• Journal of Korean Society for Geospatial Information Science
• /
• v.21 no.2
• /
• pp.107-116
• /
• 2013

This study is intended to predict variations in future land use/land cover(LULC) based on the representation concentration pathway(RCP) storyline that is a new climate change scenario and to analyze how future climate and LULC changes under RCP scenario affects streamflow in the basin. This study used climate data under RCP 4.5 and 8.5 and LULC change scenario is created by a model that is developed using storyline of RCP 4.5 and 8.5 and logistic regression(LR). Two scenarios(climate change only and LULC change only) were established. The streamflow in future periods under these scenarios was simulated by the Soil and Water Assessment Tool(SWAT) model. Each scenario showed a significant seasonal variations in streamflow. Climate change showed that it reduced streamflow in summer and autumn while it increased streamflow in spring and winter. Although LULC change little affected streamflow in the basin, the pattern for increasing and decreasing streamflow during wet and dry climate condition was significant. Therefore, it's believed that sustainable water resource policies for flood and drought depending on future LULC are required.

• Journal of Korean Society on Water Environment
• /
• v.29 no.1
• /
• pp.88-96
• /
• 2013

Much attention has been needed in water resource management at the watershed due to drought and flooding issues caused by climate change in recent years. Increase in air temperature and changes in precipitation patterns due to climate change are affecting hydrologic cycles, such as evaporation and soil moisture. Thus, these phenomena result in increased runoff at the watershed. The Soil and Water Assessment Tool (SWAT) model has been used to evaluate rainfall-runoff at the watershed reflecting effects on hydrology of various weather data such as rainfall, temperature, humidity, solar radiation, wind speed. For bias-correction of RCP data, at least 30 year data are needed. However, for most gaging stations, only precipitation data have been recorded and very little stations have recorded other weather data. In addition, the RCP scenario does not provide all weather data for the SWAT model. In this study, two scenarios were made to evaluate whether it would be possible to estimate streamflow using measured precipitation and long-term average values of other weather data required for running the SWAT. With measured long-term weather data (scenario 1) and with long-term average values of weather data except precipitation (scenario 2), the estimate streamflow values were almost the same with NSE value of 0.99. Increase/decrease by ${\pm}2%$, ${\pm}4%$ in temperature and humidity data did not affect streamflow. Thus, the RCP precipitation data for Hongcheon watershed were bias-corrected with measured long-term precipitation data to evaluate effects of climate change on streamflow. The results revealed that estimated streamflow for 2055s was the greatest among data for 2025s, 2055s, and 2085s. However, estimated streamflow for 2085s decreased by 9%. In addition, streamflow for Spring would be expected to increase compared with current data and streamflow for Summer will be decreased with RCP data. The results obtained in this study indicate that the streamflow could be estimated with long-term precipitation data only and effects of climate change could be evaluated using precipitation data as shown in this study.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2010.05a
• /
• pp.273-277
• /
• 2010

This research was performed to examine changes in the timing of the growth of crops along with changes in temperatures due tochanges and to analyze the change of water-supply-reliability by adding an analysis of the change of agricultural water supply patterns in the basin area of Miryang dam in Korea. Had-CM3 model from U.K. was the tool adopted for the GCM model, a stochastic, daily-meteorology-generation-model called LARS-WG was alsoused for downscaling and for the climate change scenario (A1B) which represents Korea's circumstances best. First of all, to calculate changes in the timing of the growth of crops during this period, the theory of GDD was applied. Except for the period of transplanting and irrigation, there was no choice but to find the proper accumulated temperature by comparing actual temperature data and the supply pattern of agricultural use due to limited temperature data. As a result, proper temperatures were found for each period. $400^{\circ}C$ for the preparation period of a nursery bed, $704^{\circ}C$ for a nursery bed's period, $1,295^{\circ}C$ for the rice-transplanting period, $1,744^{\circ}C$ for starting irrigation, and $3,972^{\circ}C$ for finishing irrigation. To analyze future agricultural supply patter changes, the A1B scenario of Had-CM3 model was adopted, and then Downscaling was conducted adopting LARS-WG. To conduct a stochastical analysis of LARS-WG, climate scenarios were generated for the periods 2011~2030, 2046~2065, 2080~2099 using the data of precipitation andMax/Min temperatures collected from the Miryang gauging station. Upon reviewing the result of the analysis of accumulated temperatures from 2011~2030, the supply of agricultural water was 10 days earlier, and in the next periods-2046~2065, 2080~2099 it also was 10 days earlier. With these results, it is assumed that the supply of agricultural water should be about 1 month ahead of the existing schedule to meet the proper growth conditions of crops. From the results of the agricultural water supply patterns should be altered, but the reliability of water supply becomes more favorable, which is caused from the high precipitation change. Furthermore, since the unique characteristics of precipitation in Korea, which has high precipitation in the summer, water-supply-reliability has a pattern that the precipitation in September could significantly affect the chances of drought the following winter and spring. It could be more risky to make changes to the constant supply pattern under these conditions due to the high uncertainty of future precipitation. Although, several researches have been conducted concerning climate changes, in the field of water-industry, those researches have been solely dependent on precipitation. Even so, with the high uncertainty of precipitation, it is difficult for it to be reflected in government policy. Therefore, research in the field of water-supply-patterns or evapotranspiration according to the temperature or other diverse effects, which has higher reliability on anticipation, could obtain more reliable results in the future and that could result in water-resource maintenance to be safer and a more advantageous environment.

• Journal of Korean Society of Forest Science
• /
• v.90 no.6
• /
• pp.774-780
• /
• 2001

Aboveground carbon storage and increment of a 31-year-old pitch pine (Pinus rigida) stand were measured for five years (1997~2001) in the Jungbu Forest Experiment Station, Gyeonggi-do, Korea. The carbon concentration in each component of aboveground and soil depth decreased in the order of needle>branch>stembark>stemwood>forest floor>0-15cm soil depth>15-30cm soil depth. The carbon storage except for root carbon was 140,600kgC/ha and the tree accounted for 61%, soil 31% and forest floor 8% of the stand carbon storage. Due to high tree mortality by Fusarium subglutinans infection and spring drought in 2001, carbon increment except for 2001 data was 3,233kgC/ha/yr and was in the order of stemwood>branch>stembark>needle. Carbon storage and increment were attributed to stand density and site quality. Carbon storage and increment were higher in the high site quality than in the lower site quality plot on similar tree density. Also, the high tree density site on similar site quality showed more carbon storage and increment compared with the lower tree density. The results suggest that site quality and tree density are a key factor determining carbon storage and increment in this pitch pine stand.

• Journal of Climate Change Research
• /
• v.9 no.4
• /
• pp.303-312
• /
• 2018

In Ethiopia, climate change and deforestation are major issues hindering sustainable development. Local Ethiopian communities commonly perceive an increase in temperature and a decrease in rainfall. Meteorological data shows that rainfall has declined in southern Ethiopia, and spring droughts have occurred more frequently during the last 10-15 years. The frequently occurring droughts have seriously affected the agriculture-dominated Ethiopian economy. Forests can play an important role in coping with climate change. However, deforestation is alarmingly high in Ethiopia, and this is attributed mainly to agricultural expansion and fuel wood extraction. Deforestation has led to a decrease in various benefits from forest ecosystem services, and increased ecological and environmental problems including loss of biodiversity. To resolve the issues effectively, it is crucial to enhance climate change resilience through reforestation and various international collaborations are urgently needed. To continue collaboration activities for resolving these issues, it is first necessary to address fundamental questions on the nature of collaboration: does collaboration aim for a support-benefit or a mutual benefit situation; dividing the workload or sharing the workload; an advanced technology or an appropriate technology; and short-term and intensive or long-term and extensive?. Potential collaboration activities were identified by sectors: in the governmental sector, advancing governmental structure and policy, enhancing international collaborations and negotiations, and capacity building for forest restoration and management; in the research and education sector, identifying and filling gaps in forestry and climate change education, capacity building for reforestation and climate change resilience research, and developing bioenergy and feed stocks; and in the business and industry sector, supporting conservation based forestry businesses and industries, while promoting collaboration with the research and education sectors. It is envisaged that international collaboration for enhancing climate change resilience through reforestation will provide a strong platform for resolving climate change and deforestation issues, and achieving sustainable development in Ethiopia.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.41 no.2
• /
• pp.77-83
• /
• 2021

Rye (Secale cereal L.) is the most tolerant to abiotic stress including low temperature, drought, and unfavorable soil conditions among the winter cereals. Rye is the rapid growth of early spring results from increasing areas for the use of the forage and green manure in the middle part of Korea. "Jungmo2509", a rye cultivar was developed by the National Institute of Crop Science (NICS), RDA in 2014. It was developed from a cross between "Olhomil", a self-compatible cultivar, and "Synthetic II", a self-incompatible line. "Jungmo2509" is an erect plant type and of a middle size, with a green leaf color, a yellowish-white colored culm, and a yellowish brown-colored, small-size grain. The heading date of "Jungmo2509" was April 23, which was 5 days later than that of "Gogu", respectively. But "Jungmo2509" showed greater resistance to lodging compared to that of the check cultivar, with similar to winter hardiness, wet injury, and disease resistance. "Jungmo2509" was a higher to than "Gogu" in terms of protein content (9.4% and 8.0%, respectively), total digestible nutrients (TDN) (55.7% and 55%, respectively). The seed productivity of "Jungmo2509" was approximately 2.08 ton 10a-1, which was 11% lower than that of the check. Almost all rye cultivars are out-crossing due to genes controlling incompatibility, but "Jungmo2509" is higher seed fertility (56%) than that of Gogu (0%). it has self-compatible genes. "Jungmo2509" is erect in plant type and resistance for lodging. Therefore, "Jungmo2509" can produce uniform seeds for processed grains of human consumption and utilize them as parents for breeding the rye hybrids with high forage yields.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.43 no.2
• /
• pp.88-94
• /
• 2023

This study was conducted to analyze and compare the dry matter yield of Italian ryegrass (IRG) cultivated under monoculture and mixed culture system to recommend suitable varieties that can be cultivated. Italian ryegrass cultivars, Green Fram (GF, extremely early-maturing), Kowinearly (KE, early-maturing), Kowinmaster (KM, mild-maturing), and Hwasan 104 (H104, late-maturing), were used for mono or mixed cultivation. The average monthly temperature in Cheonan over the past 30 years tended to be similar, but that in November and March are judged to be abnormal weather. The dry matter yield of GF+H104 was significantly higher during harvest than that of GF (p<0.05). The dry matter yields of KE and KE+KM were significantly higher during harvest than the output standards of KE and KM. There was no significant difference between the dry matter yield of H104 and KM (p>0.05), but KM had the highest yield of 16,763.1 kg/ha. Analysis showed that the highest dry matter yield during IRG harvest was obtained under monoculture and KE+KM mixed culture. Because the occurrence frequency of abnormal weather such as drought during spring is increasing recently, it is judged that IRG cultivation using early and middle growth is necessary to prepare for abnormal weather.

• Journal of Korea Water Resources Association
• /
• v.51 no.12
• /
• pp.1195-1205
• /
• 2018

In the study, the water shortage of Boryeong Dam watershed ($163.6km^2$) was evaluated under future climate change scenario. The Soil and Water Assessment Tool (SWAT) was used considering future dam release derived from multiple linear regression (MLR) analysis. The SWAT was calibrated and verified by using daily observed dam inflow and storage for 12 years (2005 to 2016) with average Nash-Sutcliffe efficiency of 0.59 and 0.91 respectively. The monthly dam release by 12 years MLR showed coefficient of determination ($R^2$) of above 0.57. Among the 27 RCP 4.5 scenarios and 26 RCP 8.5 scenarios of GCM (General Circulation Model), the RCP 8.5 BCC-CSM1-1-M scenario was selected as future extreme drought scenario by analyzing SPI severity, duration, and the longest dry period. The scenario showed -23.6% change of yearly dam storage, and big changes of -34.0% and -24.1% for spring and winter dam storage during 2037~2047 period comparing with 2007~2016 period. Based on Runs theory of analyzing severity and magnitude, the future frequency of 5 to 10 years increased from 3 in 2007~2016 to 5 in 2037~2046 period. When considering the future shortened water shortage return period and the big decreases of winter and spring dam storage, a new dam operation rule from autumn is necessary for future possible water shortage condition.

• Current Research on Agriculture and Life Sciences
• /
• v.7
• /
• pp.201-219
• /
• 1989

Rice culture in Korea has a long history ranging over two thousand years. In the agriculture economy of pre-mordern Korea, however, its importantce was not as great as generally assumed. In fact, rice culture reached full development only after the 1920s when the Japanese colonial government carried out its drive to increase rice production in the Korea peninsula. It was not until the mid-1930s that rice became the staple in Korean diet. This can be attributed to two factors : (1) a mountainous topography that provides little irrigated fields and (2) a climate characterized by droughts in spring and heavy precipitation in summer. The present paper attempts to answer some of these questions. Specifically it will focus on these : Did the development of rice culture actually result in population growth? What are the salient features of agricultural develdpment and population grow in traditional Korea? Does the case of Korea conform the prevailing generalization about the agriculture in East Asia? I have discussed the development of rice culture and population growth in the Chos$\breve{o}$n dynasty, focusing on the relation between the rapid spread of transplanting and the rapid growth of population from the seventeenth to the nineteenth century. Here are my conclusions. (1) The spread of transplanting and other technological innovationsc contributed to the rapid growth of population in this period. However, we should also note that the impact of rice culture on population growth was rather limited, for rice culture was not the mainstay of agricultural economy in pre-modern Korea. Indeed we should consider the influence of dry field cropsn population growth. Nevertheless, it is obvious that the proliferation of rice culture was a factor crucial to population growth and regional concentration. (2) How should we characterize the spread of rice culture in the whole period? Evidently rice culture spread from less then 20% of cultivated fields in the fifteenth century to about 36% of them in the early twentieth century. Although rice as a single crop outweighed other crops, rice culture was more then counter-balanced by dry field crops as a whole, due to Korea's unique climate and geography. Thus what we have here in not a typical case of competition between rice culture and day field culture. Besides, the spread of rice culture in the seventeenth and eighteenth centuries accomplished by technological innovations that overcame severe springtime drought, rather than extensive irrigation. Althougt irrigarion facilities did proliferate to some extent, this was achieved by local landlords and peasants rather than the state. This fact contradicts the classical thesis that the productivity of rice culture increased through the state management of irrigation and that this in turn determined the type of society. (3) We should further study other aspects of the transition from the stable population and production struture in the fifteenth and sixteenth centuries to the rapid population growth and excessive density of population thereafter. We should note that there were continuing efforts to reclaim the land in order to solve the severe shortage of land. Changes also took place in the agricultural production relations. The increase in land producrivity developed tenancy based on rent in kind, and this in turn increased the independence of tenants from their landlords. There were changes in family relations-such as the shift to primogeniture as an effort to prevent progressive division of property among multiplying offspring. The rapid population growth also produced a great mass of propertyless farm laborers. These changes had much to do with the disintegration of traditional social institutions and political structure toward the end of the Chos$\breve{o}$n dynasty.

• Korean Journal of Breeding Science
• /
• v.40 no.1
• /
• pp.31-38
• /
• 2008

This experiment was carried out to improve the anther culture efficiency of barley (Hordeum vulgare L.). Callus induction rates from anther cultures of the five domestic naked barley and four unhulled varieties ranged from 0 to 5.6%, and plant regeneration rate to callus was 30.4% in the donor plants grown in a greenhouse during winter, among which the green plant regeneration rates ranged from 0 to 4.4%. Plant regeneration rate was 30.4% in the donor plants grown in a greenhouse during winter, whereas 21.3% in the normal field condition in spring. In addition, callus induction rates were 19.2% in plants grown in a normal field and 7.2% in drought-stressed condition, respectively. Being Considered the anther culture efficiency affected by the sampling time, the optimum sampling stage of anthers was 3~4 days before heading when the length between the 1st and 2nd auricles reaches 5 to 10 cm and at the uninucleate of pollen which the tip of the 2nd auricle aligns with the middle of panicle in the leaf sheath. Best callus induction rates came from the anthers stored at $4^{\circ}C$ for 3 weeks in a 10 to 15 cm diameter polyethylene bag with 5 to 10 panicles and Duwonchapssalbori and Saessalbori showed the higher induction rate of 4.8% and 1.7%, respectively.