농경지 토양침식 위험지역 분석

Analysis of Soil Erosion Hazard Zone by Cropland

토양침식은 강우분포, 토양, 토지이용과 같은 많은 요인들에 의해 영향을 받는다. 이런 요인들은 시간과 공간에 의해 여러 가지 형태로 나타난다. 본 연구에서는 유역에서의 토양침식 위험지역을 평가하는 것을 목적으로 하고 있으며, 토양침식량 계산은 RUSLE를 이용하였고, RUSLE의 지형 및 공간정보 관련 인자들은 DEM, 토양도, 토지이용도를 이용하여 추출하였고 유역에서 발생하는 토양침식량을 산정하였다. 연구대상유역으로는 한강수계 제1지류인 경안천 유역의 농경지로 하였으며, 토양침식량 분석결과 보통, 특수작물(1210) 재배지역, 과수원(1220), 미경지정리답(1120), 경지정리답(1110)의 순으로 가장 큰 토양침식이 발생하고 있으며, 이 재배지역의 평균 토양침식량 또한 보통, 특수작물 재배지역에서 가장 크게 나타났다. 이 토양침식량 분석결과를 이용하여 농경지의 토양침식 위험지역을 5개 등급으로 구분하여 분석한 결과 토양침식의 위험성이 가장 크다고 판단되는 5등급의 경우 전체 농경지의 2.4%에 해당하는 72.5ha정도가 침식위험지역으로 판단하였다. 이 침식위험지역은 밭작물재배지역이 72.4ha이고 과수원이 0.1ha로 분석되었으며, 기타의 농경지역에서는 5등급의 위험지역은 나타나지 않았다. 또한 토지이용 상황에 관계없이 2등급(1~50ton/ha/yr) 지역이 전체 농경지의 70.2%로 가장 많은 비율로 나타났다.

Soil erosion is influenced from a variety of factors such as rainfall distribution, soil type, land use, etc. This paper is aimed at analyzing the soil erosion hazard zone in cropland. RUSLE was used for an analysis of soil erosion amount, and for the spatial data of basin, soil erosion amount was calculated by extracting the respect topography space related factors of RUSLE using DEM, Landuse, Soil map as base map. This paper is targeting at the watershed of Gyeongan stream in Gyeonggi-do The result of an analysis of soil erosion amount showed that soil erosion occurred in the order of crop field(1210) planting area, orchard(1220), non-adjusted paddy fields(1120), and adjusted paddy fields(1110), and also the average soil erosion in these planting areas has the most amount in crop field planting area. As a result of analysis on soil erosion hazard zone of farm land by classifying it into 5 classes using the result of that result of analysis on the amount of soil erosion, in case of Class 5 in which the hazard of soil erosion is the highest, approximately 72.5ha that corresponds to 2.4% of the total farm land was decided as erosion hazard zone. For this erosion hazard zone, it was analyzed that dry field crop planting area was 72.4ha and orchard was 0.1ha, and Class 5 hazard zone did not appear in other farming areas. Also, it showed that Class II(1~50ton/ha/yr) area had the most ratio of the entire farm land, i.e., 70.2%, regardless of land use state. According to the result of analysis on soil erosion hazard zone of farm land by classifying it into 5 classes, the Class V has the highest soil erosion hazard, approximately 72.5ha that corresponds to 2.4% of the total farm land was estimated as an erosion hazard zone. This erosion hazard shows 72.4ha in dry field crop planting area, 0.1ha in an orchard, but the highest hazard zone, the Class V was not shown in other farming areas. Also, it showed that Class II area had the most ratio of the entire farm land, i.e., 70.2%, regardless of land use state.