Extended Abstract
Introduction: Wind erosion is a critical environmental issue and a major barrier to development in arid and semi-arid regions. This destructive process causes considerable ecological damage by stripping away topsoil, reducing land productivity, and increasing dust and sandstorm occurrences. Vegetation cover, soil stability, and surface roughness are among the key factors influencing wind erosion. The Sistan region, characterized by flat topography and long-term drought, experiences severe wind erosion due to the degradation of vegetation cover. This leads to frequent dust storms, further disrupting the ecosystem. To combat these effects, the construction of contour furrows for rainwater harvesting has proven effective. These furrows increase soil surface roughness and enhance water retention, creating favorable conditions for vegetation establishment and ecological restoration.
Materials and Methods: This study was conducted in a flat area with approximately 0.5% slope and sparse vegetation, located west of Lake Hamun. Furrows measuring 40 cm in depth and 50 cm in width were constructed along horizontal lines, each 90 meters long. Seeding was conducted inside the furrows. The experimental design included three variables: precipitation storage location (inside the furrows, between the furrows, and a control area without furrows), sampling season (beginning and end of the rainy season), and year (first and second year). Each treatment was replicated four times. Vegetation characteristics, including plant height, canopy cover, bare soil percentage, and plant vitality, were assessed using 90-meter transects and quadrat sampling. Soil samples from each treatment zone were analyzed for their hydrological classification based on the SCS (Soil Conservation Service) method. Data were statistically analyzed using ANOVA in SPSS software to evaluate treatment effects.
Results and Discussion: Statistical analysis revealed that the location of precipitation storage and sampling season significantly affected plant height and canopy cover (P<0.05). Vegetation indicators improved markedly within the furrows during the second year, especially after rainfall. Plant vitality assessment showed that 54% of plants in the furrows had high vitality (first degree), 40% moderate (second degree), and only 6% low vitality (third degree). In contrast, in the control area, 73% of plants exhibited low vitality and 27% moderate vitality, with no high-vitality plants observed. Soil infiltration capacity also improved significantly in the furrowed areas. While infiltration rates in the control zone ranged from 0.3 to 1 mm/hour, they increased to between 1.3 and 3.8 mm/hour in furrowed zones. This improvement enhances water availability in the root zone, increasing soil moisture and thereby creating a suitable environment for plant growth and stabilization of the soil surface.
Conclusion: This study demonstrates that contour furrows are an effective technique for vegetation restoration and soil conservation in wind-eroded, arid environments such as the western area of Lake Hamun. By improving infiltration and increasing soil moisture, furrow construction facilitates vegetation establishment and resilience. Given the region’s limited precipitation, high evaporation rates, and compact soil layers, furrows represent a practical and low-cost solution for managing water resources and combating desertification. Their application can greatly enhance the effectiveness and sustainability of restoration efforts in degraded arid lands.