of Hydro-meteorological Services
in Turkey


1. Introduction

1.1. General : In Turkey, Hydrometeorological measurements are being conducted by mainly State Hydraulic Works (DSI), Electrical Power Resources Survey and Development Administration (EIE), and State Meteorological Services (DMI). The gauging stations of EIE are mainly located on the main channel whereas the ones of DSI are installed also on the tributaries. While only limited number of parameters such as rainfall, evaporation and temperature are observed in the meteorological stations of DSI, the ones of DMI make observations for synoptic and climatological purposes.

1.2. Water Resources of Turkey : There are 26 river basins in Turkey. Mean annual water potential values of 26 basins in Turkey can be seen in the table given in annex. Some other data for water resources of Turkey are given below :

Mean (arithmetic) annual precipitation 642.60 mm
Mean annual volume of precipitation 501.00 km³
Annual surface runoff 186.05 km³
Annual surface runoff / rainfall ratio 0.37
Annual depletible volume (surface water) 95.00 km³
Actual annual utilization (surface water) 28.20 km³
Annual available groundwater reserve 12.20 km³
Actual annual utilization (groundwater) 6.00 km³

1.3. Storage Facilities : The number of storage facilities can be seen in the table showing the land and water resources potential of Turkey by basins.

1.4. Hydro-Meteorological Gauge Stations : State Meteorological Services (DMI) is in the charge of establishing and operating of meteorological stations to collect data for national weather conditions.

The data collected from hydrometrical stations are supported by data of meteorological stations. The DSI-established meteorological stations are in conformity with rules that are fixed by a protocol between DSI and DMI. Meteorological observations are fulfilled once a day at local hour 7.00. Stations of DSI mainly aim at meeting the needs of project rather than climatic observation. Automatic recorders are also used in the meteorological stations of DSI.

In hydrometric stations, water level observations are made twice each day, at hours 8.00 and 16.00. Some stations operates for relatively short time and they are closed as soon as their functions are over. As for lakes, observation is fulfilled once every day in the morning at hour 8.00. In case of flood, extra water level observation is achieved by observer.

Observations of discharge are done by current meters in the hydrometrical stations. Mostly type of A. Ott current meters are used by State Hydraulic Works (DSI). As for General Directorate of Electric Power Resources Survey and Development Administration (EIEI), Gurley's small current meters are employed. But the method used by DSI and EIE in measuring the discharge curve is the same. The data are published yearly for corresponding water year.

By the end of 1996 water year, in the hydrometeorological network of Turkey, stations which are currently in action is tabulated as following :

Organization Station type Number of stations
DSI Meteorological station 398
DSI Hydrometrical stations 1104
DSI Lake observation stations 123
EIE Hydrometrical stations 285
EIE Lake observation stations 12
EIE Snow observations 45
DMI Meteorological stations 1158

Snow depth is only a measured parameter in the stations of DMI. DSI and EIE measure not only snow depth, but also calculate density in location of snow observations. To calculate the snow/water equivalent value more efficiently, researchers in State Hydraulic Works study on isotope techniques.

2. Water-related Institutions in Turkey

Institutions that are in charge of development of water resources are summarized, to some extent, in this section. Regarding with water-related issues in Turkey, there are public organizations such as State Meteorological Services (DMI), State Hydraulic Works (DSI), Electric Power Resources Survey and Development Administration (EIE), Rural Affairs and Forest Administration (KHGM).

2.1. State Hydraulic Works (DSI) :

The General Directorate of State Hydraulic Works (DSI), established in 1953, is the main executive agency of Turkey for overall water resources planning , execution and operation.

DSI is charged with multiple utilization of ground and surface waters and prevention of soil erosion and flood damages. DSI is also empowered to plan, design and construct hydroelectric schemes. Further responsibilities of DSI include performing basic investigations (stream flow gauging, soil classification etc.), preparation of river basin development plans, and formulation of proposals for construction, financing and subsequent operation of the works. Until 1960, DSI had succeeded to install hydrometrical gauge network through which observations are carried out and subsequently the needed data are collected for the planned projects.

DSI is a three-tiered line organization (see organizational chart). Its top management level is the General Directorate office and the secondary of staff level is the Department offices. Both of them are located in Ankara. The tertiary level consists of the field or regional directorate offices. At present, there are 25 regional directorates dispersed throughout Turkey. It should be noted that, in general, the boundaries of the regional directorates do not coincide with river basin watersheds. Many of the 26 river which constituents basins of Turkey are therefore covered by more than one regional directorate. This situation is leading to a certain amount of organizational difficulty in the formulation of river basin development plans, the operation of water resources projects and the carrying out of other basin-wide activities.

The 25 Regional Directorates are divided into Central Regional Offices, Field Division Offices and Field Section Offices. Major functional offices are listed as mapping, hydrometric measurements, land management, classification and drainage, groundwater activities, planning and construction for major and minor water projects.

As for provincial divisions, General Directorate of DSI has 25 ea. regional directorates including 2 ea. dams and 92 ea. branch directorates. Locations of regional directorates are situated in city or country in accordance with the volume of work.

In DSI, civil engineers constitute the most important part of existing staff. Its personnel includes also agricultural engineers, meteorological engineers as hydrologists, geologists, cartographers, forest engineers, mechanical engineers and mathematicians, etc.

DSI makes investment within frame of plan, project and target that are envisaged by a five year development plan. DSI's investment budget is made up of allocation by state.

With an indisputable authority and contribution in developing of water and soil resources, DSI is considered as one of the major organizations that deal with natural resources. While state is making water policy with neighboring countries, DSI plays constructive role as a consultant. DSI is also liable for producing hydrologist who brings solutions to issues regarding water resources and makes research because there is no institution of hydrology that other countries have already. In DSI, internal services concerning education have become a sort of school at the same time, owing to the lacked institution for hydrology.

The Investigation and Planning Department is one of the main departments in DSI General Directorate. This department is responsible for all pre-construction field work (except geotechnical investigation) and laboratory testing (except hydraulic models) and for the preparation of project studies and river basin development plans. The number of personnel in this department is supplemented by staff in the regional directorates.

2.1.1. Hydrology Section : The Hydrology Section is one of the main divisions of the Investigation and Planning Department . Duties and responsibilities of the hydrology section could be classified into four main specialization areas :

Viability of water resources projects depends, more than anything, on sustained availability of water. For this reason, it is necessary to accurately identify the water potential of each project. Since most of the projects have different formulation and utilize different sources of water , each project is dealt with individually. This task comprises identifying potential water resources in the project area, locating existing and relevant stream flow and rain gauging stations, obtaining stream flow data, performing computer-aided statistical procedures to generate synthetic flows, extending -- in case where the available stream flow series is short to reach a conclusion -- and completing -- where some intermediate figures are missing -- of stream flow data by the employment of hydrological relationships. Upon completion of the studies for the determination of water supply potential, if the water potential seems adequate and promising to meet the intended objectives, reports of the projects are transferred to other sections for the examination of other aspects.

Since very diverse climatological conditions exist throughout Turkey, almost every irrigation project has different type of crop patterns. And, different crop patterns and different climatological conditions entail different crop water requirements. The process of the calculation of crop water requirements involves, given the optimal crop pattern for the project area, locating nearby meteorological stations to obtain such values as temperature, evaporation, precipitation, wind speed etc., and computing, with the help of -- especially of Blainey -Criddle -- widely-used techniques whose computer code is available, the crop water requirements ; and through some fixed coefficients depending on the irrigation type, farm and diversion requirements and consequently irrigation modules -- a variable necessary for the determination of canal capacities.

Although much of the problem is with the scarcity of water throughout the world, the problems resulting from the abundance of water cannot be overlooked. Almost all projects related with water should take into account the extreme conditions that might happen during the life of the project. Flood is one of the most important of these events when the safety of the project and most importantly of people is concerned. Several experienced meteorological engineers specialized in flood hydrology carry out statistical techniques through computers to compute design flood of each project to help in the design of water discharge facilities such as spillways. Other than that, hydrologic conditions of existing dams are monitored for the continued safe operation.

Performing reservoir operation studies is yet another responsibility of the hydrology section. Experienced personnel responsible for reservoir operation studies carry out different scenarios to determine the optimal reservoir size. Since the reservoir size is the most essential component of the project, the size of it affects almost everything in the project and even small differences in size might result in considerable cost reduction. For this reason , great emphasis is given to the reservoir operation studies to determine the optimal size of the reservoir and every other component of the project.

2.1.2. Hydro-meteorologic Observation Section : Although some information has been given in the former section, additional information can be issued, herewith, about hydrometric studies in DSI. Duties and responsibilities of this section are given as following :

Measurement studies are being conducted by both the staff in Investigation and Planning Department and the staff from the corresponding sections in the Regional Directorates.

The measurement of quality of water are being done mainly for irrigation purposes. As an example, in 1996, the number of measurements, taken from different 266 observation places all around Turkey became 1272.

Some activities conducted by Hydrometeorologic Observation Section are briefly explained as following : Water level observation : Water levels are observed by "observer man" living in the locations nearby the station place. In stations, observations for level of water by staff gauges, every day twice, at hours 8.00 and 16.00 are made; as for lakes, observation is fulfilled once every day in the morning at hour 8.00. The observation reports are sent by observers to the staff person in the regional directorates who are responsible in controlling and sending these to the office the General Directorate. Stations whose drainage area more than 100 km² are also equipped with water level recorders. Because of limited finance resource, only some of the station whose drainage area more than 100 km² have water level recorders.

In the network, there are mainly two types of recorders: Mecanic recorders plots the changes in the water levels on graphical paper. These graphs are evaluated by staff person in the location in order to find out mean, max and min values of water levels. Electronical recorders measures, automatically, the water levels in the given period and records these measurements in the memory. The data in the memory are transferred later by the technicians to the note-book to be evaluated and plotted on the graphical papers at the office. After calculating the mean , max and min values and printing of the results, the staff person sends these studies by mail to the Hydrometeorologic Observation Section in the General Directorate. Discharge measurements : Discharges are measured, at the cross-section of the station, by the staff person called "hydrolog" by using the various types of current meters. Each measurement is compared to the water level data which is read simultaneously.

In the measurement of discharges, when needed, some additional tools such as cableway, winch, threshold, crane and other gauging accessories are also being used.

In general, by the 15 day period, the discharge measurement is conducted, preferentially when water level high at most. Because of the some unexpected reasons, the measurements may not be done during the flooding time. Discharge rating curve studies : The data relating with water level and discharge values are stored in the register files. After plotting the data on logarithmic paper (Level vs. Discharge), rating curve is drawn. These curves are checked by using the existing computer programmes which use some statistical methods such as the methods of Geometric , Steven, Velocity-Area etc. Correcting of the rating curve, responsible engineer registers this curve to the corresponding file. Data evaluation : Evaluation studies are conducted, using available software, after 2 years of lag time in order to able to see the future control and corrections. Considering the mean water level data from gaging stations and corresponding discharge values from rating curves, some mathematical operations and rating table are used to calculate monthly average discharges, monthly and yearly total discharges (106 m³), min and max discharge values, yield as l/sec/km², and also runoff in mm. Data storage and publishing : Since 1988, the tables including the stream flow data are stored in data bank. All the historical discharge values and tables have been transferred to this data bank having some facilities to make query on the data. The mentioned data bank is called DSI Hydrometric Data Bank operating in DOS and using INFORMIX/SQL software language. Being suitable for only single-user systems, but not network systems, this data bank was built by Middle East Technical University (ODTU), Ankara.

Because of some reasons relating with errors during the data input and inadequacy of computer facilities, some correction studies and additional software are needed in order to use this data bank sufficiently. Besides to the data bank facility, water year discharge values are being published regularly as a book for every water year.

2.1.3. Operational Hydrology Division : Being jointed to the Department of Operation and Maintenance of DSI, this section deals with following tasks :

2.2. Electrical Power Resources Survey and Development Administration (EIE)

2.2.1. General :Electrical Power Resources Survey and Development Administration of the Ministry of Energy and Natural Resources (EIE) was founded in 1935. Having an economic state enterprise status, the Administration is governed by the provisions of private law and is administered in accordance with commercial methods while enjoying the status of a juridical person. Since 1935, EIE has begun to search into energy resources and by paying attention to the water resources, to build the early stations of gauge network and put them into operation. Until 1953, it had become consultant for DSI in the early establishment years of DSI. Today, DSI and EIE are the sister institutions. The head office of EIE is also situated in Ankara.. EIE is composed of 9 regional directorates that include branch directorates. Nine directorates are classified as project, geology and drilling, hydraulic surveys, surveying energy resources, personnel and training, accounting and fiscal affairs, equipment and supplying, researching , planning and coordination. Provincial organization of EIE is consisted of hydrometrical division chiefs whose locations are in nine provinces and fourteen drilling camps.

EIE is engaged in hydrological, foundation and map investigation and surveys both in the field and in the office with the aim of identifying the power potential of water resources of the country and of preparing dam and hydropower plant projects at convenient locations. Thereafter, the engineering services are completed in reconnaissance, master plan , feasibility and final design stages, respectively.

The rational utilization of energy resources , energy conservation , new and renewable resources of energy such as solar and wind powers are also in the scope of activities of the Administration.

EIE performs investigations, survey and engineering services on hydrology, mapping, foundation surveys, grouting, drilling for coal and other mines, design of dams and hydropower plants based on its expertise gained through previous experience.

The number of personnel employed by the Administration is 1840. Of the 794 employees at the headquarters, 507 are white collar and 287 are blue collar workers. The white collars workers consist of 196 technical, and 273 as general administrative personnel.

Aiming for the development of the country's hydroelectric potential, the Administration in the early years of establishment initiated studies to identify possible sites for future dams and hydropower plants and hydrometric measurements, foundation investigations and mapping activities for such sites.

The Administration in 61 years, completed the engineering services of more than 60 power generating installations for public and private organizations.

2.2.2. Hydrometric Observations : Department of Hydrological Surveys is the one of the main departments in the Administration. This department coordinates the regional hydrometric field offices of the Administration that operate 285 basic data hydrometric stations to estimate the values of some components of the hydrological cycle in river basins of Turkey. Some of these gauging stations are equipped with water level recorders and cable cars. All of these stations take regular readings of water level and discharges but, in some stations, in addition to these routine gauging, sediments, water quality, water temperature and ice thickness measurements are taken. From the river discharge values published in the water year books prepared by the Administration the mean annual surface water potential of Turkey has been calculated to be 185 billion m³.

Particularly in eastern Turkey the major share of water resources results from melting snow. the Administration operates snow course stations to predict snow melt runoff. At 29 such stations distributed over elevations between 1500 to 2500 meters, depth and water equivalent of snow-pack measurements are made in the early days of the winter and spring months.

The number of hydrometric stations operated by EIE can be given as following :

Flow gauging stations 285
Lake water level monitoring stations 12

2.3. State Meteorological Affairs (DMI)

General Directorate of State Meteorological Services employs agricultural engineers, physician, mathematician and meteorological engineers. DMI General Directorate, established in 1930, is located in Ankara. There are 15 regional directorates with subdivided station directorates. Being joined to Ministry of State, DMI is liable for observations, determining of climatic conditions and meteorological characteristics.

The top management level of DMI is the General Directorate office in Ankara. In addition to the department offices in Ankara, there are also regional directorate offices. The Department of Agricultural Meteorology and Climatological Surveys is one of the main department that mostly deals with the hydrological studies. The names of divisions in this department is following :

The duties of Hydrometeorology Division can be listed as following : There is also Research Department dealing with some hydrometeorological research and studies.

2.4. General Directorate of Rural Affairs

General Directorate of Rural Affairs is attached to Prime Ministry. It collaborates with State Hydraulic Works in planning, surveying and building of water installations that need water less than 0.5 m³/s. It has some research facilities examining relationships among water, soil and plant. One of the duties is to train farmers and to take up guidance in the field irrigation. It cooperates with State Hydraulic Works in searching necessary principles in agricultural economy for the irrigation projects. As per districts and suburbs, some research studies are carried out on the plant species that should be bred.