农业工程学报
農業工程學報
농업공정학보
2010年
2期
116-122
,共7页
降雨%侵蚀%土壤保持%简易算法%紫色丘陵区%人工模拟降雨
降雨%侵蝕%土壤保持%簡易算法%紫色丘陵區%人工模擬降雨
강우%침식%토양보지%간역산법%자색구릉구%인공모의강우
rains%erosion soil conservation%simple algorithm purple hilly area%artificial rainfall experiment
降雨侵蚀力是评价一个地区潜在水力侵蚀危险性和严重程度的重要参数.该文基于野外人工模拟降雨的侵蚀试验,对紫色丘陵区降雨侵蚀力的简易算法进行了模拟研究.结果表明:紫色丘陵区降雨量与土壤侵蚀产流、产沙之间存在极显著正相关,各时段降雨强度I(5、10、15、30、45 min)能很好地反映紫色丘陵区土壤流失量的变化特征.基于降雨动能E和时段降雨强度的复合因子∑EI_5和∑EI_10能够很好地反映紫色土丘陵区径流量变化特征,∑EI_5可很好地反映该地区土壤流失量变化特征.降雨量P与各时段降雨强度I的复合因子PI_5、PI_(10)、PI_(15)对紫色丘陵区坡地产流、产沙起关键作用,尤其是PI_5的作用.紫色丘陵区降雨侵蚀力简易计算公式为PI_5和∑EI_5且二者之间存在定量转换关系,该公式提高了降雨侵蚀力在土壤侵蚀预报模型中的应用价值.对于紫色丘陵区一次降雨而言,5、10、15 min降雨强度及降雨量是水土保持的关键性时段,也是水土资源利用的最佳调控时段;尤其是前5min的雨强、雨滴大小分布、降雨量对坡地水土流失起重要作用.
降雨侵蝕力是評價一箇地區潛在水力侵蝕危險性和嚴重程度的重要參數.該文基于野外人工模擬降雨的侵蝕試驗,對紫色丘陵區降雨侵蝕力的簡易算法進行瞭模擬研究.結果錶明:紫色丘陵區降雨量與土壤侵蝕產流、產沙之間存在極顯著正相關,各時段降雨彊度I(5、10、15、30、45 min)能很好地反映紫色丘陵區土壤流失量的變化特徵.基于降雨動能E和時段降雨彊度的複閤因子∑EI_5和∑EI_10能夠很好地反映紫色土丘陵區徑流量變化特徵,∑EI_5可很好地反映該地區土壤流失量變化特徵.降雨量P與各時段降雨彊度I的複閤因子PI_5、PI_(10)、PI_(15)對紫色丘陵區坡地產流、產沙起關鍵作用,尤其是PI_5的作用.紫色丘陵區降雨侵蝕力簡易計算公式為PI_5和∑EI_5且二者之間存在定量轉換關繫,該公式提高瞭降雨侵蝕力在土壤侵蝕預報模型中的應用價值.對于紫色丘陵區一次降雨而言,5、10、15 min降雨彊度及降雨量是水土保持的關鍵性時段,也是水土資源利用的最佳調控時段;尤其是前5min的雨彊、雨滴大小分佈、降雨量對坡地水土流失起重要作用.
강우침식력시평개일개지구잠재수력침식위험성화엄중정도적중요삼수.해문기우야외인공모의강우적침식시험,대자색구릉구강우침식력적간역산법진행료모의연구.결과표명:자색구릉구강우량여토양침식산류、산사지간존재겁현저정상관,각시단강우강도I(5、10、15、30、45 min)능흔호지반영자색구릉구토양류실량적변화특정.기우강우동능E화시단강우강도적복합인자∑EI_5화∑EI_10능구흔호지반영자색토구릉구경류량변화특정,∑EI_5가흔호지반영해지구토양류실량변화특정.강우량P여각시단강우강도I적복합인자PI_5、PI_(10)、PI_(15)대자색구릉구파지산류、산사기관건작용,우기시PI_5적작용.자색구릉구강우침식력간역계산공식위PI_5화∑EI_5차이자지간존재정량전환관계,해공식제고료강우침식력재토양침식예보모형중적응용개치.대우자색구릉구일차강우이언,5、10、15 min강우강도급강우량시수토보지적관건성시단,야시수토자원이용적최가조공시단;우기시전5min적우강、우적대소분포、강우량대파지수토류실기중요작용.
The rainfall erosivity factor is an important parameter to quantitatively evaluate potential water erosion risk and its serious consequence in a special area. In this article, some simple algorithm of rainfall erosivity was built up by field artificial ra:infall experiment in purple hilly area. The results in purple hilly area showed that: Runoff and sediment had significantly positive correlation with rainfall. Sediment was highly influenced by such period-rainfall intensity features as 5, 10, 15, 30 and 45 min rainfall intensity. Some compound factors as ΣEI_5 and ΣEI_(10) based on rainfall kinetic energy and period-rainfall intensity could reflect the varying process of runoff in slope erosion, ΣEI_5 could reflect the varying process of sediment at same time. Some compound factors as Pls, PI_(10), PI_(15) based on rainfall amount and period-rainfall intensity are the important factors affecting the varying process of runoff t and sediment in slope erosion in purple hilly area especially PI_5 is the most important factor affecting soil erosion process. The models with Pls and ΣEI_5 as dependent variables respectively could be chosen as simple algorithm of rainfall erosivity factor in purple hilly area and the transformed relationship between these above models is, ΣEI_5= 24.16 (PI_5), which can greatly improves the practical application of rainfall erosivity factor in these soil erosion predicting models such as universal soil loss equation (USLE) and revised universal soil loss equation (RUSLE). For a special rainfall event in purple hilly area, such period-rainfall intensity features as 5, 10 and 15 min are critical to reduce soil uosion and to increase exploitation of soil and water resources. Some precipitation features as 5 min rainfall intensity and its rainfall amount, raindrop distribution can take more important role for water and soil loss of slope land in purple hilly area.
