Trend assessment of factors affecting Hendijan dust storms using driving forces-pressure-state-impact-response framework

Dust event is one of the natural events that occur widely in the world, especially in dry areas. One of the main and effective factors in the occurrence of this phenomenon is the geographical location and climatic conditions of the regions affected by this phenomenon. The purpose of this research is to analyze the cause-and-effect relationships of dust events in Hendijan region with the approach of the Driver-Pressure-Situation-Effect-Response (DPSIR) framework. 

The DPSIR process is an analysis based on the "cause-disability" relationship of factors for policy-making and management planning. The DPSIR framework is a systems thinking framework that assumes cause-and-effect relationships between environmental and socio-economic systems. This conceptual framework uses a cycle of causes and results for the proper integration of basic economic, social and environmental data and information, specifies the relationship between environmental processes and human factors, and also leads to an understanding of the relationship between policy levels and environmental studies. The trend of each component of DPSIR was also evaluated by applying quantitative criteria for the time period of 2007-2019. 

The results of the research showed that the total index of all DPSIR components has an upward trend for the studied period. The slope of the trend related to D, P, S, I and R components was equal to 0.06, 0.03, 0.02, 0.05 and 0.02, respectively. Although some responses were made to reduce the influence of others. The components of DPSIR have been adopted to improve the dust situation, but the research results and the process of changes showed that they were not sufficient and integrated. In this research, a variety of answers related to the components of the driving force, pressure, situation, and effects were identified. The results showed that dust concentration and dusty days in the region increased during the study period and more attention was paid to reactive responses and less focus on preventive responses. Also, paying attention to the response of increasing the efficiency of irrigation due to the high correlation between the state of dust concentration and pressure factors such as the amount of rainfall, soil moisture, and exploitation of water resources in the research area, special attention to the development of water extraction systems as one of the most important responses. Management issues due to the existence of negative and high correlation with the dust situation during the years of research, adequate and sustainable supply of water resources by reducing and minimizing the diversion dams downstream of the Kowsar and Ask dams due to the increase in dust concentration with the increase of flood diversion operations and construction Reservoir and diversion dams since 2009, Considering the water rights of wetlands in the region with the aim of preventing wetlands from drying up and creating a dust center, especially in the west of Hendijan city, and carefully choosing the appropriate plant species, as well as carrying out desertification operations (planting saplings, mulching, building windbreaks). With the ecological conditions of the region, due to the negative correlation between the desertification operation and the reduction of dust concentration since 2014, it can help to improve the dust situation in the research area. 

In this regard, it is recommended to respond to driving forces (D) and pressures (P) so that while improving the conditions and adverse effects caused by it, the drivers and pressures that create the current situation can also be controlled. Based on this, the incomplete implementation of the answers is another reason for not achieving management goals and making the situation and the number of dusty days more unfavorable. It is also suggested to implement the integrated watershed management program in Hendijan city through the development of a joint water, agriculture, and natural resources program upstream of the watershed in order to clarify the effective measures of the water production, distribution, and consumption chain in the upstream lands.