438 results about "Surface runoff" patented technology

The present invention provides compositions and methods for amending the availability of phosphate and other nutrient supplies in soil, especially acidic sandy soils, while ensuring reduced leaching and / or surface runoff of phosphorous and other nutrients. Compositions of the invention comprise granulated dolomite phosphate rock in combination with organic materials, wherein the level and rate of phosphorous and other nutrients released from the composition is controlled. Use of the compositions of the invention increases the availability of phosphorous and other nutrients while eliminating soil acidity, and also stimulates plant growth, enhances plant vigor, and / or improves crop yield.

An insert for use in a sewer system to remove oils and solvents carried by surface water runoff. The insert includes a holder and a quantity of water permeable, hydrophobic, oil and solvent absorbing material such as melt blown polypropylene. The holder has two functions. It holds an effective quantity of the absorber and holds it in such a way that the surface water is exposed to the absorber to allow oils and solvents to be absorbed. The insert in preferably placed, cartridge-like, at the inlet or outlet of the sewer system so that it may be quickly checked, replaced and serviced. In one embodiment, the insert also contains a leaf trap.

The invention discloses a device for simulating a pollutant migration and transformation process of purple soil slope farmland. The device comprises a soil bin, an artificial rainfall device and a slope ground surface incoming flow simulating device, wherein the soil bin is filled with purple soil and placed obliquely; slope ground surface incoming flow is simulated by the slope ground surface incoming flow simulating device in a manner that a peristaltic pump supplies water to an overflow water tank and enables the overflow water tank to overflow; a water conveying pipe of the artificial rainfall device is provided with a plurality of spray heads, and the spray heads are evenly arranged relative to the surface of the soil bin; and a plurality of surface runoff sampling ports and subsurface flow sampling ports are formed in the tail end of the soil bin and side faces of purple soil. According to the device disclosed by the invention, rainfall, slope incoming flow and the coupling of the rainfall and the slope incoming flow can be simulated, the temporal and spatial distribution characteristics of purple soil slope farmland pollutant migration and transformation in multiple hydrological processes are researched through adjusting various factors, and thus, the device is used for disclosing an interaction mechanism between the surface runoff and subsurface flow of the purple soil slope farmland and the pollutant migration and transformation.

The invention discloses an urban rainstorm waterlogging assessment and modeling method. The method comprises the steps that an urban earth's surface runoff producing model is established, a time-integration method is adopted to calculate accumulated infiltration and accumulated produced runoff at a moment t, wherein t represents rainfall time; according to the calculated accumulated infiltration and accumulated produced runoff at the moment t, hour-by-hour continuous simulation is conducted on a ponding zone and ponding depth of rainstorm waterlogging by obtaining the rainfall capacity hour by hour and utilizing an equal-volume method, and an urban earth's surface confluence model is established to obtain urban rainstorm waterlogging simulation result at corresponding moment. The time-integration method is adopted to respectively process a water permeable zone and a water non-permeable zone, hour-by-hour continuous simulation can be performed by inputting hour-by-hour rainfall capacities, and real-time forecasting and estimation of the rainstorm waterlogging are achieved through butt joint with rainfall forecasting. According to the method, the whole urban waterlogging and water receding process is considered, and hour-by-hour elaborate simulation of urban waterlogging can be achieved, so that real-time operation influencing the model in forecasting becomes possible.

The invention discloses an ecological canal for preventing and controlling agricultural area source pollution, which is realized by the following steps: A, constructing an artificial canal for collecting agricultural sewage and farmland surface runoff in a watershed, wherein the canal comprises a sewage runoff inlet and a main canal; B, making the width of the artificial canal between 60 and 240 cm, the depth between 40 and 70 cm, and the length unlimited; C, setting the shape of the canal according to the landform of the watershed; D, setting the sewage inlet of the canal according to the water volume of the sewage and the surface runoff rate in the watershed; and E, making the inlet a trapezoidal open inlet, arranging a physical barrier, a small bio-ball and a sedimentation basin at the inlet, wherein the physical barrier comprises a coarse screen and a fine screen; the two side walls of the main canal are embedded with large bio-balls; emergent plants, floating leaf plants and submerged plants are planted in the canal; and epiphytic algae and floating algae are inoculated in the sewage. The ecological canal for preventing and controlling the agricultural area source pollution is suitable for stopping, degrading, absorbing and utilizing water pollutants in watersheds of mountain region and hill farming areas.

The invention discloses a debris flow forecasting method based on soil and water coupling in a drainage basin, and aims to overcome the technical defect of insufficient consideration of soil and water conditions triggering a debris flow due to the fact that in the existing debris flow forecasting method, whether a debris flow happens or not is judged only by a rainfall threshold value acquired by a statistical forecast method. According to the characteristic that the debris flow is a mixture of water and soil, the debris flow forecasting method based on the coupling of unstable soil slope and surface runoff in a small drainage basin under the condition of rainfall is provided. According to a volume weight p-value of the mixture of the water and soil coupling in the drainage basin of a forecasting area, probability interval of occurrence of the debris flow under the condition of the rainfall is determined to be forecasted, and corresponding warning level of the debris flow is released as needed. The debris flow forecasting method is reliable in principle, scientific and simple in calculation. Since a distributed hydrologic model and a mechanics judging formula are introduced to expand soil stability and runoff of a point scale to a drainage basin scale, the technical problem that the existing forming mechanism of debris flow only focuses on the point scale and cannot be applied to debris flow forecasting is solved, and forecasting precision is improved.

The invention relates to a simulation testing system of a water circulation process under human activity disturbance conditions. The system comprises a simulation platform for simulating nature and human activities, which affect water circulation, and a monitoring platform for monitoring through a sensor, as well as a computer monitoring platform for controlling the simulation platform and performing data sampling and data processing on the monitoring platform, a seepage-proof pool, experimental soil, a rain shelter, a simulation rainfall device, a groundwater level simulation device, a water intake well, an observation device related to vorticity, an automatic weather station, a runoff detection device, a surface runoff sensor, a runoff instrument, a sensor for water content in the soil, a detection device and a control device. The simulation platform, the monitoring platform and the computer monitoring platform of the system disclosed by the invention are organically combined to form specific water circulation sub-systems among the various parts, namely the simulation device, the detection device and a control platform, and the integration of the sub-systems can realize the omnibearing simulation concept of a complex water circulation system of nature-manual work.

This invention relates to film layer earth flow measurement system, which is composed of water system independently slope earth area, earth flow and earth surface collection measurement system, wherein, the slope radium area forms water system with complete slope radium area; the radium flow down earth and rock or mother mass interface to establish earth flow measurement system; collection test whole radium area earth flow through flow test system to test earth flow to reflect slope flow match process and dynamic status.

The invention discloses an ecological restoration structured approach for an unstable earth and rockfill side slope, comprising the following steps: reinforcing a slope with iron threaded anchor rods and galvanized wire meshes; then restoring by a wet type spraying and sowing technique; further reducing loss soil loss tolerance of a sowing layer by the pore retaining effect of a three-dimensional vegetation network; constructing surface runoff retaining ditches and reinforcing walls at the joint of naked abrupt slopes and undamaged massifs to prevent the fall of the slope crest; constructing a collecting basin at the slope base to collect slope runoff and massif predominant current. The approach disclosed by the invention effectively realizes effective fixation of a plant matrix of the unstable earth and rockfill side slope, so that a restored vegetation layer can be formed in a short period of time and is not easy to be damaged; meanwhile as water power retention period increases, adaptability is good, the restored matrix does not run off easily.

The invention discloses an orchard underground hole irrigation method which belongs to underground irrigation. The orchard underground hole irrigation method is characterized in that 'fertilizer water holes' are buried in a root system distribution layer of a fruit tree, the 'fertilizer water hole' consists of four parts, namely an underlay plastic film (10), a water absorption and fertilizer storage material (9) mixed with a fertilizer, broken brick bats (8) wrapped by the water absorption and fertilizer storage material, an irrigation tube (3) inserted into the center of the broken brick bats. Each fruit tree is provided with 4-8 'fertilizer water holes', water is injected into the 'fertilizer water holes' by the irrigation tube (3) via a funnel and 10-20 L of water is filled into each hole. During fertilizing, the fertilizer water can be injected into the 'fertilizer water holes', thus the nutrient is directly transported to the root system centralized distribution area and fertilizer efficiency is improved. The method has the advantages of easily available materials, low production cost, water saving and drought resistance, not only can reduce evaporation from land surface and surface runoff, but also can prevent irrigation water from seeping to the deep soil layer; meanwhile the orchard underground hole irrigation method takes advantage of the 'hydrotaxis' and 'fertilizer anemotaxis' of the root system to confine the root system in or around the 'fertilizer water holes', thus improving the utilization rate of nutrient and water.

The invention provides a stable water flow field-based method for simulating confluence of basin surface runoff and a real-time calculation device. The method comprises the following steps: S1, establishing an N-S equation under a grid mode; S2, performing water flow mixing simulating in a runoff confluence mode; and S3, iterating a water flow field in a basin by utilizing the runoff confluence model obtained in the S2 so as to obtain a stable water flow field. The method can provide decision support to quick simulation and evaluation for rainstorm and flood disasters in a basin, and has a relatively high application value.

The invention discloses a method and system for forecasting urban accumulated water by means of rainfall forecasts. The method comprises the steps that rainfall forecast information of a target city is obtained by means of a data interface of a meteorological department, and the rainfall forecast information is converted into rainfall duration data; simulation computation is conducted on surface runoff in the rainfall process and the drainage process according to the rainfall duration data and by combining urban drainage pipe point and pipeline data and geographical information data, and running status data of a drainage pipe network in the drainage process is obtained; calculation is conducted on the water accumulation process by means of a multi-source non-single depression accumulated water simulation method according to the running status data of the drainage pipe network and combination with surface elevation information, raster data of one surface accumulated water depth is correspondingly obtained by conducting calculation on each rainfall time step, all the raster data of the surface accumulated water depths of the whole rainfall duration process are obtained, and the surface accumulated water information data of each preset time is obtained, wherein the accumulated water information data comprises but not limited to the position, depth and range of surface accumulated water.

The present invention discloses a farmland underground eluviation and surface runoff monitoring integration device which belongs to the fields of environment science, agrology and plant nutrition. The device of the present invention comprises of runoff pool, eluviation disk, outlet pipe, sampling bottle and runoff collecting pipe; eluviation disk is mounted horizontally on the runoff pool at aim depth of upright soil section, sampling bottle is connected with water outlet of eluviation disk through outlet pipe to collect eluviation solution; runoff collecting pipe is a four-way pipe like a Chinese word 'Shang' containing one water outlet and three lockable infall with different high; each runoff pool is communicated with at least one water outlet of runoff collecting pipe. The present invention is particularly suitable for monitoring the affects of ground water of soil solute such as nitrogen, phosphor, pesticide and so on, specially under the condition of original monitoring, can monitor soil eluviation and runoff at the same time and the same position, the nicety is improved and the sampling process is easy and rapid.

The invention discloses a rainwater collection and water-saving irrigation system used for an upland sloping field. The system comprises a rainwater collection pond or weir, a high-position water storage reservoir, a plurality of low-position water storage reservoirs, a water pump and a water conveying pipe, wherein the rainwater collection pond or weir is arranged on the middle part or lower part of a valley; the high-position water storage reservoir is arranged on the upper part of a hill body with maximum height in each hill body close to the rainwater collection pond or weir; the plurality of low-position water storage reservoirs are arranged on each hill body at the periphery of the high-position water storage reservoir respectively and are lower than the high-position water storage reservoir; the water pump is arranged beside the rainwater collection pond or weir; a water inlet of the water pump is connected with the rainwater collection pond or weir, and a water outlet of the water pump is connected with the high-position water storage reservoir; and the water conveying pipe is laid between the high-position water storage reservoir and each low-position water storage reservoir. By using the rainwater collection and water-saving irrigation system, surface runoff water produced by rainwater is accumulated in the rainwater collection pond or weir, water in the rainwater collection pond or weir is lifted to the high-position water storage reservoir by the water pump, water of the high-position water storage reservoir is conveyed to each low-position water storage reservoir through the water conveying pipe respectively, and water accumulated in each low-position water storage reservoir is used for irrigation when the irrigation is needed.

The present invention discloses a mobile measuring device and a measuring method for grade-change runoff components. The device comprises a square groove to hold soil for experiment. The upper part of the square groove is provided with a rainfall recorder. One end of the bottom face of the square groove is connected to a drive device through a support rod. The drive device controls the inclination degree of the square groove. The left side of the square groove is provided with a control area. Between the square groove and the control area are provided a grade-change slope runoff guiding pipe and a soil middle layer guiding pipe. The invention adopts the hydraulic drive device to drive the square groove to rotate to achieve the function of grade adjustment. For the guiding pipes arranged at the lower end face of the square groove and at different heights, it is possible to simultaneously measure and calculate, under the condition of different rainfall intensities and slope grades, the components of surface runoff which is concentrated on the same soil slope in a non-uniform manner and the components of runoff at different soil depth levels. And based on water balance equation, the vaporization of soil and plants can be further calculated.

An insert for use in a sewer system to remove oils and solvents carried by surface water runoff. The insert includes a holder and a quantity of water permeable, hydrophobic, oil and solvent absorbing material such as melt blown polypropylene. The holder has two functions. It holds an effective quantity of the absorber and holds it in such a way that the surface water is exposed to the absorber to allow oils and solvents to be absorbed. The insert in preferably placed, cartridge-like, at the inlet or outlet of the sewer system so that it may be quickly checked, replaced and serviced. In one embodiment, the insert also contains a leaf trap.

The invention discloses a BIM technology and simulation technology-based green building design method. The method comprises the following steps of: analyzing a current-situation site by utilizing simulation software at the beginning of a building scheme, wherein the analysis comprises earthwork analysis and overland runoff analysis; preliminarily deciding a designed elevation of the site; establishing a project site in Revit according to the designed elevation; carrying out wind and light environment analysis by combining the simulation software; carrying out general drawing design on the basis of the wind and light environment analysis so as to propose a plurality of schemes; establishing a plurality of mass model in the Revit; carrying out wind and light environment analysis on different layouts by combining the simulation software, so as to help comparison and selection to optimize a general drawing layout; finally obtaining a most reasonable general drawing and furthermore deepening the schemes; and carrying out wind, light and heat environment analysis on indoor space by using above method, so as to carry out comparison and selection to optimize a final scheme. According to the method disclosed by the invention, the correctness of an analysis model is ensured, and the reliability of an analysis result is ensured; and a BIM technology is fused with simulation and analysis, so that a design and analysis optimized feedback mechanism is formed and then the correctness and efficiency of green building design and simulation are improved.

The invention requests to protect a drainage system used in cities, towns and communities, which is formed by connecting at least a co-line divided-flow dual-layer drainage pipe and channel or a common drainage pipe and channel with a rainwater-sewage compound dual-layer manhole. An intercepting rainwater-sewage compound dual-layer drainage manhole can be arranged on the drainage system accordingto the requirement so as to realize that the initial surface runoff is intercepted into a sewage pipe and channel and is delivered to a sewage treatment plant to be treated, and a non-intercepting rainwater-sewage compound dual-layer drainage manhole can be arranged according to the requirements of direction change, gradient change, connector change, pipe and channel intersection, examination andrepair of linear pipes and channels every certain distance and other special purposes. The drainage system can realize individual delivery and drainage of the rainwater and sewage by layers on the same pipeline and has the characteristics of simple pipelines, few manholes, low investment, operation and maintenance cost, capability of reducing the pollution effects of first rain runoff in an economic and effective manner, and no rainwater-sewage interflow and overflow water pollution, etc.

A process for ecologically treating and reclaiming the sewage generated during making paper includes regulating the ratio of BOD5 to CODcr in setting tank, digestion in anaerobic pool and facultativepool, regulating the ratio of CODcr:N:P in regulating tank, flowing the water through the wet ground on the surface of earth, and returning the water back to aerobic pool and regulating tank.

The invention relates to a wheel type overland runoff sampling device which can be applied to large-scale road overland runoff automation sampling. The wheel type overland runoff sampling device comprises a fluid director, a pedometer, a vehicle wheel, a rotation motor, an electric controller, a memory and a chassis. The wheel type overland runoff sampling device is suitable for urban overland runoff sampling and is used for solving the current situation that usual pumping type and intercept type samplers can not effectively collect overland runoff due to the fact that water level of road overland runoff is low. Meanwhile, the wheel type overland runoff sampling device integrates the wheel type part, the sampler realizes movable sampling, the sampling area is effectively expanded, and the sampling efficiency is improved. A step counting device is designed, a stepping motor control circuit is combined, and overland runoff with various lengths can be classified and collected by the control circuit to realize sampling automation.

The invention relates to a device and method to measure precipitation runoff in farm field water conservancy. The runoff well and seepage well are connected by runoff-seepage communicating pipe. A water counter is set on water-yielding port of communicating pipe. Runoff bucket is at the bottom of well. There is a micro-water pump in well. Water counter connects radio-transmitting set. The method is suitable for measurement of seepage discharge, crop requirement and water quality. Surface runoff observation is divided to runoff Q track, moisture-holding Q soil and seepage water Q seepage, that is: Q fall=Q track + Q soil + Q seepage. The formula of water capacity is: Q soil=Q fall - Q track - Q seepage. According to duty Q fill and moisture variety DeltaQ soil, crop water requirement (water consumption Q crop in a period) is achieved: Q crop= Q fall+ Q fill- Q track- Q seepage+ DeltaQ soil. The invention resolves the problem of large error and high cost by using runoff field to measure.

The invention provides a mudslide early warning method based on rainfall monitoring. The mudslide early warning method comprises the following steps of according to historical rainfall data, establishing a mudslide event feature rainfall model, a surface runoff event feature rainfall model and a normal rainfall event feature rainfall model, and determining a discrimination function; according to the discrimination function, determining an attenuation coefficient, a weight coefficient and a critical threshold value; collecting rainfall data of previous n days, and using the attenuation coefficient to calculate the effective rainfall of previous n days; using the weight coefficient and the rainfall data of current day, and calculating the feature rainfall according to the weight coefficient, the rainfall data of current day and the effective rainfall of previous n days; comparing the feature rainfall with the critical threshold value, and determining whether the rainfall of current day is enough to cause a mudslide event or not according to the comparison result. The method has the advantage that the accuracy of early warning of the mudslide can be effectively improved.

The invention relates to a recovery method of bare red sandstone abrupt slope vegetation, which comprises the steps of: preparing an abrupt slope; preparing grass square lattices; distributing and fixing the grass square lattices in an interlaced way along the abrupt slope; preparing plants growing base material with soil, sand and fertilizer; filling the plants growing base material into nutrition bags; growing herbal and shrub plants in the growing base material; digging growing points in the grass square lattices; and embedding the nutrition bags and the herbal and shrub plants into the growing points together. By adopting the method, the grass square lattices and slope soil layers are jointly formed into a protection system of the abrupt slope, thereby effectively preventing the abrupt slope from being directly splashed by raindrops to avoid that the surface of the ground is washed by radial flow and play an important part in the stabilization of the abrupt slope; the nutrition bags provide a good growing condition for growing the vegetation; and the grass and the shrub are grown in a mixing way to be capable of guaranteeing that the vegetation can take roots on the bare red sandstone abrupt slope, thereby recovering the vegetation in a large area and achieving the aim of soil and water conservation. The method has convenient construction, small investment, wide application and good effect, is hardly destroyed by water, can fast conserve the soil and the water, and performs ecological restoration.

The present invention discloses one apparatus for collecting surface runoff flow and measuring the sediment content in runoff flow. The technological scheme is that the apparatus consists of sampling chamber, stirrer, drainage valve, valve controller, upper liquid level probe and lower liquid level probe on the side wall of sampling chamber, controller, gamma ray output device and gamma ray set separately on the two sides of the sampling chamber, and automatic calibrator. The apparatus has simple structure, simple installation, reliable work performance, long service life and high automation and may be used in the fast, real-time and accurate in-situ measurement of the sediment content in runoff flow.

The invention provides a one-two-dimensional hydrodynamic coupling analysis method based on urban surface and underground pipe network, which comprises the following steps: establishing the urban pipenetwork model; the urban pipe network model comprises a runoff generation calculation model, a one-dimensional pipe network model and a two-dimensional coupling model; inputting surface water data and groundwater data, and establishing surface-subsurface connection relationship according to the surface water data and groundwater data; generating and optimizing grid elements; calculating surface runoff and drainage pipe network flow respectively; calculating the exchange water quantity of surface runoff and drainage pipe network flow; and in order to realize the hydrodynamic coupling of two-dimensional underground pipe network on the surface, checking the calculated exchange water quantity. The invention realizes coupling analysis and calculation of surface groundwater flow for urban rainstorm waterlogging.

The invention relates to an analysis technology in comprehensive consideration of fresh water input need of different ecological functions of lake ecological systems.. In the analysis technology, lakeecological water need functions are divided into an ecological function, an environment function and a production function, and further, lake ecological need water is divided into 9 types, includingevapotranspire water need quantity, leakage water need quantity, aquatic organism and habitat need water, lake out surface runoff need water, lake out subsurface runoff need water, energy production need water, self-purification need water, shipping need water and landscape recreation need water. The water resource function coefficient is determined according to the difference of a maximum principle and a lake management target, and the lake ecological water need quantity under multi-target requirement is determined finally, the requirements on lake ecological system production, life and ecological comprehensive water need are met, and the problem that the water need requirement for the integral ecological system is difficult to provide because of single original lake ecological need water computation target is solved.

The invention relates to an urban waterlogging monitoring and pre-warning system and pre-warning method. The urban waterlogging monitoring and pre-warning system comprises a processing unit, a surfacerunoff water depth monitoring unit, an underground drainage network monitoring unit, a meteorological information monitoring unit, a rainfall monitoring unit, a communication unit and a drainage unit, wherein the surface runoff water depth monitoring unit is electrically connected with the processing unit; and the processing unit is suitable for judging the urban waterlogging condition accordingto the actual surface runoff flow of various monitoring points, an excess surface water depth, an underground drainage network drainage state, weather information and rainfall, and uploading the urbanwaterlogging condition to a server through the communication unit in real time, and controlling the drainage unit to drain water when the processing unit judges urban waterlogging. According to the urban waterlogging monitoring and pre-warning system and the pre-warning method, analysis and statistics are carried out by comprehensively transmitting and processing monitoring data and combining bigdata with deep learning artificial intelligence, early prewarning information is issued, processing planning measures are generated in advance and intelligent control is implemented on electrical equipment at various sites.

The invention discloses a rainwater collecting and recycling method. The method comprises the following steps: collecting rainwater into a buried sedimentation tank by virtue of a roof rainwater collection system and a surface runoff rainwater collection system, so as to form primary stored water; introducing 50-60% of the primary stored water in the upper layer of the sedimentation tank into a primary reservoir by virtue of a water pump, so as to form secondary stored water; introducing 50-60% of the secondary stored water in the upper layer of the primary reservoir into a secondary reservoir by virtue of a water pump, so as to form tertiary stored water; and introducing 80-90% of the tertiary stored water in the upper layer of the secondary water reservoir into a tertiary reservoir by virtue of a water pump, so as to form quaternary stored water. The method provided by the invention has functions of 'intercepting', 'absorbing', 'maintaining', 'purifying' and 'releasing' the rainwater, and the like, so that novel urbanized municipal facilities have excellent 'elasticity' in such aspects as adapting to environmental change, responding to natural disasters and the like. The method is energy-saving and environment-friendly.

The present invention relates to a low conservation zoysia japonica lawn planting method. Said invention is characterized by that it selects the local lawn plant material-zoysia japonica which can be adapted to low conservation and utilizes seed stem cultivation method or turf directly-laying method to plant lawn, before said lawn is planted, the weeds must be removed and the fertilizer can be applied in the place where the zoysia japonica lawn can be planted.

The invention relates to a preparation method of a sludge biocharcoal water permeable brick with high adsorption performance, which can effectively solve the problems of the conventional building brick produced by sludge that the sludge content of the single brick is low, the sludge utilization rate is low, and the strength of the brick produced independently by sludge or sludge biochaircoal is insufficient. According to a technical scheme, the preparation method comprises the following steps: after dewatered sludge is rinsed to remove partial heavy metal, the dewatered sludge is press filtered by virtue of a plate frame, then coal ash or blast furnace slag is added and uniformly mixed, after being granulated and dried, the mixture is pyrolysed at a high temperature to obtain the sludge biocharcoal, crushed stone aggregates are mixed with processed waste fabric, the stirred concrete and the biocharcoal are loaded into a mold together and then pressurized, molded, demolded and maintained, thus obtaining the sludge biocharchaol water permeable brick. The biochaircoal water permeable brick prepared by the method of the invention can prevent heavy metal nitrogen, phosphorus, organic pollutants and the like in direct surface runoff from being migrated into underground water and from polluting the underground water, and the method is an innovation for synergistic treatment and recycling of waste.