Measurement and classified governance strategies of farmland parcel fragmentation in hilly and mountainous areas

Cultivated land fragmentation is one of the key factors to hinder the high-quality agriculture. It is of great significance to construct a parcel-scale measurement system of the cultivated land fragmentation. Differentiated governance strategies are often required to promote the cultivated land fragmentation. This study aims to measure and classify the farmland parcel fragmentation in the hilly and mountainous areas. An example was then taken in the Hekou Town, Yunan County, Guangdong Province, China. A theoretical review was presented on the concept and connotation of the cultivated land fragmentation. Natural, tenure and cultivation of the parcels were then incorporated to combine with the questionnaire surveys and the decision-making on the high-standard farmland. A parcel-scale fragmentation measurement index system was constructed using the “natural endowment degree, tenure dispersion degree, and cultivation accessibility degree”. The three-dimensional composite index of parcel fragmentation was then calculated using TOPSIS model. The local spatial autocorrelation was utilized to explore the spatial aggregation relationship. Each administrative village was evaluated for the balance and differences in the variation of the mean and coefficients. Finally, the three-dimensional Rubik's cube model was used to form the guidance program for the classified consolidation. The results showed that: 1) In the dimension of natural endowment degree, the comprehensive evaluation level of the parcels in the study area was ranged from 0.219 to 0.716, where the majority was in the the lower and higher levels. In terms of the spatial differentiation, there was the relatively balance in the variation of the mean level and coefficient after comprehensive evaluation on each administrative village. Parcels with the superior natural endowment degree were formed the contiguous clusters in space. While the rest parcels exhibited the smaller clusters or lower levels of the aggregation, due to the low natural endowment degree. In the dimension of tenure dispersion degree, the comprehensive evaluation level of the parcels was ranged from 0 to 0.902, where the majority was in the lower and low grades. Parcels with the different comprehensive evaluation grades exhibited the relatively homogeneous spatial distribution. In the dimension of cultivation accessibility degree, the comprehensive evaluation level of the parcels was ranged from 0.026 to 0.974, with the majority in the lower and higher grades. Higher and high-grade parcels were tended to cluster spatially, due to the denser, higher-grade road networks and greater parcel adjacency. Other parcels, however, were largely constrained by natural conditions, leading to the high levels of the parcel adjacency. 2) In terms of the spatial correlation, the natural endowment degree was dominated by the high-high and low-low aggregation. The tenure dispersion degree was dominated by the low-low aggregation. And the cultivation accessibility degree was dominated by the high-high and low-low aggregation. 3) Three-dimensional Rubik's cube model was combined with the spatial combination and control constraints. The parcels were classified into the high-quality conservation, endowment enhancement, tenure adjustment, facility improvement, comprehensive consolidation, and prohibited consolidation. Differentiated consolidation strategies were proposed after optimization. The finding can also provide a strong reference to construct the parcel consolidation of the high-standard farmland in the hilly and mountainous areas.