1.Teaching Method of Experiment

The experimental teaching project relies on the Ministry of Education's Landscape Environment Engineering Center of Beijing Forestry University, which uses modern information technology and other techniques and vigorously promotes the reform of experimental teaching. Combined with the school's actual teaching situation, independently developed, it is based on a virtual immersion environment experience, taking the actual built and used campus landscape which students are familied with as the teaching content, taking virtual construction of landscape, answering the related landscape construction problems, evidence-based learning on the results of stormwater simulation and landscape performance as the teaching method, to carry out self-directed, collaborative and inquiry-based learning methods, committing to the development of students' problem awareness, innovation, active learning and self-reflection skills.

（1）Purpose

1. Arouse students'building cognition and learning interest in the evidence-based design

In the virtual environment, students can observe and participate in the whole process of landscape design from site selection to construction through simulation. Through the simulation of the real environment of solid construction, the construction process of multiple styles of galleries, rainwater gardens, paving, the construction of the subsequent engineering, estimation of the economic indicators and the specific measurement process of landscape performance, students are able to understand the real situation of landscape design and construction in depth and in detail, and closely integrate the knowledge learned in the classroom with practice. The real, concrete and interactive learning mode not only stimulates students' interest in studying the solid construction in depth, but also increases the dimension of students' understanding of theoretical knowledge, letting them fully recognize the discipline feature of landscape architecture which combines art and technology and enhance interest in professional learning.

2. Enhance students' ability to connect theory with practice, independent learning, etc.

The virtual simulation experiment addresses the problem of irreversible solid construction in landscape architecture. In the virtual environment, students are able to practice repeatedly according to their interests and the key points of the course, by which they can not only integrate the technology of solid construction with theoretical knowledge, but also obtain a concrete understanding of the general process of solid construction; students can also choose practice mode or design their own experiments to extend the more abstract concepts in the theoretical course into practical operations and real situations. This flexible approach can stimulate students' awareness of self-learning and continuous self-reflection, so that students' learning effects in class and independent learning ability are continuously enhanced.

3. Improve the learning efficiency of students' professional courses

This experiment provides students with an online classroom so that they can conduct experiments at any time without the restriction of time and space. The virtual built experimental scenario provides good immersion and high realness, which shortens the experimental cycle and improves the pertinence of the experiment through lower cost, flexibility and high participation. The system's automatic scoring function helps students get timely feedback, so that they can identify and solve problems in time, which greatly improves their learning efficiency.

（2）Implementation process (see Fig.8)

Fig.8 Process of Implementing Experimental Teaching Methods

1. Virtual immersive environment experience

Students enter the virtual campus scenario and experience the space, layout and structure of the physical environment with an intuitive perception of the basic conditions and current features of the construction site; master the real interaction between the construction process and the physical environment, as well as the real operation of the solid construction process; grasp the construction standards of galleries, paving and rainwater gardens by restoring construction process; and have a preliminary perception and understanding of the economic, technical and engineering indicators, as well as ecological and economic benefits of landscape construction through visualization methods.

2. Cases and problem-oriented cognition

In the site cognition session, using the gallery, paving site and rainwater garden on the site as specific learning examples, students will be able to compare and analyze the construction site of the gallery, paving site and rainwater garden by observations and refer to the system's explanation of the site's situation to complete the identification of doubts about the design site.

In the construction process, the system combines the theoretical knowledge of structure selection, structural composition, engineering practices, construction sequences and other theoretical points to ask students corresponding questions about the real-time process, so that they will gain a deep understanding of the steps, rationality and specific details of the construction process.

In the stormwater simulation session, the system asks students questions that require them to analyze post-rainfall runoff calculations to understand end collection and infiltration abatement.

In the indicators and benefits estimation session, the system addresses the needs of the above processes, guides students in choosing their own measurement options, and helps them to understand the evidence-based process after designing.

3. Interactive and discussive teaching

In the process of virtual simulation experiment, the system develops corresponding knowledge point analysis and guiding questions about experimental procedure for different experimental stages, requiring students to arrange and explain the subsequent experimental procedure, and providing real-time feedback and doubt analysis for the questions arising from them. After entering the practice session, the experimental system has a real-time Q&A function (Fig. 9). Students can communicate with online teachers in real time about the content of the simulation experiment to have a deeper understanding of actual problems; they can also interact with all kinds of galleries, materials and objects in real time to operate and practice.

The system has the functions of error prompts, correct operation prompts and auto-evaluation. Through human-computer interaction, students can practice, learn and adjust while practicing, so that errors and deficiencies can be corrected and supplemented in time.

Fig.9 Real-time Q&A Function of The System

4. Self-directed collaborative and exploratory learning

Students are required to work in groups during the experiments, which are divided into individual section and team-work section. The site design, planting and method design and gallery construction experiment need to be completed by individual students, while the stormwater simulation and performance evaluation experiment need to be completed by a group.

In the individual experiments section, students can conduct deep research and learning according to their interests, and achieve targeted experimental learning. In the team-work experiments section, students can actively explore the cooperation mode, which improves the quality of experiments and helps students form a systematic knowledge framework. Students can improve their innovation ability and learning efficiency through individual design and teamwork.

（3）Implementation effects

1. Improve the quality of human resources training

This project breaks through the limitations of time and space by restoring the difficult-to-realize solid construction and post-design evaluation processes in real scenes through virtual simulation, so that students can conduct experiments anytime and anywhere. What is more, the software is equipped with error correction and hint function, realizing the real-time feedback and targeted guidance of construction teaching process. Through repeated practice, students can transfer the abstract theoretical knowledge and apply it to the situation, which improves their comprehensive design ability and cognitive level. This project has greatly improved students' cognitive level of landscape construction and evidence-based evaluation process, and improved the teaching process from theory to practice, helping students to build a knowledge framework that integrates theory and practice. Since July 2017, more than 312 students have completed the project. The supply of graduates exceeds the demand and the graduates are widely welcomed by employers.

2. Improve teaching efficiency

The project built a kind of real environment, currently supports concurrent access to up to 150 people, solving problems that high-frequency, large-volume students cannot involved in in real landscape construction; also solves the problem that students cannot use real materials for repeated practice and realistic practice of various galleries and rainwater garden construction. In the virtual simulation experiment, students interact with the virtual environment, gallery and rainwater garden construction materials, not only can apply the knowledge learned in the offline classroom to online experiments, but also improve enthusiasm and interest in the profession, which greatly enhances teaching efficiency.

3. Reduce teaching costs

Virtual simulation involves the construction of galleries, rainwater gardens and paved areas, which requires the use of large engineering equipment and a large number of raw materials to achieve. The traditional landscape construction is mostly displayed and operated by structure dismantling, model production and other ways, while the benefits evaluation process after design requires a long period of time and the use of professional equipment. This project allows students to experience the relevant construction and post-design benefit evaluation in a short period of time, saving material and time costs. In 2018, 200000 yuan has been saved in transportation. Students significantly save on the purchase of lab equipment and materials by interacting with virtual subjects and lab materials. The money saved in this item has been over 500000 yuan since 2018.

4. Share teaching resources

The project can be accessed and used via the Internet, enabling a wide range of class experiments to be easily conducted and madding it available to the community. At present, the virtual simulation teaching resources not only benefit teachers and students of this program, but also support the virtual simulation experimental teaching of similar majors in other universities.

5. Has significant effects in serving the society

The program has significant advantages in cultivating professional landscape construction skills, attracting many professional company personnel to actively accept the training and enhancing the professional level of industry practitioners.