The significance and effective use of water, one of the most basic requirements for sustaining vital activities, is gaining importance every day. Population growth and unprogrammed industrialization accelerate the consumption of available water resources. However, drought, as a result of climate change, poses a threat to water resources. Factors such as the exhaustibility of water resources, rapid population growth, unscheduled industrialization and drought increase the tendency towards alternative water resources. Rainwater harvesting is based on the principle of using the rainwater falling into the regions after it is stored. Water collected through rain harvesting can be utilized in many different areas, such as agricultural irrigation, landscape irrigation and domestic use. Among agricultural activities, the idea of water harvesting in greenhouse areas comes to the fore. Due to the gutters on the greenhouse roofs, water can be stored. In Antalya, which has about half of the greenhouses in Turkey, the amount of water in the rain harvest that can be obtained in greenhouses is 224,992,795.8 m³ per year. Monthly calculations throughout the year showed that the minimum water can be harvested in August (938,447.53 m³) and the maximum (54,771,210 m³) in December. Therefore, it is thought that some plant water consumption can be met by building sufficient storage in areas close to the greenhouse.

Lakes are the most important freshwater resources for humans. It is stated that together with population growth, unplanned urbanization, excessive water consumption, industrialization, and unconscious irrigation, global climate change causes changes in the water levels and volumes of lakes. Lake Eğirdir in Turkey, which is important in terms of drinking and irrigation water use, was chosen as the study area. Lake Eğirdir water level (LWL) and water volume (LWV) values measured between 1988–2019 were used. Dependencies in the annual LWL and LWV were examined by autocorrelation analysis, and trend changes were examined by regression analysis, the Mann-Kendall rank correlation test, and the Şen innovation trend test. The research has shown a significant decrease since 2000 in LWL and since 1990 in LWV. The LWL has decreased by −1.272 to −3.514 m and the LWV has decreased by −72.980 to −1082.134 hm³ in approximately 32 years. The actions to be taken based on the values determined in this study will help protect the water resources of lakes. As a result of the tests used in our study, it was determined that there were decreases in both the water level and the volume of the lake. The climatic changes in the lake basin and the decrease in the water resources feeding the lake are shown as the biggest factor in these reductions.

Recently, with the development of technology, the number of studies on the need for energy and the possibilities of covering this need in a sustainable way has been increasing. The management of agricultural biomass and waste is cited as one of the challenges as well as a solution. Mersin and Antalya sites, where banana production is intensively practiced in Turkey, were selected as the study region. The potential amounts of energy values obtained from the waste generated during banana cultivation in the field area of study were calculated. The energy potential was calculated on the basis of the conversion of biogas that can be obtained from the waste. The values obtained were analyzed and compared with the levels of electricity used to determine the economic gains that can be achieved for Mersin and Antalya regions. The data on bananas used in study were obtained from the Turkish Statistical Institute (for the years 2016–2020). It is calculated that 2884.43 MWh of electricity can be generated in Mersin and 2218.26 MWh in Antalya per 5 years from the waste generated during banana production. The values of the number of houses whose needs can be met with the calculated five-year potential electricity amount are 1237 in Mersin and 952 in Antalya. It can be considered that reusing the potential energy that can be obtained from banana waste, examined as material for energy, used in agricultural production will result in a positive impetus to agricultural activities. Energy obtained from banana waste can cover a very small amount of the electrical energy needs of agricultural production, ranging from 0.19% to 0.34%. However, it is concluded that the potential amount of energy to be obtained by recycling not only banana waste but also other agricultural and food waste will be even higher.

This research aimed to analyze the potential amount of electrical energy from biogas energy obtained from animal wastes in Turkey and Poland. Animal waste values were calculated by taking into account the recommended literature values. In determining the biomass energy potential of livestock enterprises in Turkey and Poland, FAO’s 2012–2021 data were taken into account. The animal breeds selected as material in this study were cattle, goat, sheep, chicken, duck, goose, turkey, horse, pig, mule and donkey. Considering 10-year calculations, the potential amount of biogas energy that can be obtained from animal wastes for Turkey is 28,845,975 GJ, which is equivalent to 8,105,058 MWh of electrical energy. In Poland, the potential amount of biogas energy that can be generated from animal waste is 13,999,612 GJ, which is equivalent to 3,902,020 MWh of electricity. Moreover, it is estimated that the percentage of the potential amount of electricity to be obtained in 2021 to cover the amount of electricity consumed is 0.303% for Turkey and 0.392% for Poland. For 2021, the amount of economic gains that can be from electricity obtained was also calculated, and it was determined that this value can be 78,650,302 Euro for Turkey and 62,182,435 Euro for Poland. At the same time, it was calculated that the electricity needs of 406,170 houses in Turkey and 171,958 houses in Poland can be met in 2021. As a result, it is thought that the potential electricity to be obtained will contribute to determining energy gains and investment plans for biogas plants.

Rapid population growth, urbanization, and industrialization have many negative environmental effects. These adverse effects are felt more in urban areas than in rural areas. Considering the high rate of urban development, the idea that green roof structures can be used on rooftops is important in reducing the current negative effects. In addition, water retention on these roof areas can be helpful in the face of drought periods. In this study, the amount of water that can be retained on a 100 m² roof area in Antalya Province, Turkey was calculated. As a result, it was determined that August is the month when the least water can be retained due to rainfall. It was calculated that between 0.168 m³ and 0.363 m³ of water can be retained in August. Furthermore, the month in which the most water can be retained due to rainfall is December, and the amounts of water that can be retained are between 5.762 m³ and 21.640 m³. These calculated values are anticipated to be important in understanding how much water can be retained in the planned green roofs. In addition, it has been determined that the energy savings that can be made for heating purposes in a 100 m² green roof area can be between 3900 kWh and 11,250 kWh.