3.2.1. Innovation Agglomeration

According to the above, innovation agglomeration emphasizes the concentration of innovation level in a region. Due to the type of available data and in order to reduce the potential for multicollinearity, this study uses the number of granted patents, which is processed to remove the effect of economic volume, to reflect more realistically the level of innovation agglomeration in the region. The processing steps are as follows:

$$\text{Inno\\_agg}\_{\text{it,p}} = \sum\_{i=1}^{30} \mathbf{e}\_{\text{it,p}} / \mathbf{G}\_{\text{it}} \tag{14}$$

where, Inno\_ aggit,p represents level of innovation agglomeration of province i in period t. Git is GDP of province i in period t.

#### 3.2.2. Human Capital Dimension

Knowledge is the original force of innovation-driven, and people are the carrier and core of knowledge. On the one hand, the higher the human capital of a region, the higher the innovation development of the region, the higher the rate of return on capital, thereby promoting land use transition and achieving energy conservation and emission reduction. On the other hand, higher levels of human capital will require a higher quality of life. These will force the local governmen<sup>t</sup> to improve their infrastructure and beautify the environment to retain talents and elites. Accordingly, this study selects the following three variables to reflect the level of human capital and makes further hypotheses. (I) Population density. People are agglomerated and will gather in areas with more employment opportunities, a more developed economy and a higher living environment. Observing domestic and foreign cities, it can be found that the population density of such high-quality cities is usually high (of course, it does not mean that cities with higher population density must be high-quality). (II) Average educational level. Education is a medium for passing on knowledge and the basis for generating new knowledge. Innovative agglomeration will attract more highly educated people to settle here, which will increase the average education level of local residents [45]. Average educational level is proportion of (population of college and above \* 16 + population of high school \* 12 + population of junior high school \* 9+population of elementary school \* 6) in population over 6 years old. (III) Full-time equivalent ofR&D personnel. It reflects the degree of hard work of scientific researchers in the region. R & D is a time-consuming and labour-intensive process, and a large number of valuable innovations are based on the work of scientific researchers day and night. The average weights corresponding to urban population density, average educational level and full-time equivalent of R & D personnel are 0.2907, 0.2280 and 0.48124, respectively (Appendix A Table A1 for the complete data).

**Hypothesis 3a (H3a).** *The land use transition driven by human capital dimension can reduce industrial pollution emissions on the region.*

**Hypothesis 4a (H4a).** *The land use transition driven by human capital dimension can reduce industrial pollution emissions on surrounding regions.*

#### 3.2.3. Material Capital Dimension

Just as production and operation are inseparable from material capital investment, innovation requires a lot of capital support (such as the development of COVID-19 vaccines). In terms of innovation agglomeration, it will gather a large amount of material capital (mainly capital). On the one hand, money capital has a certain degree of speculation. Therefore, high capital clusters often have a higher rate of return on capital, thereby accelerating land use transition. On the other hand, the agglomeration of material capital cannot only speed up the progress of scientific research but also clear its funding barriers, thereby improving various pollution emission, also alleviating the problem of "financing difficulties" for companies using environmental protection equipment. Accordingly, this study chooses the following three variables to reflect level of material capital and makes further hypotheses. (I) Internal expenditure of R & D funds. It refers to the actual expenditure of enterprises and institutions for internal R & D activities (including basic research, applied research and experimental development). This is the most intuitive capital investment directly used for scientific research. (II) Financial institutions density. Financial institutions can promote the financing, which is the inevitable outcome of financial development to a certain period. High financial institutions density is the inevitable product of innovation development. It can not only improve the investment and financing efficiency of enterprises but also form a competitive environment, thus reducing the investment and financing costs [46]. The average weights corresponding to internal expenditure of R & D funds and financial institutions density are 0.6072 and 0.3928, respectively (Appendix A Table A2 for the complete data).

**Hypothesis 3b (H3b).** *The land use transition driven by material capital dimension can reduce industrial pollution emissions on the region.*

**Hypothesis 4b (H4b).** *The land use transition driven by material capital dimension can reduce industrial pollution emissions on surrounding regions.*

#### 3.2.4. Urban Function Dimension

Urban function refers to the role and division of labour that a city plays in the economic and social development of a certain area, and it can also be simply described as the characteristics of a city. Urban development often has a significant negative impact on ecosystems [47], especially in developing countries that need to develop industries to improve their economic levels. After the reform and opening-up, the industrial-based development mode has brought "miracle growth" to China, but it has also been accompanied by many environmental problems. At that time, developing industry and increasing GDP were the main theme of most cities. Nowadays, with China's national power is becoming stronger and stronger, people's requirements for the quality of the living environment are constantly increasing, and China's economic development has new requirements, that is, an innovation-driven development mode. In the process of innovation agglomeration, the urban functions need to be improved, and land use transition gradually is taking shape. On the one hand, the industrial structure of the city has changed, and the proportion of the secondary industry has decreased, while the proportion of the tertiary industry has increased year by year, which reduces the industrial pollution emissions. On the one hand, the industrial structure of cities has undergone changes, the proportion of the secondary industry has decreased, and the proportion of the tertiary industry has increased year by year, reducing industrial pollution emissions. On the other hand, as the government's focus gradually shifts to the quality of life of residents, the city's infrastructure will be improved accordingly. In the context of innovation agglomeration, local governments will build more humane and better infrastructure to meet the development needs of innovation, thereby accelerating land use transition and reducing industrial pollution emissions. Accordingly, this study chooses the following two variables to reflect level of urban function and makes further hypotheses. (I) Industrial structure evolution. Kuznets defines the industrial structure evolution as a re-allocation process of economic resources among agriculture, industry and service industries [48,49]. With the increase in economic development and the level of innovation agglomeration, the trend of economic servitization has accelerated, and the proportion of tertiary industry in GDP has also increased, thereby reducing the level of industrial pollution emissions. Although the industrial structure evolution is a comprehensive process, this study mainly focuses on the change phenomenon of the primary, secondary, and tertiary industries. Therefore, the ratio of tertiary industry's GDP to total

GDP is used to measure it. (II) Urban road area per capita. With the deepening of urbanization and the adjustment of urban functions, infrastructure is developing in the direction of convenience. Urban road area per capita directly reflects the city's traffic convenience and indirectly reflects the city's tendency to improve the life quality of residents. The average weights corresponding to industrial structure evolution and urban road area per capita are 0.6961 and 0.30392, respectively (Appendix A Table A3 for the complete data).

**Hypothesis 3c (H3c).** *The land use transition driven by urban function dimension can reduce industrial pollution emissions on the region.*

**Hypothesis 4c (H4c).** *The land use transition driven by urban function dimension can reduce industrial pollution emissions on surrounding regions.*

### 3.2.5. Government Dimension

The governmen<sup>t</sup> dimension reflects what the governmen<sup>t</sup> has done to strengthen the role of innovation agglomeration in industrial pollution reduction. China's special national conditions and development history determine that the position and authority of the Communist Party of China as the ruling party are recognized [50], and the behaviour of local governments has a strong influence on social development [10]. On the one hand, innovation agglomeration urges the governmen<sup>t</sup> to further increase the investment in science and technology expenditure in the general governmen<sup>t</sup> budget, promote innovation and development, so as to promote land use transition and reduce industrial pollution emissions. On the other hand, under the requirement of sustainable development, the local governmen<sup>t</sup> has restricted the pollution emission of enterprises with large industrial pollution emission, and gradually controlled the total industrial pollution emission from the total amount. Accordingly, this study chooses the following two variables to reflect the governmen<sup>t</sup> dimension and makes further hypotheses. (I) Proportion of technology expenditure. Similar to internal expenditure of R & D funds, this variable is the proportion of science and technology expenditure in the general governmen<sup>t</sup> budget, which reflects the government's support and attitude to science and technology research. (II) Green coverage. Since it is difficult to directly measure the degree of governmen<sup>t</sup> restrictions on industrial pollution emissions from enterprises, this study uses green coverage to indirectly reflect the government's focus on the environment. The average weights corresponding to proportion of technology expenditure and green coverage are 0.7636 and 0.2364, respectively (Appendix A Table A4 for the complete data).

**Hypothesis 3d (H3d).** *The land use transition driven by government dimension can reduce industrial pollution emissions on the region.*

**Hypothesis 4d (H4d).** *The land use transition driven by government dimension can reduce industrial pollution emissions on surrounding regions.*
