Comparisons were stratified by sex, age group (0–1, 1–14, 15–59, 60–74, 75+), hygiene and sanitation, and socioeconomic status. Results: A total of 13,957 of interviewed households (31%) were flooded in the summer 2004. Overall, there was a slight but nonsignificant excess compared to pre-flood mortality during the flood, June–September (RR = 1.16; 95% CI: 0.93–1.45) and no excess after the flood; RR = 1.02 (95% CI: 0.89–1.17), 0.93 (95% CI: 0.81–1.07) and 0.99 (95% CI: 0.86–1.18) in the year 1, 2, and 3, respectively, after the flood. Subgroup analyses showed suggestive excesses in the year after the flood in persons aged above 75 (RR = 1.20; 95% CI: 0.92–1.57) and in the low income group (RR = 1.16; 95% CI: 0.82–1.62), but precision was limited. Conclusion: We found no evidence of an adverse effect of flood on mortality persisting beyond the flood period itself. Although power was limited, upper confidence interval suggest that risks above 1.2 in the population overall, and above about 1.6 in important sub-groups are unlikely, which contrasts with some other reports. Results for diarrhea or ARI morbidity, for which power will be greater, are being computed and will be presented.