Abstract:

Dianchi Lake basin is the core area of the Kunming City, which accounts for 0.7% of land area and 24% of GDP of Yunnan Province. Cities around the basin are the most developed area of Yunnan Province. Based on the urban growth in Dianchi Lake basin during 1992-2010, urban construction land growth showed two kinds of patterns. One was Boundary Growth which showed sustained growth of the existing urban area. The other pattern was Roadsaffected Growth which showed new urban units came into being along with roads surrounding the Dianchi Lake. According to the remote sensing data of the urban growth of Dianchi Lake basin, calibration model of SLEUTH urban growth simulated three prearranged plans of the Kunming City growth in 30 years (2010-2040). Three kinds of simulation results showed as follows. Arbitrary Growth plan led to unlimited urban sprawl. Population and urban land presented an explosive growth pattern. Great quantity of farm land and forest land were transformed to urban construction land. Dianchi Lake coast was surrounded by urban land, and the construction land area reached to 495 km2 (an increase of 200 km2) in 2040, and the population reached to 5.4 million, which were almost close to the upper limits of admissible capacities of land and population of the Dianchi Lake basin, and would greatly threaten the water environment of the Dianchi Lake. Land Total Quantity Control plan showed that Kunming City growth was controlled by urban master planning, without population and economic factors taken consideration. The construction land area was going to be 411 km2 and the population was 411 million in the year of 2040. South area of the city was the main development direction of Kunming. This kind of plan could not meet the need of the Dianchi Lake environment protection. Dianchi water resource protection was the aim of Ecological Protection plan. The construction land area and population were strictly controlled. Urban growth speed obviously slowed down. Population was 3.17 million in 2030, less than the current amount of the population and 3.92 million in 2040, lower than the upper limit of admissible capacity of population. Ecological Protection plan could effectively control urban construction land growth, and reduce the occupation of the forest land, farm land and wet land, which helped to protect Dianchi Lake environment. According to the prediction, per capita water resources were still in the situation of “critical shortage” in three urban growth plans. In order to improve the water resource situation, measures should be taken to adjust urban system layout and industry distribution, to reduce urban primacy ratio and population, to employ more stringent spatial regulations, which would effectively control urban growth. Diversion works may help to relieve strain on water