نوع مقاله : پژوهشی
نویسندگان
1 گروه مهندسی آبخیزداری، دانشکده منابع طبیعی دانشگاه تربیت مدرس، نور، ایران
2 مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی استان اردبیل
3 بلوار امام رضا (ع)، دانشکده منابع طبیعی دانشگاه تربیت مدرس
4 بلوار امام رضا (ع)، دانشکده منابع طبیعی دانشگاه تربیت کدرس
5 کروه منابع طبیعی، دانشگاه ملایر
6 مؤسسه ژئوفیزیک دانشگاه تهران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Introduction and Goal
Watershed health is a broad term that encompasses water resources, ecological quality (including vegetation, plant and animal communities, native plants, geomorphological features, and precipitation-runoff processes), and morphological features. Improper management of water and land resources has threatened the country's water and food security, which are the main national goals. On the other hand, comprehensive assessment and management of watersheds are considered effective and efficient approaches by international scientific communities for managing water, land, and their dependent resources, and for balancing the socio-economic needs of watershed communities with the health and sustainability of ecosystems. Also, awareness of watershed health is considered one of the most fundamental aspects of sustainable, comprehensive watershed management. Therefore, the present study was conducted to predict the impact of pressure, state, and response indicators on the health of the country's third-order watersheds.
Materials and Methods
For this purpose, first, more than 520 different criteria related to pressure, state, and response indicators from environmental, climatic, and human factors were identified and collected for about 640 watersheds. Then, because of the correlation among variables, the variance inflation factor test was used to reduce the data and eliminate variables with severe multicollinearity. Finally, the indicators were divided into two categories: static and dynamic. In the following, the criteria affecting the health and security status of watersheds were extracted with appropriate spatial accuracy at the sub-watershed and PSR model levels, and their values were calculated for the current conditions (2023). After determining the dynamic criteria, various methods, including regression, the SARIMA model, and machine learning algorithms, were used to predict dynamic criteria for 2033, 2043, and 2053. After predicting the dynamic criteria, the PSR conceptual model was applied to future years, and the health zoning of the country's third-order watersheds was conducted in ArcGIS 10.8. To assess future status, dynamic indicators were predicted from time-series data for 2033, 2043, and 2053, and the effects of each indicator on watershed health were analyzed.
Results and Discussion
A zoning analysis of the health of the country's third-order watersheds in 2033, 2043, and 2053 showed that health status was heterogeneously distributed. In the northern regions (Gilan, Mazandaran), due to high rainfall and dense vegetation cover, the health of the watersheds is favorable (60-70% in the good and very good classes). In contrast, the southern regions (Hormozgan and Sistan and Baluchestan) have a poorer status (40-50% in the moderate to poor classes) due to low rainfall and inappropriate human activities. In the coming years, the northwestern regions will also face a relative decline in health. In contrast, the eastern regions (such as Khorasan Razavi) will be severely affected due to drought and excessive water extraction (a decrease in health to below 20%). The results showed that the role of the response index (about 61%) was greater than the pressure and state indices in affecting the health of the study watershed system. In general, no significant change was observed in the future study years (2033, 2043, and 2053) in the impact of the PSR model indices on the watershed health index.
Conclusion and Suggestions
The analysis showed that future watershed management should focus on rapid responsiveness, as watersheds will increasingly rely on adaptive measures such as vegetation restoration and flood control. Also, although the impact of human pressures (about 20%) is relatively stable, its fluctuations highlight the need for integrated management of human activities such as agriculture and urban development. On the other hand, the relative stability of the state index (about 19 %) reminds us of the need to focus on long-term strategies, such as soil and water resource conservation. Therefore, combining flexible short-term measures with sustainable conservation policies will be the key to optimal watershed management in the face of future environmental changes. These results generally emphasize a dynamic and adaptive approach to watershed management, such that combining short-term reactive measures and long-term conservation strategies and adopting an adaptive management approach in which short-term measures (such as temporary changes in cropping patterns in response to drought) based on continuous monitoring act as feedback to correct and strengthen long-term and sustainable strategies (such as ecosystem restoration and integrated water resources management) and create a systemic correlation between these two levels, can ensure the health of watersheds against future changes.
کلیدواژهها [English]
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