• Journal of the Korean Society of Environmental Restoration Technology
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• v.10 no.6
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• pp.120-129
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• 2007

Rapid urbanization has transformed the spatial pattern of urban land use or cover. This paper concentrates that changed characteristics of landscape structure in the Tancheon Watershed, from 1995 to 2003 were investigated using land cover map. We used FRAGSTATS software to calculate landscape indices to characterize the landscape structure. We found that built up area has been increased rapidly during the study period, while cultivated area and forest area have been decreased rapidly in the same period. From 1995 to 2003, built up area was increased from 19.73% to 39.62% and cultivated area and forest area was decreased 17.60% to 5.97% and 58.31% to 49.41%. Number of patches, mean euclidean nearest-neighbor distance, contagion index, Shannon's diversity index increased considerably from 1995 to 2003, also suggesting the landscape in the study area became more fragmented and heterogeneous. but because of continuously fragmentation, landscape became homogeneity. The study demonstrates that landscape metrics can be a useful indicator in landscape monitoring and landscape assessment.

• Journal of Environmental Health Sciences
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• v.35 no.3
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• pp.220-225
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• 2009

This study evaluates the water quality of the river near the alpine farmland in the upper Naerin stream, which is a typical stream of the upper Bukhan River with muddy water generation, by the flow examination, it aims to estimate the characteristics of nonpoint sources flowing out from the investigated area and figure out effective methods to reduce them. According to the result of water quality examination, the average BOD of the area not affected by the cultivated land among the areas of the upper Naerin River was 0.47mg/l, and total phosphorous was 0.007mg/l; thus, it maintained the cleanliness level of Ia. The average BOD of the area with the alpine farmland was 0.52mg/l, which was similar to the one of the non-cultivated land. But total phosphorous concentration was 0.023mg/l, which was more than three times higher than the area belonging to level II due to the effect of fertilizer ingredients discharged from the cultivated land. About the loadings of the investigated area generated from each of the pollution sources, BOD was 878.5kg/day and total phosphorous was 79.7kg/day. Moreover, for the load density, BOD was $2.22kg/day.km^2$ and total phosphorous was shown as $0.20kg/day.km^2$. Regarding the rates generated from nonpoint sources like land among the loadings per pollution sources, BOD was 54%, total nitrogen was 91%, and total phosphorous was 73.4%. Therefore, it was shown that most of the nutrients were produced from the nonpoint sources. The level of BOD runoff loading in the Jaun River area, where nonpoint sources were mainly generated, was 37.1kg/day and total phosphorous was 1.33kg/day. The flow rates to the generated amount were estimated as 10.5% and 4.7% each.

• Korean Journal of Environment and Ecology
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• v.27 no.6
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• pp.757-764
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• 2013

This study was conducted to determine factors causing urban temperature rises in a mixed urban and rural city in Korea. The study site was Miryang City. For this study, temperature changes over a 36 year period from 1974 to 2010, as well as changes made in the urban environment of the city were examined. Changes in the urban environment included data pertaining to both urban development and changing land use, as well as the changing lifestyle patterns of the populace. The study showed that a rise in the average annual temperature and the average annual mean-maximum temperature were statistically significant and the greatest determining factor for the temperature rise was a corresponding decrease in arable land. The study also showed that the decrease in cultivated land was directly and significantly related to an expansion of regional urbanization. There is a direct relationship between the decrease in cultivated land and an increase in the annual-mean-maximum temperature compared with annual-mean temperature. This increase can be explained as arable land works as an "island" of cooler temperatures in the hottest times of the day. A decrease of $1km^2$ of arable land is expected to cause an increase of $0.08^{\circ}C$ of annual-maximum-mean temperature and $0.06^{\circ}C$ of annual-mean temperature.

• Korean Journal of Weed Science
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• v.8 no.2
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• pp.133-140
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• 1988

One hundred and one noxious weeds on cultivated land of Taiwan were investigated for the occurrence of "Kranz" leaf anatomy and activities of PEP carboxylase and $C_4$ acid decarboxylating enzymes : NADP-malic enzyme, NAD-malic enzyme, PEP carboxykinase. Based on the leaf anatomy and a/b chlorophyll ratio, twenty-seven species exhibit "Kranz" type leaf anatomy, and seventy-four species were found without it. Among the species investigated, Digitaria radicosa (Presl) Miq., Leptochloa chinensis (L.) Nees, and Sporobolus fertilis (Steud.) W. D. Clayton in the Gramineae were first recorded as $C_4$ plants. Twenty-sven species of "Kranz" type leaf anatomy, include those of monocotyledon ; sixteen species in Gramineae, six species in Cyperaceae. Those of dicotyledon ; two species each in Euphorbiaceae and Amaranthaceae and one species in Portulacaceae. The subtype of fourteen previously uninvestigated species among twenty-seven species were further determined. The properties of the three decarboxylating enzyme from representative species were also characterized.

• Korean Journal of Environmental Agriculture
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• v.39 no.3
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• pp.188-196
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• 2020

BACKGROUND: In order to cultivate upland crops in reclaimed land, economically appropriate crops should be selected. Jerusalem artichoke (Helianthus tuberosus L.) is one of the primary sources for inulin in higher plants. The objective of this study was to evaluate and compare growth and inulin of H. tuberosus L. according to the cultivation region in Korea. METHODS AND RESULTS: 21 varieties of H. tuberosus L. were collected in Korea, and then 7 varieties of H. tuberosus L. were selected for this study. To compare growth and inulin, those varieties were cultivated in reclaimed land and upland soils. The growth of H. tuberosus L. significantly decreased when cultivated in reclaimed land. There was an increas at 17.8% in the content of white H. tuberosus L. tuber inulin in reclaimed land. CONCLUSION: The content of inulin in H. tuberosus L. tubers was found to be dependent on cultivation region and tuber color. There was a difference of the inulin content between the tubers with different colors in reclaimed land. Purple tubers of P20 were considered suitable varieties for cultivation in reclaimed land. White tubers of W1 and W8 were also considered suitable varieties for cultivation in reclaimed land.

• Magazine of the Korean Society of Agricultural Engineers
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• v.13 no.1
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• pp.2162-2176
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• 1971

From the ancient times our forefathers settled down in this peninsular and cultivated the hills and waste-lands into fields. Instead of fertilizing the lands they moved to find other fertile lands and lived a feudal life of agriculture and various machines played a main role in the land reclamation. The best method of land clearing, the time and efficiency in the operation and the effect of growing crops should sysematically analized prior to the time of 3rd Five-year Economic Development(1972-1976) in order to cultivated 210,000 ha of waste-land or the modernization of our country. The present study was investigated to find out a new working-system of mechanical land clearing and development of fertile soil. The results are as follows: 1) The land reclamation in natural slope is much more encourageable in land clearing and farming when the slope is below ten grades than bench terrace. 2) Weeds were mixed with soil in the land clearing work in order to supply organic materials and to make soil swollen instead of burning of just removing. 3) The equipments such as bulldozers, harrows, power tillers and so on should be prepared in order to do a systematic work in the land clearing. 4) The work of pulling-up roots is dependent upon the forms of roots spreading under the ground. The work of the pulling-up the straight roots was most difficult. 5) The land clearing work of the wrinkled style blocks was easy in pulling up roots and in the time of first plowing. The harrowing work could also be simply done. 6) The amount of soil carried was $240m^3/10a$, 15.6% increased amount from the standard block, while the required time of clearing work was 2 hours 15 minutes 45 seconds/10a, the one third of time required for the standard block. 7) The time disc harrowing work increased 50%, or 15 minutes/10a compared to the harrowing work required in the cultivated soil. 8) The time of rotary tilling increased 2.4 times or 1 hour 47 minutes 43 seconds/10a compared to the time required in the cultivated soil. 9) The reclamed land should be fertilized according to the soil quality, especially added fertilizer should be more than 1,200kg/10a, limes 20kg/10a. In order to produce added fertilizer grass fields should be needed. 10) The experiment of pasture growing is now progressing and therefore the effect of land clearing and the degree of developed soil will be investigated before long.

• Journal of Environmental Health Sciences
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• v.27 no.2
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• pp.51-59
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• 2001

Song stream is located in the upstream of the Namhan River. Normal times, the stream flows down to the east sea through the drainage pipe but at rainy season, it flows to the Namhan River. There are large stock farm, leisure town and cultivated land in this basin. The pollutants from these contamination source cause eutrophication at lake Doam and deterioration of water quality in namdai stream. In this case, this study was carried out to evaluate water quality and environmental capacity as well as economical efficiency of each industry. The basin shape factor of subject stream was 0.315, slope is higher than usual basin. The BOD, T-N and T-P productive contamination loading from each contamination source was 2,690, 974 and 194 kg/day, respectively, and major contamination source was stock farm and cultivated land. Annual BOD, T-N, T-P distribution(median value) of Song stream showed 1.0~2.2 mg/L, 3.16~5.85 mg/L and 0.024~0.197 mg/L Doam lake showed 1.1~1.9, 2.51~3.89 and 0.042~0.114 mg/L, respectively. Being compared of water quality at main stream between past and present, it showed that the water quality has improved since last five years. BOD improvement rate was 8~50%. Run off loading of BOD, T-N, T-P was 366, 1129, 17.2 kg/day, and run off rate was 13.6%, 86.2%, 11.3% respectively. Finally, the result of productivity survey of each industry, leisure town, cultivated land and large stock farm was 118, 46, 50 billion won, per T-P 1kg productive, and productivity portion was 100, 39, 42% respectively, and the highest economical efficiency industry was leisure facilities.

• The Korean Journal of Ecology
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• v.22 no.5
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• pp.235-240
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• 1999

Characterization of water quality was performed from March 1993 to March 1998, on the purpose of clarifying the relationships between water quality and land use types. The study sites were two reservoir basins; Kaesim and Jangchan in Iwon-myon, Okchon-gun, Chungcho'ngbukdo Province. The two basins were characterized by cultivated area (Kaesim reservoir) and mountain area (Jangchan reservoir), and divided into eleven small basins, where dynamics of pollutants, and the relationship between water quality and land use types were investigated. BOD, SS and TKN became lower and lower from up-stream to down-stream, except for the small basin G where self-purification limit was exceeded. And water quality of Jangchan reservoir basin was worse because of fish nursery. Area below altitude 200m occupied 56% in Kaesim and 44% in Jangchan reservoir basins. Especially total phosphorous (Y/sub T-P/=0.2023X＋0.0991, r=0.54) and total nitrogen increased in small basins where the proportion of cultivated and residential area was higher. The analysis of influences of pollutant discharge on water quality showed that pollution charge was very high in cultivated areas. The concentrations of pollutants were attenuated flowing into watersheds through physical, chemical, biochemical, and biological processes. The pollution level of mountain area was lower than that of cultivated areas.

• Korean Journal of Soil Science and Fertilizer
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• v.51 no.1
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• pp.50-60
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• 2018

This study was to evaluate the effect of organic amendments incorporation on soil properties and plant growth under two different soil salinity levels and various cultivated crops at Saemangeum reclaimed tidal land for three years from 2012 to 2014. The soil texture of the experimental site was sandy loam. Four different crops, sesbania (Sesbania grandiflora), sorghum-sudangrass hybrid (Sorghum bicolor-Sorghum sudanense), rice (Oryza sativa L.) and barley (Hordeum vulgare) were cultivated at low (< $1dS\;m^{-1}$) and high (> $4dS\;m^{-1}$) soil salinity levels. The soil salinity was significantly lowered at the rice cultivation site compared to continuous upland crops cultivation site in high soil salinity level. But the soil salinity was increased as cultivating sesbania coutinuously in low soil salinity level. The soil organic matter content was increased with the incorporation of straw at the continuous site of rice and barley, and the average of soil organic matter was increased by $0.9g\;kg^{-1}$ per year which was effective in soil aggregate formation. The highest biomass yield plot was found in barley (high salinity level) and sesbania (low salinity level) cultivation site, respectively. Our research indicates that rice cultivation in paddy field with high salinity level was effective in lowering soil salinity and sesbania cultivation was useful to biomass production at upland with low salinity. In conclusion, soil salinity and organic matter content should be considered for multiple land use in newly reclaimed tidal land.

• Korean Journal of Environmental Agriculture
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• v.39 no.3
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• pp.204-213
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• 2020

BACKGROUND: Since the number of crops cultivated in reclaimed land is huge, it is very difficult to quantify the total crop production. Therefore, a non-destructive method for predicting crop production is needed. Salt tolerant root vegetables such as red beets and sugar beet are suitable for cultivation in reclaimed land. If their underground biomass can be predicted, it helps to estimate crop productivity. Objectives of this study are to investigate maximum leaf length and weight of red beet, sugar beet, and turnips grown in reclaimed land, and to determine optimal model with regression analysis for linear and allometric growth models. METHODS AND RESULTS: Maximum leaf length, width, and root fresh weight of red beets, sugar beets, and turnips were measured. Ten linear models and six allometric growth models were selected for estimation of root fresh weight and non-linear regression analysis was conducted. The allometric growth model, which have a variable multiplied by square of maximum leaf length and maximum leaf width, showed highest R² values of 0.67, 0.70, and 0.49 for red beets, sugar beets, and turnips, respectively. Validation results of the models for red beets and sugar beets showed the R² values of 0.63 and 0.65, respectively. However, the model for turnips showed the R² value of 0.48. The allometric growth model was suitable for estimating the root fresh weight of red beets and sugar beets, but the accuracy for turnips was relatively low. CONCLUSION: The regression models established in this study may be useful to estimate the total production of root vegetables cultivated in reclaimed land, and it will be used as a non-destructive method for prediction of crop information.