Main Watershed Research Articles

Residual circulation and freshwater transport in the Dutch Wadden Sea: a numerical modelling study

Abstract. The Dutch Wadden Sea is a region of intertidal flats located between the chain of Wadden Islands and the Dutch mainland. We present numerical model results on the tidal prisms and residual flows through the tidal inlets and across one of the main watersheds. The model also provides insight into the pathways of fresh water originating from the two sluices at the Afsluitdijk (enclosure dike) through the use of passive tracers. All these results are obtained from three-dimensional numerical simulations carried out with the General Estuarine Transport Model (GETM), at a horizontal resolution of 200 m and with terrain-following vertical coordinates with 30 layers. We concentrate on the years 2009–2010, for which we impose meteorological forcing, freshwater discharge, and boundary conditions for tidal forcing and storm surges. Results from the model show an excellent agreement with various observational data sets for sea surface height, temperature, salinity and transport through the Texel Inlet. The simulations show that although tides are responsible for a characteristic pattern of residual transport through the inlets, the wind imposes a large variability on its magnitude and can even invert its direction during strong southwesterly winds. Even though these events are sporadic, they play an important role in the flushing of the Dutch Wadden Sea, as they strongly diminish the flushing time of fresh water. In addition, wind can force a residual transport across the Terschelling watershed of the same order, if not larger, than through any of the main tidal inlets, despite the fact that its tidal prism is much smaller than any of those of the inlets. For the pathways of fresh water, the Terschelling watershed turns out to be more important than was previously thought, while the opposite holds for the Vlie Inlet.

A unique coastal watershed survey in Maine

A unique, community-based coastal watershed survey was conducted in the Stanley Brook Watershed in Seal Harbor, Maine, between June and October of 2005. The Stanley Brook Watershed Survey was specifically designed to address the pollution issues affecting Stanley Brook habitats and public health issues at Seal Harbor Beach. This novel watershed survey utilized key components of the Maine Department of Environmental Protection watershed survey process, which targets nonpoint source pollution, and the Maine Department of Marine Resources sanitary shoreline survey process, which targets point sources of bacterial pollution. The survey was coupled with water quality monitoring at Seal Harbor Beach through the Maine Healthy Beaches (MHB) program. The Stanley Brook Watershed encompasses 378 ha (935 ac) and straddles both Acadia National Park (ANP) and the village of Seal Harbor in the town of Mt. Desert on Mt. Desert Island, Maine. The headwaters of Stanley Brook begin on Day Mountain; including its tributaries, Stanley Brook is 6 km (3.7 mi) in total length, meandering through ANP before emptying into the ocean at Seal Harbor Beach. Stanley Brook is a rich habitat for local flora and fauna. Sea-run brook trout ( Salvelinus fontinalis ) have been documented in Stanley Brook (Kazyak 2011), which makes…

Hydrosedimentology of nested subtropical watersheds with native and eucalyptus forests

Information on the effects of eucalyptus forests on hydrosedimentological processes is scarce, particularly at the catchment scale. Monitoring and mathematical modeling are efficient scientific tools used to address the lack of information for natural resource management and the representation and prediction of those processes. This study evaluates the effects of eucalyptus cultivation on hydrosedimentological processes in watersheds and to use the Limburg soil erosion model (LISEM) to represent and predict hydrological processes. The study was conducted in two forested watersheds: the main watershed (94.46 ha) and a nested sub-watershed (38.86 ha), both cultivated with eucalyptus and residual riparian native forest, located in southern Brazil. Hydrosedimentalogical monitoring was conducted from 16th February 2011 to 31st December 2012, and LISEM model calibrations were performed on the bases of six storms events. The sediment yield for 2011 was 41.6 Mg km−2 and 38.5 Mg km−2 for the watershed and sub-watershed, respectively. An extreme event in 2012 provided greater sediment yield for the sub-watershed (99.8 Mg km−2) than that for the watershed (51.7 Mg km−2). Rainfall events with a greater maximum intensity generated rapid discharge and suspended sediment concentration responses in the sub-watershed due to the smaller drainage area and steeper landscape. In the main watershed, the accumulation of flood waves occurred for most events, with less steep hydrographs, and a later occurrence of the discharge peak after that of the sub-watershed. The LISEM adequately reproduced the peak discharge and runoff for the calibrated events; however, the peak time and the shape of the hydrograph were not adequately represented. The hydrosedimentological patterns of the watershed and sub-watershed, both cultivated with eucalyptus, was characterized by sedimentographs preceding hydrographs during rainfall–runoff events where scale effects occur, with maximum discharge and specific sediment yield greater in the watershed than that in the sub-watershed. Empirical models based on hydrologic variables may be used for estimating the suspended sediment concentration and sediment yield. Therefore, LISEM may be used for the prediction of hydrological variables in these forested watersheds.

Distribution of Ephemeroptera, Plecoptera, and Trichoptera assemblages in relation to environmental variables in headwater streams of Mongolia

Effects of stream environmental variables on the distribution and abundance of Ephemeroptera, Plecoptera and Trichoptera (EPT) assemblages in the headwaters of rivers and streams of Mongolia were investigated in this broad scale survey aimed to provide a baseline for future research and management of the country’s aquatic ecosystems. The survey was carried out in the first-, second- and third-order streams of 80 rivers selected from the three main watersheds of Mongolia, namely the Arctic Ocean Basin (AOB), Pacific Ocean Basin (POB) and Central Asian Internal Basin (CAIB). We sampled larvae of EPT by kick and d-nets from the headwater sites during summers of 2007–2009. Chemical and hydrological variables of the sites were measured, and habitat of those sites was assessed. We recorded 89 taxa belonging to 34 families of EPT orders during the survey. The family Baetidae (Ephemeroptera) was the dominant taxon among all sites. Taxon richness was higher in the POB and AOB than CAIB, while total EPT abundance was higher in the CAIB. Significant differences in the community variables, such as taxon richness, Shannon’s diversity index and evenness of EPT assemblages were observed among the basins. Results of canonical correspondence analysis suggested that altitude, dissolved oxygen, order and width of streams were the most important factors explaining the variability in EPT larval distribution in the headwater streams in Mongolia.

Temperatura del agua continental y su influencia en las migraciones de los peces en la cuenca del Río De La Plata

With a total area of 3 x 106 km2 shared by five countries and a mean discharge of 25000 m3 s –1, the Rio de La Plata is the second largest hydrographic system in America, after the Amazon. The Rio de La Plata basin is composed of two main watersheds, the Parana and Uruguay Rivers, which together form the Rio de la Plata estuary. From hydrological, physical and biological standpoints, the Rio de la Plata basin is a complex system, where singular biological phenomena occur, as migrations and massive fish deaths. This paper refers strictly to the temperatures in the subtropical potamous axis from the “great swamp” at 20 ° S and extending linearly to about 1200 km south to the Rio de la Plata, with a strong temperature gradient. This analysis includes some pampasic ‘lagunas’ (37° S) because they are the southern end of distribution of brazilic ichthyofauna. In pampasic lagunas the mean annual water temperature has no significant difference with annual mean air temperature. In the Rio de La Plata basin the water temperature is higher than the air temperature; the difference varies between 4.5 and 2.2 °C. The results are discussed in relation to massive fish deaths and migrations.

On the origin and diversification of Venezuelan freshwater fishes: the genus Gephyrocharax (Ostariophysi: Characidae) a case study

We conducted a phylogeographic analysis of the genus Gephyrocharaxin Venezuela to evaluate geomorphologic evidence for the formation of the country's main watersheds and to establish a biogeographical hypothesis of possible diversification mechanisms of the Neotropical freshwater fish fauna. We assayed eight enzyme systems and general proteins to estimate genetic variability (H, P), intraspecific structuring in several Gephyrocharax valencia and G. venezuelae populations (FIS, FIT, and FST), and a phylogenetic approach for the three species of Gephyrocharax in Venezuela, using Corynopoma riisei as the external group. Fourteen presumptive lociindicate that populations of the three species of Gephyrocharaxanalyzed show a clear genetic inter-specific differentiation, determined by four loci with fixed alleles (GPI-B*,IDH*, ME-1*, and ME-2*). The resulting cladogram shows two major clades: a monophyletic group consisting of Gephyrocharax n. sp. and G. venezuelae(restricted to the northwest of the country) and a group formed exclusively by G. valencia (distributed along the largest geographic range). Speciation of the Venezuelan lineages of the genus Gephyrocharaxcould be explained by the origin and course movements of the present Orinoco River together with geomorphologic processes that have occurred in northern Venezuela since the Miocene.

Microbial enzyme activity at the watershed scale: response to chronic nitrogen deposition and acute phosphorus enrichment

Microbial enzymes play a critical role in organic matter decomposition and enzyme activity can dynamically respond to shifts in inorganic nutrient and substrate availability, reflecting the nutrient and energy limitation of the microbial community. We character- ized microbial enzyme response to shifting nitrogen (N) and phosphorus (P) availability across terrestrial and aquatic environments at the Bear Brook Watershed in Maine, the site of a whole-watershed N enrichment experiment. We compared activity of b-1,4-glucosi- dase (BG); b-1,4-N-acetylglucosaminidase (NAG); acid phosphatase (AP) in soil, leaf litter in terrestrial and stream habitats and stream biofilms in a reference and N enriched watershed, representing whole-eco- system response to chronic N enrichment. In addition, we used shorter, experimental P enrichments to address potential P limitation under ambient and elevated N availability. We found that BG and NAG activity were not affected by the long-term N enrichment in either habitat. Enhanced P limitation due to N enrichment was evident only in the aquatic habitats with 5- and 8-fold higher treated watershed AP activity in stream biofilms and stream litter, respectively. Acute P additions reduced AP activity and increased BG activity and these effects were also most pronounced in the streams. The stoichiometry of enzyme activity was constrained across ecosystem compartments with regression slopes for lnBG:lnNAG, lnBG:lnAP, and lnNAG:lnAP close to 1, ranging 1.142-1.241. We found that microbial enzyme response to shifting N and P availability varied among watershed compartments, typically with stronger effects in aquatic habitats. This suggests that understanding the response of ecosystem function to disturbance at the watershed scale requires simultaneous consideration of all compartments.

Simulating High-Elevation Hydropower with Regional Climate Warming in the West Slope, Sierra Nevada

Water systems in snowmelt-dominated hydroregions such as California's Sierra Nevada mountains are sensitive to regional climate change, hydropower systems in particular. In this study, a water resources management model was developed for the upper west slope Sierra Nevada to understand the potential effects of regional climate warming on hydropower at the watershed scale, a scale that has been largely neglected but is important for hydroregional planning. The model is developed with the Water Evaluation and Planning system (WEAP) and includes most water management infrastructure in the study region. Hydropower is simulated assuming historical long-term electricity demand and a spill minimization rule. The method is suitable for simulating generation for most of the main watersheds in the region. To assess the potential effect of climate warming, uniform air temperature increases of 0°C, 2°C, 4°C, and 6°C were considered, with no change in precipitation, to approximate regional warming through 2100. The highly productive northern Sierra Nevada sees large re- ductions in hydropower generation with decreases in annual runoff. The central watersheds see less reduction in annual runoff and can adapt better to changes in runoff timing. Generation in southern watersheds, which are less productive, decreases. Results from this study can help identify which watersheds might easily adapt to climate change, where hydropower is likely to conflict with other uses, and where more detailed operational studies are needed. DOI: 10.1061/(ASCE)WR.1943-5452.0000373. © 2014 American Society of Civil Engineers.

Flash Flood Risk Assessment Using Morphological Parameters in Sinai Peninsula

Flash floods are considered to be one of the worst weather-related natural disasters. They are sudden and highly unpredictable following brief spells of heavy rain. Egypt is subjected to flash floods, especially the eastern desert and Sinai Peninsula where floods from the mountains of Red Sea and Sinai are causing heavy damage to man-made features. This manuscript presents the methodology adopted to generate a weighted risk map for main watersheds located in Sinai according to main morphological parameters. Using digital elevation model (DEM) implemented into a Geographic Information System (GIS) the Sinai watersheds were delineated and morphological parameters calculated. The parameters where then used in a multi criteria analysis process to calculate a morphological risk factor. The resulted risk maps of this study can help initiating appropriate measures to mitigate the probable hazards in the area with prioritization.

Soil Drainage Class Influences on Soil Carbon in a New England Forested Watershed

Imperfectly drained soils under forests can occupy extensive areas of the landscape and understanding how they might differ from upland forest soils can be critical for understanding soil organic carbon (SOC) across forested landscapes. Research on forest SOC across drainage gradients has been limited. This research was a case study at the Bear Brook Watershed in Maine (BBWM), a long‐term ecological research site, that focused on SOC pools and fluxes across three soil drainage classes (moderately well drained‐MWD, somewhat poorly drained‐SWPD, poorly drained‐PD) and two forest types (coniferous‐CF, broadleaved deciduous‐BLD). Soil respiration (RS), soil temperature, soil moisture content, and extractable soluble C were measured from May through November to assess Rsas an indicator of biological activity. The MWD mineral soil had significantly higher C concentrations(0.71 g kg−1) compared to SWPD (0.30 g kg−1) and PD (0.34 g kg−1). The MWD soils in CF had significantly greater C content (433.3 Mg C ha−1) compared to SWPD (113.95 Mg C ha−1) and PD (103.3 Mg C ha−1). Soil C concentration and content was not significantly different between SWPD and PD soils. Mean mineral soil C fraction concentrations (active, stable, passive) expressed as a percent of the total soil mass were significantly different among soil drainage classes. Results from this case study suggest that pedogenesis, above and belowground plant productivity, and moisture availability across the growing season play important roles in determining SOC dynamics in these forests.

Contribution to Surface Water Contamination Understanding by Pesticides and Pharmaceuticals, at a Watershed Scale

This study aims at understanding the presence of regulated and emerging micropollutants, particularly pesticides and pharmaceuticals, in surface water, regarding spatial and temporal influences at a watershed scale. The study of relations between micropollutants and other water quality and hydroclimatic parameters was carried out from a statistical analysis on historical and experimental data of different sampling sites from the main watershed of Brittany, western France. The outcomes point out the influence of urban and rural areas of the watershed as well as the impact of seasons on contamination variations. This work contributes to health risk assessment related to surface water contamination by micropollutants. This approach is particularly interesting in the case of agricultural watersheds such as the one studied, where more than 80% of surface water is used to produce drinking water.

Chronic catchment nitrogen enrichment and stoichiometric constraints on the bioavailability of dissolved organic matter from leaf leachate

Summary1. Chronic nitrogen (N) deposition may alter the bioavailability of dissolved organic matter (DOM) in streams by multiple pathways. Elevated N deposition may alter the nutrient stoichiometry of DOM as well as nutrient availability in stream water.2. We evaluated the influence of a decadal‐scale experimental N enrichment on the relative importance of DOM nutrient content and inorganic nutrient availability on the bioavailability of DOM. We measured the consumption of dissolved organic carbon (DOC) and changes in nutrient concentration, DOM components and enzyme activity in a bottle incubation assay with different DOM and nutrient treatments. To evaluate the effect of DOM stoichiometry, we used leaf leachates of different carbon/N/phosphorus (C : N :P) ratio, made from leaf litter sourced in the reference and N‐enriched catchments at the Bear Brook Watershed in Maine (BBWM). We also manipulated the concentration of inorganic N and P to compare the effect of nutrient enrichment with DOM stoichiometry.3. DOC from the N‐enriched catchment was consumed 14% faster than that from the reference catchment. However, mean DOC consumption for both leachates was more than doubled by the simultaneous addition of N and P, compared to controls, while the addition of N or P alone increased consumption by 42 and 23%, respectively. The effect of N and/or P enrichment consistently had a greater effect than DOM source for all response variables considered.4. We subsequently conducted DOC uptake measurements using leaf leachate addition under ambient and elevated N and P in the streams draining the reference and N‐enriched catchments at BBWM. In both streams, DOC uptake lengths were shorter when N and P were elevated.5. Although both DOM stoichiometry and inorganic nutrient availability affect DOM bioavailability, N and P co‐limitation appears to be the dominant driver of reach‐scale processing of DOM.

Soil Solution Chemical Response to Two Decades of Experimental Acidification at the Bear Brook Watershed in Maine

We examined long-term changes in soil solution chemistry associated with experimental, whole watershed-acidification at the Bear Brook Watershed in Maine (BBWM). At BBWM, the West Bear (WB) watershed has been treated with bimonthly additions of ((NH4)2 SO4) since 1989. The adjacent East Bear (EB) watershed serves as a biogeochemical reference. Soil solution chemistry in the EB watershed was relatively stable from 1989–2007, with the exception of declining SO4–S concentrations associated with a progressive decline in SO4–S deposition during this period. Soil solution chemistry in WB reflected a progressive change in acid-neutralization mechanisms from base cation buffering to Al buffering associated with treatment during this period. Total dissolved Al concentrations progressively increased over time and were ~4× higher in 2007 than in 1989. Treatment of WB was also associated with long-term increases in soil solution H+, SO4–S, and NO3–N, whereas soil solution dissolved organic carbon (DOC) was unresponsive to treatment. For solutes such as Ca, H+, and SO4–S, changes in stream chemistry were generally parallel to changes in soil solution chemistry, indicating a close coupling of terrestrial and aquatic processes that regulate the chemistry of solutions in this first-order stream watershed. For other solutes such as Al and DOC, solute concentrations were higher in soil solutions compared with streams, suggesting that sorption and transformation processes along hydrologic flow-paths were important in regulating the chemistry of solutions and the transport of these solutes.

Has urbanization changed ecological streamflow characteristics in Maine (USA)?

This paper examines the potential effects of urbanization on streamflow in Maine, USA, from 1950 to 2000. The study contrasts nine watersheds in southern Maine, which has seen steady urban growth over the study period, with nine rural watersheds from northern Maine. Historical population data and current land cover data are used to develop an urbanization score for each watershed. Trends in watershed urbanization over the study period are compared to trends in ecologically relevant streamflow characteristics. The results indicate that trends in northern, rural watersheds are much more consistent than the trends in the southern watersheds. Additionally, trends in the southern watersheds are inconsistent with the hydrological characteristics observed in urban watersheds elsewhere, likely due to the comparatively low level of current urban development in Maine's urban watersheds. Our study suggests that urban areas in Maine have not yet reached an urbanization threshold where streamflow impacts become consistently detectable. Editor Z.W. Kundzewicz Citation Martin, E.H., Kelleher, C., and Wagener, T., 2012. Has urbanization changed ecological streamflow characteristics in Maine (USA)? Hydrological Sciences Journal, 57 (7), 1337–1354.

Tetrabromobisphenol A: tissue distribution in fish, and seasonal variation in water and sediment of Lake Chaohu, China

Tetrabromobisphenol A (TBBPA) is the most widely used brominated flame retardants (BFRs). It has been detected in various environment media and has been approved to be high toxic to aquatic organisms. However, the exposure levels of TBBPA in the main watersheds in China have not been investigated sufficiently. In this study TBBPA concentrations in water, sediment and tissues of four fish species from Lake Chaohu were determined. Spatial and temporal distribution patterns of TBBPA in water and sediment, and the relationship among TBBPA concentrations in fish tissues and fish size were analyzed. The results showed that the maximum TBBPA concentration in sediment was 518 ng/g in March 2008. It is almost the highest value than those ever reported anywhere in the world. In lake water, TBBPA level reached the maximum value of 4.87μg/L in July. Tissue distributions of TBBPA in four fish species were similar, and the mean concentrations in the fish were in the range of 28.5-39.4 ng/g, much higher than those reported in Japan, Europe, and the United States. The maximum concentrations of TBBPA were found in kidneys where TBBPA concentration was positively correlated with fish size of Cyprinus carpio. Results demonstrated a widespread distribution of TBBPA in Lake Chaohu. The source was mainly inflow rivers near the cities. The distribution coefficient among water, fish, and sediment was 1:28:117. This indicated that sediment was the main repository for TBBPA within Lake Chaohu. Furthermore, TBBPA may pose a potential ecological risk in the lake during summer.

Phenology at the Bear Brook Watershed in Maine, USA: Foliar Chemistry and Morphology

Annual developmental events in biological systems are dependent, in part, on environmental conditions and can be valuable bio-indicators of environmental change. Many studies have been done on the effects of temperature and photoperiod on phenophases, but fewer have explored the consequences of nutrient availability in terrestrial ecosystems on forest phenology. Here we examined phenological phenomena at a long-term experimental forested watershed subjected to decadal-scale ecosystem acidification and nitrogen (N) enrichment. Phenophases of Acer rubrum, Acer saccharum, and Picea rubens in both watersheds were observed throughout the 2010 growing season and included bud burst, flowering (A. rubrum), leaf or needle emergence and unfolding, leaf senescence (Acer spp.), and leaf fall (Acer spp). Clear species-specific phenological patterns were observed, but no treatment effects were evident. Chemical phenology of canopy tree foliage was also examined on a monthly basis from May through October 2010. Nitrogen was the only element that was significantly higher in the WB watershed for all species, although not all months showed significant differences. Other treatment differences in elemental composition of foliage are discussed. Foliar N and P concentrations decreased in all species throughout the growing season, while foliar Ca, K, and Al concentrations increased or were constant. This study found clear species-specific patterns of morphological and chemical phenology with time, but did not show evidence for visible alterations in seasonal development as a result of ecosystem acidification and N enrichment. Treatment effects on chemical phenology, as applied here, showed some responses and warrant further consideration for application to coupled chemical-biological indicators of a changing chemical and physical climate.

Influences of Hatchery Supplementation, Spawner Distribution, and Habitat on Genetic Structure of Chinook Salmon in the South Fork Salmon River, Idaho

We evaluated the genetic influence of hatchery supplementation on distinct naturally spawning populations of Chinook salmon Oncorhynchus tshawytscha in the South Fork Salmon River (SFSR), Idaho. Genetic tissue samples were collected from unmarked natural-origin and McCall Fish Hatchery (MFH)-reared Chinook salmon carcasses, and fish were identified by an adipose fin clip at five main-stem sites located both upstream and downstream of a seasonal exclusionary weir in the upper SFSR. We evaluated allele frequency data across 95 single-nucleotide polymorphism loci to determine the extent of genetic differentiation among collections. Genetic distance analyses and homogeneity tests indicated little subpopulation distinction in the upper SFSR. The weak overall genetic structure (global F ST = 0.010) is likely reflective of a population diversity similar to the historical structure with introgression by MFH stock in the naturally spawning population of the upper SFSR. Further analyses were conducted to evaluate the genetic structure among the upper SFSR and spawning aggregates in two adjacent SFSR tributaries: the Secesh River, which is devoid of any hatchery stocking, and Johnson Creek, where a discrete supplementation program has been implemented using only Johnson Creek fish. Our results indicated variable abundances of SFSR hatchery spawners distributed spatially among the three main watersheds. Gene flow appears to be restricted and genetic differentiation to be relatively large despite substantial hatchery releases in the upper SFSR. Three historical aggregates of Chinook salmon appear to persist in the SFSR metapopulation, where variable hatchery influences are coincident with the distribution of suitable spawning habitat and watershed-specific management objectives. Received January 5, 2011; accepted December 12, 2011

Influence of paddy rice terraces on soil erosion of a small watershed in a hilly area of Northern Vietnam

Soil erosion is the main cause of soil degradation in northern Vietnam. In this study, soil erosion was measured in 2 m2 field plots, a 19.1-ha sub-watershed, and a 248.9-ha main watershed in Tam Quan commune, Tam Duong district, northern Vietnam during 2 years, i.e., 2004–2005. The main watershed includes lowland paddy fields, and is representative for watersheds in the northern Vietnamese landscape. Soil erosion was measured for eight events, at all the three scales to increase our understanding of erosional processes and to assess the effects of paddy fields within the main watershed. The results show that total discharge and sediment yield in both sub-watershed and main watershed were much lower than those in the field plots. Total discharge per unit area in the main watershed was higher than in the sub-watershed, because during the growing season, the paddies are filled with water and any rainfall on them therefore becomes runoff. Sediment yield in the main watershed fluctuated, depending on the soil erosion contribution from many sub-watersheds. Annual rainfalls in 2004 and 2005 were 1,172 and 1,560 mm, respectively, resulting in corresponding total discharges of 54 and 332 mm and total soil losses of 163 and 1,722 kg ha−1 year−1. High runoff volumes occurred in July, August, and September, but April, June, the last 10 days of September and October, were the susceptible periods for soil erosion in the study area because of low plant cover and many agricultural activities during these periods.

The Sequence Diversity of Zacco platypus 16S rRNA in South Korean Main Watersheds

A freshwater minnow (Zacco platypus) is a freshwater fish widely distributed in South Korea. The study was conducted in order to confirm genetic variation with regards to water system via sequence of the mitochondrial 16S rRNA. The freshwater minnows used in the study was collected from 10 sites in four watersheds systems of the Hangang, Geumgang, Yeongsan·Seomjingang and Nakdonggang. Sequence analysis of the 16S rRNA using PCR revealed that sequence length is 624bp. According to Bayesian Analysis, unique sequence was determined in two freshwater minnows, Tamjingang A and Yeongsangang A, of the Yeongsan·Seomjingang water system. There was no sequence variation which was specific to the individual Hangang, Geumgang and Nakdonggang water systems. The 16S rRNA sequence of the Korean freshwater minnow as recorded by the NCBI showed 94% sequence similarity to the Japanese minnow (Zacco sieboldii). Study result was not able to clearly confirm sequence variation regards to geographical classification using the 16S rRNA alone in this species. Therefore, there is a need for analysis with regards to geological differences using Cytb or other nuclear sequence.

(P1-5) How Does Land use Pattern could Effect to Mitigate the Risk Flash Floods” a Success Story on a Model Project Implementing at the Upper Catchments Area of Badullu River in Sri Lanka

The watersheds are the home for our key natural resources and have been one of the basic elements in land use management systems throughout the hydraulic civilization of our country. “Badulla River” is one of the main watersheds in Sri Lanka extend about 1400sq.km consisting five sub catchments high steep lands. It mainly represents tea estates and agricultural lands with a weak land use pattern due to poor maintenance and unsuitable human involvements. This has contributed to reduce the rain water infiltration in to the soil increasing a huge amount of runoff water drainage. Situation has resulted frequent floods even in a small precipitation causing widespread damages to community. Hence, an initial project was started on surface water management, soil conservation and livelihoods development to control the frequent floods highlighting the urgent actions for an optimal land use management with support of field experts. Improved surface water drainage and soil conservation are the main options that might lead to mitigate the flash floods. Efforts were sharpened by integrating GIS Mapping for such initiation to enhance the effectiveness of the design. Results achieved could address many issues in relation to flood protection, habitat management, water protection and water quality management. Food risk generally related to the specific characters in a particular catchments and this model project proved that such issues can effectively be addressed through a joint program properly designed.