CN104933626A - River basin agricultural non-point source pollutant channel reduction coefficient calculation method - Google Patents

Abstract

The invention provides a river basin agricultural non-point source pollutant channel reduction coefficient calculation method, which comprises the steps of acquiring typical small river basin data in a target river basin, and constructing a soil and water assessment tool (SWAT) of the typical small river basin according to the typical small river basin data; acquiring a nitrogen and phosphorus load LoadLr getting into a river in each sub-basin of the typical small river basin and a contribution rate LoadLo of each sub-basin of the typical small river basin for a river basin water outlet port according to the SWAT; acquiring producing and emitting pollutant coefficients of a crop farming source, a livestock and poultry farming source, an aquaculture source and a rural domestic pollution source in typical small river basin agricultural non-point source nitrogen and phosphorus emission monitoring, and acquiring the sum LoadLs of the agricultural non-point source nitrogen and phosphorus emission of each sub-basin of the typical small river basin by being combined with basic information survey data of the typical small river basin; and acquiring an agricultural non-point source pollutant channel reduction coefficient of the target river basin according to the sum LoadLs and the nitrogen and phosphorus load LoadLr. The method provided by the invention can acquire the river basin agricultural non-point source pollutant channel reduction coefficient simply, accurately and quickly, is low in cost and can be carried out comprehensively in a large scale.

Description

Coefficient calculation method cut down by basin agricultural area source pollutants irrigation canals and ditches

Technical field

The present invention relates to field of measuring technique, particularly relate to a kind of basin agricultural area source pollutants irrigation canals and ditches and cut down coefficient calculation method.

Background technology

Along with the fast development of agricultural, fertilizer and pesticide consumption, livestock and poultry cultivation quantity and life in the countryside level grow at top speed, and widespread pollution from the overuse of fertilizers and pesticides in rural area becomes one of principal element affecting quality of water environment gradually.There is due to current widespread pollution from the overuse of fertilizers and pesticides in rural area the features such as randomness, intermittence and wide regional coverage, and pollutant exists complicated physics, chemistry and bioprocess from discharge of pollutant sources to irrigation canals and ditches, in the transmitting procedure in river course, determine basin widespread pollution from the overuse of fertilizers and pesticides in rural area and enter the difficulty that lake load quantitativeization estimates.

Basin irrigation canals and ditches are the transport channels before pollutant such as agricultural area source discharge nitrogen, phosphorus etc. enters river course, nitrogen wherein, phosphorus can be trapped in Transport And Transformation process, thus final minimizing enters the pollutional load of water body, therefore, the control of irrigation canals and ditches to loss nitrogen, phosphorus plays an important role.

At present, the discharge coefficient that the measuring and calculating of China's widespread pollution from the overuse of fertilizers and pesticides in rural area load mainly obtains with the sample of small scale ground in-situ monitoring is estimated as master, as " the first time national Pollutant source investigation " work to carry out for 2007, in China according to essential species implant model feature, lay National Agricultural pollution of area source state controlling/monitoring net, estimate the nitrogen of agricultural area source, phosphorus emission.But these class methods ignore in contaminant transportation process, the impact that the series of complex process of generation is estimated pollutional load, do not estimate that widespread pollution from the overuse of fertilizers and pesticides in rural area produces actual enter lake (river) amount.Enter lake (river) although the cross-section monitoring of mouth more adequately can obtain the amount of pollutant target approach water body, manually, time, the input cost such as cost be comparatively large, is unfavorable for that large scale is fully under way; And the pollutional load obtained due to the method for this terminal estimation formula is the combined amount in each landscape cell point source of water catchment area, upstream, source, face, what be difficult to quantize a certain concrete component units enters lake (river) amount.

Producing based on pollutant of prior art, the pollution of area source mechanism model of transmitting procedure, as Non-point Source Pollution Model (ArealNon-pointSource WatershedEnvironment ResponseSimulation, be called for short ANSWERS), from the chemical substance of farmland management system, runoff and erosion models (Chemicals Runoff and Erosion for Agricultural Management Systems, be called for short CREAM), water erosion forecast model (WaterErosionPredictionProject, be called for short WEPP), agricultural non-point source model (AgriculturalNon-pointSource, be called for short AGNPS) and water and soil evaluation model (Soil and Water Assessment Tool, be called for short SWAT) etc., solve the problem that contaminant transportation process is difficult to quantize on the one hand, solve on the other hand different concrete unit pollutant and enter the problem that lake (river) amount is difficult to distinguish.But because model structure is complicated, basic data, supplemental characteristic demand are large, constrain it to a certain extent compared with the effect in large scale.

Given this, how simply, obtain basin agricultural area source pollutants irrigation canals and ditches reduction coefficient accurately and rapidly and become the current technical issues that need to address.

Summary of the invention

For defect of the prior art, the invention provides a kind of basin agricultural area source pollutants irrigation canals and ditches and cut down coefficient calculation method, can obtain basin agricultural area source pollutants irrigation canals and ditches simply, accurately and rapidly and cut down coefficient, cost is low, can large scale fully under way.

The invention provides a kind of basin agricultural area source pollutants irrigation canals and ditches and cut down coefficient calculation method, comprising:

Obtain Typical Small Watershed data in target basin, described Typical Small Watershed data comprise: the hydrology-water quality data of the essential information enquiry data of Typical Small Watershed, Typical Small Watershed and sub basin water delivering orifice periodic sampling thereof, weather data, digital complex demodulation data and land data, and described hydrology-water quality data comprise: the run-off of Typical Small Watershed and sub basin thereof, quantity of sand and mud, nitrogen pool, total phosphorus content;

The water and soil evaluation model SWAT of Typical Small Watershed according to described Typical Small Watershed data configuration;

Obtain in described Typical Small Watershed according to described SWAT and in each sub basin, enter river course nitrogen and phosphorus load Load _lrand the contribution rate Load of each sub basin watershed water delivering orifice in described Typical Small Watershed _lo;

Obtain the plant husbandry source of each sub basin of described Typical Small Watershed agricultural area source nitrogen phosphorus emission monitoring, livestock and poultry breeding industry source, culture fishery source and life in the countryside source and produce discharge coefficient, in conjunction with the essential information enquiry data of described Typical Small Watershed, obtain each sub basin agricultural area source nitrogen phosphorus emission sum Load in described Typical Small Watershed _ls;

According to Load _lsand Load _lr, obtain described target basin agricultural area source pollutants irrigation canals and ditches and cut down coefficient.

Alternatively, described weather data, comprising: the rainfall of Typical Small Watershed, temperature, solar radiation, wind speed and relative humidity.

Alternatively, obtain the land data in the data of Typical Small Watershed in target basin, comprising:

Collect the land-use map of Typical Small Watershed in target basin, analyze land use pattern and distribution, set up Land Use Database;

Collect the soil type map of Typical Small Watershed in target basin, based on soil type map, by the soil types transformation of ownership, in conjunction with secondary overall survey of soil database and soil space sampling, set up soil space, attribute database.

Alternatively, after the water and soil evaluation model SWAT of described Typical Small Watershed according to described Typical Small Watershed data configuration, enter river course nitrogen and phosphorus load Load in each sub basin described to obtain in described Typical Small Watershed according to described SWAT _lrand the contribution rate Load of each sub basin watershed water delivering orifice in described Typical Small Watershed _lobefore, also comprise:

Running SWAT model, and according to obtained hydrology-water quality data, parametric calibration and checking are carried out to described SWAT model;

Correspondingly, described acquisition in described Typical Small Watershed according to described SWAT enters river course nitrogen and phosphorus load Load in each sub basin _lrand the contribution rate Load of each sub basin watershed water delivering orifice in described Typical Small Watershed _lo, be specially:

According to the SWAT after parametric calibration and checking, obtain in described Typical Small Watershed and in each sub basin, enter river course nitrogen and phosphorus load Load _lrand the contribution rate Load of each sub basin watershed water delivering orifice in described Typical Small Watershed _lo.

Alternatively, described running SWAT model, and according to obtained hydrology-water quality data, parametric calibration and checking are carried out to described SWAT model, comprising:

By ditch extraction, watershed partitioning, Hydrologic response units generation, meteorological process, running SWAT model, and according to obtained hydrology-water quality data, parametric calibration and checking are carried out to described SWAT model.

Alternatively, discharge coefficient is produced in the plant husbandry source of each sub basin of described acquisition described Typical Small Watershed agricultural area source nitrogen phosphorus emission monitoring, livestock and poultry breeding industry source, culture fishery source and life in the countryside source, in conjunction with the essential information enquiry data of described Typical Small Watershed, obtain each sub basin agricultural area source nitrogen phosphorus emission sum Load in described Typical Small Watershed _ls, comprising:

Obtain the plant husbandry source of each sub basin of described Typical Small Watershed agricultural area source nitrogen phosphorus emission monitoring, livestock and poultry breeding industry source, culture fishery source and life in the countryside source and produce discharge coefficient, in conjunction with the essential information enquiry data of described Typical Small Watershed, obtain the plant husbandry source nitrogen phosphorus emission in each sub basin of described Typical Small Watershed, livestock and poultry breeding industry source nitrogen phosphorus emission, culture fishery source nitrogen phosphorus emission and life in the countryside source nitrogen phosphorus emission;

According to the plant husbandry source nitrogen phosphorus emission in each sub basin of described Typical Small Watershed, livestock and poultry breeding industry source nitrogen phosphorus emission, culture fishery source nitrogen phosphorus emission and life in the countryside source nitrogen phosphorus emission, obtain each sub basin agricultural area source nitrogen phosphorus emission sum Load in described Typical Small Watershed _ls.

Alternatively, described according to the plant husbandry source nitrogen phosphorus emission in each sub basin of described Typical Small Watershed, livestock and poultry breeding industry source nitrogen phosphorus emission, culture fishery source nitrogen phosphorus emission and life in the countryside source nitrogen phosphorus emission, obtain each sub basin agricultural area source nitrogen phosphorus emission sum Load in described Typical Small Watershed _ls, comprising:

According to the plant husbandry source nitrogen phosphorus emission in each sub basin of described Typical Small Watershed, livestock and poultry breeding industry source nitrogen phosphorus emission, culture fishery source nitrogen phosphorus emission and life in the countryside source nitrogen phosphorus emission, obtain each sub basin agricultural area source nitrogen phosphorus emission sum Load in described Typical Small Watershed by the first formulae discovery _ls;

Described first formula is:

Load _Ls＝∑(Load _Lp+Load _Ll+Load _La+Load _Lc)，

Wherein, Load _lpfor certain sub basin plant husbandry source nitrogen phosphorus discharge negative quantity of described Typical Small Watershed, Load _llfor certain sub basin livestock and poultry breeding industry source nitrogen phosphorus emission of described Typical Small Watershed, Load _lafor certain sub basin culture fishery source nitrogen phosphorus emission of described Typical Small Watershed, Load _lcfor certain sub basin life in the countryside source nitrogen phosphorus emission of described Typical Small Watershed.

Alternatively, described according to Load _lsand Load _lr, obtain described target basin agricultural area source pollutants irrigation canals and ditches and cut down coefficient, comprising:

According to Load _lsand Load _lr, coefficient Factor cut down by the agricultural area source pollutants irrigation canals and ditches being obtained described target basin by the second formulae discovery _cr;

Described second formula is:

${\mathrm{Factor}}_{\mathrm{cr}}=\frac{({\mathrm{Load}}_{\mathrm{Ls}}-{\mathrm{Load}}_{\mathrm{Lr}})}{{\mathrm{Load}}_{\mathrm{Ls}}}.$

As shown from the above technical solution, coefficient calculation method cut down by basin of the present invention agricultural area source pollutants irrigation canals and ditches, and can obtain basin agricultural area source pollutants irrigation canals and ditches simply, accurately and rapidly and cut down coefficient, cost is low, can large scale fully under way.

Accompanying drawing explanation

Fig. 1 is that basin widespread pollution from the overuse of fertilizers and pesticides in rural area drains into lake approach schematic diagram;

The schematic flow sheet of the basin agricultural area source pollutants irrigation canals and ditches reduction coefficient calculation method that Fig. 2 provides for one embodiment of the invention;

The phoenix plumage river small watershed location drawing that Fig. 3 provides for one embodiment of the invention.

Embodiment

For making the object of the embodiment of the present invention, technical scheme and advantage clearly, below in conjunction with the accompanying drawing in the embodiment of the present invention, clear, complete description is carried out to the technical scheme in the embodiment of the present invention, obviously, described embodiment is only the present invention's part embodiment, instead of whole embodiments.Based on embodiments of the invention, those of ordinary skill in the art, not making the every other embodiment obtained under creative work prerequisite, belong to the scope of protection of the invention.

Fig. 1 shows basin widespread pollution from the overuse of fertilizers and pesticides in rural area and drains into lake approach schematic diagram, wherein, 1 is agricultural planting industry source nitrogen phosphorus discharge approach, 2 is agriculture livestock and poultry breeding industry source nitrogen phosphorus discharge approach, 3 is agriculture culture fishery source nitrogen phosphorus discharge approach, and 4 is agriculture life in the countryside source nitrogen phosphorus discharge approach, and 5 is basin agricultural area source nitrogen phosphorus irrigation canals and ditches transition processes, 6 is basin agricultural area source nitrogen phosphorus channel migration processes, and 7 is that basin agricultural area source nitrogen phosphorus enters interface, lake.

The schematic flow sheet of coefficient calculation method cut down by the basin agricultural area source pollutants irrigation canals and ditches that Fig. 2 shows one embodiment of the invention to be provided, and as shown in Figure 2, the basin agricultural area source pollutants irrigation canals and ditches reduction coefficient calculation method of the present embodiment is as described below.

101, Typical Small Watershed data in target basin are obtained, described Typical Small Watershed data comprise: hydrology-water quality data, weather data, digital elevation model (the Digital ElevationModel of the essential information enquiry data of Typical Small Watershed, Typical Small Watershed and sub basin water delivering orifice periodic sampling thereof, vehicle economy M) data and land data, described hydrology-water quality data comprise: the run-off, quantity of sand and mud, nitrogen pool, total phosphorus content etc. of Typical Small Watershed and sub basin thereof.

In a particular application, when obtaining the essential information enquiry data of Typical Small Watershed in target basin, by consulting local statistical data and peasants participation, obtain farmland management and the social industry such as population, the cultivation data such as farming in described Typical Small Watershed, fertilising, irrigation, for model provides background information; Should at described Typical Small Watershed water delivering orifice and its sub basin water delivering orifice setting long-term tillage sampled point, taken at regular intervals water sample, observes the data such as the run-off of described Typical Small Watershed and sub basin, quantity of sand and mud, total nitrogen, total phosphorus; Described weather data can comprise: the rainfall of Typical Small Watershed, temperature, solar radiation, wind speed and relative humidity etc.

In a particular application, obtain the land data in the data of Typical Small Watershed in target basin, can comprise: the land-use map collecting Typical Small Watershed in target basin, analyze land use pattern and distribution, set up Land Use Database; Collect the soil type map of Typical Small Watershed in target basin, based on soil type map, by the soil types transformation of ownership, in conjunction with secondary overall survey of soil database and soil space sampling, set up soil space, attribute database.

Will be understood that, this step obtains digital elevation model dem data, can provide basic geographical spatial data for model.

It should be noted that before this step 101, first should select Typical Small Watershed in target basin.Cross-section study district generally should meet following feature: (1) typicalness, consistent with the nature such as meteorology, the hydrology, landform of the large regions of target and the characteristic of human nature such as cropping pattern, Soil management measure, contain all soil typess of large regions and Land-Use; (2) data integrity, the attribute datas such as the spatial datas such as the elevation required for modeling, soil, land-use map and soil attribute, meteorology, the hydrology, water quality are complete; (3) convenience, traffic is convenient in present position, basin, and is closed basin, exports comparatively single, is convenient to the hydrology, water quality monitoring.

102, the water and soil evaluation model SWAT of Typical Small Watershed according to described Typical Small Watershed data configuration.

103, obtain in described Typical Small Watershed according to described SWAT and in each sub basin, enter river course nitrogen and phosphorus load Load _lrand the contribution rate Load of each sub basin watershed water delivering orifice in described Typical Small Watershed _lo.

104, obtain the plant husbandry source of each sub basin of described Typical Small Watershed agricultural area source nitrogen phosphorus emission monitoring, livestock and poultry breeding industry source, culture fishery source and life in the countryside source and produce discharge coefficient, in conjunction with the essential information enquiry data of described Typical Small Watershed, obtain each sub basin agricultural area source nitrogen phosphorus emission sum Load in described Typical Small Watershed _ls.

In a particular application, above-mentioned steps 104 can comprise not shown step 104a and 104b:

Discharge coefficient is produced in 104a, the plant husbandry source obtaining each sub basin of described Typical Small Watershed agricultural area source nitrogen phosphorus emission monitoring, livestock and poultry breeding industry source, culture fishery source and life in the countryside source, in conjunction with the essential information enquiry data of described Typical Small Watershed, obtain the plant husbandry source nitrogen phosphorus emission in each sub basin of described Typical Small Watershed, livestock and poultry breeding industry source nitrogen phosphorus emission, culture fishery source nitrogen phosphorus emission and life in the countryside source nitrogen phosphorus emission.

104b, plant husbandry source nitrogen phosphorus emission, livestock and poultry breeding industry source nitrogen phosphorus emission, culture fishery source nitrogen phosphorus emission and life in the countryside source nitrogen phosphorus emission according in each sub basin of described Typical Small Watershed, obtain each sub basin agricultural area source nitrogen phosphorus emission sum Load in described Typical Small Watershed _ls.

Wherein, described step 104b can comprise:

According to the plant husbandry source nitrogen phosphorus emission in each sub basin of described Typical Small Watershed, livestock and poultry breeding industry source nitrogen phosphorus emission, culture fishery source nitrogen phosphorus emission and life in the countryside source nitrogen phosphorus emission, obtain each sub basin agricultural area source nitrogen phosphorus emission sum Load in described Typical Small Watershed by the first formulae discovery _ls;

Described first formula is:

Load _Ls＝∑(Load _Lp+Load _Ll+Load _La+Load _Lc)，

Wherein, Load _lpfor certain sub basin plant husbandry source nitrogen phosphorus discharge negative quantity of described Typical Small Watershed, Load _llfor certain sub basin livestock and poultry breeding industry source nitrogen phosphorus emission of described Typical Small Watershed, Load _lafor certain sub basin culture fishery source nitrogen phosphorus emission of described Typical Small Watershed, Load _lcfor certain sub basin life in the countryside source nitrogen phosphorus emission of described Typical Small Watershed.

105, according to Load _lsand Load _lr, obtain described target basin agricultural area source pollutants irrigation canals and ditches and cut down coefficient.

In a particular application, this step 105 can comprise:

According to Load _lsand Load _lr, coefficient Factor cut down by the agricultural area source pollutants irrigation canals and ditches being obtained described target basin by the second formulae discovery _cr;

Described second formula is:

${\mathrm{Factor}}_{\mathrm{cr}}=\frac{({\mathrm{Load}}_{\mathrm{Ls}}-{\mathrm{Load}}_{\mathrm{Lr}})}{{\mathrm{Load}}_{\mathrm{Ls}}}.$

Coefficient calculation method cut down by the basin agricultural area source pollutants irrigation canals and ditches of the present embodiment, by obtaining the data (data of Typical Small Watershed comprise: the hydrology-water quality data of the essential information enquiry data of Typical Small Watershed, Typical Small Watershed and sub basin water delivering orifice periodic sampling thereof, weather data, digital complex demodulation data and land data, and hydrology-water quality data comprise: the run-off, quantity of sand and mud, nitrogen pool, total phosphorus content etc. of Typical Small Watershed and sub basin thereof) of Typical Small Watershed in target basin; According to the water and soil evaluation model SWAT of Typical Small Watershed data configuration Typical Small Watershed; Obtain in Typical Small Watershed according to SWAT and enter river course nitrogen and phosphorus load Load in each sub basin _lrand the contribution rate Load of each sub basin watershed water delivering orifice in Typical Small Watershed _lo; Obtain the plant husbandry source of each sub basin of Typical Small Watershed agricultural area source nitrogen phosphorus emission monitoring, livestock and poultry breeding industry source, culture fishery source and life in the countryside source and produce discharge coefficient, in conjunction with the essential information enquiry data of Typical Small Watershed, obtain each sub basin agricultural area source nitrogen phosphorus emission sum Load in Typical Small Watershed _ls; According to Load _lsand Load _lr, obtain described target basin agricultural area source pollutants irrigation canals and ditches and cut down coefficient, can obtain basin agricultural area source pollutants irrigation canals and ditches simply, accurately and rapidly and cut down coefficient, cost is low, can large scale fully under way.

After above-mentioned steps 102, before above-mentioned steps 103, can also not shown step 103 be comprised ':

103 ', operate SWAT model, and carry out parametric calibration and checking according to obtained hydrology-water quality data to described SWAT model;

Correspondingly, above-mentioned steps 103 is specially:

According to the SWAT after parametric calibration and checking, obtain in described Typical Small Watershed and in each sub basin, enter river course nitrogen and phosphorus load Load _lrand the contribution rate Load of each sub basin watershed water delivering orifice in described Typical Small Watershed _lo.

In a particular application, in above-mentioned steps 103 ', by ditch extraction, watershed partitioning, Hydrologic response units (Hydrologic Research Unit, be called for short HRU) generate, meteorological process, running SWAT model, and according to obtained hydrology-water quality data, parametric calibration and checking are carried out to described SWAT model.

By carrying out parametric calibration and checking to SWAT model, it is more accurate that coefficient cut down by the target basin agricultural area source pollutants irrigation canals and ditches that the present embodiment obtains.

For example, the present embodiment can select plateau lake Typical Small Watershed---and Feng Yu river, Dali City, yunnan Province small watershed is example, and coefficient cut down by the irrigation canals and ditches calculating basin, plateau lake.

Phoenix plumage river valley is located in east longitude 99 ° of 51 ' 31 〞-100 ° 01 ' 46 〞, north latitude 25 ° of 52 ' 48 〞-26 ° 05 ' 52 〞, and being positioned at south, the west of a city, From Western Yunnan Dali prefecture Eryuan County, is Erhai Lake basin typical sub basin.Landform is mountain and hill, height above sea level 2072-3621m, drainage area 219km2.Weather belongs to north subtropical plateau monsoon weather, and the four seasons temperature difference is little, average annual temperature 13.9 DEG C; Mean annual precipitation 745mm, Winter-Spring arid, Xia Qiu is rainy, and rain two seasons of drought are clearly demarcated, and the 5-10 month is rainy season, and the rainy day is many, and rainfall amount is large and concentrated; April November to next year is dry season, fine drying, and rainfall is rare.Land-Use is based on paddy field, nonirrigated farmland, forest land and wild grass ground, and chief crop has paddy rice, corn, garlic, broad bean and rape.Soil types is based on dark soup soil, numb grey soup soil, reddish brown soil and rice soil.

Fig. 3 shows the phoenix plumage river small watershed location drawing that one embodiment of the invention provides, and the basin agricultural area source pollutants irrigation canals and ditches reduction coefficient calculation method of the present embodiment is as described below.

201, Zhong Fengyu river, basin, plateau lake small watershed data are obtained, described phoenix plumage river small watershed data comprise: the hydrology-water quality data of the essential information enquiry data of phoenix plumage river small watershed, phoenix plumage river small watershed and sub basin water delivering orifice periodic sampling thereof, weather data, digital complex demodulation data and land data, described hydrology-water quality data comprise: the run-off, quantity of sand and mud, nitrogen pool, total phosphorus content etc. of phoenix plumage river small watershed and sub basin thereof.

In a particular application, when obtaining the essential information enquiry data of phoenix plumage river small watershed, by consulting phoenix plumage river small watershed statistical data and peasants participation, to obtain in basin farmland management and the social industry such as population, the cultivation data such as farming, fertilising, irrigation, for model provides background information; Ying Feng plumage river small watershed water delivering orifice and its sub basin water delivering orifice setting long-term tillage sampled point, at flood season, non-flood period taken at regular intervals water sample, observe the data such as run-off, quantity of sand and mud, total nitrogen, total phosphorus of phoenix plumage river small watershed and sub basin in continuous 3 years; Download by weather site or the monitoring of self-built small-sized weather station, collect the weather data such as rainfall, temperature, solar radiation, wind speed and relative humidity gathering model needs; Digital complex demodulation data are downloaded, for model provides basic geographical spatial data from national basis information center; Collect land-use map from soil resource department of local, analyze land use pattern and distribution, set up Land Use Database; Based on the soil type map of the Chinese Academy of Sciences native institute 1:100 ten thousand in south, by the soil types transformation of ownership, consult secondary overall survey of soil database and soil space sampling, set up soil space, attribute database.

202, the water and soil evaluation model SWAT of Typical Small Watershed according to the small watershed data configuration of phoenix plumage river.

203, by ditch extraction, watershed partitioning, Hydrologic response units generation, meteorological process, running SWAT model, and according to obtained hydrology-water quality data, parametric calibration and checking are carried out to described SWAT model.

204, according to the SWAT after parametric calibration and checking, obtain in the small watershed of phoenix plumage river and enter river course nitrogen and phosphorus load Load in each sub basin _lrbe the contribution rate Load of each sub basin watershed water delivering orifice in 179.4 tons/year and phoenix plumage river small watershed _loit is 79.4 tons/year.

205, obtain the plant husbandry source of each sub basin of phoenix plumage river small watershed agricultural area source nitrogen phosphorus emission monitoring, livestock and poultry breeding industry source, culture fishery source and life in the countryside source and produce discharge coefficient, in conjunction with the essential information enquiry data of phoenix plumage river small watershed, obtain each sub basin agricultural area source nitrogen phosphorus emission sum Load in the small watershed of phoenix plumage river _lsfor 319.4t/.

In a particular application, this step 205 first can obtain the plant husbandry source of each sub basin of described Typical Small Watershed agricultural area source nitrogen phosphorus emission monitoring, livestock and poultry breeding industry source, culture fishery source and life in the countryside source and produce discharge coefficient, in conjunction with the essential information enquiry data of described Typical Small Watershed, obtain the plant husbandry source nitrogen phosphorus emission Load in each sub basin of described Typical Small Watershed _lpfor, livestock and poultry breeding industry source nitrogen phosphorus emission Load _ll, culture fishery source nitrogen phosphorus emission Load _lawith life in the countryside source nitrogen phosphorus emission Load _lcbe respectively 78.2t/, 226.2t/, 0t/ and 15.0t/, obtain each sub basin agricultural area source nitrogen phosphorus emission sum Load in described Typical Small Watershed by the first formulae discovery _lsfor 319.4t/;

Described first formula is:

Load _Ls＝∑(Load _Lp+Load _Ll+Load _La+Load _Lc)。

206, according to Load _lsand Load _lr, coefficient Factor cut down by the agricultural area source pollutants irrigation canals and ditches being obtained basin, plateau lake by the second formulae discovery _crbe 44%;

Described second formula is:

${\mathrm{Factor}}_{\mathrm{cr}}=\frac{({\mathrm{Load}}_{\mathrm{Ls}}-{\mathrm{Load}}_{\mathrm{Lr}})}{{\mathrm{Load}}_{\mathrm{Ls}}}.$

Coefficient calculation method cut down by the basin agricultural area source pollutants irrigation canals and ditches of the present embodiment, and can obtain basin, plateau lake agricultural area source pollutants irrigation canals and ditches simply, accurately and rapidly and cut down coefficient, cost is low, can large scale fully under way.

One of ordinary skill in the art will appreciate that: all or part of step realizing above-mentioned each embodiment of the method can have been come by the hardware that programmed instruction is relevant.Aforesaid program can be stored in a computer read/write memory medium.This program, when performing, performs the step comprising above-mentioned each embodiment of the method; And aforesaid storage medium comprises: ROM, RAM, magnetic disc or CD etc. various can be program code stored medium.

Last it is noted that above each embodiment is only in order to illustrate technical scheme of the present invention, be not intended to limit; Although with reference to foregoing embodiments to invention has been detailed description, those of ordinary skill in the art is to be understood that: it still can be modified to the technical scheme described in foregoing embodiments, or carries out equivalent replacement to wherein some or all of technical characteristic; And these amendments or replacement, do not make the essence of appropriate technical solution depart from the scope of the claims in the present invention.

Claims (8)

1. a coefficient calculation method cut down by agricultural area source pollutants irrigation canals and ditches in basin, it is characterized in that, comprising:

Obtain Typical Small Watershed data in target basin, described Typical Small Watershed data comprise: the hydrology-water quality data of the essential information enquiry data of Typical Small Watershed, Typical Small Watershed and sub basin water delivering orifice periodic sampling thereof, weather data, digital complex demodulation data and land data, and described hydrology-water quality data comprise: the run-off of Typical Small Watershed and sub basin thereof, quantity of sand and mud, nitrogen pool, total phosphorus content;

The water and soil evaluation model SWAT of Typical Small Watershed according to described Typical Small Watershed data configuration;

Obtain in described Typical Small Watershed according to described SWAT and in each sub basin, enter river course nitrogen and phosphorus load Load _lrand the contribution rate Load of each sub basin watershed water delivering orifice in described Typical Small Watershed _lo;

Obtain the plant husbandry source of each sub basin of described Typical Small Watershed agricultural area source nitrogen phosphorus emission monitoring, livestock and poultry breeding industry source, culture fishery source and life in the countryside source and produce discharge coefficient, in conjunction with the essential information enquiry data of described Typical Small Watershed, obtain each sub basin agricultural area source nitrogen phosphorus emission sum Load in described Typical Small Watershed _ls;

According to Load _lsand Load _lr, obtain described target basin agricultural area source pollutants irrigation canals and ditches and cut down coefficient.

2. method according to claim 1, is characterized in that, described weather data, comprising: the rainfall of Typical Small Watershed, temperature, solar radiation, wind speed and relative humidity.

3. method according to claim 1, is characterized in that, obtains the land data in the data of Typical Small Watershed in target basin, comprising:

Collect the land-use map of Typical Small Watershed in target basin, analyze land use pattern and distribution, set up Land Use Database;

Collect the soil type map of Typical Small Watershed in target basin, based on soil type map, by the soil types transformation of ownership, in conjunction with secondary overall survey of soil database and soil space sampling, set up soil space, attribute database.

4. method according to claim 1, it is characterized in that, after the water and soil evaluation model SWAT of described Typical Small Watershed according to described Typical Small Watershed data configuration, enter river course nitrogen and phosphorus load Load in each sub basin described to obtain in described Typical Small Watershed according to described SWAT _lrand the contribution rate Load of each sub basin watershed water delivering orifice in described Typical Small Watershed _lobefore, also comprise:

Running SWAT model, and according to obtained hydrology-water quality data, parametric calibration and checking are carried out to described SWAT model;

Correspondingly, described acquisition in described Typical Small Watershed according to described SWAT enters river course nitrogen and phosphorus load Load in each sub basin _lrand the contribution rate Load of each sub basin watershed water delivering orifice in described Typical Small Watershed _lo, be specially:

According to the SWAT after parametric calibration and checking, obtain in described Typical Small Watershed and in each sub basin, enter river course nitrogen and phosphorus load Load _lrand the contribution rate Load of each sub basin watershed water delivering orifice in described Typical Small Watershed _lo.

5. method according to claim 4, is characterized in that, described running SWAT model, and carries out parametric calibration and checking according to obtained hydrology-water quality data to described SWAT model, comprising:

By ditch extraction, watershed partitioning, Hydrologic response units generation, meteorological process, running SWAT model, and according to obtained hydrology-water quality data, parametric calibration and checking are carried out to described SWAT model.

6. method according to claim 1, it is characterized in that, discharge coefficient is produced in the plant husbandry source of each sub basin of described acquisition described Typical Small Watershed agricultural area source nitrogen phosphorus emission monitoring, livestock and poultry breeding industry source, culture fishery source and life in the countryside source, in conjunction with the essential information enquiry data of described Typical Small Watershed, obtain each sub basin agricultural area source nitrogen phosphorus emission sum Load in described Typical Small Watershed _ls, comprising:

Obtain the plant husbandry source of each sub basin of described Typical Small Watershed agricultural area source nitrogen phosphorus emission monitoring, livestock and poultry breeding industry source, culture fishery source and life in the countryside source and produce discharge coefficient, in conjunction with the essential information enquiry data of described Typical Small Watershed, obtain the plant husbandry source nitrogen phosphorus emission in each sub basin of described Typical Small Watershed, livestock and poultry breeding industry source nitrogen phosphorus emission, culture fishery source nitrogen phosphorus emission and life in the countryside source nitrogen phosphorus emission;

According to the plant husbandry source nitrogen phosphorus emission in each sub basin of described Typical Small Watershed, livestock and poultry breeding industry source nitrogen phosphorus emission, culture fishery source nitrogen phosphorus emission and life in the countryside source nitrogen phosphorus emission, obtain each sub basin agricultural area source nitrogen phosphorus emission sum Load in described Typical Small Watershed _ls.

7. method according to claim 6, it is characterized in that, described according to the plant husbandry source nitrogen phosphorus emission in each sub basin of described Typical Small Watershed, livestock and poultry breeding industry source nitrogen phosphorus emission, culture fishery source nitrogen phosphorus emission and life in the countryside source nitrogen phosphorus emission, obtain each sub basin agricultural area source nitrogen phosphorus emission sum Load in described Typical Small Watershed _ls, comprising:

According to the plant husbandry source nitrogen phosphorus emission in each sub basin of described Typical Small Watershed, livestock and poultry breeding industry source nitrogen phosphorus emission, culture fishery source nitrogen phosphorus emission and life in the countryside source nitrogen phosphorus emission, obtain each sub basin agricultural area source nitrogen phosphorus emission sum Load in described Typical Small Watershed by the first formulae discovery _ls;

Described first formula is:

Load _Ls＝∑(Load _Lp+Load _Ll+Load _La+Load _Lc)，

Wherein, Load _lpfor certain sub basin plant husbandry source nitrogen phosphorus discharge negative quantity of described Typical Small Watershed, Load _llfor certain sub basin livestock and poultry breeding industry source nitrogen phosphorus emission of described Typical Small Watershed, Load _lafor certain sub basin culture fishery source nitrogen phosphorus emission of described Typical Small Watershed, Load _lcfor certain sub basin life in the countryside source nitrogen phosphorus emission of described Typical Small Watershed.

8. method according to claim 1, is characterized in that, described according to Load _lsand Load _lr, obtain described target basin agricultural area source pollutants irrigation canals and ditches and cut down coefficient, comprising:

According to Load _lsand Load _lr, coefficient Factor cut down by the agricultural area source pollutants irrigation canals and ditches being obtained described target basin by the second formulae discovery _cr;

Described second formula is:

${\mathrm{Factor}}_{\mathrm{cr}}=\frac{({\mathrm{Load}}_{\mathrm{Ls}}-{\mathrm{Load}}_{\mathrm{Lr}})}{{\mathrm{Load}}_{\mathrm{Ls}}}.$