Exploring long-term datasets of land use, economy, and demography variations in karst wetland areas to detect possible microclimate changes

This study explores the possibility of deciphering changes in the total area of a karst wetland due to shifts inland use, economy and population over a long-term period (35 years) and microclimate changes (1958-2019). To achieve this goal, we focused on Huangcaozhou Karst Wetland, a national karst wetland park located in China. Based on remote sensing interpretation, long-term climate data, and statistical yearbook datasets, our results showed that from 1984 to 2019, owing to the rapid rates of urbanization and economic development, swamplands in our study area decreased by 16.4%, while urban lands increased up to 16.7%. The inflection point on the land use and land cover (LUCC) curve we constructed appeared in 2006, after which the areas of swampland, rocky desertification land, and wasteland sharply decreased and those of urban land and farmland increased. This is consistent with the increase in gross domestic production (GDP) and the totalnumber of inhabitants. From 1958, when Luxi registered an annual average temperature of 14.8 degrees C, to 2019, the air temperature increased with a gradient of 0.157 degrees C per decade, until it reached an average of 15.3 degrees C. We did not find a clear trend for the number of annual rainy days (average of 140.6 rainy days per year) but the mean torrentiality (average annual volume divided by the annual number of rainy days) shows a slight trend of increase (0.72 mm per day per decade). Precipitation we found has gradually declined. We concluded that economic and demographic changes are interacting with microclimate changes, which are affected by the regional eco-environment over a long-time scale in the Huangcaozhou Karst Wetland, causing the wetland quality significantly varied in recent decades. This would help to develop more efficient land management plans to better correctly handle new human activities allowing policymakers to regulate the wetland ecosystem in Southwestern China.