雨水收集

11.0 环境策略 ENVIRONMENTAL STRATEGY 围绕大部分湖滨的湿地种植带有助于过滤未知来源的污染（农业灌溉污染），并创造栖息地。 Band of wetland vegetation surrounding most of lake helps treat non-point source pollution (agricultural runoff) and creates additional habitat 选折一些区域挖深湖底（4-5米），为鱼类的栖息创造夏季的低水温区域，挖出的泥土可以建造湿地岛。 Selected areas for deep dredging (4-5 meters) creates cold water fi sheries habitat in summer. Dredge spoils go to make wetland island 天河的水通过滨水走廊中修建的水渠与龙子湖相连，该地有潜力成为一个积极的河滨步道或公园，而不仅仅是乡村、原始的野生通道。 Tian lake waterfl ows through restored channel with riparian corridor. An active river walk / park is potemtial here rather than a more rustic / natural wildlife corridor 浮动生物阀，过滤漂浮物以保持水湾的清洁 Floating plant rafts fi ltering fl oating material to keep cove clean 低水位时的排水河道，一年中有九个月 Low fl ow channel, fl ows for 9 months out of year 高水位时的排水河道 High fl ow fl ood control channel 另外的溪流恢复通道：这些将提供湖与山的生态通廊，最少河道两边100米的通廊。 Additional restored creek channels: these provide habitat connectivity between the lake and the mountain. Minimum 100 meter riparian / upland corridor either side of channel 恢复漫滩地的林地、洪水泛滥区的阔叶林 Restored forested fl oodplains, bottomland hardwood forest. 高地防护区 通过增加不同物种的种植，加强现有的林地 Upland preserves: Enhancing existing forest area through additional planting an diversifi cation 在主要的支流交汇处增加雨水性湿地 Additional stormwater wetlands at infl ow points of minor tribu- taries 湿地野生区（处理成最大的野生栖息地） Wildlife wetland (managed for maximum habitat) 处理后的城市废水流入地（10.000立方米） 氧气池（1-2公顷，可以设计成水生生物公园、水鸟栖 息地） Treated wastewater infl ow (10.000 Cubic meters) Oxygenation pond (1-2 hectares, could double as aquatic wildlife park, shorebird habitat) 过滤性湿地 ( 期望提升水质到最好) （最小7公顷——11公顷） Treatment wetland (Managed for maximum water quality improvement) (7 Hectares minimum-11hectares) 湿地岛屿：散落在深水位动植物栖息地之中，这些岛 屿是湖中鱼类的培养基地；这些岛屿可以被水淹没， 而岛上的种植将使其成为周期性的沼泽地。 Wetland islands: interspersed with deep water habitat, these “islands” are nurseries for fi sh in the lake. Islands would be inundated with water and plant with emergent marsh periodi- cally 湖边及河道边恢复建设的森林，一个主要的高地防护 森林应当位于山丘，并与河滨通道向联系。 Restored upland forest areas alongside creeks and lake. A major upland forest preserve should be located in foothills and connect to riparian corridors 湖边及河道边恢复建设的森林，一个主要的高地防护森林应当位于山丘，并与河滨通道向联系。 Restored upland forest areas alongside creeks and lake. A major upland forest preserve should be located in foothills and connect to riparian corridors 101 蚌埠龙子湖概念规划 BENGBU LONGZI LAKE CONCEPT PLAN 11.1生态措施建议 Ecological Manage 102 蚌埠龙子湖概念规划 BENGBU LONGZI LAKE CONCEPT PLAN 水质改善的主要目标是要达到三级水质。龙子湖现在的水质 约为五级水质标准。 水质改善策略具体分为两部分，一部分是控制流入湖中的外部污染 物，另一部分是控制湖内的营养物质负荷和有害藻类的生长。 具体水质管理措施是通过基地踏勘以及现有资料所得结论的基础上总 结而成。 • 影响水质的主要因素发生在旱季，因为旱季带来了沉淀时间的增 加，分层现象的出现以及主要生物有机物生产率的提高。 • 由于未经处理的污水直接流入龙子湖，带来了湖中过量的营养物 质，使藻类对磷和氮的含量无法控制。光照可以是限制藻类生长 的因素，或者也可以起到对氮和磷协同限制的作用。 • 未经处理的废水是旱季龙子湖的主要水源。 • 龙子湖雨季的主要水源包括废水、流径雨水以及农田径流。 控制注入龙子湖的外部污染源 通过建造湿地处理第三级废水 现有方案是使未处理的废水流入一个新建的废水处理厂，然后排放到 淮河。我们的建议是通过一个11公顷的人工湿地，对这部分废水中的 一部分（约10,000吨/天）进行循环，以便在水流直接直接排到龙子湖 前去除其中的氮、磷和生化需氧量。人工湿地在旱季（12月和4月）将 第三级水流注入龙子湖，以防止此阶段湖体在水平衡模型中显示的水 位下降。 非点污染源直接经过农田和大地的地表径流进入龙子湖。沿湖周围 50米宽的小型湿地将发挥处理这些营养物和沉淀物源的作用。与湖体 岸线水平的一个低矮的堤岸可以阻止径流物直接从湿地流入湖体。而 径流是流入边缘湿地，然后从单独的出水口排出。 The primary goal of the Water Quality Improvement Plan is to meet Level III water quality standards. The existing water quality of Dragon Lake approxi- mates Level V water quality standards. The following water quality improvement strategies are divided into two groups; those that control external pollutant loads to the lake, and those that control internal nutrient loading and nuisance algae growth. The management actions are based on the following conclusions derived from site visits and review of existing data. • The main water quality concern occurs during the dry season due to in- creased residence time, stratification and primary productivity. • Due to the overabundance of nutrients entering Dragon Lake from raw sewage inputs, algae is likely to be neither phosphorous nor nitrogen lim- ited. Light may be the limiting factor for algae growth, or possible co-limita- tion by both nitrogen and phosphorous. • Untreated wastewater is the main source of water to the lake during the dry season. • Combined wastewater and stormwater runoff as well as runoff from ag- ricultural fields are the main sources of water to the lake during the wet season. Control of External Pollutant Sources to Dragon Lake Constructed Wetland for treatment of Tertiary Wastewater. The existing plan is to divert untreated wastewater to a new wastewater treatment plant, and discharge effluent to the Huai river. We recommend that a portion of this wastewater (approximately 10,000 tonnes/day) be recycled through an 11 hectare constructed wetland for additional removal of nitrogen, phosphorous and BOD prior to discharge back into Dragon Lake. The con- structed wetland will return tertiary effluent to the lake during the dry season only (December through April) to prevent lake level decline during this period as indicated by the water balance model. Non-point pollution enters Dragon Lake via surface runoff directly from fields and agricultural lands. This source of nutrients and sediment will be treated in small wetlands, fifty meters wide, which fringe the Lake’s perimeter. A low berm running parrallel to the lake’s shoreline will prevent runoff from penetrat- ing directly through the wetland to the lake. Runoff will instead flow through the fringe wetland to isolated outlet points. 边缘湿地 Fringe Wetlands 人工湿地 Constructed Wetland 现状湖岸 Existing Lake Edge 现状排水 Existing Wastewater Inflow 11.2水质改善方案 Water Quality Improvement Plan 103 蚌埠龙子湖概念规划 BENGBU LONGZI LAKE CONCEPT PLAN 小型雨水花园 A small rain garden 雨水湿地范例 Example of a Stormwater Wetland 经恢复的河道及滨水植物缓冲带 从最大的溪流流入龙子湖的沉淀物和营养物负荷，将通过恢复自然功 能和河道的形式，并建立所有主要支流沿线全程的滨水植被缓冲带， 进行管理。河道恢复应包括涝原坡度的重新调整，软质驳岸加固和大 块碎木块的引用。位于龙子湖西南、南和东南的三条支流将以这种方 式进行恢复。小支流的一些选定流域，尤其是那些毗邻农田的区域也 将采用滨水缓冲种植带。 低影响设计(LID)和雨水湿地 低影响设计策略包括：渗透径流的雨水花园、绿色街景、绿色屋顶和 可透水铺地。这些策略应在整个分水岭范围内的适当位置实施。低影 响设计不但能改善水质而且能提高防洪能力，并且比低效的传统工程 做法更经济、易行。这主要归功于管道使用量的下降。这些天然的雨 水控制元素共同构成流入龙子湖的主要雨水排水道，并应采用雨水湿 地去除径流中的沉淀物、营养物、油脂、氮、重金属和其它污染物。 控制湖区内部营养物负荷和藻类管理 人工循环和换气 龙子湖中大部分磷可能是在低氧情况下来自内部沉淀物。人工循环和 换气可以通过建立一个有氧沉淀层，有效减少内部的磷负荷。冬季和 潮湿季节，湖体可能由于太阳日照热量的不足和较低的湖水沉淀时 间，保持水体内部与氧气的完全混合。但在夏季，湖水会发生分层现 象，使沉淀物与水的交接面形成一个缺氧层。因此，人工循环只适合 在干旱和温暖的季节实施。 人工循环通过以下方法，可以减少含氮的藻类繁殖： • 减少细胞在水表面停留的时间，由此削弱光合作用 • 减少鱼类对大面积浮游植物的掠食，由此增加对绿色藻类细 胞的消耗 人工循环方法的实施应通过多孔管、软管或陶瓷喷嘴在湖底中心线位 置，将压缩空气注入湖水内。 Restored Stream Channels and Vegetated Riparian Buffers Sediment and nutrient loading from the largest streams flowing into Dragon Lake will be managed by restoring the natural function and form of river chan- nels and establishing vegetated riparian buffers along the entire lengths of all major tributaries. Stream channel restoration shall consist of floodplain regrad- ing, soft edge bank stabilization, and introduction of large woody debris. Three tributaries in the southwest, south, and southeast of the lake will be restored in this manner. Selected reaches of smaller tributaries, particularly those border- ing agricultural lands will also receive riparian buffers. Low Impact Design (LID) and Stormwater Wetlands Low Impact Design Strategies including rain gardens for infiltration of runoff, green streetscaping, green roofs, and permeable pavement shall be imple- mented at appropriate locations throughout the watershed. LID design im- proves both water quality and flood control and are often cheaper and easier to implement than their less effective conventional engineering counterparts. This is due mainly to a reduction in the use of pipes. Where these naturalistic stormwater control features combine to form major stormdrains entering Drag- on Lake, stormwater wetlands shall be implemented to remove sediment, nutri- ents, oils, hydrocarbons, heavy metals, and other pollutants from the runoff. Control of Internal Nutrient Loading and Algae Management Artificial Circulation and Aeration A large portion of phosphorous in Dragon Lake may be derived from internal loading from sediments during periods of low oxygen. Artificial circulation and aeration will help to reduce internal phosphorous loading by creating an oxy- genated sediment layer. During the wet and winter months, the lake probably remains fully mixed due to the absence of solar heating, and a lower lake residence time. However, in the summer time, the lake is likely to experience stratified conditions leading to anoxia at the sediment water interface. There- fore, artificial circulation should only occur during the dry and warm months. Artifical circulation also helps to reduce nuisance algae blooms by: • reducing the amount of time a cell spends at the surface thus reducing net photosynthesis; and • reducing fish predation on large zooplankton, thus increasing the con- sumption of green algae cells Artifical circulation should be implemented through the injection of compressed air into lake water from a perforated pipe, hose or ceramic diffusers along the bottom at the lake’s centerline. 龙子湖周围被破坏的河道 A Damaged River Corridor at Dragon Lake 恢复后的河道走廊 Example of a Restored River Corridor 11.2水质改善方案 Water Quality Improvement Plan 104 蚌埠龙子湖概念规划 BENGBU LONGZI LAKE CONCEPT PLAN 吹扫 在现有条件下，大约每年有一个月时间，龙子湖都有水流出湖区。龙 子湖的高沉淀时间表示水在湖中停留时间长，新水流的补充流速慢。 水平衡模型显示在新的水文状况下，来自天湖和从第三级废水处理厂 循环的废水补充，一年中可以有九个月的时间使龙子湖中的水可以流 出湖体。这样将有效减少湖水的沉淀时间。另外，从湿地和天湖流入 湖体的水流的水质也将比湖水自身的水质好，并且可以起到改善水 质，消除藻类生长的作用。 磷元素灭活 磷元素是藻类的主要营养源之一。如果湖水中的磷元素的来源已经得 到显著减少，这个减少磷元素含量的方法就是唯一有效的方法。因 此，只有在控制外部污染物注入龙子湖的所有方法都已得到实施时， 才能施行磷元素灭活的方法。 明矾、铝盐和硝酸盐将形成湖水的沉淀。相对而言，这个方法保持效 果的时间较长，但在夏季当大量沉淀物集聚时，它的效用相对较差。 在夏季，结合人工循环方法施行，这个沉淀方法将会非常见效。初步 估计表明，明矾剂量约为每年6万磅，效果可持续2到3年。 Flushing Under existing conditions, water fl ows out of Dragon Lake during approximate- ly one month out of each year. The lake’s high residence time means that water spends a very long time in the lake and water replenishment occurs at a slow rate. The water balance model indicates that under the new hydrologic regime, with supplemental water from Tian Lake and recycled wastewater from the tertiary treatment plant, water will be able to fl ow out of Dragon Lake during up to nine months out of each year. This will signifi cantly reduce the residence time of the lake. In addition, the water fl owing into the lake from the wetlands and Tian Lake will be of higher quality than the lake itself, and will improve water quality and diminish algae growth. Phosphorus Inactivation This method of reducing phosphorous, one of the main nutrients involved in algae growth, is only effective if most major sources of phosphorous to the lake have been drastically reduced. Therefore, phosphorus inactivation should only be undertaken after all of the recommendations for controlling external pollutant loading have been completed. Alum, aluminum sulfate, will form precipitates with phosphate in the water col- umn. This is a relatively permanent method for phosphorous removal unless highly anoxic conditions occur at the sediments during the summer. In combi- nation with artifi cial circulation during the summer, this method should be quite effective. Preliminary estimates indicate that alum dosage should be approxi- mately 60,000 pounds per year for a duration of about two to three years. 氧气池，1.5公顷 Oxygenation Pond 1.5ha 阶梯式跌落结构，提供氧气 Cascade Drop structure Provides Oxygen 淹没区 Submerged Berms 开放式水体 Open Water 雨水流入 Flood Water Infl ow 水闸和溢洪道 Flood Control Gates & Spillway 水溢出到河里 Outfl ow To River 沉积池，1公顷 Sediment Pond 1 Ha 废水流入（10，000吨/天） Wastewater Infl ow (10,000 Tons/Day 过滤性湿地河道，9.2公顷 Treatment Wetland Cells Total Area 9.2 Ha 南部湿地系统示意 South Wetland Treatment System Diagram A A 11.2水质改善方案 Water Quality Improvement Plan 105 蚌埠龙子湖概念规划 BENGBU LONGZI LAKE CONCEPT PLAN 清淤 我们并不建议采用清淤的方法对龙子湖的水质进行管理，但在有些情 况下，清淤可以帮助改善内部营养物负担，还可以意想不到地带来营 养物和有毒物质聚集的增加。在缺乏土壤成分进一步研究结果的情况 下，清淤的效果仍然是一个未知数。另外，其它建议的管理策略足以 实现湖水向三级水质标准改善的目的。清淤不一定是有必要的，只有 在其它策略实施若干年后可以考虑采用。 生物处理 生物处理是一种通过对水生食物链处理减少藻类生长的方法。本项目 中考虑采用此方法，但并不建议，原因是由于缺乏记载龙子湖现状食 物链的资料。另外还要求进行一些其它的研究，有效利用生物处理方 法作为湖水管理策略。 栖息地改善 龙子湖栖息地改善计划是以实现沿湖高地、河滨和水生生态系统间生 态平衡目的为基础的。本计划的旨在通过创造广泛类型的栖息地，增 加生物物种多样性。栖息地改善计划还将带来包括休闲机会、游客景 点在内的一系列社会价值，减少人类健康威胁，提升地产价值，改善 生活品种。 冷水生物避难所 龙子湖南端几大块区域将清淤至5到6米的深度。当夏季湖体其它区域 水温升高的情况下，这里的这些区域将作为那些喜欢冷水的鱼类的避 难所。这些冷水生物避难所将增强龙子湖的渔业，并为食鱼鸟提供食 物源基地。 孤岛 龙子湖南部区域规划了一些孤立的湿地岛屿，这些岛屿将借助清淤来 的建造，形成冷水生物的避难所，并与湖体深水区相邻。岛屿构 成边缘沼泽开放水道，和包括短期池塘、耐淹植物和开放湿牧场的高 地区域。这些孤立与陆地的岛屿也是鸟类产卵的理想地点，比如燕欧 和一些欧类，它们经常在陆地上筑巢，但却经常受到陆地捕食者的威 胁，如狗和猫。沿岛屿周围的湿地可以成为有利的鱼苗基地，增强整 个龙子湖的渔业产量。 Dredging We have not recommended dredging as a management approach for Dragon Lake. While in some instances, dredging can improve internal nutrient loading, it can also cause unexpected increases in nutrient and toxic substance con- centrations. Without further research of the composition of soils, the effects of dredging remain uncertain. In addition, the effects of the other proposed management strategies may be suffi cient to improve lake water quality to Level III standards. Dredging may not be necessary and should only be considered after several years of implementation of the other strategies. Biomanipulation Biomanipulation, the method of manipulating the aquatic food chain to reduce algae growth, was considered for this project. However, biomanipulation is not recommended due to lack of information regarding the existing food chain structure at Dragon Lake. Additional research would be required to effectively utilize biomanipulation as a lake manegemnet strategy. Habitat Improvement Plan The Dragon Lake Habitat Improvement Plan is based on the goals of achiev- ing an ecological balance between upland, riparian, and aquatic ecosystems surrounding the lake. The Plan aims to increase biological species diversity, through the creation of a wide range of habitat types. The Habitat Improve- ment Plan will also provide a range of social benefi ts including recreational op- portunities, visitor attractions, reduced human health risk, increased property values, and quality of life improvements. Isolated Islands Isolated wetland islands are proposed for the southern area of the lake. These islands will be constructed from the material dredged to form the cold water refugia and will be located adjacent to the deep lake zones. The islands will consist of fringe marshes open water channels and vegetated upland areas consisting of ephemeral pools, fl ood tolerant forests and open wet meadows. The isolation of the islands from the land is ideal for breeding birds such as terns and some gull species which nest on the ground and are often suscep- tible to land predators such as dogs and cats. The wetlands surrounding the islands will provide valuable fi sh nurseries and will enhance the overall fi sher- ies production of the lake. Deep Emergent Marsh Flood Level Baseline Water Flow Slough Shrub Swamp Pool Channel Ephemeral Pool Wet Woodland Shallow Emergent Marsh Typical Wetland Park Cross Section (not to Scale) Flood Level Shrub Swamp Shrub SwampMixed Hardwood Swamp Ephemeral Pool Oxbow Lake Typical Flood Plain Cross Section (not to Scale) Ephemeral Pool Low Marsh Native Upland Species High Marsh Submerged Berm 耐淹的物种 Flood Tolerant Species River Flood Plain Typical Treatment Wetland Cross Section (not to Scale) 1.6m 1m 0.3m 0.5m 2m 浮动的水位 水浇基座线 自发的深地沼泽 淤泥 灌木沼泽 水池 自发的浅地沼泽 湿地林地 临时池塘 典型湿地公园断面（无比例） Baseline Water Flow 水浇基座线 浮动的水位 灌木沼泽 多样阔叶林沼泽 灌木沼泽 临时池塘 曝气湖 典型溢洪区断面（无比例） 临时池塘 本土的高地物种 浅沼泽 深沼泽 淹没的沟坝 耐淹的物种 Flood Tolerant Species 河道溢洪区 典型湿地治理断面（无比例） 11.3未来管理方法的考虑 Management Approaches for Future Consideration 106 蚌埠龙子湖概念规划 BENGBU LONGZI LAKE CONCEPT PLAN 野生动物湿地 野生动物湿地位于龙子湖东南端，湖体主要支流之一的河口区域。这 些湿地的做法沿用11公顷专门用于水处理的处理湿地和前面在水质改 善计划中提到的。野生动物湿地主要针对多样的微地貌，创造一些类 似高地和低地沼泽、滨河和沼泽林地、滩涂、短时池塘的小生境，吸 引并支持多种动植物的生存和生长。 高地保护区与野生动物走廊 在龙子湖周围的几个位置规划了几个大面积的高地保护区。主要沿现 有河道的野生动物走廊将这些高地保护区与湿地和湖体的水生生态系 统联系起来，形成从开放湖体到密植山脉的连续栖息地类型系统。高 地保护区内的植栽应该物种类型繁多。 恢复后的大面积河谷涝原 规划了两个位置的恢复涝原，它们毗邻淮河，沿水流从龙子湖流向淮 河的低流速水渠。恢复的涝原将种植大量耐水的乔木和灌木，并为个 别当地的动植物种提供栖息地。恢复的涝原上对洪水的同化作用还将 有助于暴雨季节排涝作用的发挥。 低流速河流走廊 水流出湖体，将在流入淮河前进入低流速河道走廊。该走廊坡势平 缓，包括多条溪流、小型的溪流涝原、滨河和高地植被和短时池塘。 穿过区域中心的铁路将采用隔音构筑物和绿化走廊，遮挡和缓冲对野 生动物的影响。 Cold Water Refugia Several large areas at the south end of the Lake will be dredged to a depth of approximately 5 to six meters. During the summer months, when the rest of the lake warms up, these areas will serve as a refuge for fi sh species which prefer cooler water. These cold water refugia will enhance Dragon Lake’s fi sh- ery and provide foraging habitat for fi sh feeding birds of prey. Wildlife Wetlands The wildlife wetlands are located at the southeastern end of the lake at the mouth of one of the main tributaries to the lake. These wetlands follow the 11 hectare treatment wetlands designed specifi cally for water treatment and discussed above in the Water Quality Improvement Plan. Wildlife wetlands are designed with a diversity of microtopography to create ecological niches such as high and low marsh, riparian and swamp forests, mudfl ats, and ephemeral ponds, and will attract and support a high diversity of plants and animals. Upland Preserves and Wildlife Corridors At several locations surrounding Dragon Lake, large areas of upland preserves are proposed. Wildlife corridors, primarily along existing river channels, will link these upland preserves with the wetland and aquatic ecosystems of the Lake creating a continuous spectrum of habitat types from open lake to the for- ested mountains. Planting in the upland preserves shall be extremely diverse Restored Large River Floodplain Two locations have been proposed for fl oodplain restoration. These are asd- jacent to the Huaihe, and alongside the low-fl ow channel which delivers water from Dragon Lake to the Huahe. The restored fl oodplains will be planted with a broad variety of fl ood tolerant trees and shrubs to provide habitat for specifi c native plant and animal species. Assimilation of fl ood waters onto the restored fl oodplains will also provide fl ood mitigation during large storm events. Low Flow River Corridor Water fl owing out of the lake will enter the low fl ow river corridor prior to reach- inh the Quaihe River. This corridor will be gently sloping and will consist of multiple stream channels, small stream fl oodplains, riparian and upland veg- etation, and ephemeral pools. The train tracks which run through the center of this area will be buffered from wildlife by a structural sound barrier and a vegetated corridor. 11.3未来管理方法的考虑 Management Approaches for Future Consideration 107 蚌埠龙子湖概念规划 BENGBU LONGZI LAKE CONCEPT PLAN 方法 龙子湖水平衡模型使用的资料由安徽省水源与污染控制局提供。资料 包括全年三个时期（雨季/年中/旱季）的湖面水位，湖水容量/表明区 域/水位标高关系，目前流入湖体未经处理的废水流速，月降雨资料， 分水岭区域及用地，灌溉速度和规划的天湖水流速度。蒸发速度是根 据月平均气温估计而来（这种方法是很粗糙的，但现有资料的欠缺（ 辐射和风速）无法改善估计结果的精确程度）。支流的径流根据不同 用地的径流系数进行估计。采用的径流系数在雨季高于季节中期使用 的系数，但比旱季使用的系数还是要高。流向/来自湖体的渗流损失根 据已知的季节湖面水位，在模型上的估计相应刻度所得。 现状假定 在现状假定情况下，湖水水位保持在16.3米到18米之间。水流来源包 括每月约300,000 方的未经处理废水和来自湖体周围支流的水流。在 假定现状条件下，8月到10月三个月时间内湖体内的水可以排出。允许 湖体内的水流出是一种比较理想的状况，因为湖水的流到带来了循环 和水流补充的发生。 无废水假定 在假定无废水的情况下，取消未经处理的废水注入。废水被排入一个 新建的废水处理厂，然后流入淮河。需注意在这种情况下，湖水水位 降低到15.5米的重要高度。这时总湖体水面约为4.5平方公里（或者当 水面水位在17米高时，湖面面积刚过湖体的1/2）。对湖体而言这种状 况不是理想状况，因为在可开发区域和湖面之间可能有一个难看的滩 涂，而且导致水质的进一步恶化。 Methods The Dragon Lake water balance model uses data provided by the Water Re- sources and Pollution Control Bureaus of Anhui Province. Data provided in- clude lake surface elevations during three periods of the year (wet/mid/dry), lake volume/surface area/elevation relationships, inflow rates for the raw sew- age currently entering the lake, monthly rainfall data, watershed area and land uses, irrigation rates, and delivery rates from the planned Tian Lake connec- tion. Evapotranspiration rates were estimated based on mean monthly tem- peratures (While this is a crude method, data were not available (radiat