Comprehensive trend analyses of climatic variables in Muş and Bitlis provinces

ABSTRACT COMPREHENSIVE TREND ANALYSES OF CLIMATIC VARIABLES IN MUŞ AND BITLIS PROVINCES MASTER THESIS Sertaç ATABEY DEPARTMENT OF CIVIL ENGINEERING INSTITUTE OF NATURAL AND APPLIED SCIENCES UNIVERSITY OF DICLE 2018 From the past to present, there are numerous studies on global climate change put forward by scientists and researchers working in diverse fields. Both the global as well as the local scale of the region have been proposed as to whether the climate is affected by global climate change. However, there were not many studies found in the literatüre about Bitlisand Mus province in terms of climate change. It has been tried to investigate whether a variety of climate variables are changing due to global climate change in a certain period of time in Bitlisand Mus provinces, and in which direction this change has a tendency if such a change occurs. Within the scope of this study, it has been conducted on whether Bitlisand Muş provinces are affected by global climate change over a period of thirty years and tried to determine how and how much this change occurred if affected. There are a number of climatic/meteorological variables those form climatic conditions and these variables are closely related to each other. Because of climatic/meteorological variables directly affect each other, this subject has been studied with a large number of climatic variables and investigated how as well as how much they changed in the long term. For investiagtion, monthly sunny and cloudy days, daily mean temperature, cloudiness, monthly total precipitation, daily mean wind speed, maximum temperature and total sunshine duration data of both Bitlisand Mus are used. The meteorological data for both cities were obtained from the Provincial Directorate of Meteorology in Bitlis. First, the time series graphs of the data have been obtained. Thus, both the trend lines and the equations depends on simple linear regression analises (SLRA)are created for all these variables. From the trend lines, monthly tendency line, the starting point, and the trend line ending points were calculated, and then the trend line change amounts were determined on a day-by-day basis by taking the difference of these values. These obtained equations and values are tabulated. The calculated trend line change values are examined in terms of the long term for the meteorological variable studied and interpreted in terms of variable whether there is a change in the climate of Bitlisand Mus provinces. In addition to the statistical analysis, contour maps were also created for each month of the year, with data length ranging from 26 to 31 years according to the variable data of all data. From the color changes in the contoured maps, it has been tried to analyze which ternds each of the variables have in which years. In this context, the contour maps generated for each variable were interpreted to try to explain the effect of the region on the global climate change, if so, on which direction. As a result of these studies, for he Bitlisprovince, it has been found that there is considerable decrease in the sunny days in long-term, increase in cloudy days, decrease in overcast days, increase in average temperatures, decrease in average cloudiness, decrease in total rainfall, decrease in average wind speed, increase in maximum temperatures and decrease in total sunshine duration. For the Mus province, increase in the sunny days in long-term, decrease in cloudy days, decrease in overcast days, increase in average temperatures, decrease in mean cloudiness, decrease in total precipitation, decrease in average wind speed, increase in maximum temperatures and decrease in total sunshine duration have been determined. In the light of the findings and conclusions, it has been seen that the long-term changes in the climate variables of Bitlisand Mus provinces, and the changes in the climate are generally parallel to each other. There is a change and tendency in the same direction for all variables except sunny day number and cloudy day number variables. It is claimed that temperature variability is best demonstrated by the existence of global climate change. Therefore, in this study, the average and maximum temperatures for both Bitlisand Mus provinces have been examined in more detail over a period of thirty years and it has been seen that there are significant increases in the temperatures. In addition, other meteorological variables have been found to have significant trends in either direction of increase or decrease. This change was also detected in total rainfall amounts for both provinces. As a result of the research carried out within the scope of this study, significant changes in the climate of the local region in which Bitlisand Mus are located are influencing the precipitation, thus reinforcing the belief that the region may have been affected by global climate change. Key words: Global climate change, global warming, temperature, precipitation.