경상북도 봉화군 토석류 발생지 40개소를 대상지로 선정하여 강우의 특성 및 다양한 산림환경인자 별 로 조사하여 토석류발생 특성을 분석하였다. 토석류 발생 수는 총 40개소였으며, 토석류 발생 평균 발생 면적은 1,614.1㎡, 평균 발생토사량은 2,450㎥, 평균 길이는 120.7m, 평균 폭 11.8m로 나타났다. 토석류 가 비교적 많이 발생한 산림환경인자는 사면경사도(41°이상), 북서사면, 해발(401m~500m 이하), 종단사면 (복합), 횡단사면(오목), 침엽수, 변성암, 하천차수는(0차), 사면위치(산복), 임종(인공림), 수고(11m~15m), 흉고직경은 중경목(17cm 이상)에서 나타났다. 토석류 발생길이와 산림환경인자와의 상관분석을 실시한 결과는 사면경사(31°~40°), 종단사면(복합) 횡단사면(오목) 에서 1% 수준 내에서 정의 상관관계를 보였 고, 사면경사(41°이상), 종단사면(직선)에서 1% 수준 내에서 부의 상관관계를 보였다.
This study was carried out to analyze the characteristics of debris flows, and the effects of forest environmental factors on debris flow that occurred in Bonghwa-gun located in Gyeongsangbuk- do province in Korea. The results obtained from this study are summarized as follows: The total number of debris flows that occurred was 40; the average area of debris flow was 1,614.1 ㎡; the average sediment volume of debris flows was 2,450 ㎥; the average length of the debris flows was 120.7 m, and average width was 11.8 m. The debris flows highly occurred in areas having slope gradient(<41。), slope gradient(NW), vertical slope(complex), cross slope(concave), altitude(401~500 m), forest type(coniferous), parent rock(metamorphic), stream order(0 order), position(middle), forest type(artificial forest), tree height(<11 m), and DBH(<17 cm), as well as in areas of igneous rocks. Correlation analysis between debris flow length with environmental factors showed that variables such as slope gradient(31~40。), vertical slope (complex), cross slope(concave) had positive correlation with debris flow length and was statistically significant at 1% level, whereas slope gradient(<41。), and vertical slope(straight) had negative correlation at 1% level.