Hongzhen Ni

Agricultural land use in arid regions is subject to binding water-resource constraints, yet existing studies of crop rotation and fallowing have focused mainly on cultivated-land restoration and crop production, with limited attention to spatial allocation and compensation under water constraints. This study develops a plot-level framework under the principle of determining land use by water availability. Taking Yanchi County, Ningxia, as a case study, ecological, water-resource, and land-resource constraints are integrated through spatial overlay and suitability assessment, and groundwater-, ecological-, and cultivated-land-protection schemes are developed. Results identify 9309 hm² as potentially feasible for crop rotation and 4568 hm² for fallowing. Under the high scenario with maize–potato rotation, irrigation-water reductions are 6.37, 4.69, and 4.31 million m³, with corresponding net-profit losses of 13.75, 9.53, and 9.60 million yuan, respectively. The groundwater-protection scheme achieves the largest absolute water savings and best matches current groundwater-management needs. Baseline compensation standards are 6357, 1390, and 615 yuan/hm² for maize fallowing, maize–potato rotation, and maize–sorghum rotation, respectively. The findings support differentiated, phased implementation combined with loss protection and water-saving incentives.

Water conservation in agriculture is one of the key measures for alleviating the imbalance between water supply and demand, and a comprehensive assessment of the economic effects of agricultural water conservation is crucial for advancing the implementation of water conservation policies. Based on a traditional CGE model, this study incorporates “water resources” as an intermediate input and couples it with a mathematical model of water conservation costs to accurately reflect the relationship between the physical quantity of water resources and their economic value. The study establishes eight water conservation scenarios to simulate the impact of varying levels of water conservation on macroeconomic aggregates, water savings, and water conservation costs, and analyzes the marginal costs and marginal benefits under different conservation intensities. The results indicate that agricultural water saving can significantly improve economic water-use efficiency and drive macroeconomic growth through industrial linkage effects; nevertheless, the scale of reallocation of water saved from agriculture to non-agricultural sectors is limited. As water-saving intensity increases, the rate of change in economic output of each sector gradually rises and then stabilizes during 2022–2030. Among all sectors, the secondary sector exhibits the largest output change rate, ranging from 0.7% to 3.0%, while the tertiary sector shows the smallest change rate, varying from 0.4% to 1.7%. Under scenarios J1–J7, the marginal cost of water saving rises from 19.2 m³ per yuan to 52.1 m³ per yuan, and the marginal output decreases from 81.1 m³ per yuan to 6.8 m³ per yuan. The pattern of marginal cost–benefit follows general economic principles. The economically reasonable water-saving threshold occurs where marginal cost equals marginal benefit, corresponding to a water-saving volume of 8.2 × 10⁸ m³ and agricultural water withdrawal of 43.9 × 10⁸ m³. The research findings can serve as a reference for high-quality water-saving agricultural development in irrigation districts of arid and semi-arid regions.

With the rapid economic and social development and the increasingly severe water shortage situation, the sustainable utilization of unconventional water resources is of great significance. As one of the “second water sources”, the full utilization of highly mineralized mine water (HMMW) is a key strategy for promoting sustainable development in water-scarce regions. It has obvious resource, environmental, and economic benefits that are central to sustainability. However, the mechanism of the impact of HMMW utilization on water utilization, the environment, and the economy is still unclear, making it difficult to evaluate its overall sustainability performance and to provide scientific data support to promote HMMW utilization. Therefore, this paper develops a novel sustainability-oriented accounting framework to assess the environmental–economic sustainability of HMMW utilization. Firstly, this paper proposes the method of calculating the HMMW utilization environmental benefits, proposes a novel integrated environmental–economic input–output accounting framework, which refines the HMMW sector from the traditional water industry and integrates the environmental benefits into a balanced input–output table. Secondly, taking Ningdong Energy Chemical Industry Base (NECI Base) as an example, this paper conducts applied research on the integrated environmental–economic accounting of HMMW utilization: (I) The HMMW environmental benefits of NECI Base are calculated, the utilization of 22.69 million m³ of HMMW generated environmental benefits, valued at 233.69 million CNY, demonstrating its substantial contribution to environmental sustainability. The compiled environmental–economic input–output table passed the balance verification, confirming the robustness and practicality of the accounting method.

Rapid urbanization and industrialization have intensified the contradiction between water scarcity and economic growth. Achieving synergy between economic development and water conservation through taxation and subsidy policies has emerged as a critical research focus. This study develops an extended Computable General Equilibrium (CGE) model incorporating a water resource module to evaluate the impacts of production tax and subsidy policies in Wenling City, Zhejiang Province, China, a typical water-scarce city. By integrating a nested Constant Elasticity of Substitution (CES) production function for various water sources, the model captures the interactions between water supply and industrial output. Six policy scenarios of taxations and subsidies are designed. The impacts on macroeconomic aggregates, industrial output, and water usage are simulated. Results indicate that standalone taxation policies (Water Conservation Taxation Policy A1/Industrial Transformation Taxation Policy B1) reduce water usage by 3.35–3.80% but suppress Gross Domestic Product (GDP) growth by 0.37–0.76%. Among combined policies, the Water Conservation Combined Policy A3 achieves the optimal synergy between water conservation and economic growth, increasing real GDP by 1.00% while reducing water usage by 4.97%. This study reveals that taxation curbs the expansion of water-intensive industries, whereas subsidies redirect production factors toward water-efficient industries. Combining these policies effectively balances water conservation and economic development objectives. This study demonstrates how differentiated tax instruments drive water conservation through industrial transformation, providing a quantitative framework for production tax policy formulation in water-scarce regions.

Accurate short-term water demand forecasting assumes a pivotal role in optimizing water supply control strategies, constituting a cornerstone of effective water management. In recent times, the rise of machine learning technologies has ushered in hybrid models that exhibit superior performance in this domain. Given the intrinsic non-linear fluctuations and variations in short-term water demand sequences, achieving precise forecasts presents a formidable challenge. Against this backdrop, this study introduces an innovative machine learning framework for short-term water demand prediction. The maximal information coefficient (MIC) is employed to select high-quality input features. A deep learning architecture is devised, featuring an Attention-BiLSTM network. This design leverages attention weights and the bidirectional information in historical sequences to highlight influential factors and enhance predictive capabilities. The integration of the XGBoost algorithm as a residual correction module further bolsters the model’s performance by refining predicted results through error simulation. Hyper-parameter configurations are fine-tuned using the Keras Tuner and random parameter search. Through rigorous performance comparison with benchmark models, the superiority and stability of this method are conclusively demonstrated. The attained results unequivocally establish that this approach outperforms other models in terms of predictive accuracy, stability, and generalization capabilities, with MAE, RMSE, MAPE, and NSE values of 544 m³/h, 915 m³/h, 1.00%, and 0.99, respectively. The study reveals that the incorporation of important features selected by the MIC, followed by their integration into the attention mechanism, essentially subjects these features to a secondary filtration. While this enhances model performance, the potential for improvement remains limited. Our proposed forecasting framework offers a fresh perspective and contribution to the short-term water resource scheduling in smart water management systems.

As one of the important policy measures to promote water conservation and efficient utilization, the evaluation of water resources tax reform policy regarding its water saving and economic impact (WSEI) is a fundamental prerequisite for policy implementation. In this study, multiple types of water production modules, including surface water, groundwater, and unconventional water, were integrated into a CGE model. Hebei Province, the first pilot area in China, was used as a case study. Through a “with–without” comparative analysis scenario, three water resources tax policy simulations were designed to address the three key issues, and the results showed that the implementation of water resources tax policy would have a certain negative impact on industry economic output in the short term, but it could effectively suppress the use of conventional water and promote the utilization of unconventional water, which is beneficial for long-term water resource conservation and sustainability. The imposition of higher differential tax rates on high water-consuming industries is more effective in further promoting the use of unconventional water and reducing the use of conventional water to achieve water conservation targets. Moreover, providing tax refunds as subsidies to water-using industries could alleviate the economic impact of water resources tax and promote water conservation. From the perspectives of water quantity, water use efficiency, and economic impact, the optimal policy scenario (S3) was selected, involving implementing differential water resources tax rates of 23% for high water-consuming industries and 18% for general water-consuming industries, coupled with tax refunds and subsidies for sectors. Based on this, corresponding recommendations in terms of differential tax rate setting, tax utilization, government regulation, and agricultural water resources tax collection were provided. These findings can offer a scientific reference for the formulation and implementation of water resources tax policies in other regions.

Refined allocation of water resources is an important means of sustainable water resources utilization. Based on General Water Allocation and Simulation (GWAS), this study uses a Geographic Information System (GIS) to construct spatial topological relationships. A fairness optimal minimum was set as the objective function. Total quantity control, water supply potential, and quality-divided water supply were set as constraint conditions. Considering the dynamic mutual-feedback relationship between the middle-lower-reaches reservoir and the upstream reservoir, this study refines the allocation of water resources combined with the characteristics of “long cane knots melons” in the Pishihang irrigation area. Results showed that at 50%, 80%, and 90% frequencies in the base year, 2025, and 2035, respectively, the water deficient ratio is 0. For continuous drought years at 90% frequency, all water users are faced with different degrees of water shortage. In water source structures, water diversion in the irrigated area is the largest, followed by local surface water; reclaimed water and shallow groundwater are used as supplements. In the case of consecutive drought years, the water shortage degree can be reduced through rational development of local water and additional external water transfer. The model has thus been well applied. This study provides a more accurate method for optimizing water resources allocation.

The arid regions of Northwest China are facing water shortages and ecological fragility. Making full use of unconventional water is one of the effective ways of solving water issues and achieving high-quality regional development. The high cost of unconventional water utilization is the main obstacle to its utilization and technological development, and the subsidy policy may become a breaking point. Taking Ningdong Energy and Chemical Industry Base (NECI Base) as a case study, the article proposes raising the Yellow River water price to subsidize the utilization of mine water. The development and utilization of mine water can be effectively improved. Considering the optimal allocation of multiple water sources and the substitution relationship between the Yellow river water and mine water, this paper extends the water resources module (WRM) of the Computable General Equilibrium (CGE) model. The model can reflect the substitution of water sources and the linkage between water prices and the economy. Ten different subsidy policy scenarios are simulated through the extended CGE model, and the laws and mechanisms of the subsidy policy on the economy and water usage are summarized. The results show that increasing the price of Yellow River water by 8% to subsidize the mine water will achieve optimal socio-economic output. Under this scenario, the industrial value added (IVA) is basically unaffected, the water-use efficiency (WUE) is significantly improved, and the affordability of the enterprise is satisfied. The Yellow River water usage decreased from 319.03 million (M)m³ to 283.58 Mm³ (11.1% saving), and mine water usage increased from 27.88 Mm³ to 47.15 Mm³ (69.1% increase).

Northwest China frequently experiences significant droughts and water shortages. To better balance the supply and demand, and provide sufficient funds for water resource projects, this study applied a computable general equilibrium model to construct an agricultural water pricing policy model that depends on the crops' economic value and regional water use characteristics. Wuwei City in Gansu Province was used as a case study to test the model. Three agricultural water price increase policies and three supporting subsidy policies were developed. The study quantitatively investigated the impact of these policies on the agricultural economy, water use, and efficiency of water use from different water sources. The results indicated that water pricing reform promotes water conservation and improves water use efficiency. Subsidies can reduce the negative impact of water pricing policies on the agricultural economy. Economic crops (e.g. vegetables) are more sensitive to water prices compared to food crops (e.g. wheat). Finally, to the best of our knowledge, this study provided the best water pricing reform scenario expected to be the most effective for local development.

As China attaches increasing importance to its ecological environment, ecology-related industries have become essential to China’s national economy. However, in the current national economic accounting practice, the ecological industry (eco-industry) is not independent, and the ecological service value ecology creates is currently not within the scope of national economic accounting. To clarify the impact of the development of the eco-industry on the whole regional economy, this paper takes Beijing as the study area. For the first time, the input–output analysis method is adopted to differentiate the eco-industry as an independent sector. Moreover, the ecosystem services value is integrated into the eco-industry, and each coefficient is quantitatively analyzed from an industrial-chain perspective. The results show that the eco-industry exerts a good pulling effect on the regional economy. The inputs and outputs of the eco-industry clearly tend to focus on eco-environmental and public-service-related industries, followed by industries for which ecological development can create value. Judging from the entire regional economy, ecological investment significantly impacts both the education and financial industries. Ecological investment can promote socio-economic development, achieving a 1.318 increase in regional GDP per unit of eco-investment. The results imply that the development of the eco-industry in China should be boosted further and social capital investment should be attracted. Finally, this paper provides a scientific basis for policymakers to better understand the overall situation of both the eco-industry and industry linkages and guide them to develop relevant ecological investment strategies.