Rainfall Characters And Its Effect On Loess Slopeland Erosion In Western Loess Hilly Region Of Dingxi Anjiagou

Based on the runoff plots located in the Anjiagou basin, Dingxi city, Gansu province anddata observed in2009—2011, rainfall characters and its effect on loess slopeland erosion in loesshilly region of western loess plateau were studied. The results showed that on the condition ofnatural rainfall, the runoff process of different methods may be divided into runoff producing,maximum runoff, stability of runoff and disappearance of runoff; soil erosion may be dividedinto erosion producing, maximum of erosion amount and curtailment erosion. Different methodsanalysis of variance significant levels are extremely significant, analysis the cross-section data ofthe intensity of rainfall and runoff, rainfall intensity and erosion are been type power correlation,model fitting degree is higher, the curve is increasing function. Analysis of correlation coefficientbetween different treatment of rainfall intensity, runoff and erosion compare their R2. The time oftreatment of erosion under the condition of rainfall change is dominated by the amount of runoff,rainfall intensity was not directly involved in the changes of erosion, but by influencing therunoff change, i.e., the change of runoff is mainly affected by rainfall intensity. Rainfall intensity,the interaction relationship between runoff and erosion is a progressive, at the same time, rainfall,runoff in different degree of mutual influence of soil erosion.By analyzing the different processing its soil and water conservation benefits, get5°OSprocessing the quantity of runoff and erosion are the smallest under5°slope, compared with theother treatment under the slope with the best benefits of soil and water conservation. Springwheat under5°,10°slope erosion increases with the increase of slope is not obvious.10°OSprocessing the quantity of runoff and erosion are the smallest under5°slope, compared with theother treatment under the slope with the best benefits of soil and water conservation.15°Hprocessing the quantity of runoff and erosion are the smallest under15°slope, compared withthe other treatment under the slope with the best benefits of soil and water conservation.20°Pprocessing the quantity of runoff and erosion are the smallest under20°slope, compared withthe other treatment under the slope with the best benefits of soil and water conservation. Analysisthe processing of the rainfall runoff and erosion through IBM SPSS Statistics19.0withhierarchical cluster, According to the principle of hierarchical cluster analysis under classdistances in0≤d≤5、d=5、d=10、d=15, the soil and water conservation benefit analysis test of different treatment, basic consistent with previous conclusions as a result, the result shows thatdifferent treatment of soil and water conservation benefit analysis is reasonable.Analysis of2009-2011test station rainfall data process, it is concluded that six times of theannual average erosive rainfall, rainfall duration was71.63h, erosive rainfall was123.09mm,total annual average rainfall of345.7mm, annual average erosive rainfall accounts for35.6%ofannual total precipitation. From the perspective of the distribution of erosive rainfall in differentmonths, rainfall events, rainfall is lowest in May, rainfall from May to August increased monthby month, and reached the peak of erosive rainfall amount in August, then began to decrease.Annual average erosive rainfall in August was2.7times, cumulative month erosive rainfall was58.03mm, number of erosive rainfall and rainfall accounts for about45%of may to September.On erosive rainfall showed evident unimodal distribution; July, August rainfall is largest, rainfallintensity is biggest; May, June, September rainfall is small, and as the light rain, a single rainfallduration is long. Different processing annual average erosion modulus sorting result with timeunder the condition of rainfall is consistent with that sort of treatment of erosion.