Geomembrane Applications in Saline-Alkali Soil Remediation: Mechanisms and Implementation Guidelines

Working Principles

1. Salt Isolation

• Blocks capillary rise of saline groundwater (reducing surface salt accumulation by 70-90%)

• Creates 0.5-1.0m non-saline root zone

2. Moisture Management

• Reduces evaporation losses by 60-80%

• Maintains soil moisture at 60-70% field capacity

3. Chemical Regulation

• Limits pH fluctuation to ±0.5 in treated zones

Material Selection Criteria

1. Performance Parameters

2. Recommended Materials

• Primary Choice: 1.5mm HDPE geomembrane

• Service life: 20+ years in saline conditions

• Carbon black content: 2-3% for UV protection

Construction Protocol

1. Site Preparation

• Grading Requirements:

• Maximum particle size: ≤10mm

• Surface slope: 2-5% for drainage

• Subgrade Treatment:

• Apply 200g/m² geotextile cushion layer

2. Installation Techniques

• Laying Method:

• Contour-parallel deployment with 1% prestress

• Overlap seams: 100mm minimum

• Welding Standards:

• Dual-track seams @ 300°C

• Seam peel strength: ≥80% parent material

3. Protective Measures

• Cover System:

  Layer	Thickness	Material
  Barrier	0.3m	Low-salt loam
  Growth Medium	0.2m	Sand-compost mix

Integrated Remediation Approach

1. Drainage Systems

• Design Standards:

• Subsurface drains @ 10m spacing

• Drainage coefficient: 5-8mm/day

2. Soil Amendments

• Application Rates:

• Gypsum: 5-10 ton/ha

• Organic matter: 20-30 ton/ha

3. Vegetation Strategy

• Salt-Tolerant Species:

  Type	Planting Density
  Tamarix	3-5 plants/m²
  Suaeda	50-80 seeds/m²

Title: "Geomembrane Technology for Saline Soil Reclamation: Engineering Solutions and Ecological Integration"

Performance Metrics:
▸ Salt Reduction: 50-70% in root zone within 3 years
▸ Crop Yield: Increases from 0 to 3-5 ton/ha
▸ Cost Efficiency: $8,000-12,000/ha (complete system)

Innovative Features:
✔ Composite Barriers: Geomembrane + bentonite layers
✔ Precision Irrigation: Drip systems with EC monitoring
✔ Long-term Monitoring: Embedded salinity sensors

Standards Compliance:

• ISO 13426: Geosynthetic durability

• FAO Salt-Affected Soils Management Guidelines

• GB/T 50485-2009 (Chinese Technical Code)