The Ili River Delta(IRD)is an ecological security barrier for the Lake Balkhash and an important water conservation area in Central Asia.In this study,we selected the IRD as a typical research area,and simulated the w...The Ili River Delta(IRD)is an ecological security barrier for the Lake Balkhash and an important water conservation area in Central Asia.In this study,we selected the IRD as a typical research area,and simulated the water yield and water conservation from 1975 to 2020 using the water yield module of the Integrated Valuation of Ecosystem Services and Tradeoffs(InVEST)model.We further analyzed the temporal and spatial variations in the water yield and water conservation in the IRD from 1975 to 2020,and investigated the main driving factors(precipitation,potential evapotranspiration,land use/land cover change,and inflow from the Ili River)of the water conservation variation based on the linear regression,piecewise linear regression,and Pearson's correlation coefficient analyses.The results indicated that from 1975 to 2020,the water yield and water conservation in the IRD showed a decreasing trend,and the spatial distribution pattern was"high in the east and low in the west";overall,the water conservation of all land use types decreased slightly.The water conservation volume of grassland was the most reduced,although the area of grassland increased owing to the increased inflow from the Ili River.At the same time,the increased inflow has led to the expansion of wetland areas,the improvement of vegetation growth,and the increase of regional evapotranspiration,thus resulting in an overall reduction in the water conservation.The water conservation depth and precipitation had similar spatial distribution patterns;the change in climate factors was the main reason for the decline in the water conservation function in the delta.The reservoir in the upper reaches of the IRD regulated runoff into the Lake Balkhash,promoted vegetation restoration,and had a positive effect on the water conservation;however,this positive effect cannot offset the negative effect of enhanced evapotranspiration.These results provide a reference for the rational allocation of water resources and ecosystem protection in the IRD.展开更多
The purpose of this study is to investigate mass valuation of unimproved land value using machine learning techniques. The study was conducted in Nairobi County. It is one of the 47 Kenyan Counties under the 2010 cons...The purpose of this study is to investigate mass valuation of unimproved land value using machine learning techniques. The study was conducted in Nairobi County. It is one of the 47 Kenyan Counties under the 2010 constitution. A total of 1440 geocoded data points containing the market selling price of vacant land in Nairobi were web scraped from major property listing websites. These data points were adopted as dependent variables given as unit price of vacant land per square meter. The Covariates used in this study were categorized into Accessibility, Environmental, Physical and Socio-Economic Factors. Due to multi-collinearity problem present in the covariates, PLS and PCA methods were adopted to transform the observed features using a set of vectors. These methods resulted in an uncorrelated set of components that were used in training machine learning algorithms. The dependent variable and uncorrelated components derived feature reduction methods were used as training data for training different machine learning regression models namely;Random forest, support vector regression and extreme gradient boosting regression (XGboost regression). PLS performed better than PCA because the former maximizes the covariance between dependent and independent variables while the latter maximizes variance between the independent variables only and ignores the relationship between predictors and response. The first 9 components were identified as significant both by PLS and PCA methods. The spatial distribution of vacant land value within Nairobi County was consistent for all the three machine learning models. It was also noted that the land value pattern was higher in the central business district and the pattern spread northwards and westwards relative to the CBD. A relative low vacant land value pattern was observed on the eastern side of the county and also at the extreme periphery of Nairobi County boundary. From the accuracy metrics of R-squared and MAPE, Random Forest Regression model performed better than XGBoost and SVR models. This confirms the capability of random forest model to predict valid estimates of vacant land value for purposes of property taxation in Nairobi County.展开更多
Economic valuation of ecosystems is increasingly being recognized as an important exercise to inform sustainable utilization and conservation of natural assets. It helps in planning and establishing fair profit margin...Economic valuation of ecosystems is increasingly being recognized as an important exercise to inform sustainable utilization and conservation of natural assets. It helps in planning and establishing fair profit margins that accrue either directly or indirectly from the consumptive and non-consumptive uses of ecosystem goods and services. This paper is based on a study which estimated the economic values of tourist hunting blocks (HBs) in Tanzania using the Analytic Multicriteria Valuation Method (AMUVAM). The study used a sample size of 12 out of 24 vacant hunting blocks which were to be auctioned to potential hunting companies in December 2022. The economic values of HBs were estimated using the time horizon of 10 years (the mean tenure for winning company). The results show that the economic values ranged from USD 6,215,588 to USD 653,470,695 per hunting block and the Existence Value (EV) constituted about 19% of the Total Economic Value (TEV). EV ranged from USD 632,210 to USD 125,147,285. The study underscores the need for decisions to allocate ecosystems, such as HBs, to both direct and indirect uses, to be guided by a though understanding of their values. We further recommend building the capacity of staff charged with the role of managing and allocating uses of these ecosystems to enable them undertake economic valuation of ecosystems using both simple and more robust analytical tools, such as the GIS, relational databases, and worldwide websites based tools, like InVEST (Integrated Valuation of Environmental Services and Tradeoffs), ARIES (Artificial Intelligence for Ecosystem Services), and Co$ting Nature.展开更多
The value of a statistical life(VSL)is a crucial tool for monetizing health impacts.To explore the VSL in China,this study examines people’s willingness to pay(WTP)to reduce death risk from air pollution in six repre...The value of a statistical life(VSL)is a crucial tool for monetizing health impacts.To explore the VSL in China,this study examines people’s willingness to pay(WTP)to reduce death risk from air pollution in six representative cities in China based on face-to-face contingent valuation interviews(n=3936)from March 7,2019 to September 30,2019.The results reveal that the WTP varied from CNY 455 to 763 in 2019(USD 66-111),corresponding to a VSL range of CNY 3.79-6.36 million(USD 549395-921940).The VSL in China in 2019 is estimated to be CNY 4.76 million(USD 689659).The statistics indicate that monthly expenditure levels,environmental concerns,risk attitudes,and assumed market acceptance,which have seldom been dis‐cussed in previous studies,significantly impact WTP and VSL.These findings will serve as a reference for ana‐lyzing mortality risk reduction benefits in future research and for policymaking.展开更多
Karst environmental issues have become one of the hot spots in contemporary international geological research. The same problem of water shortage is one of the hot spots of global concern. The peak-cluster depression ...Karst environmental issues have become one of the hot spots in contemporary international geological research. The same problem of water shortage is one of the hot spots of global concern. The peak-cluster depression basins in southwest of Guangxi is an important water connotation and ecological barrier areas in the Pearl River Basin of China. Thus, studying the spatial and temporal variations and the influencing factors of its water yield services is critical to achieve the sustainable development of water resources and ecological environmental protection in this region. As such, this paper uses the Integrated Valuation of Ecosystem Services and Tradeoffs(InVEST) model to assess the spatial and temporal variabilities of water yield services and its trends in the peak-cluster depression basins in southwest of Guangxi from 2000 to 2020. This work also integrates precipitation(Pre), reference evapotranspiration(ET), temperature(Tem), digital elevation model(DEM), slope, normalized difference vegetation index(NDVI), land use/land cover(LULC) and soil type to reveal the main factors that influence water yield services with the help of Geodetector. Results show that: 1) in time scale,the total annual water yield in the study area show a fluctuating and increasing trend from 2000 to 2020, with a growth rate of 7.3753 × 10^(8)m^(3)/yr, and its multi-year average water yield was 538.07 mm;2) in spatial pattern, with high yield areas mainly distributed in the south of the study area(mainly including Shangsi County, Pingxiang City, Ningming County, Longzhou County and Jingxi County), and low yield areas mainly distributed in Baise City and Nanning City;3) the dominant factor of water yield within karst and non-karst landforms is not necessarily controlled by precipitation, and the explanation degree of DEM factors in karst areas is significantly higher than that in non-karst areas;4) amongst the climatic factors, Pre, ET and Tem are dominant in the spatial pattern of region water yield capacity. among which Pre has the highest explanatory power for the spatial heterogeneity of annual water production, with q values above0.8, and each driver showed a significant interaction on the spatial distribution of water yield, with Pre exhibiting the strongest interaction with LULC.展开更多
To better promote forest resource management and strengthen the development of forest carbon sink marketization, this paper studied the accounting of forest carbon sinks from 2003 to 2008 based on a system of national...To better promote forest resource management and strengthen the development of forest carbon sink marketization, this paper studied the accounting of forest carbon sinks from 2003 to 2008 based on a system of national accounts (SNA) and data from the latest forest resources inventory in China. The study calculated the value of forest carbon stocks at a total of RMB 817.13 × 10^9 yuan in 2003 and RMB 839.93×10^9 yuan in 2008, with an average annual increase of 0.55 % from an increase in physical carbon sinks. The total value of forest carbon sinks in 2003 and 2008 was RMB 26.73×10^9 yuan and RMB 29.77×10^9 yuan, respectively, with an average annual growth of 2.18 %. From 2003 to 2008, both stock and flow value of forest carbon sinks increased, but the total net flow value of carbon sinks decreased. The growth rate for the environmentally adjusted Gross Domestic Product (eaGDP) for China's forest carbon sinks was 17.23 %, outstripping the average growth rate of 9.5 % for the GDP during the same period. The study alsoindicates that China's forest carbon sinks affects the GDP in the range of 0.25-0.26 %, and its economic potential is not relatively huge.展开更多
Background: Around 2000 plant species occur naturally in Lorestan Province of which 250 species are medicinal and myrtle is one of them. Myrtle is a shrub whose leaves and fruits have medicinal value and thus, if man...Background: Around 2000 plant species occur naturally in Lorestan Province of which 250 species are medicinal and myrtle is one of them. Myrtle is a shrub whose leaves and fruits have medicinal value and thus, if managed and harvested properly, could produce sustained economic benefits. In recent years, however, over half of the myrtle site areas was destroyed, due to inappropriate management and excessive harvesting practices. Thus, coming up with a practical harvesting approach along with identifying those factors damaging the sites, seems to be very crucial. Methods: In our investigation, we calculated the conservation value per hectare of myrtle in the Dooreh forest area in Lorestan Province. Using the Contingent Valuation (CV) and Double Bounded Dichotomous Choice (DBDC) methods, we determined the willingness to pay (VVTP) for myrtle conservation. The VVTP was estimated with a Iogit model for which indices were obtained based on a maximum precision criterion. Results: The results showed that 86.67 per cent of people were willing to pay for the conservation of these myrtle sites. Average monthly WTP per family was calculated as $0.79. The annual conservation value in terms of WTP for the preservation of the myrtle sites in Dooreh was estimated as $102,525. Among the variables of the model presented, education had a positive impact, while the amount proposed for payment and family size had a negative impact on the WTP. Conclusions: Our estimate of the value of myrtle conservation should provide justification for policy makers and decision making bodies of natural resources to implement policies in order to conserve the natural sites of this species more effectively.展开更多
This paper introduces a real option approach to valuation of oil companies and uses the real option pricing model to value CNOOC Ltd. at the time of its IPO. The empirical result shows that the option pricing value of...This paper introduces a real option approach to valuation of oil companies and uses the real option pricing model to value CNOOC Ltd. at the time of its IPO. The empirical result shows that the option pricing value of CNOOC Ltd. exceeds its IPO price at about 21%.展开更多
Human pressure on mountain resources poses certain threats to their natural and man-made environment. Although there are many parameters involved, one of the driving forces behind this situation is the emphasis given ...Human pressure on mountain resources poses certain threats to their natural and man-made environment. Although there are many parameters involved, one of the driving forces behind this situation is the emphasis given so far only to the market value of mountain goods and services, ignoring the true social and environmental costs of using mountain resources. Towards this direction, the use of non-market valuation techniques could prove to be beneficial. Bearing in mind the above remarks, the paper presents an application of the Contingent Valuation Method, which aims at estimating the monetary value of a mountain settlement’s vernacular architecture, namely Metsovo. For this purpose, the survey focuses on Metsovo visitors’ willingness to pay a single annual voluntary contribution to an institution that would be founded in order to undertake all necessary actions required to preserve the town’s traditional character. The results are very promising and indicate that vernacular architecture holds a significant economic value that could justify the implementation of appropriate policies towards the protection of vernacular settlements in mountain areas.展开更多
In order to characterize and enhance clay collected in Londéla-kayes in the Republic of Congo, in this work, it was a question of proceeding to the mineralogical, physico-chemical, thermal and geotechnical charac...In order to characterize and enhance clay collected in Londéla-kayes in the Republic of Congo, in this work, it was a question of proceeding to the mineralogical, physico-chemical, thermal and geotechnical characterization of this clay. Next, determine the technological properties of fired bricks. For this, various methods were used in particular: X-ray diffraction, infrared spectroscopy, gravimetric thermal analysis and differential thermal analysis, dilatometric analysis, scanning electron microscopy, specific surface and analysis chemical. It appears that, for the mineralogical characterization, kaolinite is the most abundant mineral of this clay. The results of dilatometric analysis have shown that this clay can be fired at low temperatures. The geotechnical characterization showed that it is plastic clay thus exhibiting a high shrinkage. The results of the technological properties of LON1 bricks have shown that this clay cannot be used in the manufacture of fired bricks. The geotechnical properties must be improved by adding additives in order to improve the technological properties of the fired bricks.展开更多
The concept of implicative pseudo valuations on hoops is introduced and some related properties are investigated. As an application of properties of pseudo valuations, we find the relationship between a pseudo valuati...The concept of implicative pseudo valuations on hoops is introduced and some related properties are investigated. As an application of properties of pseudo valuations, we find the relationship between a pseudo valuation and an implicative pseudo valuation and obtain some characterizations of implicative pseudo valuations. In particular, we show that a pseudo valuation on regular hoops is implicative if and only if it satisfies φ(x■x') = 0.This result will provide a more general algebraic foundation for pseudo valuations theory on algebraic structures based on substructure logic.展开更多
BACKGROUND Due to improvements in living standards,people are now paying more attention to their health.In China,more patients choose to go to large or well-known hospitals,which leads to constant crowding of outpatie...BACKGROUND Due to improvements in living standards,people are now paying more attention to their health.In China,more patients choose to go to large or well-known hospitals,which leads to constant crowding of outpatient clinics in these hospitals.AIM To establish precision valuation reservation registration aimed at shortening waiting time,improving patient experience and promoting the satisfaction of outpatients and medical staff.METHODS On the basis of the implementation of a conventional appointment system,more reasonable time intervals were set for different doctors by evaluating the actual capacity of each doctor to receive patients,and appointment times were made more accurate through intervention.The change in consultation waiting time of patients was then compared.Correlations between the consultation waiting time of patients and the satisfaction of patients or satisfaction of medical staff were analyzed.RESULTS After precision valuation reservation registration,the average consultation waiting time of patients reduced from 18.47 min to 10.11 min(t=8.90,P<0.001).The satisfaction score of patients increased from 91.33 to 96.27(t=-8.62,P<0.001),and the satisfaction score of medical staff increased from 90.51 to 96.04(t=-10.50,P<0.001).The consultation waiting time of patients was negatively correlated with their satisfaction scores(γ=-0.89,P<0.001).The consultation waiting time of patients was also negatively correlated with medical staff satisfaction scores(γ=-0.96,P<0.001).CONCLUSION Precision valuation reservation registration significantly shortened outpatient waiting times and improve the satisfaction of not only patients but also medical staff.This approach played an important role in improving outpatient services,provided a model that is supported by relevant evidence and could continuously improve the quality of management.Precision valuation reservation registration is worth promoting and applying in the clinic.展开更多
Natural resources and its condition have always had a key role in economic and social developments of different societies around the world and these resources are considered as natural capital and bankroll of economic...Natural resources and its condition have always had a key role in economic and social developments of different societies around the world and these resources are considered as natural capital and bankroll of economic growth and development for every country. In the present study, we have evaluated the outdoor recreational value of Lavizan Jungle Park of Tehran and its visitors’ willingness to pay per visit (WTP) by using Contingent Valuation method (CV) and two-dimensional choice questionnaires. We used 125 questionnaires and logit model in order to evaluate the WTP. The purpose of this study is to measure individuals’ willingness to pay for visiting and preserving the environment of Lavizan Park as well as indicating the relationship between influential factors on their WTP. Estimating the value of natural resources is very important in making environmental preservation policies because preserving these natural attractions, as a part of ecotourism, is highly important. JEL Classification: Q29, Q51, C25.展开更多
In higher engineering education,professional courses and ideological and political theory courses go in the same direction,which is an important task of the current professional curriculum construction.This paper intr...In higher engineering education,professional courses and ideological and political theory courses go in the same direction,which is an important task of the current professional curriculum construction.This paper introduces the key and difficult problems in the teaching content of the course Engineering Valuation in the Department of Engineering Management and Real Estate of Jiangxi Normal University.Based on the characteristics of simulation information technology such as BIM and VR and the differences of ideological and political elements,it updates and improves the cases of courses for ideological and political education,gives full play to the synergistic effect,and realizes the"triple"talent training goal of knowledge,ability and literacy.展开更多
Ecosystem services valuation seeks to increase the social relevance of ecosystem characteristics, the underlying biological mechanisms that support services, by making the contribution of ecosystems to human well-bein...Ecosystem services valuation seeks to increase the social relevance of ecosystem characteristics, the underlying biological mechanisms that support services, by making the contribution of ecosystems to human well-being explicit. Economic valuation can help management by clarifying the full range of benefits and costs of proposed management actions. In the past two decades, economic valuation of wetland ecosystem services has become one of the most significant scientific priorities for wetland protection. In this paper, we provide an overview of ecosystem services, and summarize the main interdisciplinary approaches to measure and value wetland ecosystem services. We identified four main methodological gaps preventing progress on wetland valuation of ecosystem services in China, which are: 1) confusion on terminology like intermediate and final ecosystem services, 2) lack of ecological production functions to link ecosystem characteristics to final ecosystem services, 3) static valuation making it difficult to evaluate the trade-offs and synergies among ecosystem services, and 4) lack of clear guidance on relating ecological compensation programs to conservation targets. Overcoming these gaps is important to inform wetland compensation mechanisms and conservation policies. We propose future research on wetland ecosystem services in China should be focused on: 1) defining final ecosystem services based on beneficiary preferences and underlying biophysical mechanisms, 2) establishing wetland monitoring programs at specific sites to collect data on final ecosystem service indicators and ecosystem characteristic metrics to create ecological production functions for economic valuation and rescaling techniques, and 3) incorporating wetland ecosystem service values into decision-making processes to inform wetland management.展开更多
In light of the practical need for research to inform policy in Beijing,this study evaluates the economic cost of the impact of PM 10 pollution in Beijing from 2001 to 2006,taking health as the main impact,and mortali...In light of the practical need for research to inform policy in Beijing,this study evaluates the economic cost of the impact of PM 10 pollution in Beijing from 2001 to 2006,taking health as the main impact,and mortality as the main outcome.Based on the literature review,this study adopts relatively conservative parameters as the basis for calculating the health impacts.It concludes that nearly 30%of mortality among registered residents above age 30 in Beijing can be attributed to PM 10 pollution,and that the economic cost equals 0.8%-1.2%of the city's GDP over the same period.This is lower than the results of previous studies,but still high enough to warrant a commitment to solve the city's air pollution problem.展开更多
Ideas and methods of evaluating economic benefit of regulatory detailed planning were introduced firstly,and then the framework and concrete steps of valuation of economic benefit of regulatory detailed planning were ...Ideas and methods of evaluating economic benefit of regulatory detailed planning were introduced firstly,and then the framework and concrete steps of valuation of economic benefit of regulatory detailed planning were analyzed.Afterwards,the economic benefit of regulatory detailed planning was valued by using case analysis method.Finally,some suggestions of application were proposed,such as introducing the valuation of economic benefit of a third party into the adjustment scheme of regulatory detailed planning,and publicizing the scheme of regulatory detailed planning and valuation results at the same time.展开更多
In the asset valuation of oil and gas reserves, it is discovered that the production decline trend of wells is not very obvious and that it is hard to make a production forecast matching the production history, thus r...In the asset valuation of oil and gas reserves, it is discovered that the production decline trend of wells is not very obvious and that it is hard to make a production forecast matching the production history, thus resulting in a significant deviation of oil and gas asset value. For production with a significant fluctuation, the value deviation is also considerable if the matching production, which is predicted with classical decline methods, cannot appropriately reflect the time value distribution of actual production. To mitigate such a deviation, a concept is proposed concerning the value constrained production forecast and the value constrained production decline model is developed. A field case is demonstrated as an application of such a model. The model can significantly decrease the risk in the value deviation of a production decline analysis and be applied to the production forecasts for a single well, well clusters, blocks or field scale, and even for other mining industries.展开更多
In this paper, firstly, a necessary condition and a sufficient condition for an isomorphism between two semiring-induced valuation algebras to exist are presented respectively. Then a general valuation homomorphism ba...In this paper, firstly, a necessary condition and a sufficient condition for an isomorphism between two semiring-induced valuation algebras to exist are presented respectively. Then a general valuation homomorphism based on different domains is defined, and the corresponding homomorphism theorem of valuation algebra is proved.展开更多
In this paper we show that if R is a discrete valuation ring, then R is a filtered ring. We prove some properties and relation when R is a discrete valuation ring.
基金funded by the National Natural Science Foundation of China(42071245)the Xinjiang Uygur Autonomous Region Innovation Environment Construction Special Project&Science and Technology Innovation Base Construction Project(PT2107)+2 种基金the Third Xinjiang Comprehensive Scientific Survey Project Sub-topic(2021xjkk140305)the Tianshan Talent Training Program of Xinjiang Uygur Autonomous Region(2022TSYCLJ0011)the K.C.Wong Education Foundation(GJTD-2020-14).
文摘The Ili River Delta(IRD)is an ecological security barrier for the Lake Balkhash and an important water conservation area in Central Asia.In this study,we selected the IRD as a typical research area,and simulated the water yield and water conservation from 1975 to 2020 using the water yield module of the Integrated Valuation of Ecosystem Services and Tradeoffs(InVEST)model.We further analyzed the temporal and spatial variations in the water yield and water conservation in the IRD from 1975 to 2020,and investigated the main driving factors(precipitation,potential evapotranspiration,land use/land cover change,and inflow from the Ili River)of the water conservation variation based on the linear regression,piecewise linear regression,and Pearson's correlation coefficient analyses.The results indicated that from 1975 to 2020,the water yield and water conservation in the IRD showed a decreasing trend,and the spatial distribution pattern was"high in the east and low in the west";overall,the water conservation of all land use types decreased slightly.The water conservation volume of grassland was the most reduced,although the area of grassland increased owing to the increased inflow from the Ili River.At the same time,the increased inflow has led to the expansion of wetland areas,the improvement of vegetation growth,and the increase of regional evapotranspiration,thus resulting in an overall reduction in the water conservation.The water conservation depth and precipitation had similar spatial distribution patterns;the change in climate factors was the main reason for the decline in the water conservation function in the delta.The reservoir in the upper reaches of the IRD regulated runoff into the Lake Balkhash,promoted vegetation restoration,and had a positive effect on the water conservation;however,this positive effect cannot offset the negative effect of enhanced evapotranspiration.These results provide a reference for the rational allocation of water resources and ecosystem protection in the IRD.
文摘The purpose of this study is to investigate mass valuation of unimproved land value using machine learning techniques. The study was conducted in Nairobi County. It is one of the 47 Kenyan Counties under the 2010 constitution. A total of 1440 geocoded data points containing the market selling price of vacant land in Nairobi were web scraped from major property listing websites. These data points were adopted as dependent variables given as unit price of vacant land per square meter. The Covariates used in this study were categorized into Accessibility, Environmental, Physical and Socio-Economic Factors. Due to multi-collinearity problem present in the covariates, PLS and PCA methods were adopted to transform the observed features using a set of vectors. These methods resulted in an uncorrelated set of components that were used in training machine learning algorithms. The dependent variable and uncorrelated components derived feature reduction methods were used as training data for training different machine learning regression models namely;Random forest, support vector regression and extreme gradient boosting regression (XGboost regression). PLS performed better than PCA because the former maximizes the covariance between dependent and independent variables while the latter maximizes variance between the independent variables only and ignores the relationship between predictors and response. The first 9 components were identified as significant both by PLS and PCA methods. The spatial distribution of vacant land value within Nairobi County was consistent for all the three machine learning models. It was also noted that the land value pattern was higher in the central business district and the pattern spread northwards and westwards relative to the CBD. A relative low vacant land value pattern was observed on the eastern side of the county and also at the extreme periphery of Nairobi County boundary. From the accuracy metrics of R-squared and MAPE, Random Forest Regression model performed better than XGBoost and SVR models. This confirms the capability of random forest model to predict valid estimates of vacant land value for purposes of property taxation in Nairobi County.
文摘Economic valuation of ecosystems is increasingly being recognized as an important exercise to inform sustainable utilization and conservation of natural assets. It helps in planning and establishing fair profit margins that accrue either directly or indirectly from the consumptive and non-consumptive uses of ecosystem goods and services. This paper is based on a study which estimated the economic values of tourist hunting blocks (HBs) in Tanzania using the Analytic Multicriteria Valuation Method (AMUVAM). The study used a sample size of 12 out of 24 vacant hunting blocks which were to be auctioned to potential hunting companies in December 2022. The economic values of HBs were estimated using the time horizon of 10 years (the mean tenure for winning company). The results show that the economic values ranged from USD 6,215,588 to USD 653,470,695 per hunting block and the Existence Value (EV) constituted about 19% of the Total Economic Value (TEV). EV ranged from USD 632,210 to USD 125,147,285. The study underscores the need for decisions to allocate ecosystems, such as HBs, to both direct and indirect uses, to be guided by a though understanding of their values. We further recommend building the capacity of staff charged with the role of managing and allocating uses of these ecosystems to enable them undertake economic valuation of ecosystems using both simple and more robust analytical tools, such as the GIS, relational databases, and worldwide websites based tools, like InVEST (Integrated Valuation of Environmental Services and Tradeoffs), ARIES (Artificial Intelligence for Ecosystem Services), and Co$ting Nature.
基金supported by the National Natural Science Foun‐dation of China[Grant No.71773061].
文摘The value of a statistical life(VSL)is a crucial tool for monetizing health impacts.To explore the VSL in China,this study examines people’s willingness to pay(WTP)to reduce death risk from air pollution in six representative cities in China based on face-to-face contingent valuation interviews(n=3936)from March 7,2019 to September 30,2019.The results reveal that the WTP varied from CNY 455 to 763 in 2019(USD 66-111),corresponding to a VSL range of CNY 3.79-6.36 million(USD 549395-921940).The VSL in China in 2019 is estimated to be CNY 4.76 million(USD 689659).The statistics indicate that monthly expenditure levels,environmental concerns,risk attitudes,and assumed market acceptance,which have seldom been dis‐cussed in previous studies,significantly impact WTP and VSL.These findings will serve as a reference for ana‐lyzing mortality risk reduction benefits in future research and for policymaking.
基金Under the auspices of National Natural Science Foundation of China (No. 42061020)Natural Science Foundation of Guangxi Zhuang Autonomous Region (No. 2018JJA150135)+3 种基金Guangxi Key Research and Development Program (No. AA18118038)Science and Technology Department of Guangxi Zhuang Autonomous Region (No. 2019AC20088)The Program of Improving the Basic Research Ability of Young and Middle-aged Teachers in Guangxi Universities (No. 2021KY0431)High Level Talent Introduction Project of Beibu Gulf University (No. 2019KYQD28)。
文摘Karst environmental issues have become one of the hot spots in contemporary international geological research. The same problem of water shortage is one of the hot spots of global concern. The peak-cluster depression basins in southwest of Guangxi is an important water connotation and ecological barrier areas in the Pearl River Basin of China. Thus, studying the spatial and temporal variations and the influencing factors of its water yield services is critical to achieve the sustainable development of water resources and ecological environmental protection in this region. As such, this paper uses the Integrated Valuation of Ecosystem Services and Tradeoffs(InVEST) model to assess the spatial and temporal variabilities of water yield services and its trends in the peak-cluster depression basins in southwest of Guangxi from 2000 to 2020. This work also integrates precipitation(Pre), reference evapotranspiration(ET), temperature(Tem), digital elevation model(DEM), slope, normalized difference vegetation index(NDVI), land use/land cover(LULC) and soil type to reveal the main factors that influence water yield services with the help of Geodetector. Results show that: 1) in time scale,the total annual water yield in the study area show a fluctuating and increasing trend from 2000 to 2020, with a growth rate of 7.3753 × 10^(8)m^(3)/yr, and its multi-year average water yield was 538.07 mm;2) in spatial pattern, with high yield areas mainly distributed in the south of the study area(mainly including Shangsi County, Pingxiang City, Ningming County, Longzhou County and Jingxi County), and low yield areas mainly distributed in Baise City and Nanning City;3) the dominant factor of water yield within karst and non-karst landforms is not necessarily controlled by precipitation, and the explanation degree of DEM factors in karst areas is significantly higher than that in non-karst areas;4) amongst the climatic factors, Pre, ET and Tem are dominant in the spatial pattern of region water yield capacity. among which Pre has the highest explanatory power for the spatial heterogeneity of annual water production, with q values above0.8, and each driver showed a significant interaction on the spatial distribution of water yield, with Pre exhibiting the strongest interaction with LULC.
基金supported by National Key Social Science Research Project(11&ZD042)Forestry Public Welfare Scientific Research Project of the State Forestry Administration in China(200904003)DAAD-K.C.Wong Postdoctoral Fellowship Programme,Germany
文摘To better promote forest resource management and strengthen the development of forest carbon sink marketization, this paper studied the accounting of forest carbon sinks from 2003 to 2008 based on a system of national accounts (SNA) and data from the latest forest resources inventory in China. The study calculated the value of forest carbon stocks at a total of RMB 817.13 × 10^9 yuan in 2003 and RMB 839.93×10^9 yuan in 2008, with an average annual increase of 0.55 % from an increase in physical carbon sinks. The total value of forest carbon sinks in 2003 and 2008 was RMB 26.73×10^9 yuan and RMB 29.77×10^9 yuan, respectively, with an average annual growth of 2.18 %. From 2003 to 2008, both stock and flow value of forest carbon sinks increased, but the total net flow value of carbon sinks decreased. The growth rate for the environmentally adjusted Gross Domestic Product (eaGDP) for China's forest carbon sinks was 17.23 %, outstripping the average growth rate of 9.5 % for the GDP during the same period. The study alsoindicates that China's forest carbon sinks affects the GDP in the range of 0.25-0.26 %, and its economic potential is not relatively huge.
文摘Background: Around 2000 plant species occur naturally in Lorestan Province of which 250 species are medicinal and myrtle is one of them. Myrtle is a shrub whose leaves and fruits have medicinal value and thus, if managed and harvested properly, could produce sustained economic benefits. In recent years, however, over half of the myrtle site areas was destroyed, due to inappropriate management and excessive harvesting practices. Thus, coming up with a practical harvesting approach along with identifying those factors damaging the sites, seems to be very crucial. Methods: In our investigation, we calculated the conservation value per hectare of myrtle in the Dooreh forest area in Lorestan Province. Using the Contingent Valuation (CV) and Double Bounded Dichotomous Choice (DBDC) methods, we determined the willingness to pay (VVTP) for myrtle conservation. The VVTP was estimated with a Iogit model for which indices were obtained based on a maximum precision criterion. Results: The results showed that 86.67 per cent of people were willing to pay for the conservation of these myrtle sites. Average monthly WTP per family was calculated as $0.79. The annual conservation value in terms of WTP for the preservation of the myrtle sites in Dooreh was estimated as $102,525. Among the variables of the model presented, education had a positive impact, while the amount proposed for payment and family size had a negative impact on the WTP. Conclusions: Our estimate of the value of myrtle conservation should provide justification for policy makers and decision making bodies of natural resources to implement policies in order to conserve the natural sites of this species more effectively.
文摘This paper introduces a real option approach to valuation of oil companies and uses the real option pricing model to value CNOOC Ltd. at the time of its IPO. The empirical result shows that the option pricing value of CNOOC Ltd. exceeds its IPO price at about 21%.
文摘Human pressure on mountain resources poses certain threats to their natural and man-made environment. Although there are many parameters involved, one of the driving forces behind this situation is the emphasis given so far only to the market value of mountain goods and services, ignoring the true social and environmental costs of using mountain resources. Towards this direction, the use of non-market valuation techniques could prove to be beneficial. Bearing in mind the above remarks, the paper presents an application of the Contingent Valuation Method, which aims at estimating the monetary value of a mountain settlement’s vernacular architecture, namely Metsovo. For this purpose, the survey focuses on Metsovo visitors’ willingness to pay a single annual voluntary contribution to an institution that would be founded in order to undertake all necessary actions required to preserve the town’s traditional character. The results are very promising and indicate that vernacular architecture holds a significant economic value that could justify the implementation of appropriate policies towards the protection of vernacular settlements in mountain areas.
文摘In order to characterize and enhance clay collected in Londéla-kayes in the Republic of Congo, in this work, it was a question of proceeding to the mineralogical, physico-chemical, thermal and geotechnical characterization of this clay. Next, determine the technological properties of fired bricks. For this, various methods were used in particular: X-ray diffraction, infrared spectroscopy, gravimetric thermal analysis and differential thermal analysis, dilatometric analysis, scanning electron microscopy, specific surface and analysis chemical. It appears that, for the mineralogical characterization, kaolinite is the most abundant mineral of this clay. The results of dilatometric analysis have shown that this clay can be fired at low temperatures. The geotechnical characterization showed that it is plastic clay thus exhibiting a high shrinkage. The results of the technological properties of LON1 bricks have shown that this clay cannot be used in the manufacture of fired bricks. The geotechnical properties must be improved by adding additives in order to improve the technological properties of the fired bricks.
基金Supported by a grant of National Natural Science Foundation of China(11571281)
文摘The concept of implicative pseudo valuations on hoops is introduced and some related properties are investigated. As an application of properties of pseudo valuations, we find the relationship between a pseudo valuation and an implicative pseudo valuation and obtain some characterizations of implicative pseudo valuations. In particular, we show that a pseudo valuation on regular hoops is implicative if and only if it satisfies φ(x■x') = 0.This result will provide a more general algebraic foundation for pseudo valuations theory on algebraic structures based on substructure logic.
文摘BACKGROUND Due to improvements in living standards,people are now paying more attention to their health.In China,more patients choose to go to large or well-known hospitals,which leads to constant crowding of outpatient clinics in these hospitals.AIM To establish precision valuation reservation registration aimed at shortening waiting time,improving patient experience and promoting the satisfaction of outpatients and medical staff.METHODS On the basis of the implementation of a conventional appointment system,more reasonable time intervals were set for different doctors by evaluating the actual capacity of each doctor to receive patients,and appointment times were made more accurate through intervention.The change in consultation waiting time of patients was then compared.Correlations between the consultation waiting time of patients and the satisfaction of patients or satisfaction of medical staff were analyzed.RESULTS After precision valuation reservation registration,the average consultation waiting time of patients reduced from 18.47 min to 10.11 min(t=8.90,P<0.001).The satisfaction score of patients increased from 91.33 to 96.27(t=-8.62,P<0.001),and the satisfaction score of medical staff increased from 90.51 to 96.04(t=-10.50,P<0.001).The consultation waiting time of patients was negatively correlated with their satisfaction scores(γ=-0.89,P<0.001).The consultation waiting time of patients was also negatively correlated with medical staff satisfaction scores(γ=-0.96,P<0.001).CONCLUSION Precision valuation reservation registration significantly shortened outpatient waiting times and improve the satisfaction of not only patients but also medical staff.This approach played an important role in improving outpatient services,provided a model that is supported by relevant evidence and could continuously improve the quality of management.Precision valuation reservation registration is worth promoting and applying in the clinic.
文摘Natural resources and its condition have always had a key role in economic and social developments of different societies around the world and these resources are considered as natural capital and bankroll of economic growth and development for every country. In the present study, we have evaluated the outdoor recreational value of Lavizan Jungle Park of Tehran and its visitors’ willingness to pay per visit (WTP) by using Contingent Valuation method (CV) and two-dimensional choice questionnaires. We used 125 questionnaires and logit model in order to evaluate the WTP. The purpose of this study is to measure individuals’ willingness to pay for visiting and preserving the environment of Lavizan Park as well as indicating the relationship between influential factors on their WTP. Estimating the value of natural resources is very important in making environmental preservation policies because preserving these natural attractions, as a part of ecotourism, is highly important. JEL Classification: Q29, Q51, C25.
基金The Teaching Reform Project in Jiangxi Province-the Application of BIM Simulation Information Technology in the Teaching of Engineering Valuation Course Group(JXJG-19-2-48)Jiangxi Educational Planning Project-Research on the Realization of Synergistic Effect of BIM and MOOC in Higher Engineering Education(16YB014).
文摘In higher engineering education,professional courses and ideological and political theory courses go in the same direction,which is an important task of the current professional curriculum construction.This paper introduces the key and difficult problems in the teaching content of the course Engineering Valuation in the Department of Engineering Management and Real Estate of Jiangxi Normal University.Based on the characteristics of simulation information technology such as BIM and VR and the differences of ideological and political elements,it updates and improves the cases of courses for ideological and political education,gives full play to the synergistic effect,and realizes the"triple"talent training goal of knowledge,ability and literacy.
基金Under the auspices of Forestry Nonprofit Industry Scientific Research Special Project(No.201204201)National Key Technology Research and Development Program of China(No.2011BAJ07B05)
文摘Ecosystem services valuation seeks to increase the social relevance of ecosystem characteristics, the underlying biological mechanisms that support services, by making the contribution of ecosystems to human well-being explicit. Economic valuation can help management by clarifying the full range of benefits and costs of proposed management actions. In the past two decades, economic valuation of wetland ecosystem services has become one of the most significant scientific priorities for wetland protection. In this paper, we provide an overview of ecosystem services, and summarize the main interdisciplinary approaches to measure and value wetland ecosystem services. We identified four main methodological gaps preventing progress on wetland valuation of ecosystem services in China, which are: 1) confusion on terminology like intermediate and final ecosystem services, 2) lack of ecological production functions to link ecosystem characteristics to final ecosystem services, 3) static valuation making it difficult to evaluate the trade-offs and synergies among ecosystem services, and 4) lack of clear guidance on relating ecological compensation programs to conservation targets. Overcoming these gaps is important to inform wetland compensation mechanisms and conservation policies. We propose future research on wetland ecosystem services in China should be focused on: 1) defining final ecosystem services based on beneficiary preferences and underlying biophysical mechanisms, 2) establishing wetland monitoring programs at specific sites to collect data on final ecosystem service indicators and ecosystem characteristic metrics to create ecological production functions for economic valuation and rescaling techniques, and 3) incorporating wetland ecosystem service values into decision-making processes to inform wetland management.
基金Supported by the Research Fund for the Doctoral Program of Higher Education(Grant no.20070001049):pricing policy for resources products incidence of welfare impactBeijing Science and Technology Commission D09040903670905:Study on the Regional Air Pollution Control Strategy and Policy
文摘In light of the practical need for research to inform policy in Beijing,this study evaluates the economic cost of the impact of PM 10 pollution in Beijing from 2001 to 2006,taking health as the main impact,and mortality as the main outcome.Based on the literature review,this study adopts relatively conservative parameters as the basis for calculating the health impacts.It concludes that nearly 30%of mortality among registered residents above age 30 in Beijing can be attributed to PM 10 pollution,and that the economic cost equals 0.8%-1.2%of the city's GDP over the same period.This is lower than the results of previous studies,but still high enough to warrant a commitment to solve the city's air pollution problem.
文摘Ideas and methods of evaluating economic benefit of regulatory detailed planning were introduced firstly,and then the framework and concrete steps of valuation of economic benefit of regulatory detailed planning were analyzed.Afterwards,the economic benefit of regulatory detailed planning was valued by using case analysis method.Finally,some suggestions of application were proposed,such as introducing the valuation of economic benefit of a third party into the adjustment scheme of regulatory detailed planning,and publicizing the scheme of regulatory detailed planning and valuation results at the same time.
文摘In the asset valuation of oil and gas reserves, it is discovered that the production decline trend of wells is not very obvious and that it is hard to make a production forecast matching the production history, thus resulting in a significant deviation of oil and gas asset value. For production with a significant fluctuation, the value deviation is also considerable if the matching production, which is predicted with classical decline methods, cannot appropriately reflect the time value distribution of actual production. To mitigate such a deviation, a concept is proposed concerning the value constrained production forecast and the value constrained production decline model is developed. A field case is demonstrated as an application of such a model. The model can significantly decrease the risk in the value deviation of a production decline analysis and be applied to the production forecasts for a single well, well clusters, blocks or field scale, and even for other mining industries.
基金The NSF(60873119)of Chinathe Higher School Doctoral Subject Foundation (200807180005)of Ministry of Education of China
文摘In this paper, firstly, a necessary condition and a sufficient condition for an isomorphism between two semiring-induced valuation algebras to exist are presented respectively. Then a general valuation homomorphism based on different domains is defined, and the corresponding homomorphism theorem of valuation algebra is proved.
文摘In this paper we show that if R is a discrete valuation ring, then R is a filtered ring. We prove some properties and relation when R is a discrete valuation ring.