A kind of reservoir regulate and control method that ensures lake, Tongjiang, downstream water supply security
Technical field
The present invention relates to a kind of reservoir optimizing regulate and control method that ensures lake, Tongjiang, downstream water supply security, belong to basin water resources protection and hydraulic engineering control technique field.
Background technology
The lake, Tongjiang communicates with the river, and current can freely exchange between the rivers and lakes, and water resource allotment in the basin is had a very important role.Often densely populated around the lake, Tongjiang, the industrial or agricultural prosperity, water supply security also is the important leverage of the sustainable development of socio-economy and ecological environmental protection concerning the people's vital interests.But in recent years, under the double influence of Global climate change and artificial action, the trend of water resource spatial and temporal distributions inequality is constantly aggravated in the basin, and the water supply security problem in lake, Tongjiang becomes increasingly conspicuous, and the Poyang, lake, Tongjiang of the Yangtze river basin, Hubei and Hunan Provinces, Dongting Lake are typical case's representatives wherein.Statistics shows for many years, and the flow that becomes a mandarin of Poyang Lake is attenuation trend, and the lake region coverage of water in dry season is often not as good as 1/20th of the wet season.And for example, Dongting Lake water retention capacity when dry season can be low to moderate 7.7 billion cubic meters, less than 1/10th of normal water retention capacity of wet season.Poyang, Hubei and Hunan Provinces, Dongting Lake the crisis of repeatedly supplying water occurred in dry season in recent years, are not only threatening the ecological environment health of lake region, and living water use, industrial and agricultural production, navigation, fishery are also caused huge negative effect.Different with closed lake, lake, Tongjiang and river are indivisible complete water systems, and the lake, Tongjiang self is subjected to the strong influence that upper river is built hydraulic engineering.Hydraulic engineering is to the artificial action of basin water system and disturbance, both may be positive, also may be negative.The reservoir operation mode that China is existing mainly is dependent on design objective and the economic results in society of reservoir self, seldom takes into account the water requirements in lake, Tongjiang, downstream.Particularly outstanding is that the most withered season in upper pond retaining phase and lake, Tongjiang is often overlapping, significantly the low water situation in aggravation lake, downstream.
The optimizing scheduling of reservoir of now knowing is many to be target to increase economic benefit, as Zhang Shuguang and Zhou Man in " Three Gorges Pivot Project reservoir traffic control " literary composition, preliminary discussion has been carried out in optimization measure to Three Gorges Pivot Project scheduling, has related to the flood aspects such as float in the position, medium and small flood scheduling, retaining in advance of restricting water supply; Zhang Jishun etc. are in the document of " Three Gorges Reservoir optimization scheduling research ", come the operation characteristic of water characteristic, hinge according to the Upper Yangtze River basin, disappear before the reservoir flood, aspects such as flood is restricted water supply a mobilism, flood end retaining and Real-Time Scheduling, the optimization scheduling mode of each stage reservoir in the Three Gorges key water control project error-free running period has been proposed.But must be pointed out, prior art scheme or pattern are discussed all and only are optimized scheduling at the upper pond number one, its basic goal is only in order to improve the economic worth of Reservoir region inside, dam self, do not consider the water supply security problem in Tongjiang, downstream withered season of lake, do not see the withered season water supply security that has realistic plan to ensure the lake, Tongjiang.
It has been indisputable fact that the operation condition variation meeting of upper pond causes strong influence to the distribution of water resources situation in downstream river course and lake, Tongjiang.Generally speaking, the utilization of the later stage of large water conservancy hydroelectric engineering still has bigger optimization space, presses for to propose a kind of upper pond optimization control technique scheme to alleviate the water supply crisis in lake, Tongjiang, downstream.For this reason, the present invention by taking more scientific and reasonable reservoir drainage regulation measure to optimize the rivers and lakes relation, avoids occurring the lake and crosses low water stage under the prerequisite of following whole basin water circulation law under the changing environment, ensures lake, Tongjiang, downstream water supply security.
Summary of the invention
Goal of the invention: at the deficiencies in the prior art, a kind of reservoir regulate and control method that ensures lake, Tongjiang, downstream water supply security is provided, by alleviating the upper pond operation to the adverse effect in lake, Tongjiang, downstream, improve the rivers and lakes relation in river and lake, Tongjiang, to overcome the contradiction of drainage and downstream water supply demand in the conventional scheduling of reservoir, the water supply security in guarantee reservoir downstream withered season of lake, Tongjiang.
Technical scheme: the technical scheme that the present invention solves above technical problem is:
A kind of reservoir regulate and control method that ensures lake, Tongjiang, downstream water supply security, in upper pond retaining phase and specific period in dry season, implement the reservoir optimizing regulation and control, hold in advance and subtract the staggered retaining mode that engages of holding by reservoir, the low vent flow of the upper pond that staggers and lake, Tongjiang, downstream be the overlap period in withered season, increase the downstream river course flow in retaining phase and dry season, it is excessive to suppress lake region, lake, Tongjiang outflow, and then ensures lake, Tongjiang, reservoir downstream water supply security, may further comprise the steps:
(1) reservoir filling period regulation: at major flood season not, be scheduling to the basis with the routine of the controlled reservoir of upper river, reduce letdown flow to improve reservoir water level, carry out the reservoir phase I and hold in advance; In latter stage wet season, strengthen reservoir and hold dynamics in advance, further reduce letdown flow to accelerate improving reservoir water level, carry out the reservoir second stage and hold in advance; Implement the formal retaining of reservoir at the flood end, hold preparation in advance by preceding two stages, formal optimization retaining process is compared obviously with the routine scheduling and is slowed down, the conventional scheduling of corresponding optimization letdown flow obviously increases, downstream river course flow and natural river course discharge process are agreed with, and Tongjiang, downstream lake level is also raised thereupon;
(2) regulation and control in dry season: at the beginning of the dry season after the retaining phase, keep normal pool level constant, for regulating and control to provide enough water yield deposit and regulation and control spaces in the most withered season to lake, Tongjiang, downstream; During mid-term, increasing the decrease speed of reservoir level near low water, increase letdown flow; In the mid-term in dry season of lack of water, significantly improve the decrease speed of reservoir level, letdown flow obviously increases, and water level is down to upper water level for flood control in advance.
Above-mentioned steps can avoid upper pond retaining phase and lake, Tongjiang of the most withered phase low water stage to occur, ensures water supply security.
Particularly, further restriction such scheme of the present invention is: described step () and (two) implement according to the following steps according to actual conditions and timing node:
(1) after the major flood season, begin to reduce letdown flow, this process continues 10-18 days, and the conventional scheduling of day letdown flow reduces 100-600 m
3/ s makes and if run into the upstream flood, then comes flow to sluice by the upstream by water level day rising 0.02-0.03 m/d;
(2) speed is held in further quickening in advance at the major flood season end, accelerates to hold in advance speed, and this process continues 5-7 days, in conjunction with upstream incoming flow process, continues to reduce letdown flow, and day letdown flow routine scheduling reduces 300-500 m
3/ s, reservoir level day rising 0.06-0.07 m, after this section finished, reservoir level was raised to 146 ± 0.2 m, held in advance to provide in advance for second stage subsequently and prepared;
(3) in latter stage wet season, reduce greatly owing to bear pressure of flood, reservoir daily increases water level and can obviously accelerate, and further reduces letdown flow, and this step continues 6-8 days, reservoir level day rising 1.0-1.2 m/d, average daily letdown flow reduces 6000-9000 m
3/ s, after this section finished, water level was raised to 156 ± 0.2 m, and keeps this water level constant during subsequently always, for necessary condition is created in the formal retaining of slowing down subsequently;
(4) at the flood end, start formal retaining process, but the scheduling of retaining process and routine compares to some extent and slow down, make reservoir level even rising 20-23 m in month, average daily rising water stage is down to 0.5 m/d by 0.83 m/d of routine scheduling, corresponding day increase amount of water to be discharged 600-4000 m
3/ s;
(5) at the beginning of dry season, keep normal pool level constant, for regulating and control to provide enough water yield deposits and scheduling space to lake, Tongjiang, downstream the most withered season subsequently, near mid-term in dry season the time, average daily 0.14 m/d that descends is increased to average daily decline 0.21 m/d by the water level of routine scheduling, corresponding day letdown flow 5000-5500 m
3/ s, conventional scheduling increases 400-1000 m
3/ s;
(6) mid-term in dry season, be down to the position of falling into water that disappears dry season for guaranteed water level, suitably accelerate letdown flow, average daily 0.29 m/d that descends is increased to average daily decline 0.33 m/d by the water level of routine scheduling, corresponding day letdown flow 5200-6000 m
3/ s, conventional scheduling increases 500-1000 m
3/ s goes out the lake current amount with what improve the downstream river course water level and suppress the lake, Tongjiang, resists lake, Tongjiang of the most withered phase and low water stage occurs, ensures the water supply security in lake, Tongjiang.
Above-mentioned a kind of operating principle of the reservoir regulate and control method of lake, Tongjiang, downstream water supply security that ensures is:
Divide two stages to carry out reservoir at major flood season end and hold in advance, wherein step (1) be the early stage of phase I, progressively slows down reservoir filling speed this moment, on the basis of assurance flood control by reservoir regulation safety, for the later stage holds in advance transition condition is provided; Step (2) is the later stage of phase I, by accelerating reservoir filling speed, reservoir level is arrived hold the water level in mid-term in advance, holds in advance to provide in advance for the second stage of step (3) and prepares.Step (3) starts from latter stage wet season, and this moment, the conventional scheduling of therefore average daily letdown flow significantly reduced because the required pressure of flood of bearing of reservoir reduces greatly, and reservoir daily increases water level and can obviously accelerate, and the average daily rising water stage of reservoir increases thereupon to some extent.After this step finished, reservoir level remains on pre-water storage level in a period of time constant, up to the retaining phase that enters conventional scheduling.On the basis that reservoir held in advance before step (4) was based upon, for the reservoir filling process of routine scheduling, the letdown flow advantage of reservoir increases, reservoir day, rising water stage reduced to some extent, therefore the reservoir letdown flow more agrees with the river discharge of natural situation, and the water level during the formal retaining under the conventional scheduling situation of the water table ratio in lake, Tongjiang, downstream is also raised to some extent.Step (4) had both guaranteed that dry season exerted oneself and increase generated energy in the power station, had also weakened the adverse effect of reservoir filling to the lake, Tongjiang.Step (5) (6) divides two stages that reservoir is regulated and control in dry season, at the beginning of phase I is dry season, be water yield deposit and the scheduling space that guarantees when the most withered season lake, Tongjiang, downstream being dispatched, to provide enough, keep normal pool level constant earlier, and then increase letdown flow on the basis of routine scheduling; Second stage is the most withered season, suitably further strengthen letdown flow, can guarantee that reservoir level is down to the position of falling into water that disappears dry season after this process finishes, can improve the downstream river course water level again and go out the lake current amount with what suppress the lake, Tongjiang, resist lake, Tongjiang of the most withered phase and low water stage occurred, very favourable to ensureing water supply security.
The present invention is scheduling to the basis with routine, following under the circulation law prerequisite of basin water Wenshui, by adopting upper pond to hold in advance and subtracting the staggered retaining mode that engages of holding, the overlap period in withered season of the low vent flow in river and Tongjiang, downstream lake region, lake has staggered, what effectively reduce lake, Tongjiang, downstream goes out the lake current amount, avoid the lake low water stage to occur, can either satisfy conventional benefits such as flood control by reservoir regulation, generating, shipping, can ensure the water supply security of lake, Tongjiang dry season again, economy and ecological benefits are considerable, and are workable.
Description of drawings
Fig. 1 is for implementing upper pond and geographical position, lake, Tongjiang, downstream schematic diagram in certain basin of the present invention.
Fig. 2 is the conventional dispatching method of upper pond and implements optimization regulate and control method comparison diagram of the present invention.
Fig. 3 is for the conventional scheduling of upper pond normal flow year and implement the letdown flow comparison diagram that the present invention optimizes regulation and control.
Fig. 4 dispatches and implements the water level comparison diagram that the present invention optimizes lake, Tongjiang, downstream when regulating and control for the upper pond normal flow year is conventional.
The specific embodiment
Below technical scheme of the present invention is elaborated, but protection scope of the present invention is not limited to described embodiment.
Embodiment: use the present invention, be optimized regulation and control by the upper pond to certain basin, to ensure lake, Tongjiang, downstream water supply security.Figure 1 shows that the geographical position schematic diagram of upper pond and lake, Tongjiang, downstream in certain basin, in the construction of upstream, river course a large reservoir is arranged, have lake, two Tongjiang directly to link to each other with the river course respectively in the downstream, current can freely exchange between the rivers and lakes.The mean depth in lake, Tongjiang is respectively 6.7 and 8.5 meters, and water surface area is about 3900 and 3200 square kilometres respectively during the period when a river is at its normal level, but water surface area all can obviously be reduced to about 500 square kilometres in the time of dry season.In the above-mentioned basin, when river water level was higher than the Tongjiang lake level, the lake, Tongjiang admitted the river to come water formation to pour in down a chimney, and the lake region water level can progressively rise; When if river water level is lower than the lake, water body enters the river course by mouthful outflow that crosses in the lake, Tongjiang, and the lake region water level can corresponding decline.Extreme climate takes place frequently in recent years, and have in advance and the trend that prolongs dry season in the basin, and the upstream large reservoir builds up the back lake, Tongjiang, downstream water supply security has also been caused appreciable impact simultaneously.Especially, the low vent flow of upper pond and taken place the most withered season of lake region, downstream overlappingly causes that very easily causing Tongjiang, downstream lake level in reservoir filling phase and dry season crosses low phenomenon, causes the water supply crisis occurring in the zone, lake, Tongjiang.
Fig. 2 compares the optimization regulate and control method that adopts among the conventional dispatching method of this upper pond and the present invention.As seen from the figure, for serving flood control and power benefit, the conventional scheduling process of this upper pond is guaranteeing that flood season, water level before come was down to flood control flood position 145 m that restrict water supply, and water level began to descend from January 1, and the decline process adopts piecewise continuous mode to carry out:
(1) from early January to early Febuary, water level day the range of decrease be 0.14 m/d;
(2) early Febuary is to late March, water level day the range of decrease be 0.29 m/d, this moment, water level fell after rise to upper water level for flood control 156 m, and kept this water level to late May;
(3) since late May, water level accelerates to descend, and a day range of decrease is 0.83 m/d;
(4) to mid-June, water level is reduced to flood control 145 m;
(5) early June in flood season to late September, water level maintains flood control operation as far as possible, prepares to regulate contingent flood to reserve storage capacity, the water yield that surpasses the power station conveyance capacity is let out by under the release floodwatering facility.Only when reservoir inflow surpasses the downstream river course safety discharge, the reservoir water conservation, reservoir level is raised.After the flood, reservoir level in time is reduced to flood control, to meet contingent flood next time;
(6) since late September, reservoir level raises gradually, 175 m to the late October retaining to normal pool level, and keep this water level to early January.
Under conventional reservoir operation pattern, because late September has crossed major flood season, the upland water amount reduces gradually on the one hand, reservoir filling has been tackled the upstream portion water of assigning on the other hand, and aspect two under the superposition, the more natural situation of reservoir letdown flow is compared obvious minimizing at this, the downstream river course water level occurs on the low side, the flow that the lake, Tongjiang flows into the master stream obviously increases, and the water yield reduces relatively in the lake region, and lake, Tongjiang, downstream water supply security has been produced adverse influence.
For overcoming the problems referred to above, adopt the present invention when the retaining phase ensures lake, Tongjiang, downstream water supply security, the regulate and control method that adopts is:
(1) August 12 began to reduce letdown flow at the major flood season end, the conventional scheduling of day letdown flow reduces 100-600 m
3/ s makes water level be become water level and slowly risen by 145 m that maintain in the routine scheduling, water level day ascensional range reach 0.02-0.03 m/d, this process continues 10-18 days, then comes flow to sluice by the upstream if run into the upstream flood;
(2) rose August 30 at the flood end, accelerate to hold in advance speed, this process continues 5-7 days, in conjunction with upstream incoming flow process, continues to reduce letdown flow, and the conventional scheduling of day letdown flow reduces 300-500m
3/ s, reservoir level day rising 0.06-0.07 m, after this section finished, reservoir level was raised to 146 ± 0.2 m;
(3) in the early September in latter stage wet season, reservoir daily increases water level and can obviously accelerate, and further reduces letdown flow, and this step continues 6-8 days, reservoir level day rising 1.0-1.2 m/d, and average daily letdown flow reduces 6000-9000 m
3/ s, after this section finished, water level was raised to 156 ± 0.2 m, and keeps this water level constant during September subsequently always;
(4) on the basis that preceding several stages holds in advance, start formal retaining process, make reservoir level about 20-23m of even rising about month, average daily rising water stage is down to 0.5 m/d by 0.83 m/d of routine scheduling, corresponding day increase amount of water to be discharged 600-4000 m
3/ s, in the formal retaining process, lake, Tongjiang, downstream mean water is raised 0.5m, and maximum is raised 1.0 m, implements to show lake, Tongjiang, the downstream water supply security that can largely improve in the retaining phase.
Subsequently, further adopt the present invention when ensure lake, Tongjiang, downstream water supply security dry season, the regulate and control method that adopts is:
(1) in early January in dry season, keep normal pool level constant, the duration is about 10 days, and from water level decline mid-January, average daily 0.14 m/d that descends is increased to average daily decline 0.21 m/d by the water level of routine scheduling, corresponding day letdown flow 5000-5500 m
3/ s, conventional scheduling increases 400-1000 m
3/ s;
(2) from early Febuary to late March, be down to the position of falling into water that disappears dry season for guaranteeing reservoir level, suitably accelerate letdown flow, average daily 0.29 m/d that descends is increased to average daily decline 0.33 m/d by the water level of routine scheduling, corresponding day letdown flow 5200-6000 m
3/ s, conventional scheduling increases 500-1000 m
3/ s, lake, Tongjiang, downstream mean water has been raised 0.15 m, and senior general has raised 0.18 m, can obviously alleviate the water supply security problem in the lake region, lake, Tongjiang, downstream.
Fig. 3 has compared the situation of change of reservoir letdown flow when typical normal flow year enforcement the present invention is optimized regulation and control to lake, Tongjiang, downstream water supply security.Fig. 4 has provided the regulation and control front and back effect of Tongjiang, downstream lake level this moment.As can be seen from Figure 3, in the formal retaining phase, by holding in advance of last stage, anasarca with shortness of breath retaining phase downstream flow increases to some extent than conventional scheduling, and letting out average daily flow increases by 1850 m down
3/ s, Tongjiang, downstream lake level also thereupon correspondence increase (Fig. 4), but need the regular hour because the stream that sluices down flow to the lake, Tongjiang from dam, increasing of the rising in lake, Tongjiang and letdown flow delayed slightly, average daily 0.63 m that raises of lake level has effectively improved retaining phase lake water supply security; In dry season, by the dispatching method that the present invention adopts, letting out average daily flow increases by 560 m down
3/ s, lake level 0.17 m that daily raises has effectively guaranteed lake water supply security in dry season.
Although represented and explained the present invention that with reference to specific preferred embodiment it shall not be construed as the restriction to the present invention self.Under the spirit and scope of the present invention prerequisite that does not break away from the claims definition, can make various variations in the form and details to it.