• Journal of Wetlands Research
• /
• v.19 no.4
• /
• pp.403-408
• /
• 2017

This study aims to set up the basic data to manage the waterfowl habitat through the analysis of the changes of physical structure according to the time series of Hangang(Riv.) as water birds' habitat. Study area was 41.5km in length from Paldang bridge to Hangju bridge. during total length of 497.52km and horizontal boundary was based on the protected lowland in year 1975. As the analysis result of land use from the center of water to adjacent road to the river, ratio of year 1975 was in order of sedimentary land(22.7%), surface water(20.7%), built-up area(16.9%), field(16.2%), paddy field(15.9%), and afterwards most of the areas were changed through the construction of arterial highway and submerged weir in order to use Hangang(Riv.). In year 1985, the area ratio of protected lowland(57.8%) and surface water(32.8%) dramatically increased. After construction of river bank the recreational areas continually increased and relatively natural areas decreased. In year 2005, the area ratio of protected lowland was enlarged to 57.6% and surface water also to 33.3%. While the length of both riversides and naturalness decreased by 10.9%, 91.5% respectively in year 2005 compared to year 1975, the depth of water increased by 1.46m. Comprehensively, the flow of changes by physical structure in Hangang(Riv.) for 30 years was divided into two periods. The main characteristics in the first period were decrease of riverside area and enlargement of the surface water through the massive construction before middle of year 1980, and afterwards revetments were intensively artificialized with changes of land use for amusement area. In terms of water fowl habitat, Hangang(Riv.) which previously had various types of habitat condition was changed into simplified habitat for few of species, and the active improvement apporach was needed for habitat diversity.

• Korean Journal of Weed Science
• /
• v.9 no.3
• /
• pp.201-213
• /
• 1989

About 233 weed species belonging to 54 families mainly occurring in summer were observed in cultivated land and its surrounding area in Cheju Island. The compositae was the most widely occurring family covering 41 weed species, followed by 28 species in gramineae, 14 in labiatae, 13 in leguminasae and 12 in polygonaceae etc.. In terms of the lands classified about 126 species in 39 families were observed in upland ared and 38 species in 20 families occurred in lowland area, 108 species in 36 families in orchard and 214 species in 50 families observed in non-cultivated area. The most dominant weed species in Cheju Island were Portulaca oleracea, Digitaria sanguinalis in both the upland and orchard, Monochoria vaginalis, Cyperus amuricus in lowland, and Digitaria sanguinalis, Artemisia princeps, Partulaca oleracea in non-cultivated land area. There were two communities in upland area, such as Phyllanthus urinaria, Siegesbeckia orinexitalis etc., and Cephalonaplos segetum, Mosla dianthera etc.. The lowland area composed of one major community like Onenanthe javanica, and Eleocharis acicularis. The orchard consisted of the communities of Stellaria aquatics, Viola mandshurica etc., and Justicia procumbens, Varedellia crustacea etc.. The non-cultivated land composed of two major communities like Amplicarpaed edgeworthii, Lactuca indica etc., and Clematis appiiforia, Aster hispidus etc..

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.39 no.2
• /
• pp.81-88
• /
• 2019

This study was carried out to investigate the growth characteristics, yield and feed value of Sorghum${\times}$Sudangrass hybrid for silage according to the drainage depths in the paddy field of lowland. The experimental design was arranged in a randomized block design with four treatments and three replication. The drainage depths of four treatments were 0cm, 20cm, 40cm and 60cm, respectively. Plant length, leaf length and leaf number were not significantly different, but leaf width increased as the higher the drainage depth(p<0.05). The number of dead leaf was higher in the order of $60cm>0cm{\geq}40cm{\geq}20cm$ treatment(p<0.05). Green degree was higher in the order of 20cm > 40cm > 0cm > 60cm treatment(p<0.05). Stem diameter and stem hardness increased significantly as drainage depth increased from 0cm to 60cm(p<0.05). Also, fresh yield, dry matter yield and TDN yield increased as the higher the drainage depth(p<0.05). Crude protein and TDN content were the highest in 40cm treatment(p<0.05). Crude ash was higher in the order of 20cm > 40cm > 0cm > 60cm treatment(p<0.05). ADF and NDF content were the highest in 0cm treatment(p<0.05). Total mineral content was higher in the order of 20cm > 0cm > 40cm > 60cm(p<0.05). Free sugar content(fructose, glucose and sucrose) was the highest in 0cm treatment(p<0.05). Total amino acid(EAA+NEAA) was higher in 40cm than the other treatments(p<0.05). There is a difference in the content of ingredients(crude protein, TDN, mineral, free sugar and amino acid) according to the treatments. But considering dry matter yield and TDN yield, Sorghum${\times}$Sudangrass hybrid cultivation is advantageous to set the drainage depth of about 60cm in the paddy field of lowland.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.60 no.2
• /
• pp.231-238
• /
• 2015

This study was carried out to determine environmental factors affecting the anthocyanin content of color-fleshed potato (Solanum tuberosum L.) tubers. After planting of two color-fleshed potato cultivars of 'Hongyoung' and 'Jayoung' in different 14 locations, their soil chemical properties and meteorological data were evaluated, and anthocyanin contents of tubers were analyzed after harvest, additionally their relationship among them was analyzed through correlation analysis. In comparison with two cultivars, purple-fleshed 'Jayoung' potatoes showed higher anthocyanin content than red-fleshed 'Hongyoung' in almost locations. When locations were divided to three categories (highland, sub-highland and lowland) according to altitude, in general, highland-grown tubers had the higher content of anthocyanin compared to those grown in lowland. An analysis of the results of chemical components of soil showed that anthocyanin content of color-fleshed potato tubers was negatively correlated with the pH of soil. In addition, mean temperature and minimum temperature from 80 to 100 days after planting most significantly affected on the accumulation of anthocyanin in color-fleshed potato tubers, that is, higher content of anthocyanin was observed in tubers produced in locations with lower mean temperature and minimum temperature from 80 to 100 days after planting. This information can be useful to producers and industries in selection of proper fields for the production of color-fleshed potato tubers having high quality in Korea.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.23 no.1
• /
• pp.15-29
• /
• 2020

Recently, the incidence of flooding in Korea has decreased by the measures by central and local governments, however the scale of damage is increasing due to the improvement of living standard. One of the causes of such flood damage is natural causes such as rainfall exceeding the planned frequency of flood control under climate change. In addition, there are artificial causes such as encroachment of river spaces and management problems in upstream basins without consideration of downstream damage potential by regional development flood. In this study, in order to reduce the inundation damage caused by flooding of river, the situation at the time of inundation damage was reproduced by the detailed topographic data and 2D numerical model. Therefore, the effect of preparing various disaster prevention measures for the lowland was simulated in advance so that quantitative evaluation could be achieved. The target area is Taehwa river basin, where flooding was caused by the flooding of river waters caused by typhoon Chaba in October 2016. As a result of rainfall-discharge and two-dimensional analysis, the simulation results agree with the observed in terms of flood depth, flood arrival time and flooded area. This study examined the applicability of hydraulic analysis on river using two-dimensional inundation model, by applying detailed topographic data and it is expected to contribute to establish of disaster prevention measures.

• Journal of Wetlands Research
• /
• v.17 no.1
• /
• pp.91-100
• /
• 2015

The aim of this study is to compare and analyze plant monitoring results of 2012 and 2013 for three artificial wetlands of Binae, Sedo, and Okpo areas in Namhan river, Keum river, and Nakdong river respectively. As the results, the Binae wetland in 2013 shows the same environment with 2012, that is, Willow and Common reed were dominant and the distributed plants in the wetland were Phragmites japonica Steud, Carex dispalta Boott, and Humulus japonicus in lowland of river side. Especially, Humulus japonicus was increased in summer season and Willow was increased in lowland of 초원. In Okpo wetland, Water chestnut was appeared in 2013 which it was not in 2012. Reed distribution was reduced in 2013 comparing to 2012 but Pussy willow distribution was not changed in 2013. In Sedo wetland, Secondary grassland was artificially planted in 2013 and so the colony was changed to Chinese Lespedeza and also most of plant colony was changed to Colt's-tail. Therefore, we can know that wetted transition rather than dried transition will be occurred in the Binae wetland. However, the Okpo wetland has monotonic change and so the transition will be proceeded with long time. The Sedo wetland showed wetted and dried transitions exist together. Therefore, the wetland will be changed to Reeds, Common reed, and Willow colonies.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.6 no.2
• /
• pp.91-96
• /
• 1986

This trial was carried out to find out the degree of fodder value of different plant communities and to make the plant sociological vegetation map for all plant communities at the natural grassland of the Rehberg-Alm in the Bavarian Alps, southern part of Germany during 1982-1983. 1. Allogenic succession of the plant communities at natural grassland was much more influenced by the change of soil moisture or/and surface water than sheep grazing. 2. The plant communities at the Rehberg-Alm were Nardetum alpigenum, Poo-Prunelletum, Cirsium arvense Cirsium Vulgare-Association, Caricetum davallianae, Rumicetum alphini, Caricetum paniculatae and Disturbed lowland bog-Stand. 3. By the sheep grazing will be improved the inferior plant community of Nardetum alpigenum to the most desirable Poo-Prunelletum plant community at the mountainous grassland gradually. 4. General fodder value in this area depended heavily on the composition of vegetation of the plant communities. The highest fodder value was the Poo-Prunelletum with 4.4 and the next was the Nardetum alpigenum with 2.5. The others were not suitable for grazing pasture due to less fodder value.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.35 no.2
• /
• pp.137-144
• /
• 2015

This study was carried out to investigate the growth characteristics, yield, and chemical compositions of corn hybrids for silage according to the drainage depths in a lowland paddy field. The experimental design was arranged in a randomized block design with four treatments and three replications. The drainage depths of the four treatments were 0 cm, 20 cm, 30 cm and 50 cm. Tip-filling degree, ear length, and ear circle were higher in the 30 cm and 50 cm treatments compared with the other treatments (p < 0.05); but the plant length, leaf length, leaf width, ear height, stem diameter, and stem hardness were not significantly different (p < 0.05). The brix was higher in the order of 20 cm > 0 cm > 50 cm > 30 cm treatment. The fresh yield, dry matter yield, and TDN yield increased as the drainage depth increased (p < 0.05). The crude-protein and crude-ash content were highest in the 50 cm treatment (p < 0.05), but the crude-fat, NDF, ADF, and crude-fiber levels were not significantly different (p < 0.05). The total mineral content was higher in the order of 0 cm > 30 cm > 20 cm > 50 cm treatment (p < 0.05). Fructose, glucose, and sucrose were highest in the 20 cm treatment. The total amino-acid (EAA + NEAA) content was the highest in the 50 cm treatment. Based on these results, greater drainage depths increased the yield and feed value of silage corn.

• Korean Journal of Weed Science
• /
• v.8 no.2
• /
• pp.158-163
• /
• 1988

Several factors affecting emergence and tuber formation of lowland perennial weeds were studied at the Yeongnam Crop Experiment Station in 1988. Period of tuber germination start to final tuber varied by species. Eleocharis kuroguwai and Sagittaria trifolia required longer than 10 days at $30^{\circ}C$ for this while Cyperus serotinus and S. pygmaea needed about 4 days. Application of gibberellic acid shortened this period while Uniconazole application delayed. E. kuroguwai and C. serotinus had ability to emerge under 20cm depth placement. However, S. trifolia could not emerge under 15cm depth. All species decreased their growth with increase in planting depth. E. kuroguwai had least correlated between dry matter production and tuber formation. Clipping of above ground part negatively related with tuber formation eventhough the effect of clipping time was differed by species. The most critical clipping time was 60 days after eremergence (DAE) for E. kuroguwai and 90 DAE for C. serotinus. Covering of colored polyethylene film was also related with tuber formation with varing effects. In general, the order of effectiveness for tuber formation were black. orange. blue and red. Application of Uniconazole and Pachlobutrazol effectively controlled the formation of tuber of E. kuroguwai and this effect enhanced by early application.

• Horticultural Science & Technology
• /
• v.19 no.3
• /
• pp.334-337
• /
• 2001

This study was conducted to investigate the effect of highland (Daekwallyung, altitude of 800m above sea level) production of cucumber (Cucumis sativus L.) seedlings for retarding culture in lowland (Kangnung, altitude of 20m above sea level). Cucumbers (cv. Jangilbanbaek, Jeongsunyeoreum and Ginseollok) were raised during 25 days from 31st July to 25th August, and then planted under the rain-shelter at Kangnung 25th August. Mean and minimum temperature during raising seedlings at Daekwallyung, $20.9^{\circ}C$ and $16.1^{\circ}C$ were $3.7^{\circ}C$ and $5.3^{\circ}C$ lower than those of Kangnung, respectively. T/R ratio of the seedlings produced at Daekwallyung was lower than that of Kangnung, but chlorophyll contents were higher. Daekwallyung seedlings were higher female/male ratio compared with seedlings from Kangnung. Marketable yield from cucumber seedlings (cv. Jeongsunyeoreum) produced at Daekwallyung was 32% higher than that of Kangnung. These results showed that cucumber seedling raising place was Daekwallyung for the retarding culture during summer season, particularly, and the best cultivars was Baekchim (cv. Jeongsunyeoreum).