Investigating the effects of implementing desertification projects on agricultural development in Takab Shahdad region

Dissertation

To receive master degree

Management of dry and desert areas

In the name of God

1-1 Introduction:

The country of Iran is located on the geographical dry belt of the world, as a significant part of the country's area is covered by deserts and desert lands.

The existence of climatic and edaphic limitations, the ecological structures in this The areas are very vulnerable in such a way that any pressure caused by unusual natural developments or unprincipled human activities in these ecosystems will lead to the destruction of the land and the emergence of the desertification phenomenon.

The phenomenon of desertification in our country has always been considered as one of the most important environmental challenges, which in recent years is the result of factors such as population growth, industrial development, excessive use of water and land resources, and unprincipled land development. Agriculture, various environmental pollutions and the emergence of unusual climate changes have intensified this phenomenon.

Desertification consequences such as water and soil riots, floods, severe erosion and quicksand invasion create serious obstacles in the path of achieving sustainable development goals. And the rehabilitation and improvement of degraded lands is inevitable in the development planning, and thanks to God and the efforts of the experts and those involved in this sector, in the last four decades, valuable measures have been taken regarding this issue in our country. Desertification, so far, few studies have been done on how and the extent of the effect of these measures on the economic, social and environmental parameters, which has attracted the attention of some researchers in this sector in recent years. Based on the investigation carried out in the researches that have been carried out in this field so far, more descriptive and content analyzes of the subject have been done and less statistical methods have been used in order to quantitatively analyze and explain these effects.

Since the agricultural sector is considered one of the most important economic pillars in each region and is directly dependent on water and soil resources, any change in these resources has a tangible and visible effect on the activity of this sector. Therefore, investigating the effect of desertification activities on the agricultural sector is more capable than other affected sectors.

In this study, considering the need that was felt in this field, an attempt was made to present a quantitative and comprehensive analysis of the impact of desertification measures on agricultural development by referring to statistical methods in social and economic studies. The direction of the study was chosen in which the majority of people's livelihood is provided through agriculture and animal husbandry. It is hoped that the presentation of the results of this research can help the experts and those involved in the matter to some extent in the correct evaluation of past achievements and basic planning in the field of future actions. Analyzing the socio-economic and environmental dimensions of the studied area and providing a suitable model in this field 1-2-2-Technical and economic justification of several years of desertification achievements in the region and the use of its results at higher levels 1-2-3- Introducing the role of desertification measures and its effects in laying the foundation for sustainable development 1-2-4- Using research results in agricultural and natural resources planning In the region, according to determining the size of the impact of desertification activities on the influencing factors in agricultural development by each factor

1- The implementation of desertification projects provides the necessary platform for the development of agricultural activities.

2- The implementation of desertification activities by creating environmental security and reviving water and soil resources in desert areas play a significant role in the development of agriculture.

Several definitions of different points of view regarding desert have been presented, but based on the latest ecological definitions provided by UNEP[1] in 1977, desert refers to degraded ecosystems in which the ability to produce natural plants (biomass) has decreased or completely disappeared. And this importance depends not only on climatic factors, but also on other environmental factors such as geological structures, topography, the quality of water and soil resources, and especially the destructive interventions of humans in the environment. [6].                                                                             

Accordingly, deserts are divided into two general categories:

A) natural deserts of environmental origin, which are mainly found in dry and ultra-arid regions of the world and have natural landscapes that are bare and devoid of vegetation, including desert surfaces, sand dunes, and paved surfaces.

However, according to the latest definition provided by UNEP in 1990, desertification is the destruction of lands in dry, semi-arid and dry and semi-humid areas due to various effects caused by the destructive actions of the human factor [5]. This definition was amended as follows in 1992 in the United Nations Environment and Development Conference (Agenda 21) held in Brazil. The importance of the world community in the 21st century.

Desertification does not mean removing and destroying the desert biome, which, like other natural biomes, is the result of complex ecological processes and is a special manifestation of nature. In fact, what is meant by the word "desertification" in the first stage is the prevention of desertification of lands that are exposed to desertification due to the destructive actions of humans, and in the next stage, the correction and restoration of degraded lands whose adverse effects have made the living conditions difficult and sometimes impossible for the residents of these areas.

Regarding the prevention and control of desertification, the most basic solution is proper planning and management for the optimal use of water and soil resources. However, there have been different methods regarding the rehabilitation and restoration of destroyed lands, which depend on the intensity, quality, extent of destruction, and even the economic and social conditions of the region. Among the most important of these methods, the following can be mentioned:

A) Planting:

In this method, in order to restore and revive degraded lands, using compatible and suitable species, saplings are planted in the field.

Caring and irrigation operations are necessary for at least a three-year period for the project of planting seedlings.

B) Seeding:

This method is for areas where It is used that the amount of rainfall is less than 100 mm, planting time, species selection and implementation method are very important and effective in the success of this project.

c) Mulching:

In areas where the activity intensity of sand dunes is so much that it is not possible to establish seeds or seedlings in them. In order to temporarily stabilize the field, they sprinkle oil mulch on the sand dunes. Carrying out this project is not cost-effective due to the heavy costs of transporting mulch from the refinery to the operational areas, as well as its processing and preparation, except in special cases.

d) Sediment traps:

One of the biomechanical methods in reducing and controlling wind erosion is the use of sediment traps. In this method, channels are built perpendicular to the wind direction, whose dimensions and distances are calculated and determined according to the intensity and quality of erosion. Usually, after the accumulation of sand inside the construction canals, saplings with compatible and suitable species are planted in them.