Determining the territory and effects of monsoon in Iran

Dissertation for Master degree (M.A)

Trend: Climatology

Abstract:

Iran has little rainfall due to its geographical proximity to the subtropical high pressure center of STHP and the prevailing weather conditions of this system. In the southern regions of the country, as a result of the longer rule of this system, the drought phenomenon becomes more acute. Rainfall changes have a significant impact on agriculture, economy and other issues of the country in general. Basic studies about rain-making systems, especially the monsoon phenomenon in these regions, provide strategies for the development of rain-making activities and climate forecasts. The scope of this research includes the south, southeast, east and central regions of the country, including the provinces of Sistan and Baluchistan, Hormozgan, Bushehr, Fars, Kerman, Yazd, Isfahan, Qom, South Khorasan, Razavi Khorasan and Tehran. By examining the number of days with rainfall and the amount of daily rainfall in the months of May, June, July, August and September during a statistical period of 38 years in 15 southern and central stations of the country and analyzing synoptic maps, it was determined that Most of the rains in the southeast of the country, especially in Chabahar and Iranshahr regions, in the months of June and July, in the amount of 147.4 and 339.4 mm, were caused by the influence of monsoon air masses. Based on this, the monsoon phenomenon is the main cause of summer rains in the southeastern regions of the country, and when this phenomenon has maximum humidity and strength, the southern, eastern and central regions of the country are also under the rule of this air mass.

Foreword

With the passage of time and the increasing progress of knowledge and technology, new doors have been opened to the eyes of human seekers and better ways to live a hardworking and tireless life. In the past, the common sciences have given way to smaller and more detailed branches, categories and categories of sciences. Now, like in the past, one person cannot study all the sciences, and a sage and a scientist is not someone who is aware of all the sciences of his time. just as he took the extreme path of determinism in the middle of the 19th century. But he was always protected by the whip of new ideas, knowledge and technologies of scientists and his love for this science. Such as the idea of ??free will that was put forward in the 19th century by prominent geographers such as Vidal Dolablache and Albert Demangen. They are formed inside a place and under certain conditions and principles, it gives order and credibility and establishes logical relationships between these phenomena (Shakuri, 1369, p. 34) The task of geographers is: 1-Knowledge of phenomena

2-Knowledge of the concept of order in phenomena

3-Establishing logical relationships between these phenomena

And no doubt to achieve the goals and perform the above tasks of each If the geographer's baggage is more full of techniques and knowledge, he will be more successful and he will be able to create movement and creativity in geography by combining natural and soulless factors with the base of human culture.

What we are witnessing in the current developed world as well as in our country is the introduction of awareness and the application of new techniques in the field of work of geographers. Today, geographers in developed countries have continuous and systematic scientific planning in sensitive and important areas. Such as, urban planning, architecture, commerce, transportation, etc., perform their duties well and one can even say fundamentally.

With the advancement of statistical science, the widespread use of computers and various software, and the precision in the ease of analyzing quantitative data compared to qualitative data, geography quickly passed the path of quantification and entered the new world with newer concepts. Meteorology, hydrology, population, etc., and the combination and integration of various data with each other and presenting practical and fruitful results has become more fruitful than in the past.

Study about the effects of monsoon on different regions of the country requires the combination and integration of meteorological and geographical data, and geographers due to their scientific characteristics are able to handle this better than anyone else with as much confidence and trust as possible.

Introduction

According to the ever-increasing growth of the population and increasing water needs, the need to implement small and large hydrological projects in order to store, divert or transfer water, as well as watershed studies, is being raised more and more, and the implementation of such projects requires detailed studies and analysis of meteorological data. Before designing any kind of structure such as irrigation and drainage canals, urban sewage disposal and collection routes, dams, bridges, etc. It is very important to predict sudden rains or water caused by melting snow, which provide a large volume of water and will cause irreparable losses of life and financial losses. The system has little rainfall. In the southern regions of the country, as a result of the stronger and longer rule of this system, the problem of drought becomes more acute. As the rule of the dry climate over the southern and central regions of the country increases more and more, villages and cities lose their population. In recent years, due to successive droughts, many farmers have abandoned their agricultural lands and migrated to the cities. This is especially noticeable in the southern regions, especially in the southeast of the country.

The location of Iran between the vast lands of Siberia in the north, the Mediterranean Sea in the west, the deserts of Africa and Arabia in the southwest, and the Arabian Sea and the land of India in the east has caused each of these neighbors to influence the climate of Iran in a certain period of the year. The weather conditions of these lands are spread by air masses and pressure systems during special conditions of the general circulation of the atmosphere in the area of ??Iran.

The phenomenon Monsoon is also one of the air masses that affect the rainfall in the southern regions of the country, which causes rains in the summer season. Considering the importance of these rains, especially in the summer season, when most parts of the country are dry and rainless, it is very important. By examining and understanding the effects of this phenomenon and determining its rainfall territory in the country, an important step can be taken in the country's progress and development. Chapter 1: Research Plan and Background Research

Problem Statement, Necessity and Importance of the Issue

Geographically, the country of Iran has little rainfall due to the rule of high-altitude subtropical zone (STHP) and the climatic conditions governing this system. In the southern regions of the country, as a result of the stronger and longer rule of this system, the problem of drought becomes more acute. Few annual rains, short rainfall period and heavy and short-term showers are the characteristic features of this type of climate. A dry area may spend many days in dry land, and when it rains, due to the physical conditions governing the nature and abnormal weather conditions of these areas, a significant amount of water falls in a few days or hours and causes destructive floods. Floods every year cause huge and irreparable damages in every corner of this country. Every year, several people die due to floods, thousands of cubic meters of fresh water enter the salty waters and are thus out of reach, while every drop of it has vital value. Every year, millions of tons of valuable soil enters the seas and lakes through floods, while it takes several decades or hundreds of years to form every centimeter of it in the conditions of our country. The rain that is expected after days is out of reach and at the same time it leaves serious and permanent damages. This problem is not only in the studied areas, but it is a serious and threatening problem for the whole country. In such a way that many construction plans of the country's construction minister have been overshadowed by this issue. Every year, a huge part of the country's annual budget is spent on rebuilding part of the damage caused by this phenomenon. Because it is not really possible to rebuild and repair many damages. Restoration and improvement of eroded soils, destroyed fields and gardens may not be possible at all. (Lashkari, 1375)

1-2- Necessity and importance of research

Since the country of Iran is located in the semi-arid and arid climate divisions, changes in the amount of precipitation have a significant impact on agriculture, economy and other issues of the country in general.