Soil moisture variations of wetland at different altitudes in desert regions, China

Abstract

Desert wetland is a special ecological environment as water is fundamental to maintaining existence. The soil water of sandy wetland links surficial water and groundwater. This study Takes Habahu National Wetland Nature Reserve as the research area and the water movement characteristics of soil profile as the research purpose. According to the altitude and topographic characteristics, the main focus is monitoring soil moisture in different layers at specific sites. The results show that: (1) In the core area of sandy wetland, the water movement of the soil profile is slow with lower infiltration and evaporation; (2) On the slopes around the wetland, the surface water is recharged by rapid leakage along with the underlying impermeable layer after precipitation due to the sand coverage; (3) In the desert hinterland outside the wetland, the water rapidly infiltrates after precipitation and flows into different groundwater systems along the structural characteristics of the underlying stratum to supplement the nearby wetlands. Based on these characteristics, we put forward the unique viewpoints of environmental protection in sandy wetlands: (1) focus on the protection of surface organisms in the core area of sandy wetland to reduce evaporation and improvethe soil water-holding capacity; (2) Appropriate engineering and biological measures should be applied to the slope outside the core area to reduce surface evaporation and plant transpiration and improve the soil moisture; (3) In the periphery area of the wetland, infiltration should be promoted to ensure the source of water supply to wetlands, which would maintain the existence of wetlands and give full play to their ecological functions. In addition, this study analyzed the relationship between soil moisture and plant diversity of 35 species. 16 plants are considered to be suitable for planting in core area of sandy wetland and 9 plants for planting in the desert hinterland outside the wetland.