The demand for fresh water is rapidly growing as a consequence of the increasing population and urbanization. Tubular solar still offers larger evaporative and condensing surface area as compared to single slope solar still. The aim of this study is to improve the performance of tubular solar still by employing eggshell powder (collected from Babcobb Broilers chicken) as the sensible energy storage material in form of bed, placed inside the basin of still to improve the water production. Results showed that the influence of eggshell powder as energy storage material in the basin improved the average water temperature by 3%, 6.2%, and 3.2% for the water thickness of 10, 15, and 20 mm, respectively. The usage of eggshells as a sensible energy storage in the basin augmented the peak hourly water yield by 67.64% with minimum water thickness. The total observed distillate output from the solar still is 1.45 kg without eggshell powder and 2.67 kg for with eggshell powder in the absorber at the lowest water thickness of 10 mm. TSS with eggshell powder as energy storage has a daily energy efficiency of 48.17%, 42.38%, and 36.38%, respectively, for water thicknesses of 10, 15, and 20 mm in the basin. Water thickness of 10, 15, and 20 mm has performance improvement ratios of 1.83, 1.81, and 1.78, respectively. Using cost analysis, it was found that the cost of drinkable water generated using eggshell as an energy storage material is 0.011$/kg, but the cost of water by traditional still without any storage material was 0.021$/kg.

This research paper deals with the experimental investigation of solar energy–based water purifier (SEBWP) of single-slope type by incorporating N similar evacuated tubular collectors (ETCs) having series connection. Experimental investigation has been done for a year from August 2018 to July 2019. MATLAB has been used for evaluating performance parameters of the system followed by the validation of these results with their experimental values. A fair agreement has been found between theoretical and experimental values. Values of correlation coefficients for condensing glass temperature, water temperature, and water yield have been found to be 0.9932, 0.9928, and 0.9951 respectively. Further, energy metrics, productivity, cost of producing 1 kg of fresh water, and exergoeconomic and enviroeconomic parameters have been evaluated. Values of energy payback time, per kilogram cost of producing fresh water and exergy loss per unit Rs. have been evaluated to be 1.72 years, Rs. 0.95/kg, and 0.128 kWh/Rs. respectively.

In the current research, the energy and economic performance in single-slope solar still using ball marbles (BMSS) has been investigated and compared the results with conventional solar still (CSS) under the similar weather conditions of Karaikal (10.92° N, 79.83° E), India, during October 2020. The experiments have been conducted on both sunny and cloudy day to evaluate the performance of solar still. The BMSS has increased the evaporation rate and productivity when compared to CSS due to the sensible heat energy stored by the ball marbles in the absorber basin. The potable water yield of the BMSS is improved by 21.23% and 22.86%, respectively, during sunny and cloudy days. The maximum cumulative productivity obtained in the BMSS is 2950 mL/m².day and 2150 mL/m².day, respectively, on sunny and cloudy days. In economic analysis, the payback period (PBP) of the BMSS is 5.7 months, whereas the PBP of the CSS is 6.5 months, respectively. Furthermore, the cost per litre (CPL) potable water produced by BMSS is 8% lower than the CPL of CSS.

Understanding the relationship among ecosystem services (ESs) is essential to promote ESs management and sustainable development. The relationship between ESs is mutual and can be expressed in terms of trade-offs, synergy, and constraints. The paper selected the InVEST model to assess the water yield (WY), soil conservation (SC), food production (FP), net primary productivity (NPP), and habitat quality (HQ) of the Yangtze River Economic Belt (YREB) and used the constraint line method to analyze the relationship of paired ecological services at three scales: landscape, watershed, and land category. The following conclusions were drawn: (1) during the study period, the spatial changes of the five ecological services in the YREB did not change much, but the spatial distribution of the ecological services was different. (2) From 2000 to 2015, the constraint line of YREB paired ecological services had a high degree of fit. Under the three levels of landscape, watershed, and land category, the YREB has a variety of constraint types, including negative lines, logarithms, paraboloids, humped shapes, and rectangles. (3) At the three levels, the constraint lines between FP, NPP, WY, and SC and HQ were stable rectangular constraints; WY-SC was hump shaped, FP-NPP, FP-SC, FP-WY, NPP-WY, and NPP-SC changed with the scale, showing different spatial scale changes. (4) The paired ESs directly determined the ecological constraint curve but under the combined effect of other factors, which would affect or change the constraint line. We discussed the effects of weather, topography, and economy on the constraint relationship, and found that all have different degrees of influence.

Understanding the factors driving ecosystem service (ES) change is essential for maintaining ES functions and achieving sustainable development. Although research on the spatial variations in the effects of driving forces on ESs provides guidance for regional ecological management, the responses of driving forces to environmental conditions have not been adequately investigated, especially in regions with high spatial heterogeneity. By using remote sensing images and socioeconomic data, this paper aims to fill this gap by estimating the spatial distribution characteristics of the effects of driving forces on ESs and their responses to different environmental conditions in Sichuan Province, China. First, the biophysical values of soil conservation (SC) and water yield (WY) were evaluated using ecological simulation models. Second, the spatial distribution of the effects of four driving forces on two services was explored using the geographically weighted regression (GWR) model. Finally, the responses of driving forces to environmental conditions were quantified by using scatter plots. The results revealed that the spatial patterns of SC and WY showed spatial heterogeneity. The effects of driving forces on ESs varied with space. Both positive and negative effects of driving forces were observed in Sichuan Province. Under different biophysical and socioeconomic conditions, the effects of driving forces on ESs showed different change trends, characterized by fluctuating trends and obvious thresholds. In our study area, urban sprawl, impervious surfaces, agricultural expansion, intensive human activities, and complex topographic features contributed to the variations in the effects of driving forces. Our results suggest that the responses of driving forces to different land-use coverage, topographical, NDVI, and socioeconomic conditions should be considered in ecological decision-making. Such research results are expected to manage the driving forces of ESs and serve as a practical reference for local management in order to maintain the functions of ESs and attain sustainable development.

The motivation of this fundamental research is to reveal the response of ecosystem services to land use change and to support the sustainable development of ecology, economy, and society. Considering the fragile eco-environment, intensive man-land relationship and the world-famous production base of Moutai liquor in China, we select Chishui River Basin (CRB) as the research region. In this study, the InVEST model is used to evaluate the impact of land use change on the spatial pattern of four ecosystem services including water yield, soil retention, carbon storage, and nitrogen export. Meanwhile, the spatial differentiation characteristics, service level, and trade-off using Pearson correlation analysis of each ecosystem service from 2000 to 2020 are explored. The results show the following: (1) The forest increased, while the grassland and cultivated decreased. Especially, the developed has increased greatly from [Formula: see text] to [Formula: see text]. (2) Each ecosystem service has spatio-temporal heterogeneity. The water yield and nitrogen export decreased, while soil retention and carbon storage showed an upward trend. (3) There are great differences in the level of ecosystem services among different land use types. The soil retention and carbon storage of forest are the highest, and the water yield of developed is the highest. (4) There are trade-offs and synergies among ecosystem services, such as the trade-off between water yield and soil retention is increasing, the synergetic relationship between water yield and nitrogen export is decreased. This is important evidence that the forest plays a major role in providing ecosystem services, and the improvement of watershed ecological services generally benefits from the implementation of ecological governance projects in recent years. However, it is worth noting that the frequent changes in land use and the intensification of urbanization have also brought potential risks to the local ecology. Therefore, all our preliminary results throw light on the nature of the impact of land use change on ecology and the trade-off relationship of ecosystem services, which is conducive to scientific protection of watershed ecological environment and the formulation of reasonable land use planning policies.

A comprehensive understanding of the multiple factors affecting ecosystem services (ESs) supply and demand balance is essential for effective ecosystem management and policy making. However, the importance of individual factors for ES balance is still unclear. Using Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) models and Structural Equation Modeling, I mapped the supply–demand balance of four types of ESs (carbon sequestration, water yield, soil conservation, and recreation) in Taihu Lake Basin, China, and quantified the causal relationships between multiple factors and ES balance. The results revealed spatial heterogeneity and imbalance in ES supply and demand in the basin, with the greatest imbalances in built-up city center areas. ES balance was influenced by multiple factors, but particularly normalized difference vegetation index (NDVI), elevation, precipitation, and human disturbance. For appropriate watershed management in the future, it is recommended that numbers of small-scale community parks in city centers be increased and that green space be expanded in the suburbs, implementing multi-objective ES management systems and step-by-step implementation plans, and optimizing the configuration of natural ecosystems by creating buffer strips for built-up areas. By carefully managing ES supply–demand balance and associated influencing factors, ecosystem status and human well-being in Taihu Lake Basin, and in other similar basins, can be substantially improved.

As a policy tool for advancing ecological progress, the Grain to Green Program (GTGP) has been operating for 20 years and has played an important role in improving ecosystem service value. However, there are few studies on the trade-off/synergy changes in ecosystem services during the implementation of the GTGP and how to select the optimal scheme for regional ecological security based on these trade-offs. Thus, we took the Chengdu-Chongqing urban agglomeration (CCUA) in southwestern China as the study area and estimated the regional food production, carbon sequestration, water yield, soil conservation, and habitat quality services. Then, the trade-off/synergy relationships among ecosystem services were clarified, and the influential mechanism of the GTGP on trade-off changes was evaluated. Finally, different risk scenarios were generated and the regional ecological security zone was simulated under the principle of the best protection efficiency and the highest trade-off degree. The obtained results indicated that the trade-offs/synergies of regional ecosystem services changed significantly during the implementation of the GTGP. Among them, food production, water yield, and soil conservation have always had trade-offs, while carbon sequestration, soil conservation, and habitat quality have all had synergistic relationships. The relationships between carbon sequestration and water yield and food production changed from noncorrelated to trade-off/synergistic, and the relationships between habitat quality and food production and water yield were not obvious. The GTGP has been an important factor affecting the change of trade-off intensities. On the one hand, it has strengthened the synergistic relationships among carbon sequestration, soil conservation, and habitat quality; on the other hand, it increased the constraints of water resources on soil conservation and vegetation restoration. The scenarios with a decision risk coefficient of α = 1.6 were the most suitable, and the ecological security zone corresponding to this scenario was located in the northwestern region of the study area, with high carbon sequestration and habitat quality services. In the future, the intensity or direction of the GTGP should be adjusted to solve the conflicts among ecosystem services in other areas except the northwest region.

The objective of the current study is to investigate the performance of the inclined solar panel basin still (ISPBS) incorporated with a spiral tube collector (STC) for various mass flow rates of water (mf). The maximum potable water yield of 8.1, 6.9, and 6.1 kg is obtained for different mass flow rates of 1.8, 3.2, and 4.7 kg/h in each instance. Also, for mf of 1.8, 3.2, and 4.7 kg per hour, the daily average energy and exergy efficiency of the ISPBS is recorded to be 47.9, 39.3, and 31.02 % and 9.8, 7.9, and 5.6 %, in each instance. The average electrical, thermal, and exergy efficiency of the PV panel is noted to be 6.5, 7.1, and 7.5 %; 15.67, 17.1, and 18.04 %; and 20.03, 22.21, and 23.36 % for mf of 1.8, 3.2, and 4.7 kg/h in each instance. The rise in mf causes a drop in the fresh water production yield; thermal, exergy, and overall thermal effectiveness; and an enhancement in the power production of the panel, electrical, thermal, exergy, and overall exergy efficiency of the system. Also, the cost of yield production is noted to be low-cost in AISS at minimum mf of 1.8 kg per hour (0.019 $/l) when compared to the other two mf of 3.2 and 4.7 kg per hour (0.022 and 0.025 $/l).

Land use and land cover changes associated with urbanization have had a significant influence on ecosystem services (ESs), but previous studies have insufficiently focused on the relationships between ES supply and demand; these relationships are seldom considered in the science-policy frameworks of land use planning. In this study, a specific supply-demand indicator was constructed to measure ES supply and demand and their disparity across multiple scales in Jiangsu Province from 2000 to 2018. High spatial heterogeneity and mismatches of ES supply and demand were found in water yield, grain production, carbon sequestration, soil conservation, heat regulation, and recreation services. At provincial scale, the supplies of carbon sequestration and heat regulation services were smaller than their demands. At the 1-km² grid scale, the ES supply and demand mismatches in urban areas were more serious than those in surrounding areas, especially for carbon sequestration and recreation services. Five ES supply-demand risk zones were identified based on the current status and trends of all ES supply and demand. Southern Jiangsu generally had high risks of ES mismatch, which should be reduced by strategic planning. Constructing the ES supply-demand indicator is a novel practice that assists in evaluating environmental issues and integrating them into further development decisions. This paper suggests that governments should reduce ES mismatches with reference to local conditions (economic development, industrial type, and ecological carrying capacity) and the actual situation of ES supply and demand.