基于系统周界模型的典型坝控流域人类活动影响

Human activity impact from basin system controlled by typical check dam based on system periphery model

基于系统周界的观控模型提出了人类活动影响的侵蚀分析方法,通过系统模型输出、内部状态以及输入之间的关系,导出了系统输出与输入、系统内部状态和人类活动影响强度的关系式。应用于陕西省榆林市子洲县西北部的小河沟流域的石畔峁坝坝控流域系统,以坝控流域上的四个侵蚀性降雨指标为输入集,以四种水保措施为内部状态集,以淤地坝层淤积量为输出集,并与传统系统分析方法进行了比较。结果表明:提出的模型方法较为合理,能更准确地分析出人类活动的变化趋势和系统内部状态对坝控流域土壤侵蚀的影响,从而说明了坝控流域系统的输出受到输入、内部状态以及人类活动的多重影响,拓宽了人类活动影响下的黄土高原土壤侵蚀研究思路。

An erosion analysis approach to the impact of human activities was proposed on the basis of the observability-controllability model of periphery. An equation between system outputs and some parameters including system inputs, system states and human activity impact was derived according to relationships between outputs, states and inputs. A case study on the basin system controlled by the Shipanmao check dam in Xiaohegou small watershed, northwest Zizhou town, Yulin city, Shaanxi province, was performed. The sets of system input, state and output are set as the four erosive rainfall indexes, the four measures of soil and water conservation and the layer amount of depositing sediment of the check dam, respectively. Compared with the traditional system approach to erosion analysis, the results show that the OCMP is more perfect and rational. The model has a stronger ability in achieving the evolvement trend of human activities and analyzing the influence of system states on soil erosion from the basin system. The results indicate that outputs of basin system controlled by the check dam are multi-affected by system inputs, internal states and human activities, which widen the impact of human activities on soil erosion in the Loess Plateau.