سلامت آبخیز (قسمت دوم): مدل مفهومی فشار، وضعیت و پاسخ (PSR)

In the last decade, several studies have been conducted in order to develop water and soil resources management tools to maintain their health. Accordingly, the first necessary action is determination of the health status in ecosystems scale. Many key criteria and indices have been developed from anthropogenic, climatic, geomorphology, edaphic and vegetation factors to assess watershed health. According to the literature, considering an individual criterion cannot represent the overall ecosystem health status well. Hence, the development and testing new approached based on integrated health indicators are to be addressed. The combination of criteria and indicators using various statistical analyses and models is needed for better management of the ecosystems. Further, based on the implications of ecological system health and the mechanism of elements interaction, a series of conceptual models such as pressure-state-response (PSR) model have been established. This model is recommended to organize pressure-state-response indicators in a systematic way. Todays, ecosystems are becoming damaged or degraded as a result of stresses especially associated with human activities. A healthy ecosystem is essential to provide the services that humans and the natural environment require and has tremendous social and economic value. So, ecosystem health assessment is essential to achieve an integrated watershed management model for the whole country. Toward this attempt, in the present study, a comprehensive state of art was explored about PSR model to be practically applied by environmental managers considering the protection of ecosystems as one of their primary goals. The watershed monitoring and its health determination developed in this study can be used as a useful tool for watershed managers.