Landforms and Wetland Landscapes

1. Landform types and distribution

According to the landform origin and morphological characteristics of Huixian Karst Wetland and surrounding areas, the landform type of Huixian Karst Wetland is divided into normal, medium and low mountains and hills. The main types include ridges, peaks and depressions (valleys), island peaks, karst slopes and valleys, peaks (lone peaks) plains and karst wetlands (lakes, swamps, etc.) (Figure 2-19).

1. Normally medium-low mountains and hills

Normally medium-low mountains are mainly distributed in the Jiaqiaoling Mountains south of Huixian, and are composed of Devonian Xindu Formation clastic rocks . The terrain of the mountain is tall and majestic. The altitude of the top of the mountain is mostly between 600 and 1200m. The highest point is Liangshawei with an altitude of 1226m (also the highest peak in the Huixian karst wetland area). The mountains of the Jiaqiaoling Mountains are nearly distributed in a north-south direction, with high in the south and low in the north. The terrain is high and steep, with dense valleys and valleys mostly running in an east-west and north-south direction. The relative cutting depth is 300 to 500m. The surface water system in the area is developed and is the main external water supply area in the southern part of the Huixian Karst Wetland. It is also the birthplace of the main rivers in the southern part of the wetland, Liangfeng River, Huixian River and Luojin River.

Figure 2-19 Distribution map of landform types in the core area of ??Huixian Karst Wetland

In the northern Longquan Forestry-Livestock Farm-Zhangcun-Baiyanjing and other areas, there are also Middle Devonian A small area of ??low mountains and hills composed of sandstone of the Xindu Formation. The altitude of the top of the mountain is generally below 700m, forming the northern surface watershed of the Huixian Karst Wetland catchment area. In addition, on the east and west sides of the wetland, especially the western edge of the wetland west of Fenghuangling-Jipai-Sitang, there are low mountains and hills composed of Devonian and Carboniferous sandstone, siltstone, siliceous rock and mudstone. It is distributed in a nearly north-south direction (Yangjiao Mountain-Zhuliantang-Fenghuang Ridge is the most typical, 1-3km wide), with an altitude of 300-600m, a relative elevation of 200-400m, and a rounded ridge; in the east, Ma'an Mountain-Yanshan Daling-Niao Affected by faults, Tsailing has low mountains and hills distributed intermittently, about 1km wide; while soft rock formations such as Carboniferous sand shale, marl and siliceous rock mostly form a nearly north-south direction, relatively gentle undulations, and an altitude of 170 Hilly ridges ranging from ~250m, typical of which are low hills and gentle slopes in Sitang Township Jiepai-Tuqiao, Yanshan District Liangfeng Farm-Guilin Horticulture Farm and other places.

2. Karst peaks and depressions (valleys)

Mainly distributed in the core of the Huangcun-Mamian anticline and the northern sloping end of the Jiaqiaoling anticline and its adjacent wings. That is, north of the line from Xiguanzhuang (Jiutou Mountain), Sitang Township, Lingui County in the north - Dulong - Mamianwei, Huixian Town, and south of Luojin - Aishan - Huixian Town - Shanwei - Liutang Town, Yongfu County .

North of the line from Xiguanzhuang (Jiutou Mountain) to Dulong in Huixian Town to Mamianwei, the altitude of the top of Fengcong Shishan Mountain is generally 250 to 500m. The peaks are steep and multi-layered caves are developed on them. There are karst underground rivers, surface water systems are not developed, and depressions and valleys of varying sizes are distributed among the peaks. There are often karst pools and underground rivers in the lowest depressions at the bottom of large depressions or valleys. During the rainy season, water accumulates to form lakes or swamps.

Luojin-Aishan-Huixian Town-Shanwei-The peak-cong depression (valley) south of Liutang Town surrounds the normal middle and low mountains in the middle of the Jiaqiaoling Mountains, forming an arc protruding to the north. shape. The arc-shaped peak cluster depression (valley) is about 5 to 8 km wide. Controlled by the geological structures (faults and joints) distributed radially with Jiaqiaoling as the center at the northern tip of the Jiaqiaoling anticline, the surface water and groundwater in the area are mostly distributed in NW, N and NE directions. . Especially near the contact zone between clastic rock and carbonate rock, affected by the strong erosion and dissolution of external water, karstification develops particularly strongly. Surface water and groundwater frequently convert, forming mainly peaks and valleys, with bright and dark rivers. Typical karst landforms passing through. The altitude of the top of Shifeng is generally 200-600m, and gradually decreases from the front of Jiaqiaoling Mountain to the periphery. During the rainy season, water accumulates in large depressions or slope valleys (such as Jiutu Cave in the southeast of Huixian Town) because the karst pipes or underflow inlets are narrow and cannot effectively discharge floodwaters.

3. Island-shaped peak cluster

It consists of two or more consecutive stone peaks standing on the plain surface or water surface (lakes, swamps). It is mostly distributed in the transition zone between peaks, depressions (valleys) and wetlands (peak forest plains). Hydrogeologically, it belongs to the transition zone from groundwater to surface water. Ecologically, it is located in the transition zone between surface karst wetlands and underground karst wetlands (*** existing ). Due to frequent surface and groundwater activities, karstification is strongly developed in the island-shaped peak cluster distribution area. Typical island peak cluster distribution areas include Jiutou Mountain near Xiguanzhuang, Sitang Township, Jiashan Mountain near Lingui County, and Lion Rock near Fengjia, Huixian Town. Most of the distribution areas are below 1.0km2, and the top elevation of the peaks is average. It is 200~350m, and the relative elevation is above 50m; there are depressions or ponds distributed among the stone peaks, and there are a large number of caves, karst springs or underground rivers of varying sizes (such as Jiutou Mountain Fushan Underground River, Lion Mountain Underground River The river (with a measured length of more than 900m) is exposed on the surface and has become the main water supply source for Huixian karst wetland. The Jiutou Mountain Fushan Underground River and the Lion Mountain Underground River (with a detected length of more than 900m) are typical representatives.

4. Hilly landforms

Distributed on the east and west sides of the study area, including the line from Liutanggou River Bridge in Lingui County to Ma'anshan-Yanshan-Yanshan Ertang The continuous distribution of narrow mountainous areas below 400m above sea level, mostly in a north-south direction, and 0.5-1km wide, as well as in the west of Luojin Dali-Sitang Jiepai-Sitang Township-Yangtang line from the west to the western watershed, extending in a north-south direction , a mountainous area about 20km long, 1-2km wide, and with a top elevation of 180-300m. The slopes and tops of mountains are gentle, mostly in the shape of steamed buns or strips.

The east and west hills are composed of Devonian-Carboniferous non-carbonate rocks or impure carbonate rocks, which not only form the eastern and western boundaries of the Huixian karst closed water storage geological body, but also Able to effectively preserve (storage) water. Multiple reservoirs built in the western hills provide good conditions for wetland replenishment and agricultural irrigation.

5. Fenglin Plain (Dissolution Plain)

Distributed in the center of Huixian Karst Wetland, it is a low-level plain ground formed by long-term karstification. There are various numbers of etc., isolated stone peaks of different sizes. Among them, Huixian, Mudong, Dulong, Mamian, Liantang and other places have low and flat terrain. Their plains are generally flat or slightly undulating, with altitudes mostly between 146 and 150m. The lowest point is at the Xiangsi River in the Dawan area in the west. River valley, 145m above sea level. There are scattered isolated stone peaks, island-shaped peak clusters, or low earth hills, gentle hills or ridges on the plain surface. Isolated stone peaks are mostly composed of thick layers of massive limestone that are brittle and gentle in appearance (multiple horizontal occurrences). They rise from the flat ground, are steep on all sides, and are small in scale (generally within 0.05km2). The peak elevation is 180~ 300m, with a relative height ranging from 30 to 150m; gentle hills or ridges are mostly composed of dolomite, argillaceous rock or thin layers of impure limestone. Their slopes and tops are gentle, and the altitude is mostly below 200m, with thick layers on them. The soil layer is the main dryland crop and forest planting area in the area. The large low-lying areas on the plain surface have long-term accumulation of water, forming lakes, ponds, water meadows, and swamps. Surface rivers and lakes are intertwined with criss-crossing water systems. It is the main rice planting area in the region and is also the core area of ??Huixian karst wetland.

The Qingshui River Basin, the Lanqiaobao karst valley and the upper reaches of the Huixian River and Liangfeng River located in Xiguanzhuang, Quandong and Miancun, Lingui County are also called flat valleys. Karst slope valley plain. The valley plain is narrow and long, and the terrain on both sides is low-lying and flat. There are occasional isolated peaks and gentle hills in the valley. The source of the river in the valley or both sides (or one side, such as Qingshui River) are peak-cluster depressions. The rivers are mainly supplied by karst underground rivers and karst springs (mostly small seepage karst springs). Due to the low and flat terrain, surface and groundwater drainage at the downstream outlet of the valley is not smooth during the rainy season, causing floods in the valley (typical examples are in the Xiguanzhuang, Jiutoushan and Dawan areas in the lower reaches of the Qingshui River).

6. Karst wetlands

Distributed in low-lying areas such as Fengcong depression, Fengcong valley and Fenglin plain. The soil is permanently or seasonally flooded or the soil is saturated for a long time. State, water or water-like humid landscape area with lush growth of aquatic or hygrophytic plants, including karst lakes, karst swamps, water grasslands, karst reservoirs (ponds) and other types. Typical karst lake landscapes (landforms) in Huixian Karst Wetland include Mutong Lake, Dulong Lake, Baxian Lake, Temple Lake, Liantang and Fenshuitang, etc. Typical karst swamps include karst river swamps along the Qingshui River and Jiutoushan swamp. With water grassland, Shenlong swamp, Dulong swamp, etc.

2. Typical karst wetland landscape

Landscape refers to the overall characteristics of a specific area on the earth's surface. Huixian karst wetland landscape is the crystallization of the fusion of karst wetland ecological landscape and karst landform landscape.

The miraculous workmanship of nature has created the Huixian Wetland, which is surrounded by mountains, blends of mountains and rivers, and has beautiful scenery and diverse karst landforms and wetland ecological landscapes. The lake here is clear, there is water in the mountains, there are mountains in the water, the mountains are surrounded by water, the water flows around the mountains, the water and the sky are the same color; the springs in front of the mountains are gurgling, the water plants are green, and there are also magical caves and underground rivers. It is a typical southern subtropical karst landform. Landscape and tourism resources are rich.

As a typical and complete karst wetland ecosystem, Huixian Karst Wetland has high landscape value. Its wide water surface, river valleys and lakes with nine twists and turns and eighteen bays, diverse and rich wetland biological resources, and the beautiful karst surface and underground landscapes in and around the wetland complement and blend with each other, forming a unique karst wetland landscape integrating mountains and rivers. The "Xiangsidai" built after the Tang Dynasty to connect the Liujiang River and the Lijiang River added rich historical and cultural connotation and landscape value to the wetland. Therefore, Huixian Karst Wetland has multiple values ??for water recreation, sightseeing, entertainment, science education and scientific research.

1. River and lake wetland biome landscape

Huixian karst wetland includes major lakes such as Mutong Lake, Dulong Lake, Baxian Lake, Temple Lake, Liantang Lake and Damatang Lake, and The wide bays and river banks of typical rivers such as the Qingshui River.

Huixian Karst Wetland has more than 100 species of hygrophytic and aquatic wetland plants, which are distributed in various rivers, lakes and on the shores. The types are diverse, the layers are rich, and the zoning is obvious (Figure 2- 20) Submerged, floating, emergent and hygrophytic plant communities with different scenery, some characteristic ornamental plants and endangered precious plants add to the ornamental value and cultural connotation of the wetland.

The currently preserved wetland plant communities with large contiguous areas and high ornamental value include the lotus community in Mutong Lake and Liantang (Figure 2-21), and the Huaklasa community in Mutong Lake and Fenshui Pond around Central Longshan. (Figure 2-22), the long-bracted cattail community in Mutong Lake between Sihu and Dulong-Longshan (Figure 2-23), the reed community along Mutong Lake and Qingshui River (Figure 2-24), As well as floating and submerged plant communities such as the wild rice community in Shizitan Lake, the Erythium striata community in Mutong Lake, and the bamboo-leaf cabbage (Figure 2-25). Especially during the lotus blooming season every year, it attracts many tourists to come and watch it. At present, the villagers around Mutong Lake have partially developed the wetland landscape for leisure tourism, but it is still in the primary development stage, and eco-tourism still has important development potential.

Figure 2-20 Coastal zoning of plants on the central island of Temple Lake

Figure 2-21 Mu Donglian

Figure 2-22 Huaklasa

Figure 2-23 Cattails

Figure 2-24 Reeds at the intersection of Temple Lake exit and Qingshui River

Figure 2-25 Colorful floating plant community landscape

2. Karst landforms and cave landscapes

Includes two types of surface karst landforms and underground karst landforms.

The surface karst landform landscape includes typical peak cluster depression landform landscape (Figure 2-26), karst peak forest plain (wetland) landscape (Figure 2-27), and island-shaped peak cluster (Figure 2-28) and various forms of karst stone peaks (tower-shaped stone peaks, cone-shaped stone peaks, etc.) and dissolution forms (Figure 2-29).

Figure 2-26 Fengcong Depression

Figure 2-27 Fenglin Plain Landform (1)

Figure 2-27 Fenglin Plain Landform (2)

Figure 2-28 Island Peak Cluster

Underground karst landforms include karst underground rivers and cave systems, karst sinkholes, etc. There are numerous karst caves and underground rivers developed in Huixian Wetland and the surrounding karst rock mountains. The various stalagmites, stalactites, stone pillars and other cave sedimentary landscapes formed by dissolution in the underground river cave system are also an important part of the karst wetland landscape and an important tourist landscape resource, with high protection and development value. Among them, the Lion Rock Underground River (the total length is about 1100m, and has been measured about 800m) and its associated karst sinkhole (underground river skylight), Bayin (Xian) Rock, Guxian Cave and other cave systems; Xiguanzhuang, Sitang Township Fushan underground river (about 200 meters long) and upper caves; Sitang Township Edi underground river, Quandong underground river and surrounding cave groups, Huixian Mapian underground river and Shendong underground river group in the south of Luojin, Yongfu County (already developed There are Jinzhong Mountain Scenic Area) and other areas with good development prospects (Figure 2-30).

Figure 2-29 Karst landform landscape

Figure 2-30 Underground karst landform landscape

3. Comprehensive karst wetland landscape

Meeting The fairy karst wetland is different from ordinary rivers, lakes (reservoirs) or swamps, and also different from the general karst landforms widely distributed in my country. The beauty of its landscape is reflected in its mountains (karst landforms), water (wetlands, lakes, rivers, swamps) , forest (wetland ecosystem), and pastoral (artificial landscape) integrate and complement each other (Figure 2-31). It can be divided into the following comprehensive landscapes:

Figure 2-31 Panoramic view of Huixian karst wetland

(1) Lakeside forest, lake, swamp and wetland landscape

Distributed in Yan Shanliantang - On the peak forest plain between the trees, there are many swamps or ponds in the low-lying areas between the lakeside or gentle hills and river valleys, where all kinds of hygrophytes and aquatic plants grow; on the lakeside or the undulating lakeside or gentle hills, On the high swamp (slightly higher than the lowest water level), there are arbors and woodlands mainly composed of slash pine and other trees (Figure 2-32), forming a wetland ecological landscape integrating karst peaks, waters, swamps and forests with a pleasant climate. Due to the low-lying terrain, the forest is frequently flooded during the rainy season.

Figure 2-32 Forest, lake, swamp and wetland

(2) Comprehensive landscape of rivers and lakes

It is a comprehensive landscape that organically integrates rivers, lakes and karst landforms . According to the spatial distribution and landscape composition of rivers, lakes and karst landforms, they are divided into various types such as mountain rings, water circles, and mountains and rivers reflecting each other, forming a reflection of the mountains. "There is water in the mountains, mountains in the water, and mountains and rivers reflecting each other." Various landscapes or picturesque pastoral scenery.

Mountain ring type river, lake and landscape landscape: also known as "Pearl of Stone Mountain", refers to the karst area around Huixian Karst Wetland dominated by karst peaks and stone mountains. Since the groundwater level is at a high level all year round, Location (usually 1 to 3m below the ground), mountain lakes, ponds or swamps, large karst pools that accumulate water all year round in depressions surrounded by peaks, valleys and low-lying areas, as well as poor drainage at the bottom, most of the year or A large depression (valley) that is seasonally flooded. During the rainy season, many depressions or valleys (Poli Valley) around the Huixian Karst Wetland accumulate large areas of water. These mountain lakes, ponds or pools are like "pearls" embedded in the mountains. The mountains are reflected, and rivers meander through them. The "pearls" are connected together to form a group of pictures. A beautiful landscape with mountains and rivers blending together. Typical "stone mountain pearls" around Huixian Karst Wetland include Quandong mountain lakes (water-filled depressions), Jiutudong water-filled slope valley, Lion Lake and Baxian Lake (Figure 2-33, Figure 2-34).

Figure 2-33 "Pearl of Stone Mountain" - Lion Lake

Figure 2-34 "Pearl of Stone Mountain" - Baxian Lake surrounded by mountains

Water Winding rivers and lakes landscape: also known as "water peak forest", refers to the flat, low-lying peak forest plain area with water (lakes, swamps and rivers) as the main body on the karst peak forest plain, with flat areas distributed It consists of isolated stone peaks (mostly distributed in the center of the peak forest plain and wetland ecological landscape) or conjoined stone peaks (island-shaped peak clusters, mostly distributed on the edge of the peak forest plain and wetland ecological landscape, that is, the transition zone between the karst plain and the mountainous area). It consists of a typical "water peak forest" (or "water peak cluster") landscape ecological landscape (Figure 2-35). The representative landscapes of "water peak forest" include Jiutoushan flood peak forest plain landscape (rainy season), Huixianlong Mountain-Mudong Lake landscape, Fenshui Pond water peak forest landscape, etc.

Some of the stone peaks in plains or lakes have strange shapes and form single peaks, such as Phoenix Mountain, Lion Mountain, Little Elephant Trunk Mountain and Qilin Mountain, which further enhance the landscape of the wetland. Ornamental. In particular, the island-shaped peaks of Lion Rock, the solitary rock mountains, the Baxian Lake and Fenshuitang lakes complement each other to form a typical "peak forest on the water" landscape. The combination with the ecological landscape of the wetland plant community is more beautiful than the "water Guilin" in Halong Bay, Vietnam. Angry, has greater ornamental value.

The landscape of rivers and lakes with mountains and rivers reflecting each other: refers to the reflection landscape formed by rivers, lakes and adjacent surrounding karst mountain landscapes, and the mountains reflected in the clear water. Huixian karst wetland includes various landscape types such as reflecting landscapes and pastoral scenery, reflecting landscapes and lakes, and reflecting mountains and rivers.

Huixian Karst Wetland currently has a total lake water area of ??about 5km2. The average water depth of each major lake is mostly below 2m. The lake water is clear, there are many lakes and bays, willow trees on both sides are shady, and rice, melons and fruits are fragrant. Together with the rivers and ditches connecting the nine winding bays between the lakes, it forms a beautiful Jiangnan water town landscape. They integrate with the surrounding karst stone mountains and various types of wetland plant communities. The mountains are reflected in the clear lake water, forming a wetland natural landscape that integrates lakes and mountains, natural ecology, and pastoral scenery (Figures 2-36 to Figure 2-42).

Figure 2-35 Water Peak Forest

Figure 2-36 Huixian Peak Forest Plain Landscape and Pastoral Scenery (Mudong)

Huixian Karst Wetland Ecosystem Research

Research on Huixian Karst Wetland Ecosystem

Figure 2-37 Huixian Mudong Lake Landscape and Lake Scenery - Reflection of Green Mountains

Figure 2-38 Huixian Mu The scenery of mountains, rivers and lakes in Donghu - the scenery of lakes and mountains

Figure 2-39 The scenery of mountains, rivers and lakes in Huixian Mutong Lake - the gathering of immortals

Picture 2-40 The scenery of lakes and mountains (1)

Figure 2-41 Lakes and mountains (2)

Figure 2-42 Green mountains, clear water, blue sky and white clouds

There are many rivers in Huixian Karst Wetland, and the riverbank landscape is beautiful. Rivers with tourism development value include Qingshui River, Ancient Guiliu Canal, Mutong River and Liangfeng River. Among them, the Qingshui River originates from Edi, Mian Village, Sitang Township. The river meanders in lakes and swamps such as Temple Lake and Quandong Marsh. The river water is clear and the scenery is beautiful (Figure 2-43); the Mutong River is like a ribbon, passing through it one after another. There are lakes and swamps such as Dulongtang and Mutong Lake and Jiutoushan flood plain wetlands. The rivers are crisscrossed and winding. The river water is clear and there are various types of submerged plants, fish and shrimp underwater. There are beautiful pastoral scenery and beautiful scenery on both sides of the river. The ecological environment is well maintained with reeds, cattails and other wet aquatic vegetation communities and broad, flat riverbank swamps. The karst landforms with towering mountains on both sides are reflected in the clear river water, creating a beautiful scene of "boats walking on the mountains and people swimming in the water" (Figure 2-44). Xiangsidai, an artificial river with a long history, passes through the entire Huixian karst wetland from east to west, connecting the Gui (Li) River and Liujiang water systems. Ancient architectural ruins such as steep gates and bridges along the river add depth to the wetland landscape. cultural heritage (Figure 2-45). The Liangfeng River originates from Jiaqiaoling, and the typical karst river landforms on both sides of the middle and upper reaches are unforgettable (Figure 2-46).

(3) Karst swamp wetland landscape

Karst swamp has the largest distribution area in Huixian karst wetland and is the main body of wetland. It is also the common wild rice and Chinese water in Huixian karst wetland. It is the main living area for many nationally precious protected plants such as leeks and an important habitat for some rare animals such as egrets (nationally protected birds).

Figure 2-43 Scenery of Qingshui River

Figure 2-44 Beautiful Mutong River

Figure 2-45 East of Nansitang Bridge Ancient Canal< /p>

Figure 2-46 The beautiful Liangfeng River (upstream section)

There are various types of swamps in Huixian karst wetland, including tidal flat swamps distributed in karst valleys or estuaries or inter-river blocks. There are lakeside swamps distributed in the low-lying areas of the karst peak forest plains, as well as water grasslands in front of underground river mouths, karst spring mouths or scattered discharge karst springs (Figure 2-47). There are many swamps that accumulate water all year round, and the soil is loose and fertile. During the rainy season, large areas are flooded, and most of the time the ground is muddy and difficult to navigate. The plants are mainly hygrophytes such as millet millet, willow leaf bamboo, and lotus seed grass. They are suitable for scientific investigation of wild biodiversity and ecology, soil and sediment, and hydrogeology, as well as ecological leisure and adventure. It is recommended to conduct it in autumn and winter, and it is better to use the route-crossing expedition method.

Figure 2-47 Swamp