Prioritization-based management of the watershed using health assessment analysis at sub-watershed scale

Examining the problems and prioritization of various parts of the watershed is one of the essential factors for presenting programs and action plans for the adaptive management of the watershed. In other words, presenting executive measures should be based on specific problem-dependent variables, determinant criteria, and effective indicators in the watershed. However, the spatial prioritization of watersheds using a problem-based health assessment approach has yet to be described. Understanding the challenges of the watershed is thus an inescapable requirement for good planning and implementation of natural resource projects, which leads to the prevention of degradation in constantly changing ecosystems and, ultimately, successful natural resource management. The health assessment of the watershed would be the best framework to identify problems and effective variables leading to sustainable watershed management, so that, at the watershed scale, a health assessment is a valuable method for assessing and identifying effective human, ecological, and environmental resource management strategies. It leads to a proper classification of effective elements and the assessment of degrees of controllability, allowing watershed managers to focus their efforts on priority sub-watersheds to efficiently address current challenges. However, such a comprehensive approach has seldom been considered. The current study, therefore, employed the health analysis initiative for the prioritization of sub-watersheds of the Mikhsaz Watershed, Mazandaran Province, Iran. The watershed health was conceptualized and consequently outlined based on various effective and problem-oriented criteria using the pressure–state–response (PSR) framework. Toward that, the PSR framework was customized and corresponding watershed indicators of pressure (P), state (S), and response (R) were conceptualized according to 17 climatic, hydrologic, physical, and anthropogenic factors. The results showed that biologic density and ratio of the number of permitted to unauthorized livestock contributed to pressure indicator at the tune of 36.54%. Hydrologic factors controlled state and response statuses at a contribution rate of 56.07 and 80.11%, respectively. Accordingly, pressure, state, and response indices were found to be 0.68, 0.61, and 0.75 leading to a dominant relatively healthy status of the watershed health (i.e., 46%) with an overall index of 0.68. Besides, pressure, state, response indices were calculated, and associated effective variables were recognized for each sub-watershed led to a prioritization zoning map. The sub-watershed prioritization map can be utilized for designating optimal strategy for the sustainable and of course problem-oriented management of the study watershed. Graphical abstract