Evaluation Report on the Impact of the South-to-North Water Diversion Project on Regional Grain Production with Emphasis on Sustainable Development Goals

Abstract

Water resources are essential for agricultural production and food security, aligning closely with the United Nations Sustainable Development Goals (SDGs), particularly SDG 2: Zero Hunger and SDG 6: Clean Water and Sanitation. Mega water infrastructure projects, such as the Middle Route of the South-to-North Water Diversion Project (MR-SNWDP) in China, play a critical role in addressing regional water allocation imbalances and meeting agricultural water demands. This study employs the Synthetic Control Method (SCM) to analyze the MR-SNWDP’s impact on agricultural water consumption and grain production in Henan Province, a major grain-producing region. Findings indicate a consistent increase in total water supply and agricultural water consumption from 2010 to 2020, with significant boosts in grain production becoming evident from 2015 and culminating after 2017. The study enhances theoretical frameworks for evaluating large-scale water infrastructure and offers insights for global water management and agricultural sustainability, contributing to the achievement of SDGs.

Introduction

Food security is a critical global challenge and a core focus of the United Nations Sustainable Development Goals (SDGs), specifically SDG 2: Zero Hunger. According to the 2024 State of Food Security and Nutrition in the World Report, approximately 733 million people faced food insecurity in 2023, predominantly in developing countries, with Asia having the largest population affected by hunger. China, with its large population, faces persistent challenges in balancing food supply and demand efficiently. Water resources are fundamental to grain yield, making their availability a key factor in food security.

The 2023 China Water Resources Bulletin reports that agricultural water consumption accounts for 62.2% of total water use, highlighting the importance of water resource management in agriculture. However, China experiences uneven spatial and temporal water distribution, leading to challenges such as supply-demand disparities and low water use efficiency, which impact grain production and food security.

To address these challenges, China has implemented long-distance, high-capacity water diversion projects, notably the South-to-North Water Diversion Project (SNWDP). This mega infrastructure project integrates water supply, ecological restoration, and economic development, supporting sustainable development goals including SDG 6 (Clean Water and Sanitation), SDG 12 (Responsible Consumption and Production), and SDG 15 (Life on Land).

Globally, similar inter-basin water transfer projects have been implemented to alleviate water scarcity and support agriculture, such as the Central Valley Project in the USA, the Snowy Mountains Scheme in Australia, and India’s National River Interlinking Project.

This study focuses on the MR-SNWDP, which supplies water to Henan Province, a vital agricultural and grain production base. The research aims to evaluate the project’s impact on agricultural water consumption and grain yield, thereby contributing to SDG 2 (Zero Hunger) and SDG 6 (Clean Water and Sanitation).

Policy Background and Theoretical Analysis

Policy Background

Food security is integral to global development and the United Nations SDGs, especially SDG 2: Zero Hunger. Challenges to food security are increasingly influenced by climate change and water resource availability. Water resources are indispensable for agricultural productivity and food production, directly affecting crop irrigation and indirectly influencing arable land availability.

China faces significant challenges in agricultural water management, including supply-demand imbalances, over-exploitation, low efficiency, and deteriorating water quality. These issues threaten the sustainability of grain production and food security, underscoring the need for efficient water resource utilization and infrastructure development, aligning with SDG 6 and SDG 13 (Climate Action).

Inter-basin water diversion projects, such as the SNWDP, are strategic responses to uneven water distribution, aiming to improve water allocation, support agriculture, and promote sustainable economic and ecological development. Evaluations of such projects typically focus on water resource systems, economic factors, and ecological impacts, but there is a gap in assessing their direct effects on agriculture and food security.

Impact of Water Resources on Grain Yield

Direct Impact

Adequate agricultural water supply, primarily through irrigation, is critical for optimal crop growth and yield. Surface water availability affects irrigation reliability, and fluctuations can disrupt agricultural productivity. The MR-SNWDP addresses agricultural water shortages caused by climate change and other factors by increasing surface water availability, thereby supporting grain production in Henan and contributing to SDG 2 and SDG 6.

Indirect Impact

Groundwater supply and irrigated farmland area indirectly influence food production. The MR-SNWDP has reduced reliance on groundwater by providing alternative water sources, promoting sustainable agricultural development and expansion of irrigated lands. This supports SDG 6 and SDG 15 by encouraging sustainable water use and land management.

Materials and Methods

Study Area

The MR-SNWDP spans 1,277 kilometers, supplying water to Henan, Hebei, Beijing, and Tianjin. Henan Province, a major grain producer contributing significantly to China’s national food security, is the focus of this study. The project has increased water supply and agricultural water consumption in Henan, supporting sustainable agricultural development and SDG 2 and SDG 6.

Synthetic Control Method (SCM)

The SCM is employed to evaluate the policy effect of the MR-SNWDP on grain yield in Henan by constructing a synthetic control group from other major grain-producing regions unaffected by the project. This method allows for counterfactual analysis to estimate the causal impact of the water diversion project on grain production.

Data Sources

• Grain yield (dependent variable)
• Agricultural water consumption, groundwater supply, surface water supply, and irrigated farmland area (control variables)

Data from 2010 to 2020 were analyzed, with 2015 marking the policy intervention year. Data were sourced from official Chinese statistical yearbooks and water resource bulletins.

Results

Counterfactual Policy Intervention Construction

Henan Province was designated as the treatment group, with nine other major grain-producing provinces as the control group. Data from provinces affected by other SNWDP routes were excluded to avoid confounding effects. Initial comparisons showed Henan’s grain yield was higher than the control group average, necessitating the use of SCM for accurate analysis.

Fitting Results

Before the MR-SNWDP operation, synthetic and actual grain yields in Henan showed similar trends. Post-2014, actual grain yield in Henan increasingly exceeded synthetic estimates, indicating a positive impact of the MR-SNWDP on grain production, supporting SDG 2 and SDG 6.

Difference in Grain Yield

Analysis of yield differences revealed a decline before 2012 due to water scarcity constraints. After the MR-SNWDP operation, the trend reversed, with yield differences increasing from 2015 and surpassing zero by 2017, demonstrating the project’s effectiveness in enhancing water availability and grain production.

Robustness Test

Placebo tests confirmed the reliability of SCM results. Synthetic control groups were iteratively reconstructed, and prediction errors compared. Henan showed a distinct upward trend in grain yield post-2015 compared to control provinces, validating the positive impact of the MR-SNWDP.

Conclusion and Policy Implications

Key Findings

1. The MR-SNWDP has significantly increased water supply and agricultural water consumption in Henan since 2014, supporting expanded irrigation and grain production.
2. The project has positively influenced grain yield, fulfilling agricultural water needs along the diversion route.
3. Effects became evident from 2015, with marked yield increases after 2017.
4. Robustness tests confirm the validity of these findings and the effectiveness of SCM in policy evaluation.

Policy Recommendations

• Integrated Water Management: Develop intelligent systems for coordinated surface water and groundwater allocation to ensure stable agricultural water supply, prevent groundwater over-exploitation, and promote sustainable water use (supporting SDG 6 and SDG 15).
• Collaborative Governance: Reform water resource management frameworks by consolidating monitoring and approval authorities, optimizing water quota systems, and implementing blockchain-based water rights registration to enhance transparency and efficiency (aligned with SDG 6 and SDG 16: Peace, Justice, and Strong Institutions).
• Market-Oriented Water Rights Trading: Establish Water Rights Banks and promote water-saving certifications to incentivize conservation. Develop water rights derivatives markets to hedge drought risks and optimize resource allocation (supporting SDG 12 and SDG 13).
• Ecological Security Mechanisms: Implement zonal ecological protection along the SNWDP to balance water supply needs with ecosystem sustainability, ensuring no ecological damage and maintaining carrying capacity (aligned with SDG 15 and SDG 13).

Limitations and Future Research

This study focused on overall grain production impact in Henan but did not differentiate effects on specific cereal crops such as wheat, corn, and rice. Future research should analyze crop-specific impacts to further inform targeted agricultural and water resource policies.

1. Sustainable Development Goals (SDGs) Addressed or Connected

• SDG 2: Zero Hunger – The article focuses on food security, grain production, and agricultural sustainability, which directly relate to SDG 2 aiming to end hunger, achieve food security, and promote sustainable agriculture.
• SDG 6: Clean Water and Sanitation – The article discusses water resource management, water supply, and water infrastructure projects, which are essential for ensuring availability and sustainable management of water and sanitation for all.
• SDG 12: Responsible Consumption and Production – The article addresses efficient use of water resources in agriculture, promoting sustainable consumption and production patterns.
• SDG 13: Climate Action – The article mentions the impact of climate change on water resources and food security, linking to the goal of taking urgent action to combat climate change and its impacts.
• SDG 15: Life on Land – The article refers to ecological restoration and ecological security mechanisms along the water diversion project, contributing to sustainable management of terrestrial ecosystems.

2. Specific Targets Under the Identified SDGs

1. SDG 2: Zero Hunger
   • Target 2.3: By 2030, double the agricultural productivity and incomes of small-scale food producers, including through secure and equal access to water resources.
   • Target 2.4: Ensure sustainable food production systems and implement resilient agricultural practices that increase productivity and production.
2. SDG 6: Clean Water and Sanitation
   • Target 6.1: Achieve universal and equitable access to safe and affordable drinking water for all.
   • Target 6.4: Substantially increase water-use efficiency across all sectors and ensure sustainable withdrawals and supply of freshwater.
   • Target 6.5: Implement integrated water resources management at all levels, including transboundary cooperation.
3. SDG 12: Responsible Consumption and Production
   • Target 12.2: Achieve sustainable management and efficient use of natural resources.
4. SDG 13: Climate Action
   • Target 13.1: Strengthen resilience and adaptive capacity to climate-related hazards and natural disasters in all countries.
5. SDG 15: Life on Land
   • Target 15.1: Ensure the conservation, restoration, and sustainable use of terrestrial and inland freshwater ecosystems.

3. Indicators Mentioned or Implied to Measure Progress

• Grain Yield (million tons) – Used to measure agricultural productivity and food security improvements in Henan province after the MR-SNWDP implementation.
• Agricultural Water Consumption (billion m³) – Tracks water used specifically for agriculture, indicating water resource allocation efficiency.
• Total Water Supply (billion m³) – Measures overall water availability in the region, reflecting the impact of water diversion projects.
• Farmland Irrigation Area (hectares) – Indicates the extent of irrigated agricultural land, linked to food production capacity.
• Groundwater Supply (billion m³) – Monitors groundwater usage and sustainability in agricultural practices.
• Water Use Efficiency – Implied through discussions on optimizing water resource utilization and reducing over-exploitation.
• Ecological Security and Environmental Sustainability Indicators – Implied through ecological restoration and protection measures along the water diversion route.

4. Table: SDGs, Targets and Indicators

Source: nature.com