Study On Eco-environmental Water Requirement Of Song-Nen-Plain Wetland

As we know, nature can balance itself by adjusting energy and distributingsubstance (Taking the circulation of water and atmosphere as a medium). Theproportion of the nature ecosystem that is not influenced by artificial effect is quitesmall along with the increasing of people and the developing of social economics.Therefore, it is the chief problem that the calculation for eco-environmental waterrequirement is on the standard of which ecosystem. The most important principle ofthe ecosystem protection in weak eco-environmental region is that the waterrequirement must be satisfied preferentially, that means the eco-environmental willnot get worse further more.In recent years, the water volume flowing to Song-nen Plain Wetland is reduce,and the wetland ecosystem is destroyed, that mainly due to the influencing of naturalfactors and human activities. In order to restrain the worsening of the wetlandeco-environment and gradually improving its ecosystem quality, these problems mustbe settled on the basis of meeting the eco-environmental water requirement. Therefore,the researches on eco-environmental water requirement of Song-nen Plain Wetlandhave magnitude meanings.Before developing this paper, we have done some researches on , , and . Thus the Song-nenPlain wetland was chosen to be the subject, and "Studies on eco-environmental waterrequirement of Song-nen Plain wetland-taking Zha-long wetland as the example" wasto be the title of the paper. The system analysis was used to classify the wetlandaccording to main plants. Zha-long wetland possesses the most and the most prevalentreed marsh. Moreover Zha-long Lake is a typical lake, which is the most, and themost prevalent lake evolving from river in Song-nen Plain. The change tendencies ofwater, marsh and saline-alkali soil etc. in Zha-long wetland are consistent with theoverall change tendency in Song-nen Plain, and the change tendency in soil utilizingis representative. In order to reduce the deterioration of eco-environment in Song-nenPlain and improve the quality, the key points are considering water utilizing inzoology chiefly and distributing water resources rationally.The zoology theory formula or water resource balance was employed tocalculate the eco-environmental water requirement, although they all have advantagesand disadvantages. The former possesses theory meaningful but lack of materiality,time-effect and maneuverability. The latter possesses practicability but lack ofdiscussion in theory and mechanism.The paper was written from the view of sustainable development, based on theprinciples and methods the ecology, the landscape ecology, water resource andagrometeorology, guided by system theory, using system analysis method. In thispaper, the basic condition and eco-environment present situation in Song-nen Plainwetland is investigated, and the main problems and the reasons causing them wereanalyzed. The foundations on which the paper was completed were in view of thewetland and the eco-environmental water requirement characteristics, summary theexisting wetland eco-environmental water requirement calculation formulas, spotinvestigation with room work. And on the basis of remote sensing interpreting,depending on 3S integration, associating theory research with practical application,utilizing system analysis and synthetic research, all researche work was finished.The suitable areas of all kinds of soil types in Zhalong National NaturalProtection Area are determined on the foundation of interpreting remote sensingimage, using 3S integration, applying soil-utilizing time, space-changing model etc.Study on calculation of eco-environmental water requirement parameters wasconducted under the guiding of the country's zoology planning. The results indicate thatthe eco-environmental water requirement in Zhalong wetland is 5.05 × 108 m3 per year,of which the eco-environmental water requirement of wetland lake (including reservoir)is 0.29 × 108 m3, the marsh covered with water is 1.07 × 108 m3, reed marsh is 3.26 ×108 m3, wetland soil is 0.43 × 108 m3. And the threshold value of minimumeco-environmental water requirement that guarantees the eco-environmental waterrequirement of core region was determined. Due to the minimum eco-environmentalwater requirement is the fundamentality that sustains the wetland survival and one ofthe eco-environmental water requirement sources is precipitation, the 45-year seriesstatistic was employed to analysis the weather data, and also the precipitation rate wastaken into account. The results showed the minimum eco-environmental waterrequirement was 2.56 × 108 m3 corresponding to a frequency of 75%, and 2.89 × 109m3 corresponding to a frequency of 95%. The results were close to the practicalrequirement.The concept "Water Utilizing Process" was introduced according toagrometeorology theory. The monthly amount of evaporation and precipitation werestudied during 45 years, by which the eco-environmental water requirement processunder different guarantee rate was advanced. The entering water process wasdetermined and optimized on the basis of 45-year's hydrometric data, and the allocationof eco-environmental water requirement of wetland was achieved which has beenrecorded in the published bySongliao Water Resource Committee. The eco-environmental water requirement canbe totally satisfied under the guarantee rate of 75%, at least 69% under the guaranteerate of 95%, and satisfied 80% of the minimum eco-environmental water requirement.The guarantee rates of environment, fish, and reed water requirement were increasedfrom 50% to 75%, which were used by Songliao Water Resource Committee in history.The eco-environmental water requirement was chiefly considered under theprerequisites of guarantying life water requirement that is required in .The spot block fragmentation degree was gradually increased year by year in ZhalongNational Natural Protection Area especially in the core area like reed marsh and themarsh covered with water according to the analyzing landscape. Therefore, theinfluence should be eliminated in the wetland replenishing process by simulatingreplenishing water in flood process.The ration of water requirement in Zhalong Wetland is 266-m3/mu according tothe results of formula and wetland areas. The ration was reasonable by comparing itwith the ration of reed irrigation and distribution ration assured by water resourcedepartment. The calculation equation was concluded on the basis of theory analysis,which was employed to calculate the linear relationship between the ration ofeco-environmental water requirement and that of referring wetland. The precisionmeets the requirement by utilizing it to the typical cases such as Xiang-hai andZha-gan Lake. Hence the equation is helpful to calculate eco-environmental waterrequirement in other wetlands, and supplies a foundation for basic water resourcemanagement.There is little research on calculation the threshold value of wetlandeco-environmental water requirement by history analyzing method and the studymethod used for the minimum eco-environmental water requirement under differentprecipitation frequency. In this paper, the concept "Water Utilizing Process" is firstintroduced to calculate the eco-environmental water requirement, the process allocationof which is also realized. And in this paper, the calculation equation for the ration ofeco-environmental water requirement in reed wetland was inducted firstly, whichgives a basis to calculate the wetland eco-environmental water requirement.This paper definitely answers the problem that the basis of dealing with currentwetland problem was determining the threshold value of eco-environmental waterrequirement, and the strategy for water supply or water replenishing. The results arehelpful to allocate water resource scientifically and reasonably, protect and improveeco-environment quality. The research results possess certain theory values andimportant application values.