Land Subsidence Risk Management Solutions in Seydan-Farooq Plain of Fars Province with the Driving Force-Pressure-State-Impact-Response Approach

One of the important natural hazards is land subsidence. This phenomenon has also been observed in Iran due to the indiscriminate extraction of underground water resources, and unfortunately, more areas are exposed to it. The DPSIR tool or Driving Force, Pressure, State, Impact, Response framework is a tool that describes environmental problems through cause and effect relationships between human activities and the environment. This framework provides a background to combine different types of indicators and considers not only the environmental effects but also the economic and social effects resulting from changes in the status of ecosystems. The purpose of this research is to present the cause and effect relationships for the most important issues and problems of the risk of land subsidence in one of the important and critical plains of Fars province (Seydan-Farooq) and the most appropriate management responses using the DPSIR tool. and provide non-management to improve the current situation.

First, the problems of Seydan-Farooq Plain were determined based on library studies, asking experts and referring to the region, and based on this, possible strategies were determined. Then, the DPSIR tool was used to identify the cause and effect relationship analysis between the factors that determine the characteristics affecting land subsidence in the plain, and the DPSIR table was prepared for the risk of land subsidence in this plain. In order to prioritize and determine the importance of the problems, pressures and management strategies of the plain, a Likert scale questionnaire was used as a measurement tool and 40 experts were surveyed. Friedman's test was used to rank the items and Cronbach's alpha method was used to check the reliability of the questionnaire using SPSS version 22 software. Then Friedman's test was used for two-way analysis of variance by ranking and also comparing the average ranking of different groups using SPSS software.

The ranking of the items of the driving force component in Seydan-Farooq plain of Fars province showed that the range of the average values of the ratings varies from 1.86 to 4.45. The ranking of the items shows a significant difference in the items of the driving force component, so that the item "Population" with an average rating of 4.45 and also the item "Development of Industries" with an average rating of 1/86, it has been ranked first and fifth respectively. Therefore, in the "driving force" component, according to the factors: population, agricultural development, garden development, climate change and industrial development, the highest priority in intensifying the risk of land subsidence in this plain. assigned Regarding the ranking of the pressure component items, the range of the difference in the average values of the ratings in the pressure component varies from 1.25 to 5.40. The ranking of the items showed a significant difference in the items of the pressure component, so that the item "withdrawal from the underground water table in the agricultural sector" with an average rating of 5.40 and also the item "withdrawal from "Underground water table in the domestic sector" with an average rating of 1.25 has been ranked first and sixth respectively. Therefore, in the "pressure" component, according to the factors: withdrawal from the underground water table in the agricultural sector, failure to comply with the environmental rights of the aquifer, decrease in rainfall, withdrawal from the underground water table in the garden sector, From the underground water table in the industrial sector and the withdrawal from the underground water table in the domestic sector, they have assigned the highest priority in intensifying the risk of land subsidence in this plain. The average values of the ranks in the response component vary from 2.35 to 5.75. The ranking in the items of the response component also shows a significant difference, so that the item "increasing irrigation efficiency" with an average rating of 5.75 and also the item "nutrition" Point of water in the plain" with an average rating of 2.35 has taken the first and sixth place, respectively. Therefore, in the "response" component, in the order of the factors: increasing irrigation efficiency, changing the cultivation pattern, controlling the harvesting of authorized wells, aquifer operations, blocking unauthorized wells, cultural measures and spot nutrition. Water in the plain has the highest priority in reducing the risk of land subsidence in this plain.

Conclusion and Suggestions :

Five driving forces (D) have caused six pressures (P) on the water resources of this plain, the most important of which are "withdrawal from the underground water table in the agricultural sector" and "not respecting the environmental rights of the aquifer". are The pressures, in turn, have created a disordered (S) situation (dropping of the water table) in this plain. This situation has two adverse effects (I) "land destruction" and "aquifer destruction". In order to improve the situation, seven management responses (R) were presented, the most important of which are "increasing irrigation efficiency" and "changing the cultivation pattern". In the current situation, it is not possible to stop the pressures; However, their adjustment and modification should be specially considered by planners and managers. It is worth mentioning that if these cases are not corrected, there will still be pressures (P) and will lead to more critical conditions than the existing situation (S) and finally, its effect (I), destruction of lands, aquifers. and the destruction of water and soil resources of this plain will be more. Due to the fact that the executive structure of the country's natural resources management is more in line with the components of pressure (P) and situation (S); It is suggested to develop suitable, practical and operational answers (R). It is also necessary to pay serious attention to the preventive approach in reducing the risk of land subsidence; Because, unfortunately, this matter has not been paid attention to in the country. Therefore, it is suggested to consider and implement a preventive approach that both understands the driving forces (D) and prevents the implementation of policies that cause pressure.