Participatory Ecosystem Management Planning at Tuzla Lake (Turkey) Using Fuzzy Cognitive Mapping

A participatory environmental management plan was prepared for Tuzla Lake, Turkey. Fuzzy cognitive mapping approach was used to obtain stakeholder views and desires. Cognitive maps were prepared with 44 stakeholders (villagers, local decisionmakers, government and non-government organization (NGO) officials). Graph theory indices, statistical methods and "What-if" simulations were used in the analysis. The most mentioned variables were livelihood, agriculture and animal husbandry. The most central variable was agriculture for local people (villagers and local decisionmakers) and education for NGO & Government officials. All the stakeholders agreed that livelihood was increased by agriculture and animal husbandry while hunting decreased birds and wildlife. Although local people focused on their livelihoods, NGO & Government officials focused on conservation of Tuzla Lake and education of local people. Stakeholders indicated that the conservation status of Tuzla Lake should be strengthened to conserve the ecosystem and biodiversity, which may be negatively impacted by agriculture and irrigation. Stakeholders mentioned salt extraction, ecotourism, and carpet weaving as alternative economic activities. Cognitive mapping provided an effective tool for the inclusion of the stakeholders' views and ensured initial participation in environmental planning and policy making.Comment: 43 pages, 4 figure

Spatial Data Management and Numerical Modelling: Demonstrating the Application of the QGIS-Integrated FREEWAT Platform at 13 Case Studies for Tackling Groundwater Resource Management

Because of the spatial nature of groundwater-related data and their time component, effective groundwater management requires the application of methods pertaining to the Information and Communication Technologies sector, such as spatial data management and distributed numerical modelling. The objective of this paper is to demonstrate the effectiveness of the QGIS-integrated FREEWAT platform and an approach combining spatial data management and numerical models to target groundwater management issues. FREEWAT is a free and open source platform integrated in a Geographic Information System environment and embedding tools for pre- and post-processing of spatial data and integrating numerical codes for the simulation of the hydrological cycle, with a main focus on groundwater. To this aim, this paper briefly presents the FREEWAT platform, introduces the FREEWAT approach, and showcases 13 case studies in European and non-European countries where the FREEWAT platform was applied. Application of the FREEWAT platform to real-world case studies is presented for targeting management of coastal aquifers, ground- and surface-water interaction, climate change impacts, management of transboundary aquifers, rural water management and protection of groundwater-dependent ecosystems. In this sense, compared to other existing software suites, FREEWAT allows data analysis and visualization to accomplish each step of the modelling workflow, i.e., from data analytics, to conceptual model definition, to numerical modelling and reporting of results. The presented experiences demonstrate that improved access to data and the portability of models and models’ results can help to promote water sustainability from the local- to the basin-scale. Furthermore, FREEWAT may represent a valuable tool to target the objective of increasing the capabilities of public authorities and private companies to manage groundwater resources by means of up-to-date, robust, well-documented and reliable software, without entailing the need of costly licensing, nowadays seldom affordable by public water authorities. Based on the strengths highlighted, the FREEWAT platform is a powerful tool for groundwater resources management, and for data collection, sharing, implementation and comparison of scenarios, for supporting planning and decision-making

Modelling surface water-groundwater interactions at the Palas Basin (Turkey) using FREEWAT

Palas Basin is a semi-arid closed basin located in the Central Anatolia region of Turkey. The major economic activity in the basin is agriculture; therefore, both surface water and groundwater are used for irrigation. However, intensive use of water resources threatens the hydrologic sustainability of a lake ecosystem (Tuzla Lake) located in the basin. In this study, we analyzed the relationships between agricultural water uses in the Palas Basin and water flows to the Tuzla Lake using groundwater flow model developed with the FREEWAT platform. The model grid with 250 m x 250 m resolution was created based on the entire watershed. Two hydrostratigraphic units were identified. The source terms defined in the model were rainfall recharge and the sink terms were evapotranspiration and wells. The model was run for one year at steady state conditions. Three scenarios were simulated to understand the effect of groundwater use on the lake hydrology. The first scenario assumed that there was no groundwater abstraction. As the second and third water management scenario, the model was run with 50% less and %50 more groundwater abstraction than that of the reference conditions. The model successfully simulated the direction of groundwater flow and groundwater levels in the basin. Annual groundwater recharge was simulated as 5.27 million m3. Groundwater losses were due to pumping (1.49 million m3/yr), leakance to Değirmen River (2.25 million m3/yr) and seepage to Tuzla Lake (1.53 million m3/yr). Water flows to Tuzla Lake were significantly related to pumping rates. Increasing groundwater pumping rates reduces groundwater flows to Tuzla Lake and lowers lake water levels. No groundwater abstraction and reduction in groundwater pumping rates increase water flows to Tuzla Lake and cause higher water levels. This analysis showed that protection of hydrologic characteristics of Tuzla Lake is only possible with more control on groundwater abstraction

A neural network model for simulation of water levels at the Sultan Marshes wetland in Turkey

An artificial neural network (ANN) model was developed for simulating water levels at the Sultan Marshes in Turkey. Sultan Marshes is a closed basin wetland located in the semi-arid Central Anatolia region of Turkey. It is one of the thirteen Ramsar sites of Turkey and a national park. Water levels at the Sultan Marshes showed strong fluctuations in recent decades due to the changes in climatic and hydrologic conditions. In this study, monthly average water levels were simulated using a multi-layer perceptron type ANN model. The model inputs consisted of climatic data (precipitation, air temperature, evapotranspiration) and hydrologic data (ground water levels, spring flow rates, and previous month water levels) available from 1993 to 2002. 70 % of the data were used for model training and remaining 30 % were used for model testing. Model training was accomplished by using a scaled conjugate gradient backpropagation algorithm. The performance of the model was evaluated by calculating the root mean square error (RMSE) and the coefficient of determination (R (2)) between observed and simulated water levels. The sensitivity of the model to input parameters was determined by evaluating the model performance when a single input variable was excluded. It was found that the ANN model can successfully be used for simulating water levels at the Sultan Marshes. The model developed using all input variables provided the best results with two neurons in the hidden layer. The RMSE and R (2) of the simulated water levels were 4.0 cm and 96 %, respectively. The sensitivity analysis showed that the model was most sensitive to previous month water levels and ground water levels

Modelling surface water-groundwater interactions at the Palas Basin (Turkey) using FREEWAT

Palas Basin is a semi-arid closed basin located in the Central Anatolia region of Turkey. The major economic activity in the basin is agriculture; therefore, both surface water and groundwater are used for irrigation. However, intensive use of water resources threatens the hydrologic sustainability of an ecologically important lake ecosystem (Tuzla Lake) located in the basin, as it is hydrologically dependent on surface and groundwater flows from the basin. In this study, we analyze the relationships between agricultural water uses in the Palas Basin and water flows in to the Tuzla Lake using groundwater flow model developed with the FREEWAT platform. The model grid with 250 m x 250 m resolution was created based on the entire watershed, where two hydrostratigraphic units were identified. The source terms defined to the model were rainfall recharge and the sink terms were evapotranspiration and groundwater abstraction from wells. The model was run for one year at steady-state conditions. The model successfully simulated the direction of groundwater flow and groundwater levels in the basin. Annual groundwater recharge was simulated as 5.27 million m(3). Groundwater losses were due to pumping (1.49 million m(3)/yr), leakance to Degirmen River (2.25 million m(3)/yr) and seepage to Tuzla Lake (1.53 million m(3)/yr). Three scenarios were simulated to understand the effect of groundwater use on the lake hydrology. The first scenario assumed that there was no groundwater abstraction. As the second and third water management scenarios, the model was run with 50% less and 50% more groundwater abstraction than that of the current conditions. Water flows to Tuzla Lake were significantly related to groundwater abstraction rates. Increasing groundwater pumping rates reduces groundwater flows to Tuzla Lake and lowers lake water level. No groundwater abstraction and reduction in groundwater pumping rates increase water flows to Tuzla Lake and allow higher lake water levels. This analysis showed that protection of hydrologic characteristics of Tuzla Lake is only possible with more control on groundwater abstraction

Lake Level Response to Climate in Minnesota

We are interested in the variability of lake levels in Minnesota, and the relationship between lake levels and climate. We analyzed historical water levels in 25 Minnesota lakes. Eight were landlocked lakes and seventeen were flow-through lakes. The data were daily values, but substantial gaps existed. The longest record reached back to 1906 (Lake Minnetonka and Upper Prior Lake in Scott County). We determined statistical parameters such as mean annual lake levels and seasonal variations of the historical lake water levels. Linear regression and Mann-Kendall test were used to evaluate the presence of trends in daily, mean annual, spring (May) and fall (October) water levels. The majority of the 25 lakes showed rising water levels in the last century (1906 to 2007). The strongest upward trend was observed in a landlocked lake (Lake Belle Taine in Hubbard County) where the rate was 0.030 m/yr. The second largest increase was observed in a flow-through lake (Marion Lake in Dakota County) with a rate of 0.024 m/yr. Swan Lake (in Nicollet County) and Swan Lake (in Itasca County) were the only lakes that showed a falling trend with a rate of -0.011 and -0.002 m/yr, respectively. The analysis also showed that lake levels have been increasing in most of the 25 lakes in the last 20-years (1987-2006). One landlocked lake and eight flow-through lakes showed their strongest upward trends in the last 20 years. Five of the eight landlocked lakes and eleven of the seventeen flow-through lakes reached their highest recorded levels after 1990. Upward trends in recorded lake water levels were found in both spring and fall in the majority of the 25 lakes analyzed. We also attempted to understand how Minnesota lake levels have responded to climate changes in the past. Correlation coefficients were calculated between annual lake water levels and mean annual climate variables. The correlation of water levels with precipitation was moderate, and the correlation with dew point and air temperatures was very weak. 48- and 36-month antecedent precipitation was the strongest indicator of average water levels. Multivariate regression analysis of lake levels did not improve the lake level predictions. Numerical indicators for ground water and surface water inand out-flows appear necessary for further improvement. The correlation between mean annual water levels was strongest among lakes in the same climate regions and weakest among lakes in distant climate regions. Lake levels in the same Minnesota climate region (with identical precipitation and temperatures) had correlation coefficients as high as 0.78, while those in distant regions were not correlated. The average correlation coefficients among annual water levels in all lakes were 0.43 for the eight landlocked lakes and 0.41 for the seventeen flowthrough lakes. Overall, the analyses showed that changes have occurred in lake levels in Minnesota in the last century and in the last 20 years. The majority of the lakes have rising lake levels. The correlation between climate parameters and lake levels was weak. The consistency of water level variations in lakes of the same region is perhaps the strongest indicator of a climate effect. If the trends continue, lakes included in this study may experience significant water level increase by 2050.Legislative Citizens Committee on Minnesota ResourcesDadaser-Celik, Filiz; Stefan, Heinz G.. (2007). Lake Level Response to Climate in Minnesota. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/117628

Lake Evaporation Response to Climate in Minnesota

In this report we analyze the variability of water losses by evaporation from lake surfaces in Minnesota, and trends in lake evaporation for the period 1964 – 2005. Daily evaporation rates were estimated using a mass-transfer equation with recorded daily weather data as input. The weather data came from six Class A weather stations (International Falls, Duluth, Minneaplis/St. Paul, LaCrosse, WI, Sioux Falls, SD, and Fargo, ND). Annual (Jan-Dec) lake evaporation ignoring lake ice-covers and annual evaporation for the actual open-water season were computed from the daily values. Trends in annual evaporation over the periods 1964 – 2005 and 1986 – 2005 were determined using a linear regression method. The trend analysis was repeated for annual water availability (precipitation minus evaporation). Finally correlation coefficients between annual average water levels of 25 Minnesota lakes, and annual evaporation or annual water availability were calculated. In the last 40 years (1964 – 2005), annual average open-water season evaporation ranged from 580 to 747 mm/yr (22.8 to 29.4 in/yr) at the six locations. The trend over the 1964 – 2005 period was upward (rising) at three stations (International Falls, Duluth, and Sioux Falls), and downward (falling) at three stations (Fargo, Minneapolis, and La Crosse). The strongest upward trend in evaporation (0.64 mm/yr) was for Duluth and the strongest downward trend (-1.65 mm/yr) for La Crosse. Annual evaporation for the 12-month (Jan-Dec) period, i.e., disregarding ice covers, was from 79 mm/yr (3.1 in/yr) to 140 mm/yr (5.5 in/yr) higher than annual evaporation computed for the open-water season at the six locations. In the last 20-years (1986–2005) annual open-water season evaporation had a decreasing trend at five of the six locations. The decreasing trends were stronger than for the 1964 – 2005 period and ranged from -0.69 for International Falls and Minneapolis to -1.57 mm/yr for La Crosse. The only positive trend was 1.09 mm/yr for Sioux Falls. Annual average measured precipitation for the 1964 – 2005 period at the six locations ranged from 536 mm/yr to 812 mm/yr (21.1 in/yr to 32.0 in/yr) and showed a rising trend at four 6 of the six stations (International Falls and Duluth were the exceptions). For the 1986 – 2005 period precipitation showed an increasing trend at all stations except Duluth and La Crosse. Water availability, calculated as the difference between annual open-water season precipitation and annual open-water evaporation, showed upward trends at all stations from 1964 to 2005. The trends ranged from 0.05 mm/yr for Duluth to 4.27 mm/yr for Fargo. From 1986 to 2005 five locations showed an upward trend and one a downward trend. The five upward trends were much stronger than for the 1964 – 2005 period, ranging from 0.58mm/yr for La Crosse to 15.06 mm/yr for Fargo. The only downward trend was -2.67 mm/yr for Duluth. Overall, the analysis showed that positive and negative trends in lake evaporation have occurred in Minnesota in the last 40 years. Trends in measured precipitation during the same time period were stronger and upwards. As a result, water availability in Minnesota also has an upward trend. No strong correlation between lake levels, annual evaporation rates or annual water availability was found, but the increase in water availability can explain the observed water level increases in 25 Minnesota lakes.Legislative Citizens Committee on Minnesota ResourcesDadaser-Celik, Filiz; Stefan, Heinz G.. (2008). Lake Evaporation Response to Climate in Minnesota. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/117629

Spatial and temporal changes at Tuzla (Palas) Lake in Turkey

Saline lakes are widespread throughout the arid and semi-arid regions of the world and have considerable ecological importance. They are also very vulnerable to climatic changes or changes in their hydrological regimes. Most saline lakes of Turkey are close to the verge of extinction due to natural and anthropogenic impacts. This study analyzes the spatial and temporal changes at a relatively pristine saline lake (Tuzla (Palas) Lake) in Kayseri, Turkey, from 1987 to 2011 using satellite imagery techniques. Landsat Thematic Mapper images acquired in 1987, 2000, 2003, and 2011 were used in the analysis. The images were geometrically corrected by registering them to ground control points. The study area on each image was classified into seven information classes, i.e., water, watery ground, dry lake, mud/vegetated flats, salt flats, shrubs/sedges, and agriculture. The accuracies of the classifications were evaluated using a standard error matrix and kappa statistics. The analysis showed that the surface area of Tuzla Lake was highly variable during the 1987-2011 period. Lake surface area was the largest in 1987 and the smallest in 2003. Analysis of the climatic conditions for 4 years showed that the surface area of the lake is highly vulnerable to changes in precipitation and air temperatures

Trends in reference evapotranspiration in Turkey: 1975-2006

This study examines the trends in reference evapotranspiration (ETo) in Turkey by analysing data from 77 weather stations for a 32-year period (1975-2006). ETo values were calculated using the Penman-Monteith method using air temperature, wind speed, relative humidity, and sunshine hours data. Trends in annual and monthly ETo were determined using the Mann-Kendall trend test with the trend-free prewhitening procedure. The magnitude of trends was estimated by calculating the Sen's slope. The collective or field significance of the trends was evaluated using Walker test. The possible causes of changes in ETo were discussed by analysing the trends in air temperature, wind speed, relative humidity, and solar radiation data collected at the same stations. The implications of ETo trends for crop water requirements were evaluated. The analyses showed that the majority of stations (88%) in Turkey had annual ETo between 750 and 1200 mm during the 32-year period and ETo decreased gradually from south to north. From 1975 to 2006, 58% of stations had upward trends in annual ETo. Upward trends were statistically significant at the 0.05 level for 32% of stations. The rates of changes in annual ETo were on average 1.20 mm year(-2). The trends detected in monthly ETo were mostly upward with an average magnitude between -0.01 and 0.14 mm month year(-1). Trends detected at the annual timescale and for the majority of the months provided the field significance at the 0.05 level. Analysis of other climatic data showed that upward trends in air temperatures, downward trends in wind speeds, and downward trends in relative humidity were widespread over Turkey for the same time period. Changes in these three parameters could explain the majority of the changes in ETo rates. The ETo changes affect crop water requirements and increase the demand for irrigation