CN104846912B - Dune area water collection irrigation system - Google Patents

Abstract

The invention discloses a water collection irrigation system in a desert area, which belongs to the technical field of water and soil conservation. The system is to choose a relatively flat area in the desert area, and flatten the sand surface into a stepped water catchment area, water storage area and irrigation area; the water catchment area is located upstream, which is a slope; the water storage area is located downstream of the water collection area , and a reservoir is built; the irrigation area is located downstream of the reservoir, including the irrigation slope and flat irrigation surface bordering the reservoir, and a water-retaining layer is laid on the irrigation surface. The present invention integrates water collection, water storage, irrigation and water retention into one system engineering, collects and makes full use of limited rainfall and water resources in desert areas, so as to promote the growth of sandy plants and improve the ecological environment in sandy areas. The system mainly uses laterite or loess, which is a large amount of clay in desert areas, as a raw material, which is not only low in cost, but also environmentally friendly, effectively avoiding the secondary pollution of the environment caused by water-retaining materials in the prior art.

Description

A catchment irrigation system for dunes

technical field

The invention relates to a water-collecting irrigation system, in particular to a water-collecting irrigation system used in sand dunes, and belongs to the technical field of water and soil conservation.

Background technique

Land desertification and desertification are a long-term problem faced by the whole world, and one of the most serious ecological problems in our country at present, as well as the focus and difficulty of our country's ecological construction. The desertification of the sand dunes degrades the ecological environment, and the people in the sandy areas live in poverty, which has caused great harm to the sustainable development of the local and national economy and society, and has become a serious obstacle to local and national development. my country's sandy area is mainly arid and semi-arid climate, which is characterized by dryness and little rain, strong sunshine and strong wind. The sandy land and Gobi in the northwest of my country have little rainfall and high variability. The annual precipitation is mainly concentrated in June-September. The sandy land and Gobi in the Hexi Corridor of Gansu Province are mainly concentrated in June. The local rainfall is not only wasteful, but also Cause different degrees of soil erosion, reduce soil fertility and arable land productivity. Therefore, the protection and utilization of water resources is particularly important in desert areas. How to collect, protect and utilize the limited water resources in desert areas has become a research hotspot.

Water harvesting technology refers to the adoption of land preparation measures and precipitation runoff regulation and utilization technology to intercept and accumulate surface runoff or collect effective precipitation, and then regulate and distribute again to improve the water status of local soil for plant growth and use. At present, the main water collection technologies mainly include reverse slope platform, fish scale pit, laying crop stalks to collect water, laying plastic shed film to collect rain, water cellars, and water storage tanks. The reverse slope platform is suitable for hillsides with sparse vegetation and relatively regular slopes. Fish scale pits are suitable for rocky mountains, red sandy soil slopes and steep slopes with irregular topography. In addition, because of the small excavation surface, it can reduce the damage to vegetation when used in places with good vegetation. The laying of crop stalks for flow collection and the laying of plastic shed film for rain collection should be used in conjunction with reverse slope platforms and fish scale pits. Water cellars and pools, also known as micro-reservoirs, are also effective water collection measures, which can effectively intercept surface runoff, so it can reduce runoff flow and delay the time of runoff concentration. Water cellars and pools have the function of storing water, so they can adjust the distribution of water in time and space, and store the runoff generated in heavy rainy days for future use. This not only solves the contradiction between water shortage and flood, but also promotes the use of sandy land and Gobi land, expands the living space of people, and promotes the benign development of the ecological environment. At present, cement and river sand are mostly used in the preparation of water cellars or pools. The sand grains in sandy areas are not suitable as raw materials for preparing water cellars and pools due to their strong alkalinity.

Water retention technology refers to the engineering and technical measures of laying an impermeable layer or a mulch that inhibits water evaporation on the soil surface to inhibit or delay the water evaporation in the soil, thereby prolonging the effective water holding time of the soil. The commonly used water retention technologies mainly include: ① Mulching to inhibit soil surface evaporation: such as plant residue covering (crop straw, chaff, sawdust, litter, etc.), gravel sand covering, plastic mulch covering, petrochemical covering (asphalt , paraffin, petroleum compounds, etc.); ②Use drought-resistant drugs: such as water-retaining agents.

Due to the strong wind and sand and strong ultraviolet rays in desert areas, most materials such as plant straw and plastic film are very easy to age and decompose, losing their efficacy; petroleum-based materials such as asphalt, paraffin, and petroleum compounds have problems such as polluting the environment; commercially available water-retaining agents are expensive , it is impossible to promote and use it in a large area in desert areas.

Contents of the invention

The purpose of the present invention is to provide a water collection irrigation system used in sand dunes.

The water collection and irrigation system of the present invention is to choose a relatively flat area in the sand dune zone, and flatten it into a water collection area, a water storage area and an irrigation area distributed in a ladder shape; the water collection area is located upstream, and is a slope with a slope of 3-30 degrees ; The water storage area is located downstream of the catchment area, and a reservoir is built; the irrigation area is located downstream of the reservoir, including irrigation slopes and flat irrigation surfaces bordering on the water storage area, and water retention devices are laid on the irrigation surface layer.

The surface layer of the slope surface of the water catchment area is excavated and cut into water channels with a depth of 10-20cm, a width of 100-200cm, and an interval of 500-1000cm, which are compacted and introduced into the water storage area.

The reservoir is an inverted cone-shaped reservoir based on clay, and its construction method is as follows: excavate a large circular pit with a small bottom and a large opening in the leveled reservoir area, and tamp the bottom and walls of the pit; Prepare red clay (the ratio of laterite to water is about 5:1, after repeated rolling to form highly viscous red clay) and lay it on the bottom and wall of the pit; the laying thickness of red clay is 20~25cm; The taper is 15~60 degrees.

In order to allow the entire slope to be irrigated evenly, the slope of the irrigated slope in the irrigation area shall not exceed 15 degrees, and the surface shall be piled up with soil or sand to form a horizontal arrangement of 10-20cm high and 20-30cm wide. 200-500cm; please open every 500cm or so (about 20cm) on the ridge, and the openings of each row of ridges are staggered.

Laying of the water-retaining layer on the irrigation surface of the irrigation area: first lay a clay layer with a thickness of 10-20cm on the sand surface of the irrigation area, and then lay a gravel layer with a thickness of 20-25cm on the clay layer.

The resource arranges the reservoir on the relatively flat area of the hillside, which is not only conducive to water storage, but also conducive to water discharge during later irrigation, and can also prevent mountain torrents from depositing clay into laterite or loess on the reservoir.

The present invention has the following advantages and beneficial effects:

1. The present invention collects and fully utilizes the limited rainfall and water resources in the desert area through the system engineering of water collection, water storage and irrigation, so as to promote their rational use;

2. A water-retaining layer consisting of a clay layer and a gravel layer is laid on the sand surface of the irrigation area. The paving of the gravel layer is conducive to water infiltration, which can prevent the clay water-retaining layer from being hardened by strong sunlight, and at the same time prevent the damage of the clay water-retaining layer by strong winds in the sandy area; because the clay is smaller than the sand, it can slow down and prevent the sand layer from forming. The evaporation of water can also provide essential nutrients for sand plants, promote the growth of sand plants, and improve the ecological environment of sandy areas;

3. The present invention mainly uses laterite or loess clay which exists in large quantities in desert areas as raw material, which not only has high strength and low cost, but also is environmentally friendly, effectively avoiding the secondary pollution caused by water-retaining materials in the prior art.

Description of drawings

Fig. 1 is a longitudinal sectional view of the water collection irrigation system of the present invention.

Fig. 2 is the distribution diagram of the ridge on the irrigation slope of the present invention.

detailed description

The structure and construction method of the water collection irrigation system of the present invention will be further described below through specific embodiments.

In sandy areas with an annual rainfall of more than 200 mm, according to the topographical characteristics, a relatively flat area in the hillside is selected, and the sand surface is flattened into a stepped distribution of catchment area, water storage area, and irrigation area, see Figure 1. Among them, the catchment area is located in the upstream, which is a slope with a slope of 3-30 degrees. The surface layer of the slope is excavated into channels with a depth of 10-20 cm, a width of 100-200 cm, and an interval of 500-1000 cm, which are compacted and introduced into the water storage area. The water storage area is located downstream of the catchment area, and a water storage tank is built; the irrigation area is located downstream of the water storage tank, including the irrigation slope and flat irrigation surface bordering the water storage area, and a water-retaining layer is laid on the irrigation surface .

The reservoir in the water storage area is in the shape of a clay-based inverted cone, with a diameter of 400cm at the bottom, a diameter of 1000cm at the mouth, and a height of 500cm. landslide). The construction method is as follows: excavate a large circular pit with a small bottom and a large opening in the leveled water storage area, and tamp the bottom and walls of the pit; then prepare red clay into red clay (the ratio of laterite to water is about 5:1 , after repeated rolling to form highly viscous red clay) is laid on the bottom and wall of the pit; the laying thickness of red clay is 20~25cm. One pool can be arranged for every 50 mu of sandy Gobi area. Arranging the reservoir on a relatively flat hillside is not only conducive to water storage, but also conducive to water discharge during later irrigation, and can also prevent mountain torrents from accumulating on the reservoir.

The slope of the irrigation slope in the irrigation area is not more than 15 degrees, and the surface is piled up with local soil or sand to form a horizontal arrangement of 10-20cm high and 20-30cm wide ridges, with an interval of 200-500cm between ridges; The opening is about 500cm (about 20cm), and the openings of each row of corrugated ridges are staggered (see Figure 2). Such arrangement of ridges and openings is conducive to the uniform irrigation of the entire slope; the laying of the water-retaining layer on the irrigation surface of the irrigation area: first lay a layer of clay layer with a thickness of 10~20cm on the sand surface of the irrigation area, and then lay the clay layer on the Lay a gravel layer with a thickness of 20-25cm on top. The clay used for laying the clay layer can be red clay or loess according to local resources. Clay can slow down and prevent the evaporation of water in the sand layer because its particle size is smaller than that of sand; at the same time, the application of clay can not only play a role in water retention, but also provide essential nutrients for sand plants, promote the growth of sand plants, and improve the quality of sand. The ecological environment of the area. The paving of the gravel layer is conducive to water infiltration, which can prevent the clay water-retaining layer from hardening due to strong sunlight, and at the same time prevent the strong wind in the sandy area from damaging the clay water-retaining layer.

Claims (3)

1. A catchment irrigation system used in sand dune areas is characterized in that: a relatively flat zone is selected to be flattened into a catchment area, a water storage area and an irrigation area in a stepped distribution; the catchment area is located in the upper reaches, for A slope with a slope of 3 to 30 degrees; the water storage area is located downstream of the catchment area, and a water storage tank is built; the irrigation area is located downstream of the water storage tank, including irrigation slopes and flat irrigation surfaces bordering the water storage area, and A water-retaining layer is laid on the irrigation surface; The reservoir is a clay-based inverted frustum-shaped reservoir, and its construction method is as follows: excavate a large circular pit with a small bottom and a large opening in the leveled reservoir area, and tamp the bottom and walls of the pit; Red clay is laid on the bottom and wall of the pit; the laying thickness of the red clay is 20-25cm; the taper of the frustum-shaped sump is 15-60 degrees; the preparation method of the red clay is to mix red soil and water at a ratio of 5:1 After mixing in the mass ratio, high-viscosity red clay is formed through repeated rolling; Laying of the water-retaining layer on the irrigation surface: first lay a clay layer with a thickness of 10-20cm on the sand surface of the irrigation area, and then lay a gravel layer with a thickness of 20-25cm on the clay layer. 2. as claimed in claim 1, is used for the catchment irrigation system of sand dune area, it is characterized in that: the surface layer of catchment area slope face is dug into deep 10-20cm, wide 100-200cm, the water channel of interval 500-1000cm, press Realized and introduced into the water storage area. 3. As claimed in claim 1, the catchment irrigation system used in the dune area is characterized in that: the slope of the irrigation slope is less than 15 degrees, and the surface is piled up with soil or sand grains into a horizontal arrangement with a height of 10-20cm and a width of 20-30cm The ridges are spaced at 200-500cm apart; the ridges are opened every 500cm, and the openings of each row of ridges are staggered.