A study on villages of the planning of water infrastructure planning: 25 villages in Shaanxi Province as an example

Given how rapidly society and the economy have evolved, the global water crisis is now one of the most critical concerns confronting humanity (Douglas et al. 2019; Liang et al. 2020). And therefore, good water quality has been becoming one of the most important problems that people faced globally (Yu et al. 2022). Recent urban growth cycles have spawned significant disparities between urban and rural developments (Grimm et al. 2008). In addition, cities in China today have a highly developed technological infrastructure for operating and managing sewage treatment plants (Hara et al. 2019). However, China's rural regions lack wastewater treatment infrastructure due to the small size, high quantity, and dispersion of villages (Addae & Oppelt 2019). Consequently, the issue of water contamination is especially severe in rural regions (Liang et al. 2021).

In China, where there were 2.45 million villages, rural infrastructure was still very ‘decrepit’. The Poverty Alleviation Program has assisted 99.9% of Chinese communities with their electricity and telecommunication challenges. Even in locations with complicated terrain, unfriendly environment, and inherited poverty, such as the Qinling-Daba Mountains, Yunnan-Guizhou Mountains, and Tibet Plateau, power supply and communication coverage have been established (Li et al. 2021). In these regions, all inter-village and inter-group roads have been paved, allowing 85% of communities to fix their road problems. Additionally, the water supply system is in outstanding shape. In recent years, as natural gas has grown more widespread, gas facilities have increased. Due to regional variances, many heating options are available. This suggests that upgrading rural infrastructure, particularly water infrastructure, may effectively narrow the gap between China's urban and rural areas. Currently, only the rural drainage facility issue has not been resolved.

President Xi emphasized the Rural Revitalization Strategy in his 2017 report to the 19th CPC National Congress. The national economy and the population's level of life are profoundly impacted by the ‘Three Rural Issues’ (problems pertaining to agriculture, rural regions, and rural people). In order to improve the rural living environment, rethink the connection between urban and rural areas, and raise the subject of rural development to a new level, the CPC must give the ‘Three Rural Issues’ top priority (Wang et al. 2021a). Infrastructure may be used to accomplish the Rural Revitalization Policy in its entirety. China, People's Republic of Outline of the 13th National Economic and Social Development Five-Year Plan. Resolving the drainage infrastructure problem, converting pit latrines to flushing toilets, and installing dumpsters, garbage collection sites, garbage disposal facilities, and garbage compost houses can significantly protect the natural ecological environment of the countryside and conform to the widely held belief that ‘green mountains are gold mountains’. In contrast to the 12th Five-Year Plan, the financial and economic committee of the National People's Congress expects that China's sewage treatment would gradually shift from urban to rural areas. Rural locations have a sewage treatment rate that is less than 1/10,000 that of urban areas, making it difficult to treat sewage. Even in communities having sewage treatment facilities, treatment effectiveness is poor owing to a lack of financial resources. Less than 40% of the sewage treatment facilities in 101 Changshu, Jiangsu Province, villages were operating properly according to field research. According to the results of a sample study conducted in Beijing, less than 60% of districts’ and counties’ sewage treatment facilities were running properly on average and, in certain cases, less than 50%.

Central-northern Shaanxi has a more acute water shortage than other regions (Wang et al. 2021a, 2021b). Dramatic overexploitation of groundwater has caused a significant decline in the groundwater level in the region over the years (Wu et al. 2021). With the economic development of rural areas in the region, so does the demand for water resources, presenting a severe danger to sustainable development. This paper presents a comprehensive analysis of the water infrastructure in rural parts of Shaanxi's central-northern region. Moreover, an operational study of selected rural instances is provided. Combining the geographical and climatic factors of the north-central area of Shaanxi led to the selection of 25 villages for the investigation. By picking the winter and summer seasons from 2016 to 2018 for in-depth analysis, Wu village was ultimately chosen as the case study to demonstrate rural water infrastructure design. Interviews with appropriate county/town administrative authorities, village committees, and farmers were used to collect all case data. And the last section concludes a summary of this study and gives relevant suggestions. In addition, we examined the existing quo of water infrastructure in that area by identifying and assessing locally persistent challenges, and we presented a water infrastructure development approach tailored to that region. Excellent allocation of water resources can not only produce a satisfactory effect on the ecosystem but also conducive to establishing the balance between the supply and demand of water to promote the sustainable population of economy, technology, and society (Wu & Wang 2022a, 2022b).

China's Shaanxi Province's north-central region is the transition zone between the central plain and the northern plateau (Li et al. 2020). This area consists mostly of four counties located in the northern portion of Weinan City, Shaanxi Province: Pucheng, Fuping, Chengcheng, and Baishui. This area receives 550–730 mm of precipitation annually, but more than 70% of that precipitation evaporates, rendering it prone to continuous water deficit and drought. Current surface rivers in the area include Baishui, Shichuan, and Beiluo; however, they have mainly dried up. The 25 rural examples examined in this dissertation are dispersed across this area, which has an average elevation high speed of 750 m.

In this study, 25 villages representative of Shaanxi Province's north-central region were selected (Table 1), including six administrative villages in Meiyuan Town, Qicun Town, and Zhuangli Town of Fuping County, seven administrative villages in Chenzhuang Town and Hanjing Town of Pucheng County, six administrative villages in Dukang Town, Beiyuan Town, and Yaohe Town of Baishui County, and six administrative villages in Wangzhuang Town, and Yaot Weinan City's 25 villages are all located on the First Tableland, but the villages of Baishui County and Chengcheng County are all located on the Second Tableland. The research was done in December 2017, March, June, and August 2018 and included all village groups’ drainage infrastructure at the time.

All information about the spatial performance was collected from official yearbooks and reports at the national, provincial, municipal, and county levels, including the urban–rural spatial input system and the urban–rural spatial output system. Numerous years’ worth of topographic data was used to compile the statistics on the growth and evolution of construction land (.dwg file or .shp file). As previously indicated, terrain information was acquired for free via the Geospatial Data Cloud website using data obtained from the planning and management agencies’ terrain graphs (Tone 2001).

Due to the surrounding tableland terrain and pervasive aridity, most local farmers plant traditional crops such as wheat and maize. In some northern locations, Sichuan Pepper accounts for 10% of total crops; however, in other regions, farmers plant a variety of fruits. Farmers often earn small wages and grow limited quantities of profitable crops. The region's communities are economically disadvantaged. The average annual income of farmers in Pucheng County, Fuping County, Baishui County, and Chengcheng County is lower than that of farmers in Weinan City. In Shaanxi Province, Pucheng County and Fuping County were just lifted out of poverty in 2018; however, Baishui County and Chengcheng County are nationally poor and are anticipated to be lifted out of poverty in 2019.

Based on our evaluation of the aforementioned 25 villages, we determined that they had all been badly emptied out and that the inequalities between ancient and contemporary communities were clear. The roads in old villages were primarily constructed with plain dirt as opposed to cement, with road widths ranging from 1.5 to 2.5 m; the houses were predominantly old-fashioned structures with rammed-earth exterior walls and single-slope roofs, and some buildings had already collapsed and were, therefore, left unused and abandoned throughout the entire year. Our investigation indicated that every resident of the medieval towns was at least 70 years old.

In contrast, new towns had roads that were between 3 and 4.5 m wider. All inter-village and inter-group roads were paved with cement, and the vast majority of homes were brick-concrete buildings with flat roofs. The village square, situated in the new village area, functioned as the only meeting and entertainment space for many community groups. Consequently, the plaza was expansive and cluttered with street lamps and wheelie bins. The majority of the water supply, gas supply, and communication infrastructure problems in that area have been remedied. Simultaneously, self-sufficient heating was ubiquitous, but drainage and lighting were not yet prevalent. In addition, the villages lacked garbage collection services, resulting in the widespread litter. Locals choose direct dumping for trash disposal, which may cause significant soil pollution.

There are still several lingering obstacles hindering the proper implementation of wastewater treatment in rural Chinese communities. The research framework is outlined below.

Using Wu Village in Meiyuan Town as an example, our analysis of outgoing migrant workers indicated that the majority of locals had gone to Fuping County, Xi'an, and more developed coastal cities. P₁ is the anticipated population, P₀ is the total registered population, r₁ is the natural growth rate, r₂ is the population conversion rate, and n is the anticipated time period. In 2017, Wu Village was home to 3,285 people. According to the master plan and other planning papers for Fuping County, the county's population conversion rate during the last 5 years was 3.87%. A section of the population returned during the construction of the settlement, industrial expansion, and the completion of major projects. Thus, the conversion rate between the medium and long-term population and the long-term population fell to 3.68% (Table 2). The population drop rate will ultimately reach 40.9% by 2030. The basis of each city's economy and industrial growth differ, resulting in various village decline rates. The population loss rate in the 25 case study localities is shown in Table 3.

With the intensification of China's New-type Urbanization Strategy and the migration of the non-farming population from rural to urban areas, it was determined that the north-central part of Shaanxi region, specifically Fuping County, Baishui County, Pucheng County, and Chengcheng County, had experienced a net outflow of population. This suggests that both the rural population and the rural vacancy rate are declining. To increase the allocation of residential service facilities in rural areas and effectively minimize waste, it is required to integrate rural construction land in a systematic way.

To avoid land waste based on the present building state of the villages and the expected increase of the resident population, the scope of rural construction land management should be firmly delimited. The public green space, squares, public service facilities, and infrastructure on the village's construction land must be protected and unoccupied to ensure the future development and construction of the villages’ public utilities and to comply with the development requirements for the villages’ communal spaces and public facilities. According to the Land Management Law (2004) and the Fuping County Land Use Plan (2006–2020), the core agricultural area must be preserved (Table 4).

Due to the lifestyles of local farmers and the agricultural history, the diversion technique is still employed to change toilet water and to separate the collection and treatment of excrement and household sewage. Three-pool photovoltaic cesspits are easy to build and affordable to maintain, and thus they are used by the locals. It consists of three linked pools, one of which is connected by a conduit for the entrance of waste. It is based on the fact that the specific weight of anaerobic fermentation, middle-layer waste, and parasite eggs is more than that of a normal mixed liquid, making it easy to precipitate. The feces in the pool ferments and decomposes for more than 30 days, and the middle-layer excrement liquid flows progressively from the first pool to the third pool, fulfilling the goal of precipitating or destroying parasite eggs and dangerous intestinal bacteria in the excrement. The liquid feces in the third pool become an amazing fertilizer in the end. When the contaminated water in the cesspit is about to overflow, a pumping vehicle will remove it and use it to fertilize fields (Scharnberg et al. 2020).

Construction concentration ranges for COD, BOD₅, SS, NH₃-N, TN, and TP are 80–200, 40–100, 60–150, 10–30, 15–40, and 1.0–5.0 mg/L, respectively (Bai et al. 2019). Manure contains around 1% nitrogen, 0.5% phosphorus, 0.5% nitrogen, and 0.13% phosphorus, whereas urine contains 0.5% nitrogen and 0.13% phosphorus. Regarding the discharge standard for village-level sewage treatment stations, the villagers may adopt the first-level B or second-level discharge standard as specified by the national standard (GB 18918-2002), giving priority to the TN and TP indices for resource utilization as fertilizers or plant nutrition, whereas the first-level A standard should be adopted for water source-sensitive areas.

Through the aforementioned study, it is feasible to infer that, compared to previous studies, we have developed a model that is more sustainable and attempts to enhance regional social, economic, and environmental cooperation in the case study of 25 administrative villages in the Chinese province of Shaanxi. The following were the results: this paper examines the population size, age proportions, level of economic development, dominant industries, main crops, characteristics of historical and folk culture, and characteristics of folk celebrations at the village, town, and county levels, predicts the urbanization process in the region as well as the decrease and outflow of the rural population, and establishes the reasonable scale of rural development. This paper develops a method to water infrastructure planning based on a survey and assessment of the present situation, successfully embracing the current scenario of rural development while adapting an approach to the shrinking rural population and the restricted construction investment. When modifying rural construction sites, the recommended drainage facilities take China's rural population reduction into account in contrast to the current rural environment and existing design options. In rural locations, the forecasting and design of sewage drainage systems based on the altered land and population enhances the resource use efficiency. In addition to the sewage and drainage network, each residence's sedimentation tank is included in the design of sewage and drainage facilities. In a short period, the sedimentation tank may alleviate the problem of stagnant water caused by heavy rains and restrict the passage of dust and debris into the sewage system. Furthermore, the sewage drainage system terminates in an ecological sewage treatment pond, and the treated water may be utilized for the irrigation of rural crops and landscape water. This water may efficiently solve the irrigation water scarcity issue in semi-arid regions. The research on water infrastructure planning, based on a reasonable scale of development, will not only improve the living environment in the region but also effectively solve the problems of water resource collection and crop irrigation on the dry tableland, achieving effective resource utilization and sustainable village development. Future research work mainly focuses on more accurate population projections and the preparation of land for construction to be adjusted. This model may be the subject of further study aimed at its improvement.

This work was supported by ‘The National Key R&D Program of China, grant no. 2019YFD1100901; The Opening Fund of State Key Laboratory of Green Building in Western China, Xi'an University of Architecture and Technology, grant no. LSKF202019; The China Postdoctoral Science Foundation Grant No. 69, grant no. 2021M692009; The Annual Project of Social Science Foundation of Shaanxi Province in 2021, grant no. 2021J027; The Project for Rural Revitalization of Philosophy and Social Science Research of Xi'an Polytechnic University in 2022, grant no. 2022ZSZX02’.

All relevant data are included in the paper or its Supplementary Information.

The authors declare there is no conflict.