چکیده:
Soil erosion results from an interaction of several parameters, which vary in space and time. Awareness of environmental changes and their impact on the intensity and spatial pattern of water erosion can effectively help in recognition of erosional reactions versus the affecting factors. The aim of this paper is to describe the development of a methodology based on present knowledge and available data, for evaluation of water erosion behavior and risk as well as an estimation of soil erosion. Accordingly, based on the conducted research on different types of water erosion in some areas of Baleghli Chay Watershed, between two hydrometric gauging stations were studied, with an exclusion of erosion due to mass movements. Four major types of water erosion namely: sheet, rill, channel and streambank which play a considerable role in sediment yields of the area, were separately studied. In order to determine the inter-effects of erosive factors, the study was conducted using multivariate statistical tests. For each erosion type, an individual model was then presented. The results indicated complex and different interactions between the likelihood of water erosion and environmental changes in the study area. Sheet and rill erosions act
differently from channel erosion while streambank erosion is completely different from others. Therefore, a study of individual types of water erosion can help in recognition of accelerating factors that effectively influence water erosion, and consequently to come up with appropriate models.
خلاصه ماشینی:
Analysis of relations between water erosion features and effective parameters on their intensity and spatial patterns (Case study: Baleghli chay watershed, Ardebil, Iran) Abstract Soil erosion results from an interaction of several parameters, which vary in space and time.
Awareness of environmental changes and their impact on the intensity and spatial pattern of water erosion can effectively help in recognition of erosional reactions versus the affecting factors.
Main affecting factors on water erosion are: climate, soil & rock erodibility, topography (mostly slope), land cover, and land utilization (Refahi 2006).
The main aim of this paper is to present the results of the research performed on factors affecting intensity and spatial pattern of different types of soil erosion by water, to develop the main parameters that in various kinds have been applied in national and international models as well as in methods of soil erosion estimates.
3. Investigation of relations between water erosion types and affecting parameters using statistical and GIS techniques The study of relationship between static and dynamic factors, and climate with different kinds of water erosion as well as density or area of each erosion type (Zhang and Nearing, 2005) was performed through simple and multivariate parametric and nonparametric correlation tests (Sonneveld and Nearing, 2003).
Results and discussion Table 1 shows that in abstract analysis (one by one), the sheet erosion is in high correlation with the parameters; P2max/Pa, slope, specific peak discharge, mean annual precipitation, maximum rainfall intensity of 30 minutes, maximum 24-hour precipitation and K factor, respectively.