• Journal of the Korean Geographical Society
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• v.44 no.1
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• pp.17-30
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• 2009

Paleostudies using lake sediment are essential to reconstruct environmental history of cental Mexico, where few documents on ancient civilizations and the colonial period exist. This study aims to reveal changes in the soil erosion rates through the calculation of sediment influx into the lake. The calculation is based on different kinds of chronologies and LOI. Sediment influx and dates for important events could be obtained in great detail through various chronological methods. Results show that corn agriculture was the most important reason to degrade the environmental status of the lake basin and European cattle raising was not much influential within the lake basin at least. It was possible to reveal a lot of recent environmental changes in detail, because the lake sediment used for this study has a very high sedimentation rate. Also, due to an accurate chronological framework, fundamental problems with the sediment were solved and reliable results could be produced.

• Journal of the Korean association of regional geographers
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• v.15 no.6
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• pp.707-719
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• 2009

A lot of different opinions have intensified the debate on environmental destruction during the pre- and post- conquest. Some respect Indian's way of living in harmony with nature, while others blame Indians for altering the environment. Also, some argue that Europeans' cattle raising resulted in highly modified ecosystem, whereas others believe that the ecosystem was not much affected by cattle raising due to their transhumance. This kind of argument shows us the point we need to consider as trying ecological restoration. If we want to find an ideal target for ecological restoration, if we like to figure out the time when human being and nature were really in harmony, advanced paleoenvironmental studies are necessary.

• Journal of the Korean Geographical Society
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• v.40 no.4 s.109
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• pp.428-440
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• 2005

There is currently no agreement among archaeologists, environmental historians, and paleoecologists as to the relative significance of pre- and post-Conquest human impact on the environments of Highland Mexico. This paper presents the results of pollen, microscopic charcoal, dung fungal spore, isotope, and magnetic susceptibility analyses on ca. 4m sediment core. The coring site is Hoya Rincon de Parangueo, one of the seven maar lakes in the Valle do Santiago. Amaranthaceae pollen, one of important disturbance indicators and Zea mays pollen obviously indicate two periods of agricultural activities. The first period begins ca. 400 B.C. and ends ca. A.D. 850. The second begins around A.D. 1550 and continues to the present. During the first period, the degree of agricultural activities was related to periodical sunspot cycles and the most intense activities were present between ca. A.D. 150-ca. A.D. 400. The abrupt increase of $\delta^{18}O$ around 280cm may reflect that an important transition to a dry phase took place around A.D. 450. People probably stopped cultivating crops due to dry conditions prevailing since ca. A.D. 450. The second period, the post-Conquest, exhibits a dramatic increase of sporormiella, dung fungal spores resulted fron the introduction of cattle. Low Poaceae frequency and charcoal production and high $\delta^{13}C$ values, magnetic susceptibility, and organic contents all indicate the arrival of the Spanish. Most importantly, it seems that mesquite (Prosopis juliflora) could have benefits from declined fire frequencies caused by cattle grazing. The study area is now entirely dominated by woody plants like mesquite, which clearly demonstrates that serious vegetation change occurred in the study area.

• Journal of the Korean association of regional geographers
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• v.22 no.2
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• pp.353-368
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• 2016

The importance of Gotjawal located in the mid-mountain area of Jeju Island has been emphasized in various aspects. This study aims to identify the value of Gotjawal as a life-cultural space. This will be illustrated by tracing the locals' previous pasturing activities and the management of village common pastures. Cheongsu Village Common Pasture and Jeoji Village Common Pasture in Cheongsu-Jeoji Gotjawal area, which are the study areas, have been actively used by local farmhouses since the establishment of the pastures in 1930's. In particular cattle were significant means for agriculture and transportation methods in 1960's and 1970's. The farmhouses were needed to breed cattle as one of the main economic means. Pasturing cattle on the village common pastures has developed a unique ranching culture. Furthermore, cooperative work of these farmhouses were performed. These include the establishment of ponds for water supply and the preparation of hay. Ranching facilities for pasturing were built on village common pastures and still remain in Gotjawal area. This has been used in the understanding of the locals' lives in the mid-mountain area of Jeju Island.

• Journal of environmental and Sanitary engineering
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• v.1 no.1 s.1
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• pp.1-29
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• 1986

The guidelines and regulations that have revised by World Health Organization, the United States of America, Canada and Japan were reviewed for standards relevant to health of the people. The substances and parameters were discussed. Various standards were presented and recent changes in policies were relighted with their scientific information.