Research on Life Cycle Risk Assessment of Public-Private Partnerships Project Project of Comprehensive Environmental Governance Based on PCA

China's implementation of public-private partnerships projects has been quite effective, involving infrastructure and other livelihood projects, a total of 19 industries, and an investment of nearly 1.5 trillion yuan. The characteristics of PPP projects such as long construction period and large investment amount determine the risks of PPP projects are also great, and the PPP projects of comprehensive environmental governance are also the same. The government and social capital use the PPP model to cooperate, and use the principal component analysis method to assess the risks of the entire life cycle of the comprehensive environmental governance PPP project. Therefore, it plays an important role in ensuring the smooth implementation of projects and reducing the losses caused by risks. According to the risk factors of the whole life cycle of the comprehensive environmental governance PPP project, an indicator system of 5 first-level indicators, 18 second-level indicators, and 43 third-level indicators has been established. Principal component analysis is used to analyze the influence weight of risk factors at each stage. The analysis shows that among the four stages, environmental pollution risk, project approval delay risk, completion risk, interest rate and financial fluctuation risk, and franchise life risk are the most influential risks in the implementation of PPP projects. Therefore, suggestions are made through the risk factors of each stage in the comprehensive environmental governance PPP project. For example, strengthen the response to the external environment risks of the comprehensive environmental governance PPP project, standardize the bidding and procurement of the comprehensive environmental governance PPP project, and strengthen the subsequent management of the transfer of the comprehensive environmental governance PPP project. In this way, the ability to resist risks of comprehensive environmental governance PPP projects is improved; the smooth implementation of the project is guaranteed, and the long-term development of comprehensive environmental governance PPP projects is promoted.

environment. Therefore, the report of the 19th National Congress once again proposed to "accelerate the reform of ecological civilization system, and build an environmental governance system dominated by the government, dominated by enterprises, and jointly participated by social organizations and the public" (2017). Up to now, PPP projects of ecological construction and environmental protection have huge investment amount, numerous participants, complicated processes involved, and long construction and operation cycle, resulting in numerous and complex risks faced by PPP projects. Therefore, the PPP project of ecological construction and environmental protection needs to accurately predict and evaluate various potential risks to ensure the smooth implementation of the project.
Public-private partnership (PPP) is a mode of cooperation between the public sector and private enterprises. It uses funds and management experience of private enterprises to operate efficiently and provide the public with required products and services (Akintoye, 2000). The social capital party provides the government with operational management experience and advanced technology, as well as financing services for PPP projects (Zou, 2008). The PPP model solves the funding difficulties for the government, and at the same time shares the risks of the project by the social capital (Doloi, 2007). The method of PPP project risk assessment originated from abroad. Through the risk assessment of the Skye Bridge project in the United Kingdom, the risk of the construction period and operation period of the social capital party is judged, and further qualitative research is carried out (Pete Moles, 1995). The risk assessment model established by Cheng's team uses the Delphi method, fuzzy mathematics method, and AHP method to conduct risk assessment and applies it to Taiwan BOT projects (Cheng, 2001). PPP project risks exist both in the micro-environment of the project itself, and in the macro-environment (Martin Loosemore, 2007). There are many methods for evaluating PPP project risks, such as the fuzzy comprehensive evaluation method of PPP project risk assessment (Chen Jingwu et al., 2006), and the network analytic method of PPP project risk assessment (Zhang Wei et al., 2012), The grey correlation theory method of PPP project risk assessment has been researched (Jia Lili et al., 2014).
Through the PCA method the risks of PPP projects was to studied by Lu who constructed the PCA method and empirically conducted 10 PPP projects in Zhejiang Province, and concluded that the predictions are consistent with actual risks (Lu Xiaoqin et al., 2017). Zhang combined with PCA Research on the risks of low-rent housing PPP projects and predict the risks (Zhang Guihua, 2016). Regarding the risk assessment of the entire life cycle, Huang builds a three-dimensional structural model of the risks generated during the entire life cycle of the PPP project, and dynamically analyzes the risks at each stage (Huang Ke, 2019). Throughout the literature, few experts and scholars at home and abroad apply the PCA method to the entire life cycle of PPP projects for risk assessment, especially for ecological construction and environmental protection PPP projects. In this paper, principal component analysis (PCA) is used to carry out risk assessment for each stage of the whole life cycle of PPP projects under comprehensive environmental governance, and the risk impact weight of each stage is evaluated. Focus on key risk factors in real time to minimize the losses caused by risks and ensure a successful completion of PPP projects under comprehensive environmental governance within the whole life cycle. Through the study on the risk assessment of the whole life cycle of THE PCA-based comprehensive environmental governance PPP project, the study on the risk assessment of the whole life cycle by using principal component analysis has played a theoretical and practical significance.

Construct risk index system
Based on theoretical research and literature review, a risk index system for the full life cycle of PPP projects under comprehensive environmental governance is constructed. The full life cycle of PPP project of comprehensive environmental governance includes identification stage, implementation stage, franchise stage and non-franchise stage. In the PPP project of comprehensive environmental governance, some risks run through the whole project, and this paper sets such risks as the firstlevel index separately. Therefore, there are five first-level indicators, namely, whole-cycle stage risk, identification stage risk, implementation stage risk, franchise stage risk and non-franchise stage risk. The five first-level indicators contain 18 secondlevel indicators, and the second-level indicators are divided into 43 third-level indicators (Table 1).  (Zhu Genhua,2015).
First, the data is reduced in dimensionality through the software of SPSS24.0, and then the linear equation of the principal components is obtained, as follows: In the formula, a1i, a2i, … , api(i=1,……,m) are the eigenvectors corresponding to the eigenvalues of the covariance matrix of X, and X1, X2,…, Xp are the original variables.
Secondly, the ratio of the feature value corresponding to each principal component to the sum of the total feature value of the extracted principal components is used as the weight to calculate the principal component synthesis model:

Result and discussion
Questionnaire design and descriptive statistics The questionnaire was designed according to the 43 risk indicators in Table 1, and the Likert scale was used for assignment.
The questionnaire was sent to PPP project companies, governments, consulting companies, and major teaching and scientific research units that have participated in PPP projects through electronic questionnaires, using the "snowball" method to expand the interview. The survey started in October 2019, and after 3 months, the questionnaire survey was implemented well.
A total of 110 questionnaires were returned, of which 1 questionnaire that was unqualified due to inconsistencies in the questionnaire responses was eliminated. A total of 109 valid questionnaires were obtained, with a response rate of 99%.
Respondents in the sample have worked for an average of 8.2 years and have participated in a number of PPP projects, involving 19 industries, with a total of 168 frequent participations. Among the participating industries, municipal engineering participated in the most frequently, with a frequency of 17.86%, followed by the transportation industry, with only one person participating in forestry. It can be seen that the interviewees have rich experience in PPP projects to ensure the reliability of the data ( Table   2). According to the reliability analysis of Cronbach's Alpha, the overall value of Cronbach's α is 0.934, which is greater than 0.9. Cronbach's α of "full cycle stage risk evaluation", "identification stage risk evaluation", "implementation stage risk assessment", "franchise stage risk assessment", and "non-franchise stage risk assessment" are all between 0.772 and 0.895, reaching A critical value of 0.7 indicates good reliability; the combined reliability CR value of the four variables is between 0.703 and 0.8016, exceeding the critical value 0.7, indicating good reliability; the average extracted variance AVE value of the four variables is 0.604 to 0.728 Time, exceeding the critical value of 0.5, indicating that the convergence validity of the four variables is better. In summary, the survey data is very reliable (Table 3). The reliability and validity of the questionnaire was tested by SPSS24.0. The independent variables are "Risk Evaluation in the Whole Cycle Stage", "Risk Evaluation in the Identification Stage", "Risk Evaluation in the Implementation Stage", "Risk Evaluation in the Franchise Stage", and "Risk in the Non-franchise Stage" Evaluation" five variables. Through KMO and Bartlett test, the KMO value is 0.891, and the significance test sig value is 0.000, indicating that the validity of the questionnaire is very high, and factor analysis is suitable. In the questionnaire with secondary indicators, the minimum KMO value is between 0.725 and 0.859, all exceeding the standard of 0.7, indicating that the questionnaire is valid (Table 4).

Analysis of the full-cycle risk assessment of PPP project of comprehensive environmental governance
The political risk, legal risk, environmental risk, and force majeure risk in the comprehensive environmental governance PPP project are risks throughout the entire project cycle, which have a great impact on the entire project. Therefore, a separate risk assessment is carried out. Through SPSS24.0 software the dimension of the data are to reduced, and a total of 9 components are obtained in all indicators, which can represent the value of the original data. Component values observed features, extracted four eigenvalues greater than 1 of the component, the cumulative contribution rate derived e. The cumulative contribution rate reaches 83.025%, and the contribution rate is greater than 80%. It has a high degree of reliability, indicating that these four components can already reflect the information of the data. Therefore, the first 4 components can be used as principal components to evaluate the risk of the whole cycle (  There are three steps to calculate the weight of risk factors. The first step is to calculate the combination coefficient of the principal component, and divide the load number of the corresponding risk index by the square root of the characteristic value of the principal component, which can be seen in Table 7

Risk assessment analysis of PPP project identification stage of comprehensive environmental governance
According to the risk analysis method of the whole cycle stage to analyze the risk in the identification stage, the SPSS24.0 software obtains 3 components with characteristic values greater than 1, which become the principal components.  According to the weight analysis method of the whole cycle, the risk weight of the identification stage is obtained (Table   9). In the identification stage of a comprehensive environmental governance PPP project, there are three main types of risks: Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 28 January 2021 doi:10.20944/preprints202101.0590.v1 land acquisition, project approval delays, and financing. The highest risk weight is the difficulty of project approval (X14).
Because the approval process is very complicated and involves a wide range of areas, this risk has the highest weight. The second is work efficiency risk (X16). If work efficiency is low, it will inevitably increase the risk of approval delays and affect each other. The risk of investment expected return (X17) has the lowest weight. The comprehensive environmental governance PPP project has conducted a lot of research and investigation and the calculation of investment income in the early stage, with all factors that affect investment income taken into account, so such risks have the lowest impact.

Analysis of Risk Assessment in the Implementation Phase of PPP Project of Comprehensive Environmental Treatment
According  (Table 10). According to the principal component analysis method, the risk weights at the implementation stage are obtained (Table   11). In the implementation phase of the PPP project of comprehensive environmental governance, there are mainly four types of risks including financing, construction, supply, and technology. The highest risk weight is the completion risk (X22). Due to the long construction period and large variables, this risk has the highest weight. The second is engineering quality risk (X21).
The design unit's qualification risk (X27) has the lowest weight, and the PPP project of comprehensive environmental governance generally selects design units with certain performance and experience for design. Therefore, such risks have the lowest impact.

Risk Assessment Analysis of PPP Project Concession Management Stage of Comprehensive Environmental Treatment
According  (Table 12). According to the principal component analysis method, the risk weight of the franchise stage is obtained (Table 13). In the concession stage of the PPP project of comprehensive environmental governance, there are mainly five types of risks such as demand, operation, finance, interest rate, and inflation. The highest risk weight is the risk of interest rate fluctuations (X38).
Due to the long operating period, generally a 30-year franchise period, the fluctuation of interest rates is relatively large, and the resulting benefits will also fluctuate. Therefore, Interest rate fluctuation risk has the highest weight; and the second is the financial market stability risk (X39). This category is also regulated by the state. It cannot be changed and can only be dealt with. All risks are also relatively large. Operation and maintenance cost risk (X33) has the lowest weight. The companies selected for the comprehensive environmental governance PPP project have a very complete operating system and a complete system, so the impact of such risks is the lowest. and 25.665, the total contribution rate reached 82.625%, and the cumulative contribution rate exceeded 80%. These principal components can reflect the information of the indicators, and principal component analysis can be performed (Table 14). According to the principal component analysis method, the risk weight of the franchise stage is obtained (Table 15). In the non-concession stage of the comprehensive environmental governance PPP project, there are mainly two types of risks: operation and residual value. The highest risk weight is the franchise signing period risk (X41). Due to the long operating period, it is generally a 30-year franchise period and will be transferred after 30 years. Great changes have taken place in the policy environment and economic environment in the past 30 years. No experts and scholars can predict the future economic environment. Therefore, this risk has the highest weight; followed by the risk of operational management experience capability (X42), and the risk of expected operating returns has the lowest weight. The comprehensive environmental governance PPP project has considered a long-term benefit when designing the benefit, so this kind of risk has the lowest impact.

Conclusion and recommendations
The four stages in the full life cycle of a comprehensive environmental governance PPP project have different risks, and some risks run through the entire project. By constructing an index system and using principal component analysis, the main risks of each stage are obtained, so as to facilitate avoidance and prevention.
The full-cycle risks of PPP projects for comprehensive environmental governance include political risks, legal risks, environmental risks, and force majeure risks, with a total of 11 risk indicators. With the help of SPSS24.0 software, the dimensionality reduction of 11 risk indicators is performed first, and then the principal component analysis is performed to obtain the weight of each indicator. It can be seen from the results that environmental pollution risks and force majeure analysis risks have the greatest impact, and government corruption analysis has the lowest impact.
The risks in the identification stage of a comprehensive environmental governance PPP project mainly include land acquisition risk, project approval delay risk, and financing risk. There are a total of 9 risk indicators. Through principal component analysis, the weight of each indicator is obtained, and it is found that the risk of project approval difficulty and the work efficiency risk of functional departments at this stage have the greatest impact, and the risk of investment income has the lowest impact.
Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 28 January 2021 doi:10.20944/preprints202101.0590.v1 The risks in the implementation stage of the comprehensive environmental governance PPP project mainly include financing risks, construction risks, supply risks, and technical risks, with a total of 12 risk indicators. Through principal component analysis, the weight of each indicator is obtained. It is found that the completion risk and project quality risk in this stage have the greatest impact, while the qualification risk of the design unit has the lowest impact.
The risks in the franchise stage of comprehensive environmental governance PPP projects mainly include demand risk, operational risk, financial risk, foreign exchange and interest rate risk, and inflation risk, with a total of 12 indicators. The weights are obtained through principal component analysis, and it is known that the risk of interest rate and financial fluctuation has the greatest impact, while the risk of operation and maintenance has the lowest impact.