Locating flood spreading using spatial multi-criteria analysis of a case study (Chenaran city, part of Mashhad Plain)

Dissertation for receiving M.Sc. degree

Natural resources engineering major, watershed management

Abstract

Currently, flood spreading on aquifers is considered one of the suitable methods for controlling and optimal use of floods and artificial feeding of underground water in arid and semi-arid areas. Chenaran watershed in the northwest of Mashhad with an area of ??299,624 hectares is located at 36.59 19 36 to 8.52 03 37 north latitude and 1.7 22 58 to 16.44 59 east longitude, 65 kilometers northwest of Mashhad city and is politically part of Khorasan Razavi province. This watershed was chosen in the highest part of Mashhad plain, which is limited to the heights of Hazar Masjid from the east and Binaloud heights from the west. In this study, economic spatial factors such as proximity to roads, aqueducts, wells, springs, and rivers along with factors of slope, permeability, vegetation and slope limitations, geology, geomorphology, and land use were analyzed using new techniques. So that in the spatial multi-criteria evaluation method, the factors were standardized using fuzzy values. The weight of the factors was also determined by different methods, including ranking. In the next step, the layers were combined using ArcGIS software, the result of which was a composite index map with fuzzy values ??from (zero to one). As a result, the suitable area for flood spreading with values ??closer to one includes an area equal to 31080 hectares and 10.4% of the basin area.

Key words: flood spreading, aquifer, watershed, economic factors, natural factors, spatial multi-criteria assessment, ArcGIS

Chapter 1

Generalities

1-1-Introduction

Water and energy resources are the most important resources that have faced a serious crisis during the last century. The destruction of natural and environmental resources has become a fundamental challenge and the concern of the early deterioration of fossil energies and the limitation of water resources leads the minds of analysts to predict the occurrence of a water crisis in the future, and in this context, Iran is at risk as one of the most water-scarce and tense regions in the world. Iran, which has about one percent of the world's land, has only 0.0002 percent of the world's water resources. The available statistics show that 74% of the country's surface has less than 250 mm of annual rainfall. Due to the lack of atmospheric precipitation, the lack of its balanced distribution in terms of time and place, as well as the lack of permanent rivers that can meet the water needs in arid and semi-arid areas, the storage and exploitation of surface runoff during heavy rains and large-scale floods can help to increase underground water reserves. On the other hand, every year, floods cause a lot of human and financial losses (Al-Sheikh et al. 2011).

Flood control, artificial feeding of aquifers and optimization of the use of renewable natural resources are among the most important goals of flood spreading operations in arid and semi-arid regions. However, due to the feasibility of using water and soil, which is an important principle in flood spreading, irrigation of pastures and artificial feeding of aquifers is realized, nevertheless, the importance of feeding empty aquifers and reviving and improving worn-out pastures, stabilizing sand fields, and finally soil protection and reducing flood losses on the one hand, and the cheap construction of networks and the great economic efficiency of flood spreading on the other hand, make dealing with this category logical and justifiable (Wahabi, 2012).

Khorasan province can be divided into 6 watersheds according to hydrological conditions: Atrak River, Qaraqom Desert, Central Iran Desert, Salt Desert, East Salt Fields and Lut Desert Watershed. Each of these basins has its own behavior and hydrological conditions, which is different from the adjacent basin. Kashf Roud watershed is a part of Qaraqom watershed. Khorasan is considered as one of the dry and semi-arid provinces of the country, where long and numerous aqueducts have been built in its plains and foothills to provide drinking water and agriculture. 602 wells have been counted in the studied area. Of these, 447 are deep wells and 155 are semi-deep wells.83% of these wells have agricultural use. The maximum depth is 210 meters and the minimum is 4.5 meters. Their total annual discharge is about 168.545 million cubic meters per year. The maximum water flow of wells is 60 liters per second and the minimum is 1.4 liters per second, and their average water flow is around 12 liters per second (Absaran Consulting Engineers 79)

One of the new methods that in recent years has a significant impact on underground water tables and the amount of water and the water quality of agricultural wells and It has aqueducts, it is the flood distribution systems that the research and experiences obtained show the positive results of such projects on underground water sources. In this research, the aim is to determine the suitable areas of flood distribution to strengthen the water of aqueducts, wells and springs in dry areas with multi-criteria spatial assessment techniques[1] to deal with drought and drought crisis.

Chenaran area in Mashhad with various factors such as aqueducts, wells, springs, very wide flood-prone alluvial plains and topographical conditions has a suitable position for proposing and implementing flood distribution areas, which is why this study The subject has been discussed.

One ??of the methods of choosing the place of expansion of floods is detailed local visits, collecting statistics and reliable information, maps and using local people in the region. On the other hand, it is very difficult to determine suitable places using traditional and common methods and it mostly causes errors. As mentioned, visiting and checking in this way will be accompanied by difficulties and will take a lot of time. One of the methods is to use telemetry data such as ETM [2] and TM [3] sensor images of Landsat satellite. The integration of remote sensing [4] and geographic information system [5] is a new method to locate the flood spread.

In this research, a multi-criteria spatial evaluation method is used to locate the flood spread. Multi-criteria spatial evaluation includes a series of techniques, such as the sum of weights or convergence analysis, which allows a range of criteria related to a subject to be scored and weighted and then ranked by experts and interest groups (Habibi and Kohsari, 2016).

In order to meet a specific goal, it is often necessary to evaluate several criteria, this is called a multi-criteria evaluation process. Another word that is sometimes used for it is modeling. Locating means determining the right place to perform a certain activity by performing a specific executive procedure and considering the criteria and factors that are effective in it. This category has been of interest since the beginning of human settlement on earth for better access to food sources, residence and other such things. In recent years, with the progress in computer science and information technology, the use of geographic information system for positioning has been expanded in various applications. The right place to perform a specific activity is determined according to the influence of a set of criteria and conditions called location factors. These criteria and conditions are selected according to the characteristics of the study area and based on the opinions of experts, and weight is assigned to each one based on its importance and value (Saadi Mesgari et al. 2014).

The aim of this project is to locate a suitable field for flood spreading with a multi-criteria location assessment method in Chenaran area and compare the results with the plan carried out in the region and locate an area where the implementation of flood spreading will have the lowest cost in terms of construction and the most efficiency.

1-2 - Problem outline

Flood control in order to use surface water and waterways in watersheds is one of the basic steps in managing water resources, especially in arid and semi-arid areas It is one of the most important steps to carry out such projects. The purpose of this research is to locate the flood spreading area in the Chenaran watershed of Mashhad city to strengthen the water of aqueducts, wells and springs in dry areas with multi-criteria evaluation techniques to deal with the drought crisis.