| As a contiguous karst area with the largest area and the most vulnerable ecological environment in the world, the Guizhou Plateau centered karst area in south China formed a unique problem of water resource shortage and drought in karst areas synthetically affected by the typical monsoon climate, particular topography and hydrogeological structure, which has a strong impact on the production and living of local residents. The engineering water shortage often happen in karst areas where the rainfall is rich and has a closely relation with the unbalance space-time distribution of the precipitation area, less soil, low vegetation coverage and the surface and underground double space structure generated by chronic and intense karstification. On the base of thoroughly understand the disaster-inducing factors of drought in karst area, the occurrence characteristics and space supply relationship of water resources and the relationship of supply and demand for water. Use the water conservation engineering measures to give a human intervention and optimize combinatorial arrangements on engineering water shortage. Make relate model and technology integration to enhance the emergency scheduling and safety control under different drought situations. This has positive affect on meeting the demand of regional water. Therefore, choosing Chaoying small watershed of Shalaxi demonstration zone in Bijie and Dingtan small watershed of Huajiang demonstration zone between Guanling and Zhenfeng as research object, this text uses documents analysis, spot monitoring, questionnaire survey, lab analysis and system science to survey and monitor water resource and water conservation project building in the two small watershed in order to analysis main factors which lead to drought and build the models of water conservation optimization matching called Caoying model and Dingtan model on the premise of multi-source data. Through technical demonstration, analyze the total efficiency and adaptability analysis on two models.(1)According to the occurrence conditions and characteristics of water resources in the two small watersheds of Chaoying and Dingtan, choose the human and livestock, crops and economic forest and grassland in the watersheds as calculated object, water consuming of human and livestock, crop and economic forest and grassland was analyzed through K value method, modified penmen formula and woodland ETj crop evapotranspiration. Conclusions are drawn as follows. At Chaoying small watershed, the total annual water demand of human and livestock is 0.20×107 m3 and annual ecological water demand is 0.22×107 m3, and the total annual water demand is 0.42×107 m3. In the current condition of water resources utilization and project configuration, the reservoir resolve water demand with 0.14×105 m3, the spring resolve water demand with 0.12×107 m3 and the ecological natural water supply is 0.27×107 m3, the unbalance amount of supply and demand of water is 0.29×106 m3. The total annual water demand of human and livestock in Dingtan small watershed is 0.35×106 m3, the total annual water demand of ecological system is 0.57×106 m3, and the total water demand in small watershed is 0.92×106 m3. In the current condition of water resources utilization and project configuration, the reservoir resolve water demand with 0.11×105 m3, the roof rainwater collecting resolve water demand with 0.42×106 m3, the small spring resolve water demand with 0.11×106 m3 and the supply for rainfall is 0.61×105 m3, the unbalance amount of supply and demand for water supply is 0.33×106 m3. In order to reach the balance of supply and demand for water resource, there would be at least 40 reservoirs with 100m3, 300 reservoirs with 60 m3 and 560 reservoirs with 30m3, as well as the desilting basins and water supply pipe network based on the scheduling needs of water resource in Chaoying small watershed. And in Dingtan small watershed there need to be 80 reservoirs with 100m3 and a reservoir with 60m3 to be built by each of 12 village groups for human and livestock demand, as well as 120 reservoirs with 60m3 and 264 reservoirs with 30m3 for production and ecological demand.(2)According to the two typical geomorphic features of Chaoying karst plateau mountain and Dingtan karst plateau canyon identify the occurrence condition and distribution characteristics of water resources, combine the existing water resource development and engineering supporting mature technology, innovate the key technique to meet the goal of daily water usage. And also meet the usage of emergent water resource control under the extreme drought situation, the configuration mode of water’s conservation project and other supported technique system. To build the Chaoying model and Dingtan model consist with the natural and social economic condition of the two small watersheds.The “Chaoying mode” mainly adopts the drinking water safety project of human and livestock and extreme drought emergency control technology, develop the water security of animal husbandry and extreme drought emergency control technology, engineering supporting and extreme drought emergency control technology for rain crop irrigation, multi-source water project construction and extreme drought emergency control technology for economic forest irrigation; Structure of Dingtan’ s the drinking water with the combination of rainwater harvesting, spring point water diversion, fall water lifting and inter-basin long distance water resources scheduling which called lift, storeand diversionunion, and the extreme drought’s emergency control technology, and the economic forest’s irrigations multi-source water project construction with the combination of slope catchment, pavement rainwater harvesting, mechanical and electrical water lifting, step-by-step water lifting and drip trickle irrigation and the extreme drought’s emergency control technology.(3)In Chaoying small watershed, the optimization of the original roof technology, the development of depression film rainwater harvesting technology, the research and development of dew collection and utilization technology, and the water conservancy projects such as the drinking water safety, the water security development of animal husbandry, crop irrigation water source protection facilities and multi-source engineering construction of economic forest irrigation water conservation, etc. gradually formed the human and animal drinking water safety project of “the roof rainwater harvesting and spring water diversion” and extreme drought emergency control technology system, the development of animal husbandry water security combined with pumping, storage and diversion and extreme drought emergency control technology system, the multi-source water project construction for Xiaoshantang Project consist of” roof rain, pavement rainwater, slope rain and depression film” for economic forest irrigation and the roof rainwater harvesting, rainwater harvesting” land remediation terracing and extreme drought emergency control technology system. In Dingtan small watershed, the technology and method for reducing the evaporation by means was proposed when the original roof rainwater harvesting technology was optimized, and through drinking water safety and developing economic forest irrigation project construction, gradually formed the human and animal drinking water safety project “the roof rainwater harvesting, spring water diversion, water lift of fall and inter-basin long distance water resources scheduling combined with pumping, storage and diversion” and extreme drought emergency control technology system; the multi-source water project construction consist of “slope rain, pavement rainwater, electromechanical lifting, step-by-step lifting and drop irrigation of hanging bottle” for economic forest irrigation and extreme drought emergency control technology system.(4) Taking the geological, hydrological and man-made conditions of two small watershed named Chaoying and Dingtan as the foundation, combining with the characteristics of regional industry structure, according to the field investigation, we’ve clarified the existing engineering configuration case and characteristic of water requirement, and selected representative places of Xiaxiaozhai, Hanjiachong, Shaba and Chaeryan, etc. as the technical demonstration sites. One Impounding reservoir of 65m3 was built by Xiaxiaozhai community of Chaoying small watershed, with DN32 PE pipe network for 0.72 km, and five slow biological filters for optimizing roof set rain technology; one high storage of 400 m3, pipe network DN50 PE, DN32 PE of total 9.1km was built in Hanjiachong community; slope- to – terrace of 9.37 hm2, six reservoirs of 60m3 and interception ditch of 20 m was built in Shaba; Meijiayakou and other economic forest area were arranged to build one pulk of 750 m3, one detritor and water transporting, water supply pipe network of 300 m. At Chaerya Village in Dingtan small watershed, installing galvanized pipe with a total of 27.3 km, which DN60 galvanized tube of 5.3 km, DN40 of 6.6 km, DN25 of 4.6 km, DN20 of 2.4 km and DN15 of 8.37 km, and the pipeline laying throughout the whole study area. 20 impounding reservoirs of 60 m3, mating 20 detritors, interception ditch of 200 m, a set of step by step carry water engineering, and the supporting pipe network of 2000 m were constructed in economic forest region. Through the implementation of the project, the crops and economic forest and grass of 122.84 hm2 were safe against the impacts of drought, and the drought and water shortage problems for 4203 persons and 668 livestock were solved.(5) Xiaxiaozhai, Hanjiachong, Shaba, Meijiayakou and Zhujiayandong at Caoying small watershed and Chaeryan Village at Dingtan small watershed are chosen as demonstration areas from January 2013 to July 2015 and the implementation effect of the project was being monitored. The results are showed as follows. After building matching reservoirs and pipe in Xiaxiaozhai community at Chaoying small watershed, the anuual amount for water transfer is 4.73×104 m3 through the reservoirs by water transfer. The mount of leakage for project has reduced 431 m3 every year and the efficiency of spring and project using has increased more than 20%. The construction of aquaculture water protection project and head tank in Hanjiachong community makes it possible for 8.96×104 m3 water transfer every year, which can meet the need for emergency scheduling of extreme drought, water demand for 69 cows and relieve the stress of water demand in Hanjiachong and Xiaxiaozhai community when the dry season coming. The construction of making land consolidation for slope to terrace with 0.94 hm2 and optimization of irrigation water in Shaba area, changes the previous cultivated condition, enhance the ability of water transfer in the condition of drought and enhance crop’s ability for drought. The yield per mu of corn increases from 350 kg to 400 kg. In demonstration, the total increased yield of corn is 7755 kg and the overall income has increased 15800 yuan. The annual storage of water is 1.08×104 m3 and soil conservation about 16.8 m3. The construction of economic forest in Meijiayakou and Zhujiayandong has positive effect on rainfall shortage and surface runoff resources. The year’s water storage of the project is 2.25×104 m3 and provides sufficient water resource for developing ecological forest. The construction of human and animal drinking water safety project in Chaeryan with sufficient water resource and the success rate more than 80%. It has resolved the 870 households in the village more than 3850 people drinking water safety problem. The construction of water source project for crop irrigation in Chaeryan use multiply measures such as Slope runoff development, surface water use step by step and drip irrigation and drought infusion bottle to ensure the 26.98×104 m3 water demand for 112.42 hm2 economic forest. |
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